Performanta Filtre UHC Si OIII

Light Pollution and various “nebula” filters have been around since the late 1970′s, and amateurs have
been using them ever since to bring out detail (and even some objects !hich !ere difficult to
im"ossible to see before in modest a"ertures# $hen % started using them in the earl& 19'0′s, s"ecific
information about !hich filter might !or( on a given object (or even !hether certain filters !ere useful
at all !as often hard to come b&# )ven those accounts that !ere available often had incom"lete or
inaccurate information# *etting some observational e+"erience !ith the Lumicon line of filters hel"ed,
but there !ere still some unans!ered ,uestions# % !ondered ho! the various filters !ould ran( on-
average against each other for a large number of objects, and !hether there !as a “best overall” filter#
%n "articular, % also !ondered if the much-maligned .-/eta filter !as useful on more objects than the
t!o or three targets most often mentioned in "ublications# %n the summer of 1999, % decided to begin
some more com"rehensive observations to tr& and ans!er these ,uestions and determine ho! to best
use these filters overall# % formulated a basic surve& covering a moderate number of emission and
"lanetar& nebulae to obtain some statistics on filter "erformance to tr& to address the follo!ing
,uestions0

1. How do the various filter types compare as to what (on average) they show on a given nebula?
2. Is there one overall “best nebula filter which will wor! on the largest number of ob"ects?
#. $re there subsets of nebular ob"ects which respond to specific filter types better than others?
%. Is there an optimal power for the use of nebula filters?
&. Is the H'(eta filter only useful on the Horsehead) *ocoon) and *alifornia +ebulae?

% "urchased a Lumicon 1ulti-filter 2elector to hel" !ith faster com"arisons and initiall& began
observations in m& 10 inch f34#5 6e!tonian# /ecause urban and suburban observing conditions varied
so much, % decided to do the observations at a consistentl& dar( s(& site to see !hat filters could do
under nearl& o"timal conditions# 7he first run !as com"leted in 8ecember of that &ear !ith 44 initial
object observations# 7he initial results !ere "resented on 9anuar& 4th, :000 to the ;1;27<= mailing
list, as !ell as being archived on several %nternet locations# ;s time !ent on, additional objects !ere
added, and e+"anded observations !ith other !ider-field instruments !ere done# 7he "roject continues
to be an on-going one !ith "eriodic revisions or u"dates in the ho"es that this article might serve as a
something of rough guide to those !ho !ish to use filters on various nebulae#

7he follo!ing is a summar& u"date (931:3:007 re"ort of visual observations of some diffuse emission
and "lanetar& nebulae com"aring the "erformance of various filters intended for such objects# 7he
instruments and "o!ers used !ere0 10 inch f/5.6 Newtonian (4:+, 71+, 10>+, and 1>1+, 9.25 inch
f/10 SCT (49+, 9'+, 8 inch f/5 Newtonian (?:+, 100mm f/6 refractor (14+, ::+# ;lso, a fe!
unaided-e&e observations !ere made using the filters hand-held and loo(ing u" at the s(& (for <osette,
6orth ;merica, @alifornia 6ebula, Lambda =rionis com"le+, and /arnardAs Loo"# 7he filters used
!ere LumiconAs DEEP-S! (broadband, "#C (narro!-band, $%%% (line, and #-&ET' (line, and
!ere usuall& all mounted in a modified Lumicon 1ulti-filter 2elector# 7his allo!ed ra"id and re"eated
com"arisons bet!een filters, thus avoiding some of the judgment "roblems caused b& the time needed
to change filters or re"orts from single-filter observation non-com"arative accounts# =bservations !ere
done onl& under clear dar( and o"timal s(& conditions (na(ed-e&e Benith Limiting 1agnitude 5#4 and
fainter, so these results do notrepresent how well these filters deal with moderate to high levels of
light pollution# =bserving !as done from several 6ebras(a dar!'s!y sites0 <oc(ford La(e, /ig %ndian
La(e (both !ith BL1 5#4 to 7#0, and 1erritt <eservoir (+ebras!a ,tar -arty. BL1 7#: to 7#5# 7he
test objects !ere initiall& selected from those nebulae "lotted on /ecvarAs $/0$, 12 /H3 H3$43+,
15&6 (2(alnate-Pleso, and ,78 $/0$, 2666.6 ($# 7irion, 1st edition, !hich !ere verified as at least
detectable !ith the C.@ or 8ee"-2(& filter in the 10 inch 6e!tonian# 7he object list !as later
e+"anded to include some "lotted on 9:$+1;3/:I$ 2666.6 (:nd edition, and the soft!are
atlas ;3<$,/$: &.6# ;dditional objects !ill ver& "robabl& be added in the future# Dor detailed
descri"tions of the objects, see an& of the various observing handboo(s# ; number of objects !ere
surve&ed more than once, as initial observations made !ith the 10 inch (the "rimar& instrument in the
earl& "hases of the surve& !ere sometimes inconclusive as to !hich filter !as best, or !ere
contradicted b& observations in the ne!er !ider-field instruments !hich later became available#
.o!ever, onl& the initial set of Lumicon filters !ere used to maintain at least some consistenc&, even
though other similar filters became available that ma& have been able to change the outcomes#

7!o methods !ere used for indicating roughl& ho! !ell each filter !or(ed on a given object# %n the
first method, each filter !as given a 0-4 "oint “2core” "erformance ran(ing behind it or each object
observedE )+am"le0 =%%% (> means the =%%% gave a large im"rovement in the vie! over non-filter use
and contributes > "oints to its overall score total# %tems such as overall surface brightness, area of
nebulosit& observed, and contrast of detail !ere used to judge ho! !ell a filter im"roved the vie!#
#owe(er) *ince thi* (i*+a, -+./ment contain* *ome of the 0er*ona, 0reference* of the o1*er(er)
the *0ecific re*+,t* for each o1-ect ma2 1e a 1it *+1-ecti(e in the ,on/ r+n. 8ifferent observers
might have some!hat different judgment of various filters on various objects, so these results should
not be considered to be rigidl& definitive# 2till, the scoring should on average give a rough idea of
!hich filters might "rove useful on a given object#

3 Scorin/4 5e/en.
(40 Fer& Large %m"rovement over no filter#
(>0 Large %m"rovement over no filter#
?0 1oderate %m"rovement over no filter#
(:0 1ild %m"rovement over no filter#
(10 Little or no %m"rovement over no filter#
(00 1uch $orse than no filter (object marginal or not visible#
666 SC$7%N8 T$T'5S 9$7 NE&"5'E S$ 9'7 S"7:E!ED 666
(94 objects as of 2e"tember 1:th, :007
C.@GG ??> "oints, average rating ?#4:
=%%%G## ?0: "oints, average rating ?#1'
8))P-2HI# :07 "oints, average rating :#1'
.-/)7;G 1>? "oints, average rating 1#41

7he second method is a "ersonal recommendation for the best filter to use on the given object, based
mainl& on a overall visual judgment, and thus is even more a matter of o"inion and taste# 7he nebular
brightness, total area sho!n, contrast of details, and overall vie! !ere considered together to give an
o"inion of !hich filter might be a""ro"riate for !hich object# =ther observers !ould doubtless have
some!hat differing vie!s on recommendations for the s"ecific objects !hich !ere observed# $hen
objects !ere best seen in t!o filters (i#e#0 nearl& e,ual or beneficial "erformance, both filters !ould be
given the recommendation for the object, !ith the one &ielding the better overall vie! being listed first
and the “close second” best listed ne+t to it#

7EC$;;END'T%$N 7'N%N8 S";;'7!
C.@ best on >1 nebulae, close second best on >7 nebulae#
7=7;L 1st and :nd <)@=11)68;7%=62 for C.@0 '' objects#

=%%% best on ?> nebulae (biased b& the inclusion of some "lanetar& nebulae,
close second best on :: nebulae# J6=7J recommended on 5 nebulae#
7=7;L 1st and :nd <)@=11)68;7%=62 for =%%%0 45 objects#
.-/)7; best on 15 nebulae, second best on : nebulae#
J6=7J recommended on ?9 nebulaeK
7=7;L 1st and :nd <)@=11)68;7%=62 for .-/eta0 1' objects#
8))P-2HI best on 7 nebulae, second best on ? nebulae#
JProvided at least some slight im"rovement for JallJ nebulae surve&ed#
7=7;L 1st and :nd <)@=11)68;7%=62 for 8))P-2HI0 10 objects#

8ENE7'5 T7ENDS %N 7ES"5TS
2o far (!ith a fe! notable e+ce"tions, the numbers sho! the C.@ and =%%% are the filters of choice for
vie!ing nebulae, and to some degree su""orts the general recommendation that if on,2 one fi,ter can
1e 0+rcha*e.) it *ho+,. 1e the "#C or a *imi,ar narrow-1an. fi,ter# /& using a variet& of "o!ers,
it !as discovered that in general, the narro!-band and line filters tend to "erform best at from about
?#5+ "er inch of a"erture (7mm e+it "u"il to around 9#9+ "er inch of a"erture (:#5mm e+it "u"il !ith
slightl& better overall "erformance often seen in the lo!er half of this range (es"eciall& for the =%%% and
.-/eta filters# 7his range should not be considered an absolute ho!ever, as there are some s"ecific
situations !here each of these filters can be successfull& used at "o!ers considerabl& higher than those
cited above# .o!ever, in general, lo!er "o!er tended to be some!hat better, es"eciall& for the larger
and more diffuse objects#

%n relative "erformance characteristics, the 9H* filter tends to reveal a slightly larger and=or brighter
area of nebulosity with many emission nebulae than the 1III does) while the 1III filter will often yield
somewhat more contrast and dar! detail on a given ob"ect# %ndeed, there are a fe! nebular objects
!hich seem to sho! a "articularl& high boost in contrast !ith the =%%%, ma(ing it the “filter of choice”
at times# .o!ever, for some of these “=%%% objects”, a fe! "eo"le ma& still "refer a narro!-band filter
over the =%%% for the some!hat brighter image it ma& &ield, "articularl& at "o!ers in the u""er half of
the ?#4+-9#9+ "er inch range# 7hus, the choice bet!een the t!o filters (narro!-band vs# =%%% can
sometimes be more a "ersonal "reference (i#e# brightness vs# contrast than some objective standard#
=verall, the greatest im"rovement in the vie! of nebulae !as seen in the faintest details, so "ro"er full
dar( ada"tation and the use of averted vision "roved essential in getting the most out of these filters#

7he =%%% tended to be a bit better for locating small "lanetar& nebulae in rich starfields using the
“blin(ing” techni,ue than the C.@ !as# .o!ever, the .-beta filter often hurt the vie! of man&
"lanetaries !ith onl& a fe! e+ce"tions# 7he inclusion of some "lanetar& nebulae ma& have slightl&
inflated the overall score of the =%%% filter, since in general, the =%%% often does a bit better on those
objects# 7he =%%% also tends to re,uire a slightl& lo!er magnification range for best results than the
C.@ did# 7hus, !ith longer focal length telesco"es that have difficult& getting to reall& lo! "o!ers,
the C.@ might sometimes be the better choice# .o!ever, the =%%% filter !as successfull& used in the
surve& for a number of emission nebulae in both '0mm and 100mm <D7 a"ertures, so the “m&th” that
it is not useful in a"ertures smaller than ' inches is sim"l& not true# ; recent “ne!comer” filter, the
8*1 ="tics 6P/ (narro!-band “C.@-li(e” filter !as not used in the surve&, but occasionall& has
been sho!n to "rovide nearl& as much contrast on some objects as the =%%% or even the .-/eta
filter# 7hus, use of this filter in "lace of the C.@ !ould undoubtedl& change some of the ratings sho!n
belo!#

7he .-/eta tended to be most useful on a more limited number of objects (about 17L of the 94 objects
surve&ed than either the C.@ or the =%%% filters# 7his ma& be due at least in "art to the fact that man&
of the so-called “.-beta objects”, are lo! e+citation ver& faint nebulae, and thus are near or be&ond the
visual limits of m& ten inch# %ndeed, larger a"ertures !ould "robabl& change some of the ratings !hile
adding to the number of objects !hich res"ond to the various filters# 7he broadband 8ee"-2(& filter
almost al!a&s "roduced at least some gain in contrast for nearl& ever& object observed (es"eciall&
!hen some s(&glo! !as "resent, but rarel& "roduced a s"ectacular im"rovement of the vie!#
.o!ever, for “mi+ed” nebulae i#e#0 reflection and emission objects, the 8ee"-2(& can be the filter of
choice# 7he broadband 8ee"-s(& filter tended to have the !idest range of a""licable "o!er, being used
as high as ::+ "er inch (1#: mm e+it "u"il# Dilter ratings of (? and above should indicate that a filter
is definitel& !orth using on a given object even if that filter didnAt get a “first” recommendation# Dilter
com"arison results for each of the objects observed are sho!n belo!, but others are encouraged to
e+"eriment a little and not let these results overl& influence their o!n choice of !hich filter to tr&#

SPEC%9%C $&<ECT 7ES"5TS
)ach object is listed !ith the instrument(s used , the magnifications used, and the various filters# )ach
filterAs numerical score (0, 1, :, ?, >, 4E see earlier comments is given in "arenthesis, follo!ed b&
comments# 7he overall filter recommendation for the s"ecific object is then stated# %n the
<)@=11)68;7%=62 "ortion, a “3” bet!een the t!o filters named indicates that JbothJ filters !ill
!or( !ell on the object, !ith the one on the left side of the slash "ossibl& being a slightl& better choice0
ie0 “C.@3=%%%” means the C.@ ma& be slightl& better overall, but the =%%% !ill be ,uite useful as !ell#

11 @<;/ 6)/CL; (26< in 7aurus
(10 inch f34#5, 4:+, 71+, 1>1+#
8))P-2HI0 (? %m"roves the contrast and brings out the !is"& arc-li(e cus" on the eastern end#
C.@0 (> 8ar(ens the bac(ground and reveals little hints of tattered detail on the edges !ith the eastern
“cus"” no! more visible#
=%%%0 (? 1uch dar(er than in C.@, and a""ears slightl& smaller and some!hat rounder, but !ith hints
of filamentar& detail on the edges and across the nebula at 1>1+#
.-/)7;0 (0 barel& visible#
<)@=11)68;7%=6 D=< 110 C.@38))P-2HI (.-beta JnotJ recommended#

1' L;*==6 6)/CL; (diffuse 6ebula in 2agittarius
(10 inch f34#5, 4:+#
8))P-2HI0 (? 2ome increase in contrast, !ith a bit more nebulosit& visible than !ithout a filter#
C.@0 (4 Large boost in contrast and visibilit& of outer nebulosit&# 6ebula a""ears much larger (nearl&
a degree !ide !ith some detail enhancement, es"eciall& in the outer regions#
=%%%0 (4 2lightl& fainter than in the C.@, but sho!s slightl& more contrast and dar( detail than C.@
does# 2ome of the outermost nebulosit& fades, but detail in inner regions is remar(able# 1a& be the
better filter under light "olluted conditions#
.-/)7;0 (: 8ims the nebula considerabl&, !ith onl& the circular ball of haMe around the .ourglass
nebula and the e+ternal arc being eas& to see#
<)@=11)68;7%=6 D=< 1'0 C.@3=%%%

115 );*L) 6)/CL; (diffuse nebula in 2er"ens
(10 inch f34#5, 4:+#
8))P 2HI0 (: Daint diffuse nebulosit& is slightl& easier to see than !ithout a filter# 6ot a great deal of
detail visible in nebula#
C.@0 (> Large increase in visible nebulosit&, sho!ing !ide diffuse fan of light in the sha"e of a broad
“7”# 2mall dar(er inclusion becomes visible along the northern side#
=%%%0 (> 2lightl& fainter than !ith C.@, !ith slightl& less faint outer nebulosit&, but sho!s more
contrast and dar( detail in the interior, including faint narro! “fingers” from south side into the center
of the nebula !ith averted vision#
.-/)7;0 (: 8ims the nebula significantl&, but “7” sha"e still vaguel& visible#
<)@=11)68;7%=6 D=< 1150 C.@3=%%%, but .-/)7; hurts the vie!#

117 2$;6 (=1)*; 6)/CL; (diffuse nebula in 2agittarius
(10 inch f34#5, 4:+#
8))P-2HI0 (? 2ome im"rovement in contrast and detail, !ith the fainter loo" of nebulosit& to the
northeast just becoming visible to form the omega sha"e#
C.@0 (> 6oticeable im"rovement in contrast and detail, !ith much of the faint nebulosit& on the outer
regions and along the “omega” loo" becoming ,uite eas& to see#
=%%%0 (4 2lightl& fainter than C.@, but contrast is also higher, !ith a rather stri(ing dar( area
becoming noticable along the !est side of the s!anAs nec(# 8ar( detail in interior of main bar is better
defined than !ith C.@#
.-/)7;0 (1 =bject is noticeabl& dimmed com"ared to the other filters, ma(ing the filter a "oor choice
for use on 117#
<)@=11)68;7%=6 D=< 1170 =%%%3C.@ (.-/)7; not recommended#

1:0 7<%D%8 6)/CL; (diffuse emission3reflection nebula in 2agittarius
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (: 2mall difference bet!een filtered and unfiltered vie!s !ith a slight gain in contrast
!ith the filter, but !ith an& light "ollution, the filter ma& be of greater use#
C.@0 (> 6ebula is slightl& fainter than !ith 8))P-2HI filter, !ith a slight gain in contrast over the
8))P-2HI and more contrast gain over unfiltered vie!s#
=%%%0 (? 6ebula is fainter than !ith C.@ or 8))P-2HI, and main trifid section a""ears slightl&
smaller (hurts the northern reflection nebulosit&, but dar( detail in the inner “lanes” sho!s u" slightl&
better#
.-/)7;0 (> 6ebula is some!hat fainter than in C.@, but trifid section sho!s a bit larger area of
nebulosit& than the C.@ does# %t (ills the reflection nebula and reduces the brightness of the detail
right around the central star#
<)@=11)68;7%=6 D=< 1:00 [email protected]/)7;#

1:7 8C1/)LL 6)/CL; ("lanetar& nebula in Ful"ecula
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (? 2ome im"rovement in visibilit& of outer haMe off the sides of the dumbell, but the
object is also slightl& fainter#
C.@0 (4 Large im"rovement in contrast and outer detail, !ith large “!ings” of light off the 8umbellAs
sides becoming eas& to see# %nterior seems brighter and bigger, !ith interesting greenish glo!#
=%%%0 (> 8immer than !ith C.@, but interior sho!s more dar( detail and contrast# ”$ings” off the
sides not as e+tensive, as in C.@ but still visible#
.-/)7;0 (1 6ebula is dimmed greatl& b& the filter, e+tinguishing the fine outer detail and onl&
sho!ing the inner dumbell-sha"e#
<)@=11)68;7%=62 D=< 1:70 C.@ (=%%% also useful in sho!ing some inner detail, but .-/)7;
is 6=7 recommended#

1>: *<);7 =<%=6 6)/CL; (diffuse nebula
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (? ; moderate boost in contrast can be seen, and much more outl&ing nebulosit& is
visible# 7his is a good filter for the general "ublic, since it still !ill sho! the stars !hile enhancing the
nebula#
C.@0 (4 Large boost in contrast over no filter is noted# =uter nebulosit& is ,uite eas& to see, !ith
south!ard loo" being easil& seen !ith averted vision# /luish and greenish colors are ,uite eas& to note
!ith direct vision#
=%%%0 (> ; fe! of the outermost nebulosit& areas are dimmed, but there is more contrast, !ith
considerable im"rovement in light and dar( detail, es"eciall& in the inner regions# 1>? is some!hat
fainter than in the C.@filter, but narro! band!idth of =%%% ma& ma(e it the filter of choice !ith light
"ollution#
.-/)7;0 (? 1uch of the fainter outer areas of the nebula vanish, but fan-li(e main "ortion and 1>?
remain, !ith interesting contrast and changes in detail visible, including a brighter linear arc in the
!estern "art of the fan# 2ome reddish hints are also visible in the Lumicon .-beta#
<)@=11)68;7%=6 D=< 1>:0 C.@3=%%% (near-tieJ

1>? (north "art of *reat =rion 6ebula
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (? higher contrast than !ithout filter, but not much detail enhancement e+ce"t !hen there
is some light "ollution#
C.@0 (? some!hat more contrast than !ith the 8ee"-2(& !ith overall “comma” sha"e no! easil&
seen#
=%%%0 (: dims the nebula, but overall sha"e is still easil& visible#
.-/)7;0 (> <eall& ma(es 1>? stand out, !ith high contrast and some irregular dar( detail in the
overall comma-sha"ed nebula#
<)@=11)68;7%=6 D=< 1>?0 .-/)7; (C.@ and 8ee"-2(& also hel"#

147 <%6* 6)/CL; ("lanetar& nebula in L&ra
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: 8ar(ens the bac(ground slightl&, and brings out hints of ver& faint nebulosit& off the
ends of the oval, but other!ise doesnAt hel" much#
C.@0 (> <eall& dar(ens the bac(ground and stars, and begins to sho! a more "rominent glo! in the
interior of the ring, !ith hints of faint outer nebulosit& around the outer edges of the ring#
=%%%0 (> 8ar(ens the nebula and the bac(ground still further, but slight increase in contrast noted#
=uter shell just visible !ith averted vision#
.-/)7;0 (0 <eall& (ills things, !ith the nebula no! being ver& dim#
<)@=11)68;7%=62 D=< 1470 C.@3=%%%# 6ebula is bright and small enough not to reall& benefit
enormousl& from filter use, but C.@ does im"rove it to a degree (.-/)7; is 6=7 recommendedK#

175 “1%6%-8C1/)LL” or /C77)<DLI 6)/CL; ("lanetar& nebula in Perseus
(10 inch f34#5, 4:+, 10>+
8))P-2HI0 (: 2ome im"rovement over no filter, !ith hints of nebulosit& off the sides of the dumbell#
C.@0 (> 1uch more nebulosit& visible, including faint "atches or loo"-li(e “!ings” off each side of
the dumbell, along !ith some interior detail#
=%%%0 (? 6ebula is some!hat fainter, but sho!s more contrast, !ith some dar( detail being seen near
each lobe of the dumbell# 7he "atches off to the sides of the dumbell loo( li(e "artial loo"s#
.-/)7;0 (0 8ims the nebula almost to e+tinction at moderate "o!ers#
<)@=11)68;7%=6 D=< 1750 C.@3=%%% (.-/)7; 6=7 recommendedK#

197 “=$L 6)/CL;” ("lanetar& nebula in Crsa 1ajor
(10 inch f34#5, 4:+, 10>+#
8))P-2HI0 (: 2light im"rovement over non-filter use (hints of the “e&es”#
C.@0 (> 1uch higher contrast than !ith 8ee"-2(& filter# =ne e&e and hints of the other are seen#
=%%%0 (4 %ncrease in contrast over C.@# /oth e&es visible !ith hints of irregular outer edge structure#
.-/)7;0 (0 6earl& obliterates the nebula#
<)@=11)68;7%=6 D=< 1970 =%%%3C.@ (.-beta JnotJ recommended#

6*@ >0 (Planetar& 6ebula in @e"heus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (? 2light increase in contrast and detail (brighter o""osing sides, but object does not
reall& re,uire a filter#
C.@0 (? 2lightl& fainter than in 8ee"-s(&, but sho!s a bit more contrast#
=%%%0 (: 2ome!hat fainter than in C.@, but dis( still ,uite visible#
.-/)7;0 (: 2ome!hat fainter than in C.@, but ver& slightl& brighter than !ith the =%%% filter (a
“near” .-beta object#
<)@=11)68;7%=6 D=< 6*@ >00 8))P-2HI3C.@ (near tie#

6*@ :>5 (Planetar& in @etus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: defines it a bit better than !ithout a filter, but still mainl& a diffuse roughl& circular
glo! around a fe! stars#
C.@0 (? .igher contrast, !ith nebula no! a fairl& !ell-defined moderate-siMed dim dis( !ith hints of
brightness variations in the interior#
=%%%0 (> %ncrease in contrast over the C.@# 2ho!s several dar( s"ots in the interior and hints of shar"
filament-li(e outer edge of the dis(#
.-/)7;0 (0 <eall& (ills the nebula (barel& visible#
<)@=11)68;7%=6 D=< 6*@ :>50 =%%%3C.@# (.-/eta JnotJ recommended#

6*@ :'1 (8iffuse emission nebula, @assio"eia
(10 inch f34#5, 4:+#
8))P-2HI0 (? 6ebula is some!hat easier to see (barel& visible !ithout filters, !ith the edges being
more defined#
C.@0 (> 6oticable im"rovement in contrast and detail, a""earing larger than !ith 8ee"-2(& filter, and
containing some dar( detail#
=%%%0 (> 6ebula is dimmer, but interior dar( lane-li(e detail becomes more noticeable, and the overall
nebula sha"e is better defined than in C.@#
.-/)7;0 (: 8ims the nebula much more than =%%%, !ith no more detail than is seen !ith the 8ee"-
2(& filter (dim#
<)@=11)68;7%=62 D=< 6*@ :'10 C.@3=%%%#

6*@ 50> (.%% region in gala+& 1?? in 7riangulum
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: slight increase in contrast over unfiltered vie!, but eas& to see !ithout filters#
C.@0 (? 1uch easier to see than in 8ee"-s(&, standing out !ell as an oval "uff, !ith much of the
detail in the gala+& remaining visible#
=%%%0 (> @onsiderable increase in contrast, almost “blin(ing” over C.@ and unfiltered vie!s# *ala+&
is much fainter, but nebula reall& stands out#
.-/)7;0 (: 1uch dimmer than in the other filters, but nebula is still seen#
<)@=11)68;7%=6 D=< 6*@ 50>0 =%%%3C.@#

6*@ '953%@ 1794 (“.eart” nebula in @assio"eia
(10 inch f34#5, 4:+#
8))P-2HI0 (? noticeable increase in visibilit&, !ith nebula being onl& a glo! !ithout the filter# 7!o
areas of dim diffuse nebulosit& seen, one large (%@ 1794 and the other smaller (6*@ '95#
C.@0 (> 1uch more "rominent, !ith better definition and a little dar( detail, along !ith a !is"& outer
arc curving around from south "art of %@ 1794#
=%%%0 (> 8immer than in C.@, but more dar( detail visible !ith faint outer loo"-li(e structure visible
arcing south, almost connecting the t!o "atches#
.-/)7;0 (1 /arel& visible#
<)@=11)68;7%=6 D=< 6*@ '953%@ 17940 C.@3=%%% (.-beta JnotJ recommended#

6*@ 1?50 (large Planetar& 6ebula in Dorna+
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: slight increase in contrast !ith nebula easier to see than !ithout a filter (but still
visible !ithout a filter#
C.@0 (> 2ignificant im"rovement in contrast, !ith nebula a""earing larger and noticeabl& oval# 2ome
irregular interior detail and central star noted#
=%%%0 (> )ven more contrast than C.@, !ith clear interior arc-li(e detail, but central star much fainter#
6ice dar( bac(ground
.-/)7;0 (0 Hills the nebulosit& !ith onl& the central star and a small hint of haMe around the star
being visible#
<)@=11)68;7%=6 D=< 6*@ 1?500 =%%%3C.@ (.-beta JnotJ recommended#

6*@ 1>91 (diffuse 6ebula in Perseus(10 inch f34#5, 4:+, 71+
8))P-2HI0 (? moderate increase in contrast over non-filtered vie!#
C.@0 (40 larger, !ith faint irregular outer nebulosit& seen and bar-li(e inner feature no! ver& obvious#
=%%%0 (>0 .igher contrast in inner regions (es"eciall& the bar, but outer-most nebulosit& dimmed#
.-/)7;0 (0, (ills most of the nebulosit& other than a hint of it#
<)@=11)68;7%=6 D=< 6*@ 1>910 C.@3=%%% (.-/eta JnotJ recommended#

6*@ 1>99 @;L%D=<6%; 6)/CL; (diffuse 6ebula in Perseus
(100mm f35 refractor, ::+, 9#:4 inch 2@7, 49+
8))P-2HI0 (: ; slight increase in contrast !as noted, but other!ise, the vie! !as similar to that
!ithout a filter#
C.@0 (: 2light increase in contrast over the 8ee"-2(& filter, ma(ing the edges of the nebula slightl&
easier to see, but nebula is still some!hat difficult# .ints of vague brightness variations across the
object are noted#
=%%%0 (1 6ebulosit& is ,uite dim in a ver& dar( field#
.-/)7;0 (> 8ramatic increase in contrast noted, ma(ing the object fairl& eas& to notice, !ith !ell-
defined borders# 2ome faint filamentar& detail is also noted, es"eciall& in 9#:4 inch 2@7 at 49+#
@alifornia 6ebula is visible to unaided e&e at a dar( s(& site !hen .-beta is held u" to the e&e#
<)@=11)68;7%=6 D=< @;L%D=<6%; 6)/CL;0 .-/)7;#

6*@ 141> “@<I27;L-/;LL 6)/CL;” ("lanetar& nebula in 7aurus
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (: 6ice faint round "uff around a faint star, easier to see than !ithout a filter#
C.@0 (> 2ignificant im"rovement in contrast, !ell-defined haM& ball !ith hints of dar( detail in the
interior of the nebula#
=%%%0 (> 1ore contrast than in C.@, !ith dar( detail and arc-li(e forms in the main shell# 8immer
than in C.@ but a bit better overall#
.-/)7;0 (0 ;lmost !i"es out the nebula#
<)@=11)68;7%=6 D=< 6*@ 141>0 =%%%3C.@ (.-/eta 6=7 recommended#

6*@ 1999 (diffuse nebula in =rion
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (: slight enhancement over no filter, and eas& !ithout one#
C.@0 (1 fainter than 8ee"-2(& or no filter#
=%%%0 (1 fainter than C.@ or 8ee"-2(&#
.-/eta0 (1 fainter than 8ee"-2(&, C.@, or no filter#
<)@=11)68;7%=6 D=< 6*@ 19990 8))P-2HI

6*@ :0:: ("lanetar& nebula in =rion
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (? visible !ithout a filter, but stands out better !ith 8ee"-s(& (small fuMM& dis(#
C.@0 (> 6oticabl& im"roves the contrast, !ith an almost annular form visible at higher
magnifications#
=%%%0 (4 1uch higher contrast and dar(er bac(ground than in C.@, but C.@ or no filter ma& be bit
better for high "o!er observations of details#
.-/)7;0 (0 ;lmost !i"es it out (barel& visible#
<)@=11)68;7%=6 D=< 6*@ :0::0 =%%%3C.@ (.-/eta 6=7 recommended#

6*@ :0:> “DL;1) 6)/CL;” (diffuse emission3reflection nebula in =rion
(10 inch f34#5, 4:+
8))P-2HI0 (? 6oticeabl& im"roves the contrast !ith the dar( lane-li(e detail visible#
C.@0 (? 8ar(er than in 8ee"-s(& but !ith onl& a slight increase in contrast#
=%%%0 (: 8ar(er than in C.@, !ith less detail than in C.@#
.-/)7;0 (1 8ar(est of all three filters, but the nebula remains visible !ith detail similar to that of
=%%%#
<)@=11)68;7%=6 D=< 6*@ :0:>0 8))P-2HI3C.@ (near tie#

6*@ :17> (diffuse nebula in northern =rion
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: ver& faint glo! around a single star !ith hints of detail (much easier to see than
!ithout a filter#
C.@0 (> Large increase in contrast over 8ee"-2(& filter, sho!ing a large circular area of haMe !ith
vague irregular interior dar( detail#
=%%%0 (> 8immer than in C.@, but has more contrast, sho!ing some dim lane-li(e structure#
.-/)7;0 (0 8ims the nebula almost to e+tinction, sho!ing less than the 8ee"-2(&#
<)@=11)68;7%=6 D=< 6*@ :17>0 C.@3=%%% (near tie (.-/eta 6=7 recommended#

6*@ :?:7 (diffuse nebula in 1onoceros
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: Fer& faint diffuse roughl& circular haMe around 7th mag# star#
C.@0 (?0 =bject is larger !ith slightl& better definition than in 8ee"-s(&#
=%%%0 (:0 nebula is no! ver& faint, !ith onl& the area round the star visible#
.-/)7;0 (>0 object is not ,uite as bright as in C.@ but is JmuchJ better defined, sho!ing a dar(
inclusion from the northeast and a brighter arc-li(e !estern edge#
<)@=11)68;7%=6 D=< 6*@ :?:70 .-/)7;3C.@

6*@ ::?7-9 “<=2)77) 6)/CL;” (diffuse nebula in 1onoceros#
(100mm f35, ::+
8))P-2HI0 (: 2ome increase in contrast, but nebula is still more of a diffuse haMe around the central
star cluster !ith hints of irregularit&#
C.@0 (4 6oticeable increase in contrast, !ith more outer nebulosit& visible and some irregular light
and dar( structure being visible# 6ebula !as visible !hen C.@ !as held u" to unaided e&eK
=%%%0 (4 .igher contrast than !ith C.@, !ith more dar( irregular detail throughout the region
(es"eciall& in the 10 inch, but not ,uite as much nebulosit& visible as in C.@#
.-/)7;0 (1 Fer& faint glo! around the star cluster, not much better than !ithout a filter (but much
dimmer#
<)@=11)68;7%=6 D=< <=2)77) 6)/CL;0 C.@3=%%%#

6*@ ::5>, “@=6) 6)/CL;” near 2 1onocerotis
(10 inch f34#5, 4:+#
8))P-2HI0 (: slight increase in contrast, !ith dim diffuse haMe no! visible and brightest s"ot $#2#$#
of 2 1on#
C.@0 (? Daint nebulosit& no! visible over entire field, nearl& a degree !ide, but onl& the area $#2#$#
of 2 1on !as ver& bright# 8ar( southern inclusion “@one” faintl& visible in southern "art of nebula#
=%%%0 (: 8immer than in C.@, but some!hat higher contrast# 7he “@one” !as hinted at, but onl& the
area south!est of 2 1on !as all that bright#
.-/)7;0 (1 =nl& a dim glo! south!est of 2 1on !as "rominent (“@one” ,uestionable#
<)@=11)68;7%=6 D=< @=6) 6)/CL;0 C.@ (other filters ma& be more useful in larger
a"ertures#

6*@ :?49 7.=<A2 .)L1)7 (diffuse nebula in @anis 1ajor
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: /etter defined than !ithout a filter but still lo! in contrast#
C.@0 (> .igher contrast than in 8ee"-s(&, !ith arc li(e detail off of a central oval ring-li(e mass#
=%%%0 (4 even more contrast than in C.@ !ith oval mass no! loo(ing li(e a loo" !ith tendrils off each
end#
.-/)7;0 (0 8ims most of the nebulosit&#
<)@=11)68;7%=6 D=< 6*@ :?490 =%%%3C.@ (.-/eta JnotJ recommended#

6*@ :?>5 (Planetar& nebula in 1onoceros
(10 inch f34#5, 4:+, 10>+
8))P-2HI (:0 slightl& easier to see than !ithout a filter#
C.@0 (? some increase in contrast, !ith hints of flarings north and south#
=%%%0 (? some increase in contrast, slightl& fainter than in C.@#
.-/)7;0 (0 nearl& e+tinguished#
<)@=11)68;7%=6 D=< 6*@ :?>50 C.@3=%%% (near tie (.-beta JnotJ recommended#

6*@ :>?' ("lanetar& nebula in Pu""is
(10 inch f34#5, 4:+, 10>+#
8))P-2HI0(: noticeabl& easier to see than !ithout a filter# .ints of annularit&#
C.@0 (? notable increase in contrast, easier to see than in 8ee"-s(& !ith annular form more noticable#
=%%%0 (> much higher in contrast !ith annular form no! fairl& obvious#
.-/)7;0 (0 nearl& (ills it com"letel&#
<)@=11)68;7%=6 D=< 6*@ :>?'0 =%%% (.-/eta JnotJ recommended#

6*@ :?71-: ("lanetar& nebula in *emini
(10 inch f34#5, 4:+, 71+, 10>+#
8))P-2HI0 (: 7!o adjacent faint s"ots, hel"ed some!hat over non-filter use#
C.@0 (> enhanced over 8ee"-2(&, !ith the t!o lobes sho!ing hints of contact#
=%%%0 (> 2lightl& higher contrast than C.@# .ints of faint outer !ings#
.-/)7;0 (0 Hills the nebulosit&#
<)@=11)68;7%=6 D=< 6*@ :?71-:0 =%%%3C.@ (near tie (.-/eta JnotJ recommended

6*@ :?9: “)2H%1= 6)/CL;” ("lanetar& nebula in *emini
(10 inch f34#5, 4:+, 1>1+
8))P-2HI0 (: enhanced slightl& over non-filter use (easier to see the outer of the t!o shells#
C.@0 (> 8ar(ens the s(& bac(ground and enhances the nebula, ma(ing both shells ,uite eas& to see#
=%%%0 (> 9et-blac( s(& bac(ground !ith higher contrast than C.@, but the t!o shells almost seem to
merge (tones do!n the central star#
.-/)7;0 (0 =nl& the inner shell is visible, much fainter than in C.@, =%%%, or 8ee"-2(&#
<)@=11)68;7%=6 D=< 6*@ :?9:0 =%%%3C.@# (.-/eta JnotJ recommended#

6*@ :>>0 ("lanetar& nebula in Pu""is
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: small fairl& bright fuMM& oval (visible !ithout filters#
C.@0 (> nice increase in contrast, but still eas& !ithout a filter#
=%%%0 (> dar(er bac(ground but still ,uite bright#
.-/)7;0 (0 inner shell barel& visible#
<)@=11)68;7%=6 D=< 6*@ :>>00 C.@3=%%% (near tie (.-/eta not recommended#

6*@ ?:>: “*.=27 =D 9CP%7)<” ("lanetar& in .&dra
(10 inch f34#5, 4:+, 71+, 1>1+#
8))P-2HI0 (: slightl& enhanced over non-filter use (eas& !ithout filters#
C.@0 (>0 much higher contrast !ith faint circular outer halo-li(e shell be&ond the t!o inner shells
no! visible#
=%%%0 (>0 much dar(er bac(ground but the t!o inner shells reall& blaMe out#
.-/)7;0 (10 much fainter (onl& the innermost shell is easil& seen#
<)@=11)68;7%=6 D=< 6*@ ?:>:0 C.@3=%%% (near tie (.-/eta not recommended#

6*@ >?51 ("lanetar& nebula in @orvus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: some!hat higher contrast than !ithout a filter#
C.@0 (> Large increase in contrast !ith faint diffuse outer e+tensions seen#
=%%%0 (> .igher contrast, a bit shar"er than in C.@ but nebula a""ears slightl& smaller#
.-/)7;0 (00 nearl& (illed b& the filter#
<)@=11)68;7%=6 D=< 6*@ >?510 C.@3=%%% (near tie, (.-/eta JnotJ recommended#

6*@ 5:10 ("lanetar& nebula in .ercules
(10 inch f34#5, 4:+, 71+, 1>1+#
8))P-2HI0 (: stands out a bit better, but filters are not needed#
C.@0 (> increase in contrast !ith faint hints of close outer shell north and south of main dis(#
=%%%0 (> dar(ens the bac(ground and also sho!s hints of the outer shell#
.-/)7;0 (1 dims the nebula, sho!ing onl& the brighter inner core#
<)@=11)68;7%=6 D=< 6*@ 5:100 =%%%3C.@ (.-/eta JnotJ recommended#

6*@ 5?0: “/C* 6)/CL;” ("lanetar& nebula in 2cor"ius
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: some!hat more contrast than !ithout a filter#
C.@0 (? noticeable im"rovement in contrast !ith central core region no! seeming much brighter and
outer )-$ flarings much easier to see#
=%%%0 (? ma(es the core region reall& stand out, although the nebula is not ,uite as bright as in the
C.@#
.-/)7;0 (0#
<)@=11)68;7%=6 D=< 6*@ 5?0:0 =%%%3C.@ (.-/eta JnotJ recommended#

6*@ 5??> (diffuse nebula in 2cor"ius
(10 inch f34#5, 4:+#
8))P-2HI0 (: nebula is a large ver& faint glo! !hich is brightest around one star near the south end#
C.@0 (> t!o se"arated "atches around t!o stars near the south end, "lus fainter "atches and dar( s"ots
visible in a dim diffuse haMe to the north#
=%%%0 (? fainter than in C.@, but still visible#
.-/)7;0 (? similar to =%%% vie! but slightl& fainter#
<)@=11)68;7%=6 D=< 6*@ 5??>0 C.@ (=%%% and .-beta also useful#

6*@ 5>>4 (Planetar& 6ebula in 2agittarius
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: ma(es it stand out better#
C.@0 (> noticeabl& im"roves the contrast over 8ee"-2(&#
=%%%0 (? dar(er more contrasting field, but slightl& fainter than C.@#
.-/)7;0 (0 (ills the nebula almost com"letel&#
<)@=11)68;7%=6 D=< 6*@ 5>>40 C.@3=%%% (.-beta JnotJ recommended#

6*@ 5?47 (diffuse nebula in 2cor"ius
(10 inch f34#5, 4:+#
8))P-2HI0 (: not eas& to see !ithout a filter, as 8ee"-2(& just barel& brings it out#
C.@0 (? 6oticable boost in contrast, sho!ing some irregularit& and a brighter "ortion around a tin&
grou" of stars#
=%%%0 (> 1ore contrast than C.@, !ith the "atch around the tin& star grou" greatl& enhanced#
.-/)7;0 (1 almost (ills the nebulosit&#
<)@=11)68;7%=6 D=< 6*@ 54?70 =%%%3C.@ (.-/eta JnotJ recommended#

6*@ 54>? “@;7A2 )I)” ("lanetar& nebula in 8raco
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: ma(es it stand out a bit better#
C.@0 (> noticeable contrast im"rovement !ith faint diffuse outer halo visible# Daint "atch !est of
main nebula barel& visible (%@ >577#
=%%%0 (> reall& dar(ens the bac(ground and boosts the visibilit& of the outer halo# %@ >577 no! slightl&
easier to see#
.-/)7;0 (1 reall& dims it but is still visible#
<)@=11)68;7%=6 D=< 6*@ 54>?0 =%%%3C.@ (.-/eta JnotJ recommended#

6*@ 5449 (diffuse nebula in 2agittarius
(10 inch f34#5, 4:+#
8))P-2HI0 (: not visible !ithout filters, glo! around one star !ith hints of e+tensions north and
north!est#
C.@0 (>, noticeabl& enhanced !ith some light and dar( structure#
=%%%0 (: still visible but much fainter than in C.@#
.-/)7;0 (: visible !ith slight structure#
<)@=11)68;7%=6 D=< 6*@ 54490 C.@

6*@ 57'1 ("lanetar& in ;,uila
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (? eas& !ithout a filter but sho!s more contrast !ith hints of annularit& even at lo!
"o!er#
C.@0 (> noticeable boost in contrast !ith strong annular form and glo!ing interior (notable
brightening along south side#
=%%%0 (> reall& dar(ens field and enhances the annularit&#
.-/)7;0 (0 (ills the nebula com"letel&#
<)@=11)68;7%=6 D=< 6*@ 57'10 =%%%3C.@ (.-beta JnotJ recommended#

6*@ 5'0> (Planetar& nebula in ;,uila
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: slightl& easier to see than !ithout a filter#
C.@0 (? brings the nebula out !ell#
=%%%0 (> nice high contrast a bit better than C.@#
.-/)7;0 (0, nearl& !i"es it out#
<)@=11)68;7%=6 D=< 6*@ 5'0>0 =%%%3C.@ (.-beta JnotJ recommended#

@<)2@)67 6)/CL; (6*@ 5''' (diffuse nebula in @&gnus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: slight im"rovement over no filter, !ith the brightest segment of the crescent going
through a star along the northern end of the nebula fairl& eas& to see#
C.@0 (> 6ebula is no! much easier to see, a""earing as a large nearl& com"lete oval ring of dim
nebulosit& !ith brightness variations and a diml& glo!ing interior#
=%%%0 (4 @om"lete oval ring !ith glo!ing interior and slightl& higher contrast than !ith C.@, but
overall nebulosit& is fainter than !ith C.@#
.-/)7;0 (1 Fer& dim, !ith onl& the brightest arc "ortion !hich !as seen in the 8ee"-2(& filter
visible at all in a ver& dar( field# 6ebula almost gone#
<)@=11)68;7%=6 D=< 6*@ 5'''0 =%%%3C.@ (near tie# .-beta JnotJ recommendedK

6*@ 5904 (“the /lue Dlash” "lanetar& 6ebula in 8el"hinus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (? noticable im"rovement over no filter#
C.@0 (> increased contrast (best of the filters
=%%%0 (> still hel"s but not ,uite as much as the C.@
.-/eta0 (1, dims the object but does not e+tinguish it#
<)@=11)68;7%=6 D=< 6*@ 59040 C.@ (.-beta JnotJ recommended#

F)%L 6)/CL; 6*@ 5950-94 (26< in @&gnus
(10 inch f34#5, 4:+#
8))P-2HI0 (? 6ebula is easier to see than !ithout a filter, !ith both sides of the loo" being visible,
including the section through 4: @&gni#
C.@0 (> Large increase in detail and contrastK 6ebula reall& stands out !ith some filamentar& detail#
.ints of other strands in the interior of the loo"#
=%%%0 (4 )6=<1=C2 %6@<);2) %6 @=67<;27 ;68 8)7;%L !ith !onderful fine filaments and
strands visible even bet!een the t!o main arcs, ma(ing the entire com"le+ closel& resemble its
"hotogra"h# =%%% is the filter of choice here#
.-/)7;0 (1 Fer& dim, but still visible (forget itK#
<)@=11)68;7%=62 D=< F)%L0 =%%%3C.@ (=%%% is some!hat better but .-/)7; is
6=7 recommended#

6=<7. ;1)<%@;6 6)/CL; 6*@ 7000 (diffuse nebula in @&gnus
(100mm f35, ::+#
8))P-2HI0 (: 6ebular overall form is easier to see than !ithout a filter, but onl& slightl&#
C.@0 (> Fer& noticeable im"rovement in contrast over the 8))P-2HI filter, !ith both “Dlorida” and
“1e+ico” no! ,uite eas& to see#
=%%%0 (> .igher contrast and slightl& more shar"ness than in the C.@, !ith brighter “s"ine” on east
side of “1e+ico” and some faint dar( detail being eas& to see, but nebula is some!hat fainter than in
C.@#
.-/)7;0 (? 8etail is similar to =%%%, but nebulosit& is fainter than =%%%#
<)@=11)68;7%=62 D=< 6*@ 70000 =%%%3C.@ (near tie but both .-/)7; and 8))P-2HI are
useful on the object#

6*@ 700' ("lanetar& nebula in @&gnus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (:, slight increase in contrast, sho!ing the irregular form#
C.@0 (>0 real boost in contrast !ith detail no! visible#
=%%%0 (>0 slightl& higher contrast than C.@ but a bit fainter#
.-/)7;0 (00 nearl& obliterates the object#
<)@=11)68;7%=6 D=< 6*@ 700'0 =%%%3C.@ (.-/eta JnotJ recommendedK#

6*@ 7009 2;7C<6 6)/CL; ("lanetar& nebula in ;,uarius
(10 inch f34#5, 4:+, 71+, 1>1+#
8))P-2HI0 (: does sho! the ansae on each end of the "lanetar& a bit better, in the form of t!o small
"uffs#
C.@0 (> ;nses become more s"i(e-li(e, !ith noticeable increase in contrast#
=%%%0 (> 6ebula is dimmer, but contrast is a bit higher, es"eciall& in the interior, !here inner shell
detail can be seen#
.-/)7;0 (1 6ebula is noticeabl& dimmer, a""earing as just a dis(#
<)@=11)68;7%=6 D=< 6*@ 70090 Dilters are not needed, but =%%%3C.@ !ill hel" bring out the
fainter detail (.-/)7; not recommended#

6*@ 70:? )mission3reflection 6ebula in @e"heus
(10 inch f34#5, 4:+#
8))P-2HI0 (? 6oticeable boost in contrast !ith nebular glo! e+"anded over no filter# 8ar(er areas
noted on east and !est sides#
C.@0 (: dimmer than in 8ee"-s(& and slightl& smaller, but nebula still sho!s u" better than !ithout a
filter#
=%%%0 (: dimmer than in C.@ but still sho!s some hints of detail#
.-/eta0 (1 dimmer than C.@ and =%%%# =nl& central area around the star remains visible#
<)@=11)68;7%=6 D=< 6*@ 70:?0 8))P-2HI#

6*@ 70:5 (Planetar& nebula in @&gnus
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (: 2light boost in contrast#
C.@0 (? slightl& better than in 8ee"-s(& filter (irregular detail#
=%%%0 (? slightl& dar(er s(& bac(ground but not much better than C.@#
.-/)7;0 (0 much fainter than !ithout a filter#
<)@=11)68;7%=6 D=< 6*@ 70:50 =%%%3C.@ Jnear tieJ (.-/eta JnotJ recommended#

6*@ 70:7 (Planetar& nebula in @&gnus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: eas& !ithout filter, but 8ee"-2(& ma(es it stand out a little better as a small bluish-
green oval#
C.@0 (> reall& ma(es the nebula almost blaMe out and hints at large faint irregular outer shell# .igh
"o!er reveals off-center central star and an interior arc southeast of the central star#
=%%%0 (> @ore slightl& dimmer than in C.@, but outer shell is easier to see !ith hints of detail in the
outer shell#
.-/)7;0 (0 <eall& dims the nebulaK
<)@=11)68;7%=6 D=< 6*@ 70:70 =%%%3C.@ Jnear tieJ (.-/)7; not recommendedK#

6*@ 70>' (Planetar& nebula in @&gnus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: faint but a bit more contrast than !ithout a filter#
C.@0 (? much higher contrast sho!ing a faint glo!ing oval#
=%%%0 (> more contrast than C.@ sho!ing dar(er center and annularit&#
.-/)7;0 (00 nearl& (ills it#
<)@=11)68;7%=6 D=< 6*@ 70>'0 =%%%3C.@ (.-/eta JnotJ recommendedK#

6*@ 71:9-?? (8iffuse )mission3reflection 6ebula in @e"heus
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (: slight increase in contrast, !ith a faint haMe visible around a central grou" of > to 5
stars#
C.@0 (? .aMe no! easier to see !ith more contrast, but still rather diffuse !ith some faint detail
!hich is brightest in the northern "ortion# 7!o other faint "atches visible slightl& a!a& from the north
one#
=%%%0 (? /rings out a little more detail (dar( inclusion in one sideN#
.-/)7;0 (1 dims the nebula significantl&, although it is still there#
<)@=11)68;7%=62 D=< 6*@ 71:9-??0 C.@3=%%%

6*@ 71?9 (faint "lanetar& nebula in @e"heus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: increased contrast over non-filter use#
C.@0 (?0 2till faint, but much easier to see#
=%%%0 (>0 1ore contrast than C.@#
.-/)7;0 (00 nebula not visible#
<)@=11)68;7%=6 D=< 6*@ 71?90 =%%%3C.@ (.-/eta JnotJ recommended#

6*@ 7:9? *%;67 .)L%@;L 6)/CL; ("lanetar& nebula in ;,uarius
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: large dim roughl& circular fuMM& "atch !ith slightl& dar(er middle, easier to see than
!ithout a filter, but does not have a lot of contrast#
C.@0 (> 6oticeable increase in contrast, sho!ing a clear fat slightl& diffuse ring !ith a glo!ing center
and hints of structure# 6ebula is no! ,uite eas&#
=%%%0 (4 2ome!hat more contrast than the C.@, !ith hints of helical nature and indications of outer
filamentar& nebulosit&# 6oticeabl& dimmer than in C.@, but stands out a bit better than in the C.@,
es"eciall& at lo!er "o!ers#
.-/)7;0 (0 /arel& visible in this filter (almost (ills the nebulosit&#
<)@=11)68;7%=6 D=< 6*@ 7:9?0 =%%%3C.@ (.-beta 6=7 recommended#

6*@ 74?' (8iffuse nebula in @e"heus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (? boosts the contrast ma(ing it easier to see than !ithout a filter#
C.@0 (> dar(ens the bac(ground and brings out the nebulosit& more than 8ee"-2(&#
=%%%0 (> dimmer, but contrast is a bit higher#
.-/)7;0 (0 8ims it nearl& to e+tinction#
<)@=11)68;7%=6 D=< 6*@ 74?'0 C.@3=%%% (.-beta 6=7 recommended#

6*@ 75?4 /C//L) 6)/CL; (diffuse nebula in @assio"eia
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: Fague diffuse oval fuMM& area around a bright star#
C.@# (> =val area of nebulosit& noted around the star running roughl& east-!est !ith large ver& dim
diffuse e+tensions noted to the north!est and southeast# ; dim “I”-sha"ed "atch can also be seen just
north of the central star#
=%%%0 (> .igher contrast, !ith the “I”-sha"ed "atch no! much more definite#
.-/)7;0 (? 6ot as good as =%%%, but nebula is still visible#
<)@=11)68;7%=6 D=< 6*@ 75?40 =%%%3C.@#

6*@ 755: /LC) 26=$/;LL ("lanetar& nebula in ;ndromeda
(10 inch f34#5, 4:+, 71+, 1>1+#
8))P-2HI0 (:# 8ee"-s(& filter does dar(en the bac(ground some!hat#
C.@0 (? <eall& dar(ens the bac(ground, but adds onl& a little nebulosit&#
=%%%0 (? 8ims the nebula slightl&, giving a jet blac( s(& bac(ground and a bit more interior contrast
(but not much more detail#
.-/)7;0 (1 2ignificantl& dims the nebula over the =%%%#
<)@=11)68;7%=62 D=< 6*@ 755:0 Dilters are not reall& needed, but C.@3=%%% ma& hel" !ith
locating it at lo! "o!er via “blin(ing” (.-/)7; is not recommended#

6*@ 7':: (faint diffuse nebula in @e"heus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: Fer& faint large elongated (east-!est glo! around a fe! stars#
C.@0 (? *lo! is noticeabl& enhanced over 8ee"-s(&, sho!s some irregularit&#
=%%%0 (: Dainter than C.@, but still visible#
.-/)7;0 (: fainter than the C.@, but sho!s about as much detail as C.@#
<)@=11)68;7%=6 D=< 6*@ 7'::0 C.@ (.-/eta and =%%% also useful#

%@ >04 DL;1%6* 27;< 6)/CL; (diffuse emission3reflection nebula in ;uriga
(100mm f35, 14+, ::+#
8))P-2HI0 (: 6ebula visible as a ver& faint diffuse glo! !ith irregularities around and to the east of
;) ;ur# 6ot clearl& visible !ithout filters#
C.@0 (? 2light increase in contrast sho!ing "atch just north-east of ;)# .ints of other nebulosit&#
=%%%0 (: =nl& hints of nebulosit&#
.-/)7;0 (> 2mall arc and one other faint "atch north of ;) !ith a bit more contrast, and large fainter
diffuse e+tension to the east and south# 9#:4 inch 2@7 at 49+ sho!s triangular arc east of ;) !ith :nd
fainter "atch north#
<)@=11)68;7%=6 D=< %@ >040 .-/)7;#

%@ >10 (6ebula assoc# !ith 6*@ 1'9? in ;uriga
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (: faint glo! running )-$ through the “I”-sha"ed cluster 6*@ 1'9? !ith south!ard
e+tension off east end#
C.@0 (> detailed arc-li(e irregular nebulosit& running east-!est and then curving south !ith dar(er
inclusion along south!est side#
=%%%0 (> /rings out more dar( detail along the east and south sides, but nebula is dimmer# <eall& stands
out, as nebula follo!s the form of the cluster#
.-/)7;0 (0 6ebula is almost !i"ed out#
<)@=11)68;7%=6 D=< %@ >100 =%%%3C.@# (.-beta JnotJ recommended#

%@ >17 (diffuse 6ebula in ;uriga
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (: 6ebula is no! barel& visible around cluster 2toc( '
C.@0 (? increase in contrast over 82 filter#
=%%%0 (? dar(er bac(ground
.-/)7;0 (> more contrast and a bit more nebulosit& visible#
<)@=11)68;7%=6 D=< %@ >170 .-/)7;3C.@

%@ >?> .=<2).);8 6)/CL; (diffuse nebula in =rion
(10 inch f34#5, 4:+, 71+, 10>+#
8))P-2HI0 (: Little change is seen from vie!ing !ithout a filter# $hen visible, it a""ears as a !ea(
dar( ga" in the dim north-south nebulosit&, and the sha"e is hard to see# 6ebula is difficult, unless
vie!ed under ver& dar( and clear conditions#
C.@0 (? .orsehead no! stands out !ea(l& from dim glo!, sho!ing some of the horsehead sha"e
!ith averted vision, a definite im"rovement over no filter or the 8))P-2HI#
=%%%0 (0 6o .orsehead seen# %@->?> nebulosit& not seen for certain#
.-/)7;0 (> 6ebula still dim, but .orsehead sha"e no! fairl& eas& to see, sho!ing u" !ith more
contrast than !ith the C.@ filter# )ast edge of %@ >?> seems brighter than the rest of the nebula !ith
the .-beta#
<)@=11)68;7%=6 D=< .=<2).);80 Lumicon .-/)7; (C.@ also hel"s, but =%%% not
recommended#

%@ >>? (su"ernova remnant in *emini
(9#:4 inch 2@7, 49+
8))P-2HI0 (1 object onl& suggested and not clearl& seen#
C.@0 (> faint but definite arc !ith hints of detail#
=%%%0 (? shar"er but not as bright or eas& to see#
.-/eta (: hinted at in brightest section onl&#
<)@=11)68;7%=6 D=< %@ >>?0 C.@

%@ 1:'? (diffuse nebula in 2agittarius
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (: slight boost in contrast over no filter#
C.@0 (? definite increase in siMe but still faint#
=%%%0 (? a bit more contrast, but fainter and smaller than C.@#
.-/eta0 (> Largest area of nebulosit& seen !ith higher contrast#
<)@=11)68;7%=6 D=< %@ 1:'?0 .-/eta

%@ 1?1' *;11; @I*6% 6)/CL; (diffuse nebula in @&gnus
(100mm f35, 14+, ' inch f34 6e!tonian at ?:+#
8))P-2HI0 (: /rings out a large faint diffuse nebulosit& in t!o elongated segments !ith a dar(er
area bet!een them east of *amma @&gni# Larger area !ell north!est of *amma also visible#
C.@0 (? %ncrease in contrast noted over 8ee"-s(& filter, !ith dar( ga" bet!een the "atches east of
*amma @&gni no! much more notable#
=%%%0 (1 Dilter almost e+tinguishes the nebulae (ver& faint#
.-/)7;0 (> 6ebula has similar brightness to C.@ but higher contrast !ith a ver& dar( s(&
bac(ground#
<)@=11)68;7%=6 D=< %@ 1?1'# .-/)7;3C.@ (=%%% JnotJ recommended

%@ 1?95 (nebula 2#$# of 1u @e"hei
(10 inch f34#5, 4:+, 9#:4 inch 2@7, 49+#
8))P-2HI0 (: 8iffuse haMe around a !ea( o"en star cluster, ,uite large !ith some vague brightness
irregularities and a "ossible dar( inclusion in the south side (/151#
C.@0 (> 6ebulosit& more visible and dar( inclusion is much more definite, but the glo! is still faint#
2ome variations in brightness are noted, but the object is still some!hat diffuse#
=%%%0 (? 8immer than in C.@, !ith outermost nebulosit& gone, but some more contrast and dar( detail
are noticable (better than in 8ee"-2(& filter#
.-/)7;0 (1 6ebulosit& is visible, but is Je+tremel&J dim in a dar( bac(ground#
<)@=11)68;7%=6 D=< %@ 1?950 C.@#

%@ 1'>'0 (“7he /ab& 6ebula”, @assio"eia
(' inch f34, ?:+, 10 inch f34#5, 4:+, 9#:4 inch 2@7, 49+#
8))P-2HI0 (: some increase in contrast !ith nebula a""earing as an elongated faint haMe going
through a s"arse cluster#
C.@0 (> 1uch easier to see, !ith nebula no! elongated )-$, brighter on northern side and dar(er
notch to!ards the east end (“the nec(”#
=%%%0 (> noticeabl& dar(er than C.@, but a little higher contrast#
.-/)7;0 (1 Fer& dim#
<)@=11)68;7%=6 D=< %@ 1'>'0 C.@ (.-beta JnotJ recommended

%@ :1770 (“2eagull 6ebula” diffuse 6ebula, 1onoceros
(10 inch f34#5, 4:+, 100mm f35, ::+#
8))P-2HI0 (: long faint irregular diffuse band of haMe not easil& seen !ithout filters# )+tends
south!ard from o"en cluster 6*@ ::?4#
C.@0 (? )asier to see, !ith some!hat more contrast# 6arro!er slightl& sinuous core filament
imbedded in more diffuse haMe visible for nearl& : degrees#
=%%%0 (: 6ebula barel& visible (mostl& just the core filament !ith much of outl&ing nebulosit& gone#
.-/)7;0 (? @ore filament is fainter than C.@, but considerabl& more contrast#
<)@=11)68;7%=6 D=< %@ :1770 .-/)7;3C.@#

%@ >5:' (diffuse nebula in 2cor"ius
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: faint diffuse irregular glo! not visible !ithout filters#
C.@0 (>0 6oticeable im"rovement, !ith nebula no! eas& to see and rather detailed, !ith some
irregular lane-li(e detail#
=%%%0 (:0 much fainter than in C.@, but still visible#
.-/)7;0 (?0 sho!s some interesting filamentar& detail, but not as bright or as detailed as in C.@#
<)@=11)68;7%=6 D=< %@ >5:'0 C.@#

%@ 4057-70 P)L%@;6 6)/CL; (diffuse nebula in @&gnus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: 6ebular overall form is easier to see than !ithout filters, !ith some hints of detail and
the overall form#
C.@0 (> Fer& noticeable im"rovement in contrast over the 8))P-2HI filter, !ith both the “bea(” and
the “bod&” no! fairl& eas& to see#
=%%%0 (> %m"rovement in contrast and detail, but nebula is dimmer than C.@#
.-/)7;0 (? 6ebulosit& is visible but is fairl& faint#
<)@=11)68;7%=62 D=< %@ 40570 C.@3=%%%, 8ee"-s(& also useful on the object (C.@ !as
brighter, but =%%% sho!s more detail#

%@ 4075 (diffuse nebula inside cluster 6*@ 5991 in @&gnus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: Fer& slight increase in contrast over no filter#
C.@0 (: 2lightl& better than 8ee"-2(&, but still marginal glo!#
=%%%0 (: 8ar(er bac(ground not ,uite as good as C.@#
.-/eta0 (? larger area of nebulosit& than the other filters !ith dar(er bac(ground and additional
nebulosit& a!a& from small sub-cluster#
<)@=11)68;7%=6 D=< %@ 40750 .-/eta

%@ 41>5 7.) @=@@==6 6)/CL; (diffuse nebula in @&gnus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: ; bit better than no filter, but object is still easil& seen as a dim roughl& circular
irregular "atch in some stars !ithout a filter#
C.@0 (? 2lightl& higher contrast !ith more irregular interior dar( detail#
=%%%0 (1 Dainter and slightl& smaller than in C.@ (=%%% hurts it#
.-beta0 (? dimmer than C.@ but sho!s larger area of outer nebulosit& and slightl& better defined dar(
detail in the form of irregular lane li(e features#
<)@=11)68;7%=62 D=< %@ 41>50 .-/)7;3C.@ Jnear tieJ (=%%% not recommended#

PH5>O4#1 “@;1P/)LLA2 .I8<=*)6 27;<” @&gnus (.eniMe :->?', P6* 5>#7O4#0
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (: onl& slight increase in contrast (small nearl& stellar dis(, slightl& reddish in color#
C.@0(?0 2light increase in contrast !ith faint outer shell hinted at#
=%%%0 (: dimmer than C.@, but slightl& more contrast than !ithout filters#
.-/)7;0 (> 6oticeable increase in contrast !ith ver& faint outer shell#
<)@=11)68;7%=62 D=< PH5>O4#10 .-/)7; (C.@ also useful#

PH:04O1>#1 “1)8C2; 6)/CL;” (large "lanetar& nebula in *emini
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: 2light increase in contrast but nebula is still just a ver& faint diffuse haM& area#
C.@0 (? noticeable increase in contrast !ith vague “@” sha"ed arc no! visible#
=%%%0 (> dimmer than in C.@, but slightl& more contrast, !ith hints of
filaments in the dar( "art (loo(s almost annular#
.-/)7;0 (0 @om"letel& (ills the nebula#
<)@=11)68;7%=6 D=< PH:0>O1>#10 =%%%3C.@ Jnear tieJ (.-beta JnotJ recommended#

PH15>O?1#1 “.);8P.=6) 6)/CL;” (large "lanetar& nebula in L&n+
(10 inch f34#5, 4:+#
8))P-2HI0 (: Fer& slight increase in contrast over non-filtered vie!#
C.@0 (? noticeabl& easier to see as t!o s"ots connected b& a vague annulus#
=%%%0 (? much easier to see the s"ots, but the annulus fades some!hat#
.-/)7;0 (0 @om"letel& (ills the nebula#
<)@=11)68;7%=6 D=< PH15>O?1#10 C.@3=%%% Jnear tieJ (.-beta JnotJ recommended#

2h:-1? (8iffuse nebula in 2cor"ius
(10 inch f34#5, 4:+#
8))P-2HI0 (: diml& visible as a ver& faint glo! but not !ithout the filter#
C.@0 (> boost in contrast, becoming ver& "atch& but still dim#
=%%%0 (: fainter but still visible#
.-/)7;0 (: similar to =%%%#
<)@=11)68;7%=6 D=< 2.:-1?0 C.@

2h:-4> (8iffuse nebula in 2er"ens
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: dim diffuse glo! not visible !ithout filters#
C.@0 (> noticeable contrast gain, !ith considerable light and dar( detail#
=%%%0 (: much fainter than in C.@ but still visible#
.-/)7;0 (? better than in =%%% !ith a little detail#
<)@=11)68;7%=6 D=< 2h:-4>0 C.@

2h:-'> (8iffuse nebula in 2agitta
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (10 onl& hint of nebula#
C.@0 (?0 faint diffuse “L”-sha"ed "atch !ith irregular edges#
=%%%0 (10 dar( field !ith just a hint of nebulosit&#
.-/)7;0 (:0 fainter than in C.@#
<)@=11)68;7%=6 D=< 2h:-'40 C.@#

2h:-101 (8iffuse 6ebula in @&gnus0
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: Fer& faint moderate-siMed diffuse haMe in t!o segments around ? stars (: stars on the
!est and one on the east#
C.@0 (? .igher contrast but still faint# 7!o definite "atches visible !ith haM& arc-li(e e+tensions# =ne
on the !est a""ears larger#
=%%%0 (: Fer& dim but still visible#
.-/)7;0 (? ;lmost as much nebulosit& visible as in C.@, but dimmer#
<)@=11)68;7%=6 D=< 2h:-1010 [email protected]/)7;#

2h:-11: (8iffuse 6ebula in @&gnus 6#$# of 8eneb
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (? faint star !ith ver& faint small diffuse "atch of nebulosit& to its immediate south#
1uch easier to see than !ithout a filter#
C.@0 (> ;lmost fan-li(e diffuse "atch e+tending from the faint star to its south# 1ore nebulosit&
visible than in 8ee"-2(&, but still some!hat small#
=%%%0 (> Dainter than C.@, but the nebula no! envelo"es the star in a diffuse faint haMe# 8ar(er
inclusion from the northeast no! visible#
.-beta0 (1 <eall& dims itK
<)@=11)68;7%=6 D=< 2h-:-11:0 =%%%3C.@ (.-beta not recommended#

2h:-1?: (8iffuse 6ebula in @e"heus
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (: better than !ithout filters as !ithout filters the object is onl& hinted at# 9ust a ver& faint
diffuse irregular glo! around several stars roughl& elongated east-!est#
C.@0 (> 1a(es a "atch on south edge easier to see and hints of other detail#
=%%%0 (> %ncreases contrast !ith an arc across the northern side and a "atch
in the middle# .igher contrast but dimmer than C.@#
.-/)7;0 (? 8ims it more than =%%%, but nebula remains visible#
<)@=11)68;7%=62 D=< 2h-:-1?:0 =%%%3C.@ (near tie

2h:-1>: (8iffuse 6ebula in @e"heus around o"en cluster 6*@ 7?'0
(10 inch f34#5, 4:+, 71+
8))P-2HI0 (: hint of a glo! across fairl& rich star cluster#
C.@0 (> big fat triangular area, faint arc-li(e a""endages#
=%%%0 (> fainter, but more dar( detail, !ith “I” sha"e to the nebula##
.-/eta0 (? fainter than =%%%, but still visible (better than 8ee"-2(&#
<)@=11)68;7%=62 D=< 2h-:-1>:0 =%%%3C.@#

2h:-144 (8iffuse nebula in @e"heus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: ver& faint diffuse area of haMe around t!o !idel&-s"aced stars (better contrast than
!ithout a filter#
C.@0 (1 =nl& hint of nebulosit& visible#
=%%%0 (1 little if an& nebulosit& visible#
.-/)7;0 (0 no nebulosit& visible#
<)@=11)68;7%=6 D=< 2h-:-1440 8))P-2HI ("robable reflection nebula#

2h:-147 (“fingers” diffuse nebula in @assio"eia
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: not easil& seen e+ce"t as a vague elongated brightening in a rich star bac(ground#
C.@0 (? )longated large diffuse and dim oval feature !ith t!o dim north!ard-"ointing arcs#
=%%%0 (? 6ebula is fainter than in C.@, but still visible !ith increased contrast, es"eciall& in the t!o
“finger” "atches#
.-/)7;0 (: Dainter than in =%%%, but nebula is still visible#
<)@=11)68;7%=6 D=< 2h-:-1470 C.@3=%%%

2h:-170 (faint diffuse nebula in @e"heus
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: not eas& to see !ithout filters# <ound ver& faint ver& diffuse "atch of haMe around a
grou" of 5 or 7 faint stars#
C.@0 (? 2ome!hat easier to see than in 8ee"-2(&, !ith a bit more contrast#
=%%%0 (: 2till visible, but fainter than in C.@#
.-/)7;0 (: 2till visible but fainter than in =%%% or C.@#
<)@=11)68;7%=6 D=< 2h-:-1700 C.@

2h:-171 (ver& faint large diffuse nebula in @e"heus
(10 inch f34#5, 4:+#
8))P-2HI0 (: Plainl& visible over non-filter, but still faint and diffuse#
C.@0 (? 2light enhancement over 8ee"-2(& !ith some light and dar( areas#
=%%%0 (: Dainter but sho!s more enhancement in several dar( lane-li(e structures#
.-/)7;0 (: 6ebula remains visible, but just a bit fainter than in the =%%%#
<)@=11)68;7%=6 D=< 2h-:-1710 C.@ (8ee"-2(& and =%%% filters also useful#

2h:-:?4 (diffuse nebula in ;uriga
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (? diffuse oval faint fuMM& "atch, slight southern e+tension#
C.@0 (?0 slightl& more contrast than 8ee"-2(&, but fainter#
=%%%0 (:0 fainter than C.@ or 8ee"-2(&#
.-/)7;0 (>0 Daint, but t!o "atches are no! seen !ith brighter one on the north# 1ore contrast than
8ee"-2(& or C.@#
<)@=11)68;7%=6 D=< 2h:-:?40 .-/)7;38))P-2HI (C.@ also hel"s##

2h:-:51 (diffuse nebula in =rion
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: slight increase in contrast ma(ing the nebula faintl& visible
and easier than !ithout a filter#
C.@0 (? nebula no! clearl& visible but still faint#
=%%%0 (? nebula visible, but fainter than C.@ !ith a bit more contrast#
.-/)7;0 (:, nebula is still visible, but not ,uite as good as in C.@3=%%%#
<)@=11)68;7%=6 D=< 2h-:-:510 C.@3=%%% (near tie#

2h:-:75 “/;<6;<8A2 L==P” (diffuse nebula in =rion
(100mm f35, 14+ JandJ 6a(ed-e&e observations !ith filter over unaided e&e#
8))P-2HI0 (1 hint of a glo! in telesco"e, but not visible na(ed e&e#
C.@0 (: Daint arc li(e glo! visible under good conditions over =rionAs /elt, continuing south!ard
east of the belt# 8etectable in 100mm f35#
=%%%0 (0 6o nebulosit& seen#
.-/)7;0 (? Daint narro! glo! visible both over the belt and curving do!n southeast along =rionAs
southeastern side# Fer& faint, but noticeabl& easier to see than in C.@ filter# Dairl& eas& in 100mm f35
sco"e !ith some vague detail although not bright#
<)@=11)68;7%=6 D=< 2h:-:750 .-/)7;3C.@# (=%%% not recommended

2h:-:4>-4-5-7-' (dim nebular com"le+ in northern =rion0 %@ :15:
(10 inch f34#5, 4:+#
8))P-2HI0 (: three dim diffuse "atches in a line#
C.@0 (?0 %ncreased contrast (2h:-:47 no! brightest of the three large ones#
=%%%0 (:0 fainter than in C.@ and 2h:-:44 no! not as large#
.-/)7;0 (?0 more contrast than C.@ but a bit dimmer#
<)@=11)68;7%=62 D=< 2h:-:4> com"le+0 .-/)7;3C.@ (near tie#

2h:-?11 (nebulous o"en cluster 6*@ :>57 in Pu""is
(10 inch f34#5, 4:+, 71+#
Fisible !ithout a filter as circular "atch in rich starfield#
8))P-2HI0 (? larger than !ithout a filter and !ith hints of outer detail#
C.@0 (> boosted contrast and brought out outer nebulosit& better#
=%%%0 (? dar(er bac(ground and more contrast, but 8ee"-2(& filter better#
.-/)7;0 (0 ver& dim but still visible#
<)@=11)68;7%=62 D=< 2h:-?110 C.@38ee"-2(& (.-/eta not recommended

vd/9? (*um-1 (diffuse nebula in 1onoceros near %@ :177
(10 inch f34#5, 4:+, 71+#
8))P-2HI0 (: 2light boost in contrast, sho!ing more nebulosit& than !ithout a filter#
C.@0 (? 1ore contrast and nebulosit& visible, but still faint#
=%%%0 (1 Dainter than in C.@, !ith onl& hint of a glo! around the central star#
.-/)7;0 (> /etter defined than an& of the other filters, !ith more light and dar( detail# Dainter than in
C.@, but sho!s better contrast and detail#
<)@=11)68;7%=6 D=< vd/9?0 .-/)7;3C.@ (=%%% not recommended#