First attempt at imaging a planet

stevejack (Steve) · #1 28-05-2011, 11:49 AM

Last night I finally received the eyepiece adapter that hooks up to my Canon DSLR. I have the 14" Skywatcher dob With GOTO.

The camera won't reach focus on the scope (not enough in-travel) so, being a truss scope, i just lowered the upper tube down a little and re-collimated (very roughly though, I just wanted to test the gear last night). Sliding down the truss tubes sure seems a lot easier than moving the mirror up the tube of a solid dob or replacing focusers.

I snapped off about 30 images with the DSLR, I had it in focus as best I could but Saturn was visibly moving around in the viewfinder... I used a reasonably high ISO (1600 for these I think) but the shutter time was still quite slow... enough so that there were only a few reasonably sharp frames to work with. I stacked the 20-odd images that weren't complete blurs with Lynkeos which I downloaded last night.

I think the tracking on the scope works well for visual use, but as one would imagine the motors just aren't up to the task of imaging.. at least not with the DSLR. You can see the motors working to bring the object close to the centre but it wobbles around way too much. Not a problem with the moon because it's so bright and the shutter can be fast, but a major problem at slower shutter speeds. Perhaps with a CCD webcam setup I will have better results. I'm sure that stacking 1000 frames as opposed to 30 will at least give me more detail

All that said, here is the result. Cheers.

BlackWidow (Mardy) · #2 28-05-2011, 11:54 AM

Nothing wrong with that at all. Great job!. I tried with my dob to get some good images of Saturn without a great deal of luck. I did not have any tracking at all so that made it hard. Good effort.

Regards
Mardy

stevejack (Steve) · #3 28-05-2011, 12:03 PM

Quote:

Originally Posted by BlackWidow

Nothing wrong with that at all. Great job!. I tried with my dob to get some good images of Saturn without a great deal of luck. I did not have any tracking at all so that made it hard. Good effort.

Regards
Mardy

Thanks mate. Yeah I couldn't imagine doing it without tracking. Just getting focus etc takes time... if it's drifting quickly out of the field it would be tough. It's not something I even attempted before i got this scope, but with the auto-track it makes things much easier.

It's certainly peaked an interest... I'll be doing more of this for sure. i wish I'd kept my 10" solid tube now... an EQ6 would have gone well with it!

Thanks for the encouragement.

renormalised (Carl) · #4 28-05-2011, 10:09 PM

Damn good first attempt!!!!. Good work

You would be much better off with a webcam than trying to use your DSLR, but you can still get quite acceptable shots, as you've proven right here.

stevejack (Steve) · #5 29-05-2011, 04:53 PM

Quote:

Originally Posted by renormalised

Damn good first attempt!!!!. Good work

You would be much better off with a webcam than trying to use your DSLR, but you can still get quite acceptable shots, as you've proven right here.

Definitely want to look into a webcam... Not sure what's out there, I haven't really looked but hopefully I can find something that will do Lunar/Planetary at a reasonable price

renormalised (Carl) · #6 29-05-2011, 05:08 PM

Go here and PM Peter. He'll knock one up for you

http://www.iceinspace.com.au/forum/s...ad.php?t=70573

midnight (Darrin) · #7 31-05-2011, 01:26 AM

Very nice Steve. Well done.

I have been keen on the DSLR video capabilities but eventually I ended up getting a DBK41 which is certainly better than the DSLR.

Cheers,
Darrin...

stevejack (Steve) · #8 31-05-2011, 11:17 PM

I hadn't thought about using video on the dslr... I think a webcam is out of reach for now but in a few months it'll definitely be something to look at. Are you having success with your purchase?

YunDog · #9 13-06-2011, 10:27 AM

Steve,

Thats a great shot of saturn. I recently purchased a t piece and ring attachment to attach my cannon EOS 350 to my Dob 12". Ive gave it a try with the moon last night but wasnt able to focus it. Im clearly missing something basic here? I dont know anything about how the camera attached set up is supposed to work, I tried with the eyepiece inside the tpiece and with just the camera attached but couldnt focus any of the set ups. What am I missing any help greatly appreciated.

renormalised (Carl) · #10 13-06-2011, 11:06 AM

Your dob is primarily a visual obs instrument and not setup for taking piccies. There's two things you can do to fix this: 1. Move your primary mirror up the tube to bring the focus to the right point, or, 2. Get a new focuser that is low profile. You'll possibly need a couple of extension tubes as well, to help with visual as you'll be inside the focus for many of your ep's.

Another thing you can do is if your dob is a truss tube design, you can get shorter trusses that bring the whole upper section down scope and closer to your mirror. These are designed for piccies in mind.

multiweb (Marc) · #11 13-06-2011, 11:28 AM

First shot at it? You're scaring me! Looking forward to more.

renormalised (Carl) · #12 13-06-2011, 11:57 AM

Quote:

Originally Posted by multiweb

First shot at it? You're scaring me! Looking forward to more.

Yeah, it's not too shabby...given a barlow/powermate and a Flea3 and we'll be seeing portraits worthy of hanging in the National Gallery

stevejack (Steve) · #13 13-06-2011, 03:25 PM

Quote:

Originally Posted by YunDog

Steve,

Thats a great shot of saturn. I recently purchased a t piece and ring attachment to attach my cannon EOS 350 to my Dob 12". Ive gave it a try with the moon last night but wasnt able to focus it. Im clearly missing something basic here? I dont know anything about how the camera attached set up is supposed to work, I tried with the eyepiece inside the tpiece and with just the camera attached but couldnt focus any of the set ups. What am I missing any help greatly appreciated.

I used to have the same camera as you. As mentioned, you need to work out a solution that involves reducing the distance from the camera to the primary mirror. My skywatcher dob has sliding truss tubes so I can lock the tubes just before they lock out. This gives me the same effect as moving the mirror up the tube. I'm not sure what scope you have so you'll need to find a solution that works for you. I'm all very new to this but I'm sure someone has already solved it for your type of scope, you just need to find the info

Quote:

Originally Posted by multiweb

First shot at it? You're scaring me! Looking forward to more.

Thanks mate - beginners luck more than anything I think. Now if only my girlfriend would let me outside at night more instead of being her preferred heat source I might get another chance to take some more

astrobob (Robert) · #14 13-06-2011, 04:27 PM

I had to cut about 2" out of my Saxson 130mm Dob but its working great now just have to get the alinement thing happening.

thanks Robert

Stu Ward · #15 14-06-2011, 11:32 AM

What eyepiece adaptor did you use ?
That image is great from a DSLR

Stu

YunDog · #16 14-06-2011, 12:11 PM

Quote:

Originally Posted by stevejack

I used to have the same camera as you. As mentioned, you need to work out a solution that involves reducing the distance from the camera to the primary mirror. My skywatcher dob has sliding truss tubes so I can lock the tubes just before they lock out. This gives me the same effect as moving the mirror up the tube. I'm not sure what scope you have so you'll need to find a solution that works for you. I'm all very new to this but I'm sure someone has already solved it for your type of scope, you just need to find the info

Ok so Ive got a flexi dob, so in theory if I dont slide the dob to full extension I should be able to find a focal range by shortening its extension?

cheers

Yun

stevejack (Steve) · #17 18-06-2011, 09:32 PM

Quote:

Originally Posted by Stu Ward

What eyepiece adaptor did you use ?
That image is great from a DSLR

Stu

If you look on the BTOW.com.au website it's the one I got from there. The only eyepiece I have that fits is my 10mm skywatcher plossl that came included with the scope for some reason the 20mm didn't work.. I only tried once though so I'll have to look at it again next time I get the scope out.

Quote:

Originally Posted by YunDog

Ok so Ive got a flexi dob, so in theory if I dont slide the dob to full extension I should be able to find a focal range by shortening its extension?

cheers

Yun

Yep that's right - tighten it up about an inch or so from full extension and it should be about right. It might depend on which adapters you're using as well. With the flexi dob it's easy to just drop it down to where you need it and re-collimate. Good luck