#1  
Old 10-03-2008, 10:15 AM
Kirkus's Avatar
Kirkus (Kirk)
Beginner-ish

Kirkus is offline
 
Join Date: Dec 2007
Location: California, USA
Posts: 207
DSLR vs. CCD for DSOs

I'm getting kind of bored chasing after Saturn every night, so I'm considering branching out into DSOs. Had a great night last night! I spotted M27, M57, M81 and M82! I was stoked!

Anyway, I'm considering the purchase of a Canon 40D (don't want to wait for the 450D). I've read that exposure time can go beyond 30 seconds if it's taken to manual mode. Does anyone have any experience with the 40D? All reviews max out the exposure time at 30 seconds. I don't want to have to modify the camera for longer exposures.

Also, I've been looking at an Imaging Source CCD camera. I notice that max. exposure time is 60 minutes. Can you successfully do long exposure imaging of DSOs with a CCD camera? I can't find any image samples on the web.

Any help would be very much appreciated.
Reply With Quote
  #2  
Old 10-03-2008, 10:34 AM
madtuna's Avatar
madtuna (Steve)
an overactive imagination

madtuna is offline
 
Join Date: Dec 2007
Location: just south of wollongong
Posts: 576
I've got the 40D although new at it and still learning the ropes, it does have bulb mode, so exposure time is up to you
Reply With Quote
  #3  
Old 10-03-2008, 01:06 PM
madwayne's Avatar
madwayne (Wayne)
Registered User

madwayne is offline
 
Join Date: Jun 2007
Location: Robertson NSW
Posts: 517
If you are getting a 40D I would strongly suggest you also get the TC-80N3 remote for it as well. This will allow you to set the camera to bulb and then dial your exposure time (up to 99 hours from memory) and number of images at that exposure into the remote. Hit start and basically walk away. I use one with my 20D and it is a god send. The instruction manual is very easy to follow and after one night's use you really don't need the manual.
Reply With Quote
  #4  
Old 10-03-2008, 01:23 PM
Matty P's Avatar
Matty P (Matt)
Star Struck

Matty P is offline
 
Join Date: Nov 2007
Location: Canberra
Posts: 2,797
Quote:
Originally Posted by Kirkus View Post
Also, I've been looking at an Imaging Source CCD camera. I notice that max. exposure time is 60 minutes. Can you successfully do long exposure imaging of DSOs with a CCD camera? I can't find any image samples on the web.
Hi Kirkus,

I have used the Imaging Source DMK CCD camera for imaging DSOs and was quite surprised. Even though the camera is not made for long exposures, it is still capable of producing pretty good results. I have yet to try a 5 or 10min exposure with the camera so I am unaware of its potential. TIS cameras are suited better for Planetary imaging.

For imaging DSOs, I would get a DSLR camera.

Here are some images I have taken with a DMK.

1. NGC 2070 - Tarantula Nebula

2. NGC 104 - 47 Tuc

Hope this helps
Attached Thumbnails
Click for full-size image (Tarantola%20Nebula0004%2008-01-29%2023-19-17[1].jpg)
174.6 KB122 views
Click for full-size image (47Tuc0001 23-19-122.jpg)
145.2 KB79 views
Reply With Quote
  #5  
Old 10-03-2008, 01:35 PM
[1ponders]'s Avatar
[1ponders] (Paul)
Retired, damn no pension

[1ponders] is offline
 
Join Date: Nov 2004
Location: Obi Obi, Qld
Posts: 18,779
http://www.iceinspace.com.au/forum/s...earchid=667432

some DMK DSO images

While it can certainly do them, go for the canon
Reply With Quote
  #6  
Old 10-03-2008, 05:23 PM
Tamtarn's Avatar
Tamtarn
Barb and David

Tamtarn is offline
 
Join Date: May 2006
Location: Warragul. Victoria.
Posts: 2,293
Hi Kirkus

The supplied canon software with the 40D allows you to take multiple long exposures automatically when connected to a laptop.

We have no need for any remote as typically we set up to do 15 images with a 7min exposure time and 10 sec delay between images.

The same applies when doing darks.

If you cannot connect to a computer, then you would need a remote.
Reply With Quote
  #7  
Old 12-03-2008, 07:31 AM
Kirkus's Avatar
Kirkus (Kirk)
Beginner-ish

Kirkus is offline
 
Join Date: Dec 2007
Location: California, USA
Posts: 207
Wonderful responses and a lot of help. Thank you all for your input!
Reply With Quote
  #8  
Old 13-03-2008, 10:01 PM
Bassnut's Avatar
Bassnut (Fred)
Narrowfield rules!

Bassnut is offline
 
Join Date: Nov 2006
Location: Sydney
Posts: 4,771
>Can you successfully do long exposure imaging of DSOs with a CCD camera? I can't find any image samples on the web.

Wha ?????
Reply With Quote
  #9  
Old 13-03-2008, 10:23 PM
Zuts
Registered User

Zuts is offline
 
Join Date: Mar 2007
Location: sydney
Posts: 1,425
Quote:
Originally Posted by Bassnut View Post
>Can you successfully do long exposure imaging of DSOs with a CCD camera? I can't find any image samples on the web.

Wha ?????
I think he means webcams, but just in case he doesnt .....

DSLR's use CMOS technology while 99.9 percent of dedicated astro cameras use CCD's so on the web most of the images you see will be from CCD's

Paul
Reply With Quote
  #10  
Old 17-03-2008, 09:21 AM
Hagar (Doug)
Registered User

Hagar is offline
 
Join Date: Oct 2006
Location: Australia
Posts: 4,646
Quote:
Originally Posted by madwayne View Post
If you are getting a 40D I would strongly suggest you also get the TC-80N3 remote for it as well. This will allow you to set the camera to bulb and then dial your exposure time (up to 99 hours from memory) and number of images at that exposure into the remote. Hit start and basically walk away. I use one with my 20D and it is a god send. The instruction manual is very easy to follow and after one night's use you really don't need the manual.

You really don't need the timer if you are using the camera with a laptop computer. The camera comes with a utility program which allows all camera controls including bulb long exposures and timming to be controlled via a single USB connection. Exposures out to 10 minutes are easilly taken as long as you take dark frames and subtract in one of the stacking programs.
The 40D does a great job and makes control and focus easy.
Reply With Quote
  #11  
Old 15-04-2008, 07:14 AM
Kirkus's Avatar
Kirkus (Kirk)
Beginner-ish

Kirkus is offline
 
Join Date: Dec 2007
Location: California, USA
Posts: 207
UPDATE and A QUESTION:

It turns out the 40D was beyond what I could afford. But I finally bit the bullet and bought a new Canon EOS XTi 400D. My T-Ring, T-Adapter, and remote shutter control should be here this week some time.

I'm really excited!!

The Mac software that came with the camera does let me control it from my laptop, but not in Bulb mode. But that's OK. I plan on giving it a go by holding the shutter open manually and will probably purchase the TC-80N3 in a month or 2.

Have I said how excited I am?!!

Anyway, I have a question. I notice on many DSO photos the photographers will say, "auto guided" or "unguided". I'm not sure what unguided means? Can you take a long exposure "unguided"?

Thanks to everyone for their help and suggestions!
Reply With Quote
  #12  
Old 15-04-2008, 07:26 AM
iceman's Avatar
iceman (Mike)
Sir Post a Lot!

iceman is offline
 
Join Date: Sep 2004
Location: Gosford, NSW, Australia
Posts: 36,709
Hi Kirkus!

ImagesPlus or other camera control software is good for controlling the camera until you get a TC-80N3. You will not have much luck holding the shutter open by hand - the shake of your hand will blur the images. Best off using a $20 infrared remote and use that to start/stop your exposures.

Unguided means the mount is tracking on it's own, but not receiving guiding commands from software, that calculates where to go based on input from a guide scope/guide camera.

Guiding is when you are using a guidescope/guidecamera.
Reply With Quote
  #13  
Old 15-04-2008, 07:37 AM
Garyh's Avatar
Garyh
Amongst the stars

Garyh is offline
 
Join Date: Jun 2006
Location: Glen Innes, N.S.W.
Posts: 2,839
Hi Kirkus,
For widefield work, piggy backing your new 400D with a camera lense on your mount you should be fine doing unguided as long as you stick with short focal length lenses like 24mm, 50mm and maybe 135mm for 5 min or more if you are well polar aligned but through your scope you most likely be limited to like 30 sec or a minute unguided. Periodic errors etc in your drive train on your mount will most likely cause star trailing and movement as everything gets magnified through the scope with only the very best and most expensive mounts being able to do longer unguided exposures....
Most of all have fun with your new toy and I would recommend doing a little widefield work with your standard lense first then when you have got the hang of that, do some prime focus stuff.
cheers Gary
Reply With Quote
  #14  
Old 15-04-2008, 08:32 AM
Kirkus's Avatar
Kirkus (Kirk)
Beginner-ish

Kirkus is offline
 
Join Date: Dec 2007
Location: California, USA
Posts: 207
Iceman: I wasn't very clear. Sorry. I meant I'll manually control the shutter with a remote until I can get the TC-80N3. I think the remote I bought will make it necessary for me to actually hold down the button to keep the shutter open (one one-thousand, two one-thousand, three one-thousand... )

Thanks for the explanation about guided/unguided. That makes perfect sense! Even though my mount "tracks", the camera's not being "guided" unless I'm using software that controls the mount, right? Which I have but haven't had a reason to learn to use it... yet. Tracking is not as accurate as guiding.

Gary: I did piggyback my camera on my mount the first night I had it and did some 30 second exposures (the longest I can do outside of bulb mode) with the 18mm - 55mm lens that came with the camera. I got a very nice 'gray-fuzzy' of M13 (and did a happy dance, just because).

I'll take your advice and work on widefield stuff in the beginning (after I do a couple prime focus things just to give it a go. ).

Thank you all so much for the words of wisdom, education, and encouragement.
Reply With Quote
  #15  
Old 15-04-2008, 11:49 AM
Ingo
Registered User

Ingo is offline
 
Join Date: Apr 2007
Location: Albany, NY
Posts: 559
Quote:
Originally Posted by Tamtarn View Post
Hi Kirkus

The supplied canon software with the 40D allows you to take multiple long exposures automatically when connected to a laptop.

We have no need for any remote as typically we set up to do 15 images with a 7min exposure time and 10 sec delay between images.

The same applies when doing darks.

If you cannot connect to a computer, then you would need a remote.
How do you do this in EOS Utility? Set it to do a number of exposures at a set time? I could never figure that out.
Reply With Quote
  #16  
Old 15-04-2008, 01:36 PM
Kirkus's Avatar
Kirkus (Kirk)
Beginner-ish

Kirkus is offline
 
Join Date: Dec 2007
Location: California, USA
Posts: 207
Quote:
Originally Posted by Ingo View Post
How do you do this in EOS Utility? Set it to do a number of exposures at a set time? I could never figure that out.
This isn't an answer to your question (don't you hate that? ), but I noticed in the manual that came with EOS Utility specifically says it can control the camera "except for bulb mode". So I'm assuming, for me anyway and possibly you, Ingo, that it has to do with the model of camera. Tamtarn was giving me advice on a 40D, which I ended up not buying.
Reply With Quote
  #17  
Old 15-04-2008, 02:35 PM
mrsnipey's Avatar
mrsnipey
Verified Astronomy Noob

mrsnipey is offline
 
Join Date: Sep 2007
Location: Corinda, Australia
Posts: 199
Hi Kirkus,
I was under the impression that the TC-80N3 wasn't compatible with the 400D. It has a different plug to connect to the camera.
Reply With Quote
  #18  
Old 15-04-2008, 03:17 PM
[1ponders]'s Avatar
[1ponders] (Paul)
Retired, damn no pension

[1ponders] is offline
 
Join Date: Nov 2004
Location: Obi Obi, Qld
Posts: 18,779
Quote:
Originally Posted by mrsnipey View Post
Hi Kirkus,
I was under the impression that the TC-80N3 wasn't compatible with the 400D. It has a different plug to connect to the camera.

That is correct. The 400D has a 2.5mm plug the same as the 300D & 350D. The 20D, 30D and 40D all take the TC-80N3 plug.
Reply With Quote
  #19  
Old 15-04-2008, 03:38 PM
Terry B's Avatar
Terry B
Country living & viewing

Terry B is offline
 
Join Date: Mar 2006
Location: Armidale
Posts: 2,759
Quote:
Originally Posted by Ingo View Post
How do you do this in EOS Utility? Set it to do a number of exposures at a set time? I could never figure that out.
This is very simple.
When you have opened the EOS utility there is a button to push. See image 1
It brings up the second screen. I have it set to take 4 images of 5 min duration every 5 mins and 10 secs. Just push start and it works. Simple
Attached Thumbnails
Click for full-size image (canon1.gif)
72.0 KB56 views
Click for full-size image (canon2.gif)
37.6 KB53 views
Reply With Quote
  #20  
Old 15-04-2008, 03:47 PM
Ingo
Registered User

Ingo is offline
 
Join Date: Apr 2007
Location: Albany, NY
Posts: 559
Quote:
Originally Posted by Terry B View Post
This is very simple.
When you have opened the EOS utility there is a button to push. See image 1
It brings up the second screen. I have it set to take 4 images of 5 min duration every 5 mins and 10 secs. Just push start and it works. Simple
Thank you very much!

When I get my laptop back working I can stop pressing the button every time I want to take an image
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 03:15 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
Celestron Australia
Advertisement
Bintel
Advertisement
Lunatico Astronomical
Advertisement
NexDome Observatories
Advertisement
Meade Australia
Advertisement
OzScopes Authorised Dealer
Advertisement
SkyWatcher Australia
Advertisement
Astronomy and Electronics Centre
Advertisement