Leibowitz
member
Reged: 01/18/13
|
Planetary Camera for Dob
#5642258 - 01/25/13 10:11 AM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
I've got an Orion XT10i and I would like to begin doing some planetary imaging. I've read through many threads and I'm still having trouble pinpointing a good camera to image planets with. It's not a Goto so I'd simply be taking video of the object drifting through the FOV and stacking. I realize my imaging capabilities are limited almost exclusively to planetary/lunar objects so I don't think I need to spend a lot of money. I'm wondering if I should go with one of the cheaper cameras that Orion and Celestron offers or should I modify a webcam? If I was to modify a webcam, does anyone have any current suggestions? Seems all the threads I come across reference models no longer made.
|
pippo
member
Reged: 01/12/13
Loc: Paris (FR), Pantelleria (IT)
|
Re: Planetary Camera for Dob
[Re: Leibowitz]
#5642783 - 01/25/13 03:18 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
You need to use a short shutter time (between 10 or 15 ms depending on the focal length) to avoid that the planet drift results in a blurred image.
A good choice is to by a BW camera.
This is a great value:
http://www.ebay.com/itm/Point-Grey-Research-USB-2-0-Digital-Camera-/290845851...
Even if they just increased the price! Follow this tread:
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/5316325/page...
|
Mirzam
Post Laureate
   
Reged: 04/01/08
Loc: Lovettsville, VA
|
Re: Planetary Camera for Dob
[Re: Leibowitz]
#5642784 - 01/25/13 03:18 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
I think you are going to need an equatorial platform to provide some level of tracking. Without it you will have only a few seconds at best before a planetary image drifts off your camera chip.
JimC
|
ToxMan
Carpal Tunnel
Reged: 01/23/11
Loc: Tucson, Arizona, USA
|
Re: Planetary Camera for Dob
[Re: Mirzam]
#5642888 - 01/25/13 04:09 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
Even alt-az mounting is better than none. There will be some field rotation after a couple minutes.
|
Jeff2011
sage
Reged: 01/01/13
Loc: Sugar Land, TX
|
Re: Planetary Camera for Dob
[Re: ToxMan]
#5643400 - 01/25/13 09:28 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
+1 on the EQ platform. I built my own but there is at least one company that will build one for you. Just google equatorial platforms.
|
jgraham
Postmaster
   
Reged: 12/02/04
Loc: Dayton, Ohio
|
Re: Planetary Camera for Dob
[Re: Jeff2011]
#5643953 - 01/26/13 08:34 AM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
You might find this thread interesting...
http://stargazerslounge.com/topic/169220-webcam-imaging-with-a-dob/
I wonder how well the 5x movie mode of a Canon DSLR would work. The idea being that you can use the super wide field of the full frame mode for locating and focusing, then the movie mode for imaging. Backyard EOS makes this fairly easy to do. I've done lunar imaging with my Lightbridge 16, but I haven't tried the planets yet. It'll be interesting to try.
|
Leibowitz
member
Reged: 01/18/13
|
Re: Planetary Camera for Dob
[Re: jgraham]
#5647769 - 01/28/13 10:39 AM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
ToxMan, I don't understand what you mean about field rotation. I know what it is but I won't be able to capture more than about 8-10 seconds before any planet passes completely through my FOV. I realize I'm very limited with no tracking at all but I've seen some decent results with people using Dobs and a webcam. I may be in the wrong location here. I was hoping to get some answers from someone who has some experience with my very crude set up. My understanding is that I should be able to get a decent final product by stacking several AVI's with Registax. Lunar should be fairly straight forward. I'm needing some help with Mars/Jupiter/Saturn. All the help I can get. There's limited info on my setup, I'm afraid.
|
bunyon
Carpal Tunnel
   
Reged: 10/23/10
Loc: Winston-Salem, NC
|
Re: Planetary Camera for Dob
[Re: Leibowitz]
#5648046 - 01/28/13 12:37 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
You can let the planet drift through the field but that will still limit you to very short avis. The only undriven images I'm aware of ever seeing are from folks who "hand-guide" the scope. That is, let the planet drift onto the chip and then try to track it as best you can manually (by moving the scope as you normally would). I'd think it very hard to pull of but have seem some decent results.
I just don't think letting the planet drift through the FOV will get you far. It will drift through in a few seconds, allowing you to get a few hundred frames. You need more.
|
pippo
member
Reged: 01/12/13
Loc: Paris (FR), Pantelleria (IT)
|
Re: Planetary Camera for Dob
[Re: Leibowitz]
#5648051 - 01/28/13 12:38 PM Attachment (26 downloads)
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
I have a LB Dobson (12") and a Intes mak (7") on a manual alt-az mount. I am able to obtain reasonable images using a spc900nc and a firefly MC cam and letting the planet to drift during the movie.
The problems are
1)field rotation (it is stronger the higher the planet is in the sky) that limits the total acquisition time to 2-4 minutes and
2) the drift speed of the planet.
The drift speed depends on the focal length. With a focal length of 4860mm and a pixel size of 6micron, you should limit the total exposition time below 1/50, 1/60 sec.
Here is a example with the firefly the mak 7" with an average turbulence.
Edited by pippo (01/28/13 12:39 PM)
|
bunyon
Carpal Tunnel
   
Reged: 10/23/10
Loc: Winston-Salem, NC
|
Re: Planetary Camera for Dob
[Re: bunyon]
#5648057 - 01/28/13 12:40 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
Also, a good camera to use would be the best ones. There won't be any difference with a Dob than any other scope. The two "leading" cams seem to be the Flea3 and the ZWO ASI120. The DMK21-618 is also very good.
|
bunyon
Carpal Tunnel
   
Reged: 10/23/10
Loc: Winston-Salem, NC
|
Re: Planetary Camera for Dob
[Re: bunyon]
#5648113 - 01/28/13 01:00 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
pippo, how long does the planet stay on the chip as it drifts across? How many frames do you get?
|
pippo
member
Reged: 01/12/13
Loc: Paris (FR), Pantelleria (IT)
|
Re: Planetary Camera for Dob
[Re: bunyon]
#5648281 - 01/28/13 02:04 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
I take 60 fps for 120 seconds: 7200 frames.
5000/6000 contains a full jupiter.
|
bunyon
Carpal Tunnel
   
Reged: 10/23/10
Loc: Winston-Salem, NC
|
Re: Planetary Camera for Dob
[Re: pippo]
#5648298 - 01/28/13 02:11 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
So do you "guide by hand"?
|
pippo
member
Reged: 01/12/13
Loc: Paris (FR), Pantelleria (IT)
|
Re: Planetary Camera for Dob
[Re: bunyon]
#5648339 - 01/28/13 02:25 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
no I let jupiter drift and when it is out of the sensor I reput jupiter on the other side of the sensor, it let it drift again,...,...,
|
mikewirths
Vendor-Baja Dark Skies
   
Reged: 06/16/08
Loc: San Pedro Martir Mexico
|
Re: Planetary Camera for Dob
[Re: bunyon]
#5648346 - 01/28/13 02:26 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
Leibowitz-- I image using a dob, but of course it is driven. I think you will be very frustrated trying to do it by hand, check out this link for a very reasonable eq platform:
http://www.faintfuzzies.com/ObservingAids.html
Its near the bottom of the page. This is far cheaper than a Tom O platform, and with it given good seeing you could get superb results!
cheers
Mike
|
Leibowitz
member
Reged: 01/18/13
|
Re: Planetary Camera for Dob
[Re: bunyon]
#5648385 - 01/28/13 02:44 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
Yes, I'm wondering how many frames you processed to get that image. Can I not let the object pass through the FOV, re-aling the scope to catch it again, and stack multiple AVI's together? Let's say for Jupiter and Saturn?
|
pippo
member
Reged: 01/12/13
Loc: Paris (FR), Pantelleria (IT)
|
Re: Planetary Camera for Dob
[Re: Leibowitz]
#5648433 - 01/28/13 03:03 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
> Can I not let the object pass through the FOV, re-aling the scope to catch it again, and stack multiple AVI's together
It is what I do.
For the image, I staked 2000 frames selected among 5000 by pipp
https://sites.google.com/site/astropipp/
stacked with registax.
Obviously an equatorial platform is much more practical and allows for longer focal length than 4800mm and longer shutter time than 1/50 s. However you can also play without it in the beginning...
Edited by pippo (01/28/13 03:10 PM)
|
Leibowitz
member
Reged: 01/18/13
|
Re: Planetary Camera for Dob
[Re: pippo]
#5649572 - 01/29/13 12:38 AM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
How do you get 120 seconds of video? If you get maybe 10 seconds before Jupiter passes through the FOV, are you repositioning 12 times to get that many frames?
|
pippo
member
Reged: 01/12/13
Loc: Paris (FR), Pantelleria (IT)
|
Re: Planetary Camera for Dob
[Re: Leibowitz]
#5649668 - 01/29/13 03:27 AM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
Yes more or less:
it takes about 10 sec, and I reposition about 10 times (some seconds are lost in repositioning Jupiter at the correct place).
Edited by pippo (01/29/13 03:30 AM)
|
Leibowitz
member
Reged: 01/18/13
|
Re: Planetary Camera for Dob
[Re: pippo]
#5650203 - 01/29/13 12:26 PM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
I won't be frustrated if I get images like that. I'm wondering if I can get similar results with a modified webcam rather than spending $300-$500 on one of the above mentioned cameras. I'm not sure I can justify spending that kind of money when all I can do is solar system imaging. I'd love to have it but surely there's a webcam out there that can get me close? I wonder if this would be a waste of time or not.
http://www.telescope.com/Astrophotography/Astrophotography-Cameras/Orion-Star...
|