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jayscheuerle
Carpal Tunnel
Reged: 01/16/06
Posts: 2989
Loc: S. Philadelphia, PA
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Will there be any notable difference between the video from these sources, other than the fact that the reflector is most likely to have larger aperture?
I don't ever think I've seen diffraction spikes on Mallincam shots... - j
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12" Green Goblin (trusser w/Protstar secondary and OWL refigured primary)• 6" f/5 Eero2 ball-scope • 6" f/5 Frankenscope • Garrett Optical 10x50 binos • Edmund 8" yoke-mounted red-tube reflector • Edmund 6" GEQ red-tube reflector (on loan to Dad)
Gone, but with lessons learned:
Skyquest XT8 • NexSTar 8i • Eeroscope 6" f/5 ball(sacrifice was not in vain) • Vixen ED80sf • Edmund red-tube 4.25" f/10 • Edmund Astroscan
Facts are stubborn things.
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Douglas
Vendor - Night Vision Astronomy
Reged: 05/21/07
Posts: 291
Loc: Pound Ridge, NY
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Great post. In fact I have been anxious to get a tracking setup for my 80mm refractor to use my MallinCam because my large Dob doesn't give me the low power, large FOV that I need on many targets. It does allow me shorter exposures with more light but I think the images I've seen using a refractor with the MallinCam are sharper.
- Doug
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Night Vision Astronomy
BIPH - Binocular Photon Machine
IDA Member
Obsession 12.5" Argo Navis/ServoCat #1528
Tak FSQ-106 EDX2 & EM-200 Temma II
Canon 450 Xsi No Modification
QSI 532ws CCD with AstroDon Filters
Home Built Gen III Image Intensifier
Denk II Binos D14s & D21s
MallinCam Hyper Plus Color
Bunch of Naglers & 13mm Ethos
Stellarvue 80mm F/7 NHNG #36
PST SolarMax 40 Double Stack
Canon 15 x 50 IS Binoculars
AstroTrac
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Bowmoreman
Carpal Tunnel
Reged: 09/11/06
Posts: 2992
Loc: Bolton, MA
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I don't know yet, cause I've really only done any serious looking (thus far) through my refractor... I'm thinking that the refractor will probably be slightly sharper/contrastier... but we shall see!
Once I get the EQ platform a rockin and a rollin, I might do an "A" "B" on the same subject to see the delta...
clear skies
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Dave
Ustream
YLive
XT10i, RTP, CGE, R200CF, TMB80SS
31T5, 22T4, 13Ethos, 8Ethos, TV 3-6 Zoom; Paracorr
MallincamColorHyperPlus,SBIG STV&237A;CanonRebel Xti
WilderSkiesObservatory(BYO #90)
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Douglas
Vendor - Night Vision Astronomy
Reged: 05/21/07
Posts: 291
Loc: Pound Ridge, NY
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That would be great Dave. I am very interested to see a side by side comparison. What mount do you use for your refractor? I think tracking options for refractors allow for longer tracking without artifacts versus a reflector. I am limited with my ALT AZ ServoCat tracking system but the light gathering ability of reflector seems to make up for alot. Hoping to get a tracking mount for the refractor soon.
- Doug
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Night Vision Astronomy
BIPH - Binocular Photon Machine
IDA Member
Obsession 12.5" Argo Navis/ServoCat #1528
Tak FSQ-106 EDX2 & EM-200 Temma II
Canon 450 Xsi No Modification
QSI 532ws CCD with AstroDon Filters
Home Built Gen III Image Intensifier
Denk II Binos D14s & D21s
MallinCam Hyper Plus Color
Bunch of Naglers & 13mm Ethos
Stellarvue 80mm F/7 NHNG #36
PST SolarMax 40 Double Stack
Canon 15 x 50 IS Binoculars
AstroTrac
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mistyridge
Carpal Tunnel
Reged: 10/28/05
Posts: 2268
Loc: Loomis, CA -26Mi E of Sacto.
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I am in the thinking and reading stage about getting a camera. The only scopes I have currently that could be used for tracking are refractors on a Celestron ASGT. So I am interested in this type of comparo.
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Mike F
Misty Ridge Observatory
Stellarvue SV115T "WOW"! What a view.
Stellarvue SV70ED
Stellarvue Nighthawk
18" f/4.5 Teeter's, Swayze mirror
12.5" f/5 Astrosky, OWL mirror
15X70 Binos
Mounts: DM-6,M-1,CG-5(ASGT)
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rolandlinda3
Carpal Tunnel
Reged: 01/24/06
Posts: 1613
Loc: Crozet VA 22932
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I know folks using both types with various apertures. The amount of aperture is fundamental: more aperture...reach farther on weaker objects. Beyond that, however, most folks tend to go with what they have...and both work fine as long as one can focus. Reaching focus can be an issue.
Contrast on a video screen is pretty adjustable and on the cameras I am familiar with contrast is adjusted by gains and integration periods, so I am not sure one could compare a refractor and a reflector unless it was a specific test with equal aperture where the camera had the same settings on both.
All this being said, I have not seen lovers of either type of scope change scopes because of contrast issues. I HAVE, however, seen people change types of scopes with astrovideo in order to achieve greater field of view. I use a little refractor to see larger fields of view with the astrovideo camera. I piggyback a refractor on my dob for the same reason: I use the Dob for the MallinCAM Hyper Color for an object, for instance, but I can shift the camera to the f/6 refractor to see a larger FOV. It is more question of want you want to see than contrast...as far as I know.
There are diffraction spikes on my monitor (like those I see with my eyes) on a reflector.
Hope this helps.
Roland
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Gord
sage
Reged: 01/06/04
Posts: 497
Loc: Toronto, ON, Canada
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So my experience thus far echo's what other have said that this type of system works with any optical-train (as long as you can reach focus) and that the main reason for trying different ones is to obtain different fields of view. That being said, I have found certain things to work better than others.
First off, the faster the system, the better. Second, bigger aperature does show more, but it needs to be coupled with an appropriate (ie faster) focal ratio.
The system I find that works the best of all I've tried (for optical performance) is the newtonian. Sharpest, deepest reaching, and best contrast by far. I've always found refractors to be very sharp in comparison to newtonians. But, I find that my MallinCam images are always better from my newts. I believe this likely has to do with IR being focused at different distances in a refractor than a newt and thus the stars can have a "halo" appearance to them. Supposedly a filter can correct this, but I don't have one to try.
But it's still kind of moot. The newts just work extremely well. For low power wide fields, I use the Orion StarBlast. Gives close to 1 deg field with my MallinCam and easily hits 15th magnitude from my suburban backyard. And then to go deep, I jump to my 10". Someday I'd love to have a 16" or bigger newt to go really deep.
Rock uses lots of different types of scopes, but especially loves Meade SCT's. He's done quite a bit with his 16" SCT. Interestingly though, I've heard him say that when compared to one of the other guys in the club who has a 14" Discovery dob (on tracking platform), that the 14" newt was pretty much equaling the 16" SCT. Contrast seemed higher in the newt and allowed it to go just that much deeper.
Ultimately though, as I said at the beginning, anything will work. Use whatever you have. You'll still have a lot of fun with it!
Cheers,
-Gord
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* Celestron C10/Normand Fullum primary
* Tasco 11TR/Normand Fullum primary
* Orion StarBlast
* Orion Apex 102
* SkyWatcher 80ED
* Celestron CG5a mount
* MallinCam Pro & Color II
* Lots of other astro toys
...and the best wife I could ever dream of for letting it all happen! 
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rolandlinda3
Carpal Tunnel
Reged: 01/24/06
Posts: 1613
Loc: Crozet VA 22932
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Your right, Gord. I remember the same debate in my head and finally a friend said to me: Roland, just write the check and get the dang thing. You know it's going to work with whatever you have. So, that's what I did. RB
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