Astrophotography with Afocal Method: Tips for Better Results

[Dagenais]

I'm trying out the old fashioned Afocal method for astrophotography. I'm using a Olympus Camedia C-4000 Digital Camera.

The pictures, don't turn out very well. Basically, you see small circle with color (the image), and a thick black border surrounding it (the eyepiece).

I can't get the camera to just focus on just the image. The camera's lens size exceeds the eyepiece by a lot.

Is there anything I can do to get better pictures?

Besides having to get another lense like https://emporium.olympus.com/innards/empProdDetails.asp?sku=200540-420.

 

[check]

I just started anthropography too. I’m using a Casio QV – R40 and a 76mm diameter 700mm f-length reflector. The telescope came with a special mount for digital cameras. Anyway, I just started trying to take pictures through it about 2 weeks ago, but I’ve only had a couple of clear nights. So far my best pictures are of the moon because it’s easy to focus on by looking at the camera’s LCD display. What I do first off, make sure the telescope's star finder is aligned, set the camera’s focus to infinity (though I’m still experimenting with this), self timer set to 10 seconds (so the camera’s shaking has stopped after I push the button) and exposure to 1 second. (My camera can go up to 2 seconds, but longer exposures result in blurred images if you don’t have a tracker for your telescope). Anyway, the camera’s lens is moved all the way to the eyepiece, almost touching it. Now, if you're not pointed at the moon already (or whatever you want to look at), it should look black on the LCD screen. To see how much of the eyepiece is obstructing the image, what I like to do is shine a flashlight through the telescope. This makes the whole viewing area light up. It helps with aligning the camera. Now, what I do once I have the camera aligned is zoom in until I can't see any of the eyepiece obstructions, making sure to not zoom to far as to be using the camera’s digital zoom. Then I find my target, most often the moon to start, and I set the focus of the telescope on that. After that, I keep the focus of the telescope the same and move onto a planet. I usually start with Jupiter cause its an easy target, but I’m still working on camera settings so if I get a good picture, I’ll post it. My camera’s batteries died early tonight so no luck.

Anyway, that’s my tip for focusing. Best to have a special mount and focus on something big and bright first.

 

[Dagenais]

set the camera’s focus to infinity

I'm not sure what you mean.

It basically auto-focuses.

 

[check]

Well, I'm not sure about your type of camera, I'll read up on it, but most digital camera's have 4 modes when it comes to focus: Manual focus, you adjust the focus yourself, Auto focus, the camera automatically determines the proper focus, Infinity focus, basically for focusing on objects far away, Macro focus, focus on objects really close. Read up on your manual, it should tell you how to focus. If not however, I don’t see why auto focus wouldn't work, just make sure you have the camera properly aligned to the eyepiece so its not focusing on the part of the eyepiece that'd obstructing the image through the telescope, but the actual image.