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lunartic65
sage
Reged: 12/26/06
Posts: 475
Loc: Dublin Ireland
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Hi all
What are the main difficulties in photographing doubles? With the colour contrast between certain doubles, Albireo comes to mind, I would imagine that they would make pretty nice pictures, yet I don't see too many attempts, is there something I'm missing?
Paul
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Paul
We have your satellite if you want it back send 20 billion in Martian money. No funny business or you'll never see it again.
Seen on a hall wall at the Jet Propulsion Lab.
William Optics Megrez 110mm
Skywatcher AZ4 Alt-Az mount
22mm Vixen LVW
11mm T6 Nagler
6.5mm Meade HD-60
4.8mm T1 Nagler
Pentax 10x50 Binos
1 Wife
4 Children
1 Cat
A Crowded House
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cvedeler
Carpal Tunnel
Reged: 12/20/05
Posts: 2203
Loc: Scottsdale, AZ
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Imaging doubles is something I've taken up. It's similar in difficulty as imaging the planets. Careful focus is essential. The results aren't as sexy as planetary or deepsky imaging as the results just look like this. This is Albireo taken with my AP160.
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Chris Vedeler
Astro-Physics 160EDF
Astro-Physics 900GTO
Q453HR / QHY8 CCD camera
Canon 450XSi
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www.aznightsky.com
Scottsdale, AZ
Edited by cvedeler (05/22/07 10:13 AM)
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lunartic65
sage
Reged: 12/26/06
Posts: 475
Loc: Dublin Ireland
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I like that image Chris, you've captured good colour, especially the blue of the companion star and it shows what can be done.
Paul
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Paul
We have your satellite if you want it back send 20 billion in Martian money. No funny business or you'll never see it again.
Seen on a hall wall at the Jet Propulsion Lab.
William Optics Megrez 110mm
Skywatcher AZ4 Alt-Az mount
22mm Vixen LVW
11mm T6 Nagler
6.5mm Meade HD-60
4.8mm T1 Nagler
Pentax 10x50 Binos
1 Wife
4 Children
1 Cat
A Crowded House
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jgraham
Postmaster
Reged: 12/02/04
Posts: 11575
Loc: Dayton, Ohio
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The challenge I've had is often the brightness difference between the stars. You have to be careful not to wash out the companion in the primary's glare. I've found simple cameras like the Phillips SPC900NC and the Meade LPI work well. I may give this a try with my 'new' twin StarBlast setup when I get a chance.
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-John
The best advice on imaging I've ever been given... don't forget to look! 
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Dennis_Oz
sage
Reged: 08/20/06
Posts: 335
Loc: Brisbane, Australia
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Hi Paul
Typically for imaging doubles I have used the following set ups:
Vixen ED102S f9 refractor + TeleVue x5 Powermate + Philips ToUcam (commercial webcam).
Takahashi Mewlon 180 + TeleVue x2.5 Powermate + DMK21AF04 (industrial webcam).
The webcam chip is quite small, being only 640x480 Pixels. I have read that a webcam “acts” like a 6mm eyepiece in terms of image magnification. So, with the Vixen 4 inch and x5 PowerMate, the effective magnification is around (918 x 5)/6 = x765. With the Tak 180mm, we get (2160x2.5)/6 = x900.
The steadiness of the atmosphere (seeing) and the capabilities of your mount (tracking) greatly influence the results.
Typically, using the webcam, I will capture a movie file (avi) for say, 3 minutes at 10 frames per second. This will give me 1800 individual frames. Some of these frames will look okay where they were captured in rare moments of steady seeing. Most of the frames will look blurry or distorted due to the turbulence of the layers of the atmosphere.
I then use a program called Registax which automatically reads the avi file, analyses it and then stacks the best frames together to produce a final image.
Here is an example of a good single frame and the final result from stacking 20 of these frames. Some of the distorted frames are barely recognisable.
Cheers
Dennis
EDIT:
Just read my notes and so have the following amendment.
The left hand frame is in fact a stack of 50 frames captured using the Meade LPI, which automatically stacks the best frames on the fly to produce a greatly enhanced and improved image (saved as a bmp) compared to a single LPI frame.
I then took 20 of these stacked and enhanced LPI images (bmp’s) and stacked them in Registax to further improve the image.
Edited by Dennis_Oz (05/22/07 05:38 PM)
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sdbodin
super member
Reged: 02/04/07
Posts: 131
Loc: Eastern Washington State
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One of my favorite activities. I have been using various videocameras to image doubles for 7 or 8 years now. Using a sensitive camera allows one to 'beat the seeing', splitting close pairs that could not otherwise be seen.
Careful calibration also allows one to measure separation and position angle to a much higher degree than visual reticle eyepieces can provide.
Plus, it can be done in bright moon conditions when DSO observing is poor.
The main difficulty is getting started. Videocam is my fav method, easy to run the data to tape, process later. But CCDs work fine too, just need a computer in the field. Biggest three problems are cable connection, connections, connections.
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Steve
Meade 16 LX200 GPS UHTC
Meade 4 107D SCT
AstroTech AT80LE
Orion Express 80
Coulter optics 17.5 DOB
Orange tube dual motor C8
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RLTYS
Post Laureate
Reged: 12/18/04
Posts: 4267
Loc: New York (Long Island)
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sdbodin
A very interesting and impressive series of shots. 
Clear Skies.
Rich (RLTYS)
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10" F4.8 Refl.
4" F5 Refr. (Genesis)
3" F4 Celestron FirstScope
50mm F12 Refr. (Tasco #6TE-5)
12x63 and 10x50 Binoculars.
"I want to do more then just look."
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