Hmmmm.... Have a couple of questions!

[drevilsmom]

I went out last night as we had a cold front push through, and the sky was just begging for me to give my camera a try. Now mind you, I only have the 18-55mm kit lens on my 40D, and I haven't tried any type of astrophotography in about 10 years. I set my camera at 1600 ISO, 30 secs, and 18mm and had it on a Mohawk tripod with a 2 sec delay. Aimed it up to Cassiopeia over my house. My results were kind of mixed. :confused::rolleyes: I never could get it to come into a crisp focus, and I tried multiple times, including at 10X on the LiveView. I also had some trailing, which I know was to be expected. What am I doing wrong to not be able to get it to focus very well? I also was wanting to know if there are any free stacking programs that are fairly user friendly. I used to stack images from our ancient CCD at my alma mater, and you would take points on say the red image (such as Sirius and Betelgeuse), and align them on the same points on the green image in order to get them to stack. Do any do that today? I would not mind taking several, say 10 second shots, and stacking them that way. Here is the best image, btw. Like I said, I'm a little bit disappointed with my first attempt.

http://i154.photobucket.com/albums/s254/drevilsmom/IMG_2687.jpg

[Jeff]

I've done this too with similar results. One thing I found by using other lenses is that they have a focus distance ring with infinity marked. That at least gets you close. The kit lens doesn't have that. You did good to use the timer to release the shutter. Other things to try: Mirror lockup to avoid and shake from the mirror slapping up. Vibrabtions can creep up through whatever surface the tripod is on, so make sure nobody is walking around near the camera. Or use some sort of vibration suppression pads. Wind. Any kind of breeze can do the same thing. I think I see a little hint of a "tail" on the stars, which makes me think something moved ever so slightly during the exposure.

I'm curious -- how well did the live view work? Were the stars pretty bright on the screen? I'm thinking about going from my 30D to a 40D just for that.

[Nighthound]

Great suggestions Jeff.

Yes, you missed focus slightly and 30 seconds is stretching a bit even at 18mm so I agree there's definitely some trailing.

The kit 18-55 has a very lacking focus ring making pin point focus a challenge. Be sure you have adjusted your dioptric dial on your camera viewfinder using a bright star before attempting final focus. I look for the star spikes to get very sharp and that's usually right on.

Here's another approach.
• Set the lens switch to AF.
• Set camera to any of the auto focus modes.
• Point at a bright star with the selected focus point and wait until it snaps to focus.
• Carefully switch the lens back to Manual
• Switch camera back to Manual
• Point camera in direction you are imaging being careful not to touch the lens.

That should do it. I like how you have this framed up through the trees. Have another go at it, it's going to be a very cool shot.

[Scoobs]

Hi, This is a free stacker program. Can't comment on how good it is as I've only just installed it myself and not had the opportunity to try it out yet. Seems to be quite well rated from what I've read.

I'm finding trying to get the focus right is one of the biggest problems. At the moment I'm using trial and error on short shots and reviewing them to see if I've a good focused shot.

http://deepskystacker.free.fr/english/index.html

[drevilsmom]

I've done this too with similar results. One thing I found by using other lenses is that they have a focus distance ring with infinity marked. That at least gets you close. The kit lens doesn't have that. You did good to use the timer to release the shutter. Other things to try: Mirror lockup to avoid and shake from the mirror slapping up. Vibrabtions can creep up through whatever surface the tripod is on, so make sure nobody is walking around near the camera. Or use some sort of vibration suppression pads. Wind. Any kind of breeze can do the same thing. I think I see a little hint of a "tail" on the stars, which makes me think something moved ever so slightly during the exposure.

I'm curious -- how well did the live view work? Were the stars pretty bright on the screen? I'm thinking about going from my 30D to a 40D just for that.


LiveView was horrible, but take that with a grain of salt.... :rolleyes: I didn't even use it for the first time until that very night, and I was unable to get any focus at all. Didn't help that I have a brand spanking new camera and the learning curve on a DSLR is pretty steep. I had a great running start from using my S1 IS on manual all of the time, but I'm running out of steam, so to speak, even as I'm starting to reach the top of the first of many hills. Still love the camera, though!

[drevilsmom]

Great suggestions Jeff.

Yes, you missed focus slightly and 30 seconds is stretching a bit even at 18mm so I agree there's definitely some trailing.

The kit 18-55 has a very lacking focus ring making pin point focus a challenge. Be sure you have adjusted your dioptric dial on your camera viewfinder using a bright star before attempting final focus. I look for the star spikes to get very sharp and that's usually right on.

Here's another approach.
• Set the lens switch to AF.
• Set camera to any of the auto focus modes.
• Point at a bright star with the selected focus point and wait until it snaps to focus.
• Carefully switch the lens back to Manual
• Switch camera back to Manual
• Point camera in direction you are imaging being careful not to touch the lens.

That should do it. I like how you have this framed up through the trees. Have another go at it, it's going to be a very cool shot.

LOL! It only took me until the middle of this afternoon for it to dawn on me to use the autofocus! :oops::lol: I was really against using it because I figure it would be good practice to get used to manual. I also didn't think about the mirror lockup as well, so I'll have to try it!