Photo using Canon EOS 100D

[TauntonJames]

Hi All

Thank you for taking the time to read this post. I have recently purchased a Canon EOS 100D and am interested in trying to use it for some Astrophotography. I have the camera, which I remove the lens from, leaving me with the camera body. I have purchased a T ring adaptor to put in place of the camera lens, and then an adaptor to fit into the eyepiece slot on my Celestron scope. It is a Celestron PowerSeeker 675, number 21045 if it is of any use. I have attached my camera and tried taking some photos and had some pretty rubbish results. I know I must be going wrong somewhere. I tried different exposure times, varying from snap photo up to 10 seconds. All I can see when looking at these is the inside of the scope with a very bright hole at the end. Its very odd. In the images, you should be seeing the moon. I am a complete beginner to this, am I taking the correct approach using the equipment, and am I even using the equipment correctly? I thought the moon would be a nice easy first target, how wrong can you be! I have more images available at much higher res but I am restricted to 1Mb on this post so hopefully these will be useful.

Thank you

James

[jambouk]

I suspect when you try to focus, you get close but then the focuser won't go in any further. This is a common problem with newtonian scopes and dslr cameras.

Read this thread:

http://stargazerslounge.com/topic/239835-help-with-canon-400d/

You will be able to get some images, just some learning / modifications / purchases first.

Good luck.

James

[JamesF]

I'd guess that you're not in focus.  The focuser will not be in the same position when the camera is attached as it would be for an eyepiece to get a focused image.

I'd try to focus using the display on the camera and see how you get on.  It may be that the drawtube lacks sufficient inwards travel to achieve focus, but there's only one way to find that out really and it's perhaps not completely insurmountable if that is the case.

It may also be worth using a remote shutter release or setting a delay on the shutter release so that the OTA isn't wobbling as a result of your adjustments or from pressing the button.

James

(another one, not far from Taunton

[Astroboffin]

Hi,

The only problem I see is that they are all way out of focus, you need to focus the telescope......simples...

Regards

AB

[JamesF]

Err, "snap", as it were

There was something else I was going to mention and I can't recall what it was now.  That's age for you.  I'll remember shortly, I'm sure.

James

[JamesF]

Ah, yes.  Exposure times.  You shouldn't need anything more than fractions of a second.  1/200th @ ISO100 might be a reasonable place to start and work from there.

James

[TauntonJames]

Hi Everyone

Thank you all for your replies. When I took the images, I tried moving the focus bit in and out all the way. It did improve the images to where they are at present but it just does not seem to move far enough! Looking at the link provided, it seems that some people have used barlow lenses to improve the focus. I will give this a go and see how it comes out. Failing that, and short of removing the eyepiece tube, is there anything else I can do to improve the quality of the images?

Thank You

James (TA2 Taunton)

[ronin]

People sort of attack the rear of the scope and adjust the screws so that they move the mirror further up the tube, this in turn moves the image further out and so the image and sensor can coincide - and you have a picture.

Depends on how happy you re at making the adjustments and then redoing the collimation.

For planets and moon a barlow is the easier and simpler option because they are brighter and so the image size can be increased without any trouble, actually often necessary to increase the size and so dim them down and draw out more detail.

Try a barlow if you have one, it will only be applicable to the moon and planets, making others DSO's etc bigger is not a good idea, they become too dim.

[Sam]

I think this is similar to a problem I had with my XT8 years ago. I moved the mirror up the tube a couple of centremetres and that was enough to bring the image into focus within the focuser travel limits.

[TauntonJames]

Hi Everyone

Thank you all for your replies and help with this. The mirror sounds like it could be fun to realign after moving, but may well give it a go in a bit. I have been waiting until a cracking moon was on show before trying out the Barlow trick. I have a 2x (Second Picture) and 3x (First Image) barlow lens, both of which I tried. Stability seems to be a small issue but I imagine tweaking with the exposure time and using a remote clicker will solve this.

I will continue with these images and have a play about with some of the settings. Thank you very much for all of your help.

James

[kalasinman]

Hi Everyone

Thank you all for your replies and help with this. The mirror sounds like it could be fun to realign after moving, but may well give it a go in a bit. I have been waiting until a cracking moon was on show before trying out the Barlow trick. I have a 2x (Second Picture) and 3x (First Image) barlow lens, both of which I tried. Stability seems to be a small issue but I imagine tweaking with the exposure time and using a remote clicker will solve this.

I will continue with these images and have a play about with some of the settings. Thank you very much for all of your help.

James

James, if you move the mirror up, yes you will have to collimate. You will have to do this anyway, in fact should have already.