square_peg
Postmaster
Reged: 03/26/04
Posts: 23948
Loc: Maple Valley, WA
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How many times have I asked that? The answer for many common nebula can be found in this CN article by our esteemed colleague, David Knisely.
Filter Performance Comparisons
This is an important read for anyone thinking of buying a new filter. IMO it should be stuck to the top of this forum.
Way to go, David! 
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Tom (Pegster)
DSH-8 (GSO Dob)
15x70 Oberwerks
SVP 100 f/6 achro
WO 66 Petzval
Sears Discoverer EQ 60/900
8x42 Regals
History is Philosophy teaching by examples.
Thucydides
Edited by square_peg (01/03/07 01:06 PM)
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Yaquina
sage
Reged: 09/07/04
Posts: 358
Loc: Newport, OR
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Thanks for the quick link / reference Tom, that is some great information.
Clear skies, Y
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Orion ED80
Orion XT10 Classic (many mods)
8x50 Nikon binoculars
14"-18" Dob in my future!(
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Anonymous
Unregistered
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And if anyone has filter comparison between Lumicon's, Baader's and whatnot's filters, share it with the group. That'd be good, since those Ls are pretty hard to come by these days...
Jake
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 6778
Loc: Beatrice, Nebraska
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Quote:
And if anyone has filter comparison between Lumicon's, Baader's and whatnot's filters, share it with the group. That'd be good, since those Ls are pretty hard to come by these days...
Jake
Well, the Lumicon filters are still available (Lumicon was bought-out by Parks). The Orion (U.S.) equivalent of the UHC is the Ultrablock, and its performance is very similar to the Lumicon model (more "Gaussian" passband, but no red passband for H-alpha). The Astronomik UHC is also pretty much the same as the Lumicon model in performance. For OIII filters, the Astronomik and Lumicon models are very similar, but the Astronomik is a bit broader, so it might not yield quite as dark a sky background as the Lumicon OIII filter. It still should work fine however. The Tele Vue OIII is *way* too broad to be considered a "true" OIII filter (more like the UHC), so if you are looking for an OIII, Tele Vue might not be a good choice. Thousand Oaks also makes its line of filters, and they are fairly similar to the Lumicon models. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
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Chris Graham
mmmm...Haggis
Reged: 04/01/04
Posts: 4869
Loc: Stirling, Scotland
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Thanks for the info and link
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-Skywatcher 8" Reflector on HEQ5 with Skyscan
-Orion ED80 Refractor
-70mm Guidescope/grab and go scope
-Canon EOS 350D
-Toucam Pro 2
Astronomy & Veggies
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Amalia
Reged: 10/16/04
Posts: 5165
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Quote:
And if anyone has filter comparison between Lumicon's, Baader's and whatnot's filters, share it with the group. That'd be good, since those Ls are pretty hard to come by these days...
Jake
This is a German link to a quite clear test:
http://www.svenwienstein.de/HTML/baader_oiii.html
Greetings
Amalia
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Amalia
Reged: 10/16/04
Posts: 5165
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Here an other::
http://home.freeuk.com/m.gavin/grism2.htm
Greetings!
Amalia
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Brian Carter
Post Laureate
Reged: 11/24/04
Posts: 3115
Loc: Atlanta, GA
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I have done some informal comparisons between Televue, Orion, Lumicon and Meade nebula filters. I say informal because they were not very methodical, but were useful for my asthetic sense.
The first filters I had were the Meade Narrowband and O-III filters. I had them both for a 10" dob. The meade narrowband is very nice, but I like the Lumicon and Ultrablock better. The meade has a higher-wavelength pass and doesn't give as much contrast. However, it is cheaper than the other two... well, I just got a 2" ultrablock cheaper than the meade 1.25" so i guess that is not true anymore. Anyway, the meade served a good purpose and it worked fine.
The Meade O-III was great. I did compare it side by side with a lumicon O-III and TV O-III. As someone said before, the TV doesn't even really compete. It would be useful on some smaller refractors though, which may be too small for a normal O-III. But I concluded that if you have the aperture, go ahead and block more light.
The Lumicon and Meade were tested on the Veil with a 32mm Plossl at F/5.6, a combination I found ideal for this object. Also used it for: M27, M42, M20, M8, and the Helix. All and all, they performed comparitively. The veil is the ideal object for an O-III, and gives the most dramatic results. With both filters I could see the same detail and more or less the same background darkness.
I have compared a 2" Ultrablock with a 1.25" UHC. This was also less methodical because I was 'blinking' the EP, and using 2" vs 1.25" EPs. But I found them to be comparable too. I sold the UHC because I moved to 2" filters.
And I sold the Meade-o-iii and bought a 2" Lumicon O-iii to fit in my Astrocrumb filter slide (which is awesome!!!!). I have used it briefly on M42 from suburbia. I want to compare it to the Ultrablock and see how the two compliment each other.
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10" F/5.5 Astrosky
SkyCommander DSCs
A loving dog, Buddha, who tolerates my hobbies
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erik
telescope surgeon
Reged: 01/30/04
Posts: 24019
Loc: Hawaii 19 N lat -155 Long.
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i've refered to that article several times. a good read and good info! 
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-Erik Wilcox
Homebuilt 16" Truss Dob
SV 80mm ED Nighthawk NG on M1 ALT/AZ
Nikon Prostaff 65mm spotter on Trekpod
Konusvue 20x80 binos/Peterson pipemount
Orion 10x50 binos
Homebuilt 80mm f/5 refractor
Mirador 60mm f/12 1960's refractor
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Amalia
Reged: 10/16/04
Posts: 5165
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Quote:
Here an other::
http://home.freeuk.com/m.gavin/grism2.htm
Greetings!
Amalia
I have seen this link in several posts since, but no one thanked me...
So:
Thank you, Amalia!
Amalia 
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Pirx
sage
Reged: 05/11/05
Posts: 374
Loc: Calgary, AB, Canada
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For everyone thinking about a nebula filter see the article in Astronomy, August 2005, page 82. Very similar review to the one on CN, but less nebulas and more filters. Nice comparison between different brands.
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Pirx
Modified Orion XT10i
SkyWatcher 80ED on AZ3
Antares 20x80 binoculars
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Amalia
Reged: 10/16/04
Posts: 5165
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Quote:
How many times have I asked that? The answer for many common nebula can be found in this CN article by our esteemed colleague, David Knisely. This is an important read for anyone thinking of buying a new filter. IMO it should be stuck to the top of this forum.
Way to go, David!
This link has changed: It is here now.
Amalia
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 6778
Loc: Beatrice, Nebraska
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Quote:
For everyone thinking about a nebula filter see the article in Astronomy, August 2005, page 82. Very similar review to the one on CN, but less nebulas and more filters. Nice comparison between different brands.
This article is misleading at best. It would be better to take it with an extremely large grain of salt. For what works on a specific object, I might recommend reading my article, but for specific recommendations, the broadband "LPR" filters like the Lumicon Deep-sky are best for reflection nebulae, and the Narrow-band filters like the UHC are probably the best overall for emission nebulae. For some objects like the Veil or for many planetary nebulae, the OIII filters are best, and for a more limited number of faint emission nebulae, the H-Beta filter may be of at least some use. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
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Scott Beith
SRF
Reged: 11/26/03
Posts: 33042
Loc: Gulfport, MS
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Initial Post is Corrected.
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  Scott
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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Amalia
Reged: 10/16/04
Posts: 5165
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The German astronomer André Knöfel measured the transmission of about 50 filters...
http://www.astroamateur.de/filter/
Amalia
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 6778
Loc: Beatrice, Nebraska
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Quote:
The German astronomer André Knöfel measured the transmission of about 50 filters...
http://www.astroamateur.de/filter/
Amalia
Well, I can't read German but I can tell that the transmission curves aren't very accurate (or if they are, then at least some of those filters need to be discarded). The Lumicon OIII and UHC do not have some of the huge bumpy secondary passbands in the deep violet that are shown with transmissions well over 40%. The various versions of the transmission curves are puzzling at best. I find that, while there are some variations between filters, the curves found in the RASC Observer's Handbook in the section on filters tends to be fairly accurate, at least for the Lumicon line. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
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Amalia
Reged: 10/16/04
Posts: 5165
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David,
all I can answer you is the following:
# 1 The 4 various versions of the transmission curves regarding the
Lumicon UHC and Olll are different because of the year of fabrication
and because André had several filters at his disposition.
# 2 I think it is very interesting to be able to see how the curves vary.
I prefer this to a single "This-is-the-truth!" curve.
This is a scientifical approach to me.
# 3 I wonder how you know the curves of the RASC Handbook are
more precise than these by André?
# 4 Right now I holded my two Lumicon Olll filters against a halogen
light. My fingers got coloured (in two different) violets by the passing
light. What is the meaning of this?
Amalia
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half meter
Postmaster
Reged: 05/05/04
Posts: 12517
Loc: Great Lakes
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Didn't Lumicon (or the company behind Lumicon) change ownership recently?
This could explain a lot.
Interference filters are very hard to make, with over 50 layers that have to be "just right". Quality control could also be a factor.
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Gary
Collins I3 (Thin Film) Image Intensifying Eyepiece
Coronado Maxscope DS 90 <0.5A w/BF30
152 mm f/8 TMB/A&M Carbon Fiber APO; f/5 with 4" Borg ED Field Flattener/Reducer
20" Obsession/OMI Mirror/Servocat/Argo Navis
First Light for the 30" Obsession at BEOTS!
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paulsky
sage
Reged: 02/17/04
Posts: 384
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Hello,
Are the O-III filter the filter ideal for the mayority of Planetaries nebulas?
PaUL
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Amalia
Reged: 10/16/04
Posts: 5165
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Well, Paul, the first post of this thread contains a link to a text which
will explain you everything!
Clear skies to you!
Amalia
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