Performanta Filtre UHC Si OIII

8/12/2019 Performanta Filtre UHC Si OIII

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Light Pollution and various nebula filters have been around since the late 1970s, 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& 19'0s, s"ecific

information about !hich filter might !or on a given object (or even !hether certain filters !ere usefulat 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 beginsome 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!inguestions

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 ulti-filter 2elector to hel" !ith faster com"arisons and initiall& beganobservations 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# he first run !as com"leted in 8ecember of that &ear !ith 44 initial

object observations# he initial results !ere "resented on anuar& 4th, :000 to the ;;2


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Lae (both !ith BL 5#4 to 7#0, and erritt "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!#

#oweer) *ince thi* i*+a, +ment contain* *ome of the er*ona, reference* of the o*erer)

the *ecific re*+,t* for each oect ma e a it *+ectie in the ,on r+n.8ifferent observers

might have some!hat different judgment of various filters on various objects, so these results shouldnot 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 Scorin4 een

(4 Fer& Large %m"rovement over no filter#

(> Large %m"rovement over no filter#

? oderate %m"rovement over no filter#

(: ild %m"rovement over no filter#

(1 Little or no %m"rovement over no filter#

(0 uch $orse than no filter (object marginal or not visible#

SC$7%N T$T'S $7 NE&"'E S$ '7 S"7:E!ED

(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'

.-/);G 1>? "oints, average rating 1#41

he second method is a "ersonal recommendation for the best filter to use on the given object, basedmainl& on a overall visual judgment, and thus is even more a matter of o"inion and taste# he nebular

brightness, total area sho!n, contrast of details, and overall vie! !ere considered together to give an


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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# nearl& eual or beneficial "erformance, both filters !ould be

given the recommendation for the object, !ith the one &ielding the better overall vie! being listed firstand the close second best listed ne+t to it#

7EC$;;END'T%$N 7'N%N S";;'7!

C.@ best on >1 nebulae, close second best on >7 nebulae#

=;L 1st and :nd nebulae (biased b& the inclusion of some "lanetar& nebulae,

close second best on :: nebulae# J6=J recommended on 5 nebulae#

=;L 1st and :nd


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=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#

he =%%% tended to be a bit better for locating small "lanetar& nebulae in rich starfields using the

blining techniue than the C.@ !as# .o!ever, the .-beta filter often hurt the vie! of man&"lanetaries !ith onl& a fe! e+ce"tions# he 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# he =%%% also tends to reuire a slightl& lo!er magnification range for best results than theC.@ did# hus, !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


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cus" no! more visible#

=%%% (? uch darer 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+#

.-/); (0 barel& visible#

2lightl& fainter than !ith C.@, !ith slightl& less faint outer nebulosit&, but sho!s morecontrast and dar detail in the interior, including faint narro! fingers from south side into the center

of the nebula !ith averted vision#

.-/); (: 8ims the nebula significantl&, but sha"e still vaguel& visible#


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defined than !ith C.@#

.-/); (1 =bject is noticeabl& dimmed com"ared to the other filters, maing the filter a "oor choice

for use on 17#

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#

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#

.-/); (1 6ebula is dimmed greatl& b& the filter, e+tinguishing the fine outer detail and onl&

sho!ing the inner dumbell-sha"e#

: *


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!ith direct vision#

=%%% (> ; 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# >? is some!hat

fainter than in the C.@filter, but narro! band!idth of =%%% ma& mae it the filter of choice !ith light"ollution#

.-/); (? uch of the fainter outer areas of the nebula vanish, but fan-lie main "ortion and >?

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#

: C.@3=%%% (near-tieJ

>? (north "art of *reat =rion 6ebula

(10 inch f34#5, 4:+, 71+#

8))P-2HI (? higher contrast than !ithout filter, but not much detail enhancement e+ce"t !hen there

is some light "ollution#

C.@ (? some!hat more contrast than !ith the 8ee"-2& !ith overall comma sha"e no! easil&seen#

=%%% (: dims the nebula, but overall sha"e is still easil& visible#

.-/); (> ? stand out, !ith high contrast and some irregular dar detail in the

overall comma-sha"ed nebula#

? .-/); (C.@ and 8ee"-2& also hel"#

47 uch more nebulosit& visible, including faint "atches or loo"-lie !ings off each side ofthe dumbell, along !ith some interior detail#


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=%%% (? 6ebula is some!hat fainter, but sho!s more contrast, !ith some dar detail being seen near

each lobe of the dumbell# he "atches off to the sides of the dumbell loo lie "artial loo"s#

.-/); (0 8ims the nebula almost to e+tinction at moderate "o!ers#

uch higher contrast than !ith 8ee"-2& filter# =ne e&e and hints of the other are seen#

=%%% (4 %ncrease in contrast over C.@# /oth e&es visible !ith hints of irregular outer edge structure#

.-/); (0 6earl& obliterates the nebula#

0 (Planetar& 6ebula in @e"heus

(10 inch f34#5, 4:+, 71+#

8))P-2HI (? 2light increase in contrast and detail (brighter o""osing sides, but object does not

reall& reuire a filter#

C.@ (? 2lightl& fainter than in 8ee"-s&, but sho!s a bit more contrast#

=%%% (: 2ome!hat fainter than in C.@, but dis still uite visible#

.-/); (: 2ome!hat fainter than in C.@, but ver& slightl& brighter than !ith the =%%% filter (a

near .-beta object#

0 8))P-2HI3C.@ (near tie#

6*@ :>5 (Planetar& in @etus

(10 inch f34#5, 4:+, 71+#

8))P-2HI (: defines it a bit better than !ithout a filter, but still mainl& a diffuse roughl& circularglo! around a fe! stars#

C.@ (? .igher contrast, !ith nebula no! a fairl& !ell-defined moderate-siMed dim dis !ith hints of

brightness variations in the interior#

=%%% (> %ncrease in contrast over the C.@# 2ho!s several dar s"ots in the interior and hints of shar"filament-lie outer edge of the dis#

.-/); (0


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8))P-2HI (? 6ebula is some!hat easier to see (barel& visible !ithout filters, !ith the edges being

more defined#

C.@ (> 6oticable im"rovement in contrast and detail, a""earing larger than !ith 8ee"-2& filter, and

containing some dar detail#

=%%% (> 6ebula is dimmer, but interior dar lane-lie detail becomes more noticeable, and the overallnebula sha"e is better defined than in C.@#

.-/); (: 8ims the nebula much more than =%%%, !ith no more detail than is seen !ith the 8ee"-

2& filter (dim#

8immer than in C.@, but more dar detail visible !ith faint outer loo"-lie structure visible

arcing south, almost connecting the t!o "atches#

.-/); (1 /arel& visible#


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=%%% (> )ven more contrast than C.@, !ith clear interior arc-lie detail, but central star much fainter#

6ice dar bacground

.-/); (0 Hills the nebulosit& !ith onl& the central star and a small hint of haMe around the star

being visible#

91 (diffuse 6ebula in Perseus(10 inch f34#5, 4:+, 71+

8))P-2HI (? moderate increase in contrast over non-filtered vie!#

C.@ (4 larger, !ith faint irregular outer nebulosit& seen and bar-lie inner feature no! ver& obvious#

=%%% (> .igher contrast in inner regions (es"eciall& the bar, but outer-most nebulosit& dimmed#

.-/); (0, ills most of the nebulosit& other than a hint of it#

91 C.@3=%%% (.-/eta JnotJ recommended#

6*@ 1>99 @;L%D= ore contrast than in C.@, !ith dar detail and arc-lie forms in the main shell# 8immer

than in C.@ but a bit better overall#

.-/); (0 ;lmost !i"es out the nebula#

=%%%3C.@ (.-/eta 6= recommended#

6*@ 1999 (diffuse nebula in =rion


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(10 inch f34#5, 4:+, 71+

8))P-2HI (: slight enhancement over no filter, and eas& !ithout one#

C.@ (1 fainter than 8ee"-2& or no filter#

=%%% (1 fainter than C.@ or 8ee"-2

.-/eta (1 fainter than 8ee"-2&, C.@, or no filter#

6oticabl& im"roves the contrast, !ith an almost annular form visible at highermagnifications#

=%%% (4 uch higher contrast and darer bacground than in C.@, but C.@ or no filter ma& be bit

better for high "o!er observations of details#

.-/); (0 ;lmost !i"es it out (barel& visible#

DL;) 6)/CL; (diffuse emission3reflection nebula in =rion

(10 inch f34#5, 4:+

8))P-2HI (? 6oticeabl& im"roves the contrast !ith the dar lane-lie detail visible#

C.@ (? 8arer than in 8ee"-s& but !ith onl& a slight increase in contrast#

=%%% (: 8arer than in C.@, !ith less detail than in C.@#

.-/); (1 8arest of all three filters, but the nebula remains visible !ith detail similar to that of

=%%%#

8))P-2HI3C.@ (near tie#

6*@ :17> (diffuse nebula in northern =rion

(10 inch f34#5, 4:+, 71+#

8))P-2HI (: ver& faint glo! around a single star !ith hints of detail (much easier to see than

!ithout a filter#

C.@ (> Large increase in contrast over 8ee"-2& filter, sho!ing a large circular area of haMe !ith

vague irregular interior dar detail#

=%%% (> 8immer than in C.@, but has more contrast, sho!ing some dim lane-lie structure#

.-/); (0 8ims the nebula almost to e+tinction, sho!ing less than the 8ee"-2

C.@3=%%% (near tie (.-/eta 6= recommended#


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6*@ :?:7 (diffuse nebula in onoceros

(10 inch f34#5, 4:+, 71+#

8))P-2HI (: Fer& faint diffuse roughl& circular haMe around 7th mag# star#

C.@ (? =bject is larger !ith slightl& better definition than in 8ee"-s

=%%% (: nebula is no! ver& faint, !ith onl& the area round the star visible#

.-/); (> 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-lie !estern edge#


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=%%% (4 even more contrast than in C.@ !ith oval mass no! looing lie a loo" !ith tendrils off each

end#

.-/); (0 8ims most of the nebulosit

5 (Planetar& nebula in onoceros

(10 inch f34#5, 4:+, 10>+

8))P-2HI (: slightl& easier to see than !ithout a filter#

C.@ (? some increase in contrast, !ith hints of flarings north and south#

=%%% (? some increase in contrast, slightl& fainter than in C.@#

.-/); (0 nearl& e+tinguished#

5 C.@3=%%% (near tie (.-beta JnotJ recommended#

6*@ :>?' ("lanetar& nebula in Pu""is

(10 inch f34#5, 4:+, 10>+#

8))P-2HI(: noticeabl& easier to see than !ithout a filter# .ints of annularit

C.@ (? notable increase in contrast, easier to see than in 8ee"-s& !ith annular form more noticable#

=%%% (> much higher in contrast !ith annular form no! fairl& obvious#

.-/); (0 nearl& ills it com"letel

?' =%%% (.-/eta JnotJ recommended#

6*@ :?71-: ("lanetar& nebula in *emini

(10 inch f34#5, 4:+, 71+, 10>+#

8))P-2HI (: !o adjacent faint s"ots, hel"ed some!hat over non-filter use#

C.@ (> enhanced over 8ee"-2&, !ith the t!o lobes sho!ing hints of contact#

=%%% (> 2lightl& higher contrast than C.@# .ints of faint outer !ings#

.-/); (0 Hills the nebulosit


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.-/); (0 =nl& the inner shell is visible, much fainter than in C.@, =%%%, or 8ee"-2

>0 ("lanetar& nebula in Pu""is

(10 inch f34#5, 4:+, 71+#

8))P-2HI (: small fairl& bright fuMM& oval (visible !ithout filters#

C.@ (> nice increase in contrast, but still eas& !ithout a filter#

=%%% (> darer bacground but still uite bright#

.-/); (0 inner shell barel& visible#

>0 C.@3=%%% (near tie (.-/eta not recommended#

6*@ ?:>: *.=2 =D CP%) Large increase in contrast !ith faint diffuse outer e+tensions seen#

=%%% (> .igher contrast, a bit shar"er than in C.@ but nebula a""ears slightl& smaller#

.-/); (0 nearl& illed b& the filter#

?51 C.@3=%%% (near tie, (.-/eta JnotJ recommended#

6*@ 5:10 ("lanetar& nebula in .ercules

(10 inch f34#5, 4:+, 71+, 1>1+#

8))P-2HI (: stands out a bit better, but filters are not needed#

C.@ (> increase in contrast !ith faint hints of close outer shell north and south of main dis#

=%%% (> darens the bacground and also sho!s hints of the outer shell#

.-/); (1 dims the nebula, sho!ing onl& the brighter inner core#


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t!o se"arated "atches around t!o stars near the south end, "lus fainter "atches and dar s"otsvisible in a dim diffuse haMe to the north#

=%%% (? fainter than in C.@, but still visible#

.-/); (? similar to =%%% vie! but slightl& fainter#

C.@ (=%%% and .-beta also useful#

6*@ 5>>4 (Planetar& 6ebula in 2agittarius

(10 inch f34#5, 4:+, 71+#

8))P-2HI (: maes it stand out better#

C.@ (> noticeabl& im"roves the contrast over 8ee"-2

=%%% (? darer more contrasting field, but slightl& fainter than C.@#

.-/); (0 ills the nebula almost com"letel

>4 C.@3=%%% (.-beta JnotJ recommended#

6*@ 5?47 (diffuse nebula in 2cor"ius

(10 inch f34#5, 4:+#

8))P-2HI (: not eas& to see !ithout a filter, as 8ee"-2& just barel& brings it out#

C.@ (? 6oticable boost in contrast, sho!ing some irregularit& and a brighter "ortion around a tin&

grou" of stars#

=%%% (> ore contrast than C.@, !ith the "atch around the tin& star grou" greatl& enhanced#


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.-/); (1 almost ills the nebulosit

? @;A2 )I) ("lanetar& nebula in 8raco

(10 inch f34#5, 4:+, 71+#

8))P-2HI (: maes it stand out a bit better#

C.@ (> noticeable contrast im"rovement !ith faint diffuse outer halo visible# Daint "atch !est of

main nebula barel& visible (%@ >577#

=%%% (> reall& darens the bacground and boosts the visibilit& of the outer halo# %@ >577 no! slightl&easier to see#

.-/); (1 reall& dims it but is still visible#

? =%%%3C.@ (.-/eta JnotJ recommended#

6*@ 5449 (diffuse nebula in 2agittarius

(10 inch f34#5, 4:+#

8))P-2HI (: not visible !ithout filters, glo! around one star !ith hints of e+tensions north andnorth!est#

C.@ (>, noticeabl& enhanced !ith some light and dar structure#

=%%% (: still visible but much fainter than in C.@#

.-/); (: visible !ith slight structure#


17/30

=%%% (> nice high contrast a bit better than C.@#

.-/); (0, nearl& !i"es it out#

increased contrast (best of the filters

=%%% (> still hel"s but not uite as much as the C.@

.-/eta (1, dims the object but does not e+tinguish it#


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6= real boost in contrast !ith detail no! visible#

=%%% (> slightl& higher contrast than C.@ but a bit fainter#

.-/); (0 nearl& obliterates the object#


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=%%% (: dimmer than in C.@ but still sho!s some hints of detail#

.-/eta (1 dimmer than C.@ and =%%%# =nl& central area around the star remains visible#

reall& maes 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#

=%%% (> @ore slightl& dimmer than in C.@, but outer shell is easier to see !ith hints of detail in the

outer shell#

.-/); (0 to 5

stars#


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C.@ (? .aMe no! easier to see !ith more contrast, but still rather diffuse !ith some faint detail

!hich is brightest in the northern "ortion# !o other faint "atches visible slightl& a!a& from the north

one#

=%%% (? /rings out a little more detail (dar inclusion in one sideN#

.-/); (1 dims the nebula significantl&, although it is still there#

ore contrast than C.@#

.-/); (0 nebula not visible#

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

=%%% (4 2ome!hat more contrast than the C.@, !ith hints of helical nature and indications of outerfilamentar& nebulosit 6oticeabl& dimmer than in C.@, but stands out a bit better than in the C.@,

es"eciall& at lo!er "o!ers#

.-/); (0 /arel& visible in this filter (almost ills the nebulosit


21/30


22/30

04 .-/);#

%@ >10 (6ebula assoc# !ith 6*@ 1'9? in ;uriga

(10 inch f34#5, 4:+, 71+

8))P-2HI (: faint glo! running )-$ through the I-sha"ed cluster 6*@ 1'9? !ith south!ard

e+tension off east end#

C.@ (> detailed arc-lie irregular nebulosit& running east-!est and then curving south !ith darerinclusion along south!est side#

=%%% (> /rings out more dar detail along the east and south sides, but nebula is dimmer# >? (su"ernova remnant in *emini

(9#:4 inch 2@, 49+


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8))P-2HI (1 object onl& suggested and not clearl& seen#

C.@ (> faint but definite arc !ith hints of detail#

=%%% (? shar"er but not as bright or eas& to see#

.-/eta (: hinted at in brightest section onl

>? C.@

%@ 1:'? (diffuse nebula in 2agittarius

(10 inch f34#5, 4:+, 71+

8))P-2HI (: slight boost in contrast over no filter#

C.@ (? definite increase in siMe but still faint#

=%%% (? a bit more contrast, but fainter and smaller than C.@#

.-/eta (> Largest area of nebulosit& seen !ith higher contrast#


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%@ 1'>' (he /ab& 6ebula, @assio"eia

(' inch f34, ?:+, 10 inch f34#5, 4:+, 9#:4 inch 2@, 49+#

8))P-2HI (: some increase in contrast !ith nebula a""earing as an elongated faint haMe going

through a s"arse cluster#

C.@ (> uch easier to see, !ith nebula no! elongated )-$, brighter on northern side and darer

notch to!ards the east end (the nec#=%%% (> noticeabl& darer than C.@, but a little higher contrast#

.-/); (1 Fer& dim#

6oticeable im"rovement, !ith nebula no! eas& to see and rather detailed, !ith someirregular lane-lie detail#

=%%% (: much fainter than in C.@, but still visible#

.-/); (? sho!s some interesting filamentar& detail, but not as bright or as detailed as in C.@#

5:' C.@#

%@ 4057-70 P)L%@;6 6)/CL; (diffuse nebula in @&gnus(10 inch f34#5, 4:+, 71+#

8))P-2HI (: 6ebular overall form is easier to see than !ithout filters, !ith some hints of detail andthe overall form#

C.@ (> Fer& noticeable im"rovement in contrast over the 8))P-2HI filter, !ith both the bea and

the bod& no! fairl& eas& to see#

=%%% (> %m"rovement in contrast and detail, but nebula is dimmer than C.@#


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.-/); (? 6ebulosit& is visible but is fairl& faint#


26/30

=%%% (> dimmer than in C.@, but slightl& more contrast, !ith hints of

filaments in the dar "art (loos almost annular#

.-/); (0 @om"letel& ills the nebula#

O1>#1 =%%%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-2HI (: Fer& slight increase in contrast over non-filtered vie!#

C.@ (? noticeabl& easier to see as t!o s"ots connected b& a vague annulus#

=%%% (? much easier to see the s"ots, but the annulus fades some!hat#

.-/); (0 @om"letel& ills the nebula#

O?1#1 C.@3=%%% Jnear tieJ (.-beta JnotJ recommended#

2h:-1? (8iffuse nebula in 2cor"ius

(10 inch f34#5, 4:+#

8))P-2HI (: diml& visible as a ver& faint glo! but not !ithout the filter#

C.@ (> boost in contrast, becoming ver& "atch& but still dim#

=%%% (: fainter but still visible#

.-/); (: similar to =%%%#

(8iffuse nebula in 2er"ens

(10 inch f34#5, 4:+, 71+#

8))P-2HI (: dim diffuse glo! not visible !ithout filters#

C.@ (> noticeable contrast gain, !ith considerable light and dar detail#

=%%% (: much fainter than in C.@ but still visible#

.-/); (? better than in =%%% !ith a little detail#

C.@

2h:-'> (8iffuse nebula in 2agitta

(10 inch f34#5, 4:+, 71+#

8))P-2HI (1 onl& hint of nebula#

C.@ (? faint diffuse L-sha"ed "atch !ith irregular edges#

=%%% (1 dar field !ith just a hint of nebulosit


27/30

.-/); (: fainter than in C.@#


28/30

8))P-2HI (: hint of a glo! across fairl& rich star cluster#

C.@ (> big fat triangular area, faint arc-lie a""endages#

=%%% (> fainter, but more dar detail, !ith I sha"e to the nebula##

.-/eta (? fainter than =%%%, but still visible (better than 8ee"-2

: =%%%3C.@#

2h:-144 (8iffuse nebula in @e"heus

(10 inch f34#5, 4:+, 71+#

8))P-2HI (: ver& faint diffuse area of haMe around t!o !idel&-s"aced stars (better contrast than!ithout a filter#

C.@ (1 =nl& hint of nebulosit& visible#

=%%% (1 little if an& nebulosit& visible#

.-/); (0 no nebulosit& visible#


29/30

8))P-2HI (: Plainl& visible over non-filter, but still faint and diffuse#

C.@ (? 2light enhancement over 8ee"-2& !ith some light and dar areas#

=%%% (: Dainter but sho!s more enhancement in several dar lane-lie structures#

.-/); (: 6ebula remains visible, but just a bit fainter than in the =%%%#

Daint, but t!o "atches are no! seen !ith brighter one on the north# ore contrast than

8ee"-2& or C.@#


30/30

2h:-:4>-4-5-7-' (dim nebular com"le+ in northern =rion %@ :15:

(10 inch f34#5, 4:+#

8))P-2HI (: three dim diffuse "atches in a line#

C.@ (? %ncreased contrast (2h:-:47 no! brightest of the three large ones#

=%%% (: fainter than in C.@ and 2h:-:44 no! not as large#

.-/); (? more contrast than C.@ but a bit dimmer#

com"le+ .-/);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-2HI (? larger than !ithout a filter and !ith hints of outer detail#

C.@ (> boosted contrast and brought out outer nebulosit& better#=%%% (? darer bacground and more contrast, but 8ee"-2& filter better#

.-/); (0 ver& dim but still visible#

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Performanta Filtre UHC Si OIII