Zad
member
Reged: 01/05/08
Posts: 13
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Hi All!
I have been doing AP with my Canon 350D, and manually guiding for a while now, and I have decided to jump into the webcam/planetary imaging arena, and I need some advice.
I have a Celestron C4-R (f/10 fl=1000mm) achro, and a Celestron Omni XLT 150 (f/5 fl=750mm) reflector. I also have a run of the mill Celestron 2x barlow.
I am considering modifiying a Logitech Fusion (1280x960, 3.5 micron pixel size) or Logitech Pro 9000 (1600x1200, 2.8 micron pixel size) camera according to Gary Honis' website instructions (Thanks Gary!).
Also note that I don't have a ton of money to spend (with the economy and all), but I don't want to end up with junk either.
My question is as follows. I have considered just using my 2x barlow, or getting the Meade Series 4000 3x barlow ($40), and using my refractor for an f/20 or f/30 and fl=2000mm or 3000mm respectivly. That would leave more money to get the better Pro 9000 camera. Or I could spend some more money on a Meade 5000 series 5x telextender ($100)with the reflector for a f/25 fl=3750, and go with the cheaper camera.
First of all, am I in the right ballpark in my thinking here? Second, the question for me is, do I spend more money on a good barlow, or a cheaper barlow and a better camera? I am leaning towards spending more money on the camera, because I can always upgrade the barlow later. One issue I am concerned with in this scenario is using my acrho instead of the reflector - will I get CA problems, and would a cheap barlow introduce more problems?
Anyway, any advice would be greatly appreciated! Thanks guys!
Joe
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Zad
Celestron C4-R (4" f/10 Acro Refractor)
Celestron Omni XLT 150 OTA (6" f/5 Newt)
CG-4 Mount with drive units
Meade RB-60 for guidescope
Canon Digital Rebel XT (350D)
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DesertRat
professor emeritus
Reged: 06/18/06
Posts: 665
Loc: Valley of the Sun
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Welcome to CN Joe!
Not familiar with the Logitech cameras but the pixel size is so small on the pro 9000 that I dont think you would have to image at f/25 with your 6" reflector. I'd give the 6" a chance at f/10&15 to begin with to get your feet wet. Should be great for lunar shots. However the number of pixels may require a fairly high end laptop to keep up with video rates.
My vote is to use the 6" with whatever camera you can get your hands on. Good luck!
Glenn
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Brandon 94mm f7, Televue TV102 f8.6; GM8
Baader Wedge & Filters, Coronado SM90/BF30
IM715; C11 & C14; G-11 Gemini
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Zad
member
Reged: 01/05/08
Posts: 13
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Thanks for the help Glenn! It's comforting to know that I don't have to barlow too extreamly to start off with.
Update: I bought the Logitech Fusion webcam from ebay for $17 including shipping! Couldn't turn down that deal. I think I will start off using my 2x barlow that I already have now. With my two scopes it gives me several combinations of f-ratios and focal lenghts to play with. Once I get some experience under my belt, I may look for a more powerfull barlow.
Now I have to figure out which 1.25" IR filter to buy, and what software to use for the video capture.
Any other advice for a webcam newbie would be greatly appreciated.
Joe
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Zad
Celestron C4-R (4" f/10 Acro Refractor)
Celestron Omni XLT 150 OTA (6" f/5 Newt)
CG-4 Mount with drive units
Meade RB-60 for guidescope
Canon Digital Rebel XT (350D)
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DesertRat
professor emeritus
Reged: 06/18/06
Posts: 665
Loc: Valley of the Sun
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Joe, when I was still using a color camera I used the Celestron 1.25" UV/IR blocking filter for CCD/NexImage, available from the sponsor of this site, Astronomics part number 37CIR for $59.95. Kind of expensive but necessary.
Glenn
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Brandon 94mm f7, Televue TV102 f8.6; GM8
Baader Wedge & Filters, Coronado SM90/BF30
IM715; C11 & C14; G-11 Gemini
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zAmbonii
scholastic sledgehammer
Reged: 01/19/08
Posts: 848
Loc: Ypsilanti, MI
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I say do without on the UV/IR blocker for now (if you want to use the newt). I haven't been using one so far with mine and I don't think it has mattered that much.
I'm kinda confused after looking at Gary Honis' pages on the 9000 pro. He seems to be getting better images with his Logitech than the Toucam.....but not many people seem to have went with logitech products and seem to prefer the Toucam/SPC900NC over it. Were his results a fluke, or is the pain in doing the mod for scope imaging that much of a pain for the Logitech?
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Check out my Astrophotos on Flickr
C6-N 150mm f/5 Newtonian
CG-5 ASGT mount
Canon 300D self modded + IDAS LPS-P2 FF
Meade 70AZ + Meade DSI for autoguiding
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Zad
member
Reged: 01/05/08
Posts: 13
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I see that there is an Astro Tech version for 39.95. Is there much difference in performance than the Celestron? 50% less in cost is significant.
Joe
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Zad
member
Reged: 01/05/08
Posts: 13
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You bring up a point that I have not considered. The reflector would not have as much problem with IR than the refractor. How do people do with reflectors without the IR filter?
Joe
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DesertRat
professor emeritus
Reged: 06/18/06
Posts: 665
Loc: Valley of the Sun
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The Astro Tech filter looks like a good buy! Its not so much the focus shift on a reflector (although some barlows will introduce a little chromatic aberration which can be seen at long focal lengths), but more color fidelity when using a color camera that makes these filters recommended. Excess IR can shift the color. With your refractor I think the filter is almost a necessity.
Glenn
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Brandon 94mm f7, Televue TV102 f8.6; GM8
Baader Wedge & Filters, Coronado SM90/BF30
IM715; C11 & C14; G-11 Gemini
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Zad
member
Reged: 01/05/08
Posts: 13
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Thanks again Glenn! I also found a IR-only (no UV filtering) for $29.95. How much does the UV come into play when imaging the moon and planets? Do you think I should stick with the IR/UV or is the IR-only enough?
Also, I was thinking about down the road a while, trying RGB filters for planetary. I know that it is better to have a monchrome camera for that type of imaging, but do you get better results using RGB (or LRGB) filters if you only have a color camera than just a IR/UF filter alone? That would be something to consider, since most LRGB filter sets come with a IR/UV filter. Perhaps I should just get the set now.
Thanks again for your help!
Joe
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Zad
Celestron C4-R (4" f/10 Acro Refractor)
Celestron Omni XLT 150 OTA (6" f/5 Newt)
CG-4 Mount with drive units
Meade RB-60 for guidescope
Canon Digital Rebel XT (350D)
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DesertRat
professor emeritus
Reged: 06/18/06
Posts: 665
Loc: Valley of the Sun
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Is the IR only a rejection or pass filter? Clearly these would be entirely different. There is not much UV in a refractor as most glass will stop it anyway. But near UV might be a factor to consider. I'd stick with the AstroTech UV/IR rejection filter.
There is no need for a RGB filter set with a color camera as the rgb masks are already on the imaging chip.
Glenn
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Brandon 94mm f7, Televue TV102 f8.6; GM8
Baader Wedge & Filters, Coronado SM90/BF30
IM715; C11 & C14; G-11 Gemini
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Zad
member
Reged: 01/05/08
Posts: 13
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It's an IR Block filter, for $29.95. Not a bad deal.
I also saw an interesting filter that is marketed as a planetery imaging filter that passes near infrared. The literature states that it helps becauase the near infrared is less disturbed by bad seeing, and it is supposed to be especially good for Mars imaging (for $39.95 for anyone interested.) Sounds interesting. Might be fun to play with that one on the upcomming Mars opposition.
Joe
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Zad
Celestron C4-R (4" f/10 Acro Refractor)
Celestron Omni XLT 150 OTA (6" f/5 Newt)
CG-4 Mount with drive units
Meade RB-60 for guidescope
Canon Digital Rebel XT (350D)
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Zad
member
Reged: 01/05/08
Posts: 13
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Found a Logitech Fusion on eBay. Modified it, and here's first light of Jupiter on an average seeing night:
Date = 11-6-9
Celestron Omni XLT 150 (6" 750mm fl. f/5 reflector)
Meade 5x TeleXtender for fl=3750mm f/25
Open Video Capture
RegiStax 5
Nebulosity 2
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Zad
Celestron C4-R (4" f/10 Acro Refractor)
Celestron Omni XLT 150 OTA (6" f/5 Newt)
CG-4 Mount with drive units
Meade RB-60 for guidescope
Canon Digital Rebel XT (350D)
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RedIrocZ-28
Pooh-Bah
Reged: 09/18/05
Posts: 1187
Loc: Grand Rapids, Michigan
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Zad, I'd say that the video capture was underexposed based on your image. You have captured detail like the GRS and defined bands which is a much better start than most of us! (My first images were light balls, no detail, I went in blind- dove in head first!)
I've never used a Fusion but I would think you still need to Get your histogram up to or slightly over 200 when you capture. Gotta get enough light to the camera chip!
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Zad
member
Reged: 01/05/08
Posts: 13
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Thanks for the help! I will definately try to get a brighter exposure next time. I used Open Video Capture to obtain the images, but it doesn't have a histogram. What software do you use to collect your images? Should I just take a short video, then open it with registax to check the histogram?
I am quite pleased with my first results. But as with any first attempt, I learned a lot that will help improve my next image. Focusing was hard, but I think I will use my focus mask on a bright star first to ensure the focus, then get better exposure levels.
The images were taken with a lot of light polution, and average seeing. When there is going to be good seeing, I will go to my friends house where the light polution is a lot lower (even though it is only 15 minutes away from me.) I hope that will help a little as well.
Thanks again for the advice! I welcome all help.
Joe
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Zad
Celestron C4-R (4" f/10 Acro Refractor)
Celestron Omni XLT 150 OTA (6" f/5 Newt)
CG-4 Mount with drive units
Meade RB-60 for guidescope
Canon Digital Rebel XT (350D)
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