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russell23
sage
Reged: 05/31/09
Posts: 419
Loc: Upstate NY
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The last few times I've observed I've tried observing open clusters with an 82A filter (73% transmission). Since open clusters tend to be dominated by younger blue stars this seems to improve the sharpness and contrast of the image with my 120mm f/8.3 achromat.
Anybody else try this?
Dave
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joelimite
sage
Reged: 09/01/08
Posts: 234
Loc: Fayetteville, AR
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Never tried, Dave, but I'll give it a shot. I just got an 82A filter and have been itching to try it out on something besides the moon (the seeing here has been too terrible lately for serious planetary observation).
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Orion XT8 Dob w/ Moonlite 2-speed Crayford focuser, Vixen A80MF w/ GSO 2-speed Crayford and Porta Mount
32mm Televue Plossl, 31mm Hyperion Aspheric, 24mm Meade SWA, 17,13,8mm Hyperions, 6,5,4mm TMB Planetary, 5mm Baader Genuine Ortho
Garrett Optical 20x80 UL Binoculars, Nikon Action Extreme 10x50 Binoculars
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starrancher
professor emeritus
Reged: 06/09/09
Posts: 580
Loc: Northern Arizona
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Not that I have yet tried this myself , but I have heard that the light blue filter can help in splitting close doubles .
Now I will give this , open clusters & maybe even globs for that matter a try .
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LXD75 AR5
LXD75 SN8
Series 4000 Plossls
Misc. other stuff
Fort Rock , Az .
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russell23
sage
Reged: 05/31/09
Posts: 419
Loc: Upstate NY
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I played around with it some more tonight before overcast conditions rolled i . I'm using it with 10mm and 20mm Pentax XW's in the 120mm f/8.3 achromat.
There is some evidence of the loss of light, but not dramatically so. I think the lost light is made up for by an increase in sharpness and contrast.
I'm hoping that later tonight the skies will clear back up so I can give it a more thorough test. I'll be anxious to hear what you guys think.
Dave
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Dakota Tobias
member
Reged: 02/17/05
Posts: 95
Loc: Central PA
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I've had great success using it on Jupiter... I just was using it last night, as a matter of fact, during a shadow transit with a 7mm Pentax XL (225x)...I'll have to try an OC... was there any particular one that especially "popped"?
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Dakota Tobias
Discovery 12.5" PDHQ
Orion XT 4.5" Dob
35mm Scopos Extreme
13mm ETHOS
8mm TMB Planetary
7mm Pentax XL
Small herd of plossls
Lumicon OIII filter
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 8273
Loc: Beatrice, Nebraska
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Quote:
The last few times I've observed I've tried observing open clusters with an 82A filter (73% transmission). Since open clusters tend to be dominated by younger blue stars this seems to improve the sharpness and contrast of the image with my 120mm f/8.3 achromat.
Anybody else try this?
Dave
I tend to use the Lumicon Deep-sky filter, as it has higher transmission characteristics (even makes a halfway decent light blue filter for revealing the clouds on Mars). Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org
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helpwanted
Carpal Tunnel
Reged: 07/04/07
Posts: 2642
Loc: Phoenix, AZ
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i have heard of using an 82a on galaxies, but haven't tried... i need to remember and give this a try!
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russell23
sage
Reged: 05/31/09
Posts: 419
Loc: Upstate NY
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Quote:
I've had great success using it on Jupiter... I just was using it last night, as a matter of fact, during a shadow transit with a 7mm Pentax XL (225x)...I'll have to try an OC... was there any particular one that especially "popped"?
NGC 6819 is one cluster in particular that I felt showed noticeably improved detail with the 82A. But in general with my achro I feel that the images are sharper with this filter. I also noticed that when the moon is washing out the sky clusters seem significantly improved with the filter.
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Sarkikos
Pooh-Bah
Reged: 12/18/07
Posts: 1043
Loc: Suburban Maryland
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helpwanted,
Quote:
i have heard of using an 82a on galaxies, but haven't tried... i need to remember and give this a try!
I've used 82A on two bright galaxies, M31 and M51. It helped somewhat to improve contrast, but it is a very subtle effect. In other words, it's hardly worth the effort.  But give it a try. YMMV. You might be better off increasing the magnification a little, maybe try a zoom eyepiece to dial in the right amount of contrast by varying the magnification.
Mike
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Celestron 10" f5 Newt on 1stBase (DSO)
Zhumell 8" f6 Newt, Bosma 6" f12 MCT (NSO)
6" f5 Newt, 130ST, 4.5" f4.4 Ball w/GLP, ST80 w/Crayford (RFTs)
C4-R (NSO/DS)
90mm f13 MCT (Luna/DS)
SkyMaster 25x100, 15x70
Zhumell 20x80
Barska XWA 10x50, 8x40
OptiView LPR 10x50
Const View 2.3x40
BV-125C
CG5, 2 drv / CG4, 2 drv, wood legs, ScopeStuff saddle / CG3, 1 drv
SV AZ / 501HDV on Bogen 055XB / P+ on Oberwerk
QuikFinder, Telrad
Orion Dynamo Pro 12, Dew-Not
Have GLP and not afraid to use it!
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