Astrophotography beginners help

[Robzy]

I've recently bought myself a telescope and I'm interested in taken photographs of the night sky. Last night when I took an exposure of 4mins 30 secs the image was HUGELY over exposed and was completely white. I tried an exposure of a minute and recieved a grey image, again with no details. A 10 second exposure should nothing but darkness, no detail.

My ISO for all these photographs were set at 1600 with an aperture of 00 (as I can't pick anything else).

I'm clearly doing something wrong. My set up is as follows:

I have a telescope with the eye pieces removed and replaced with the t adapoter and t ring which is connected to my camera (with no lens on it).

If I look through my telescope with no eye piece I only see my eye being reflected back. If I look through my camera with no lens all I see are MASSIVE circles of confusion.

I'm COMPLETELY new to any kind of telescope so I'm proberly making a very stupid mistake.

I think my problem is that there isn't a lens in my setup...

Please can someone give me some help?

PS. I have a CANON EOS 450D and a Sky-Watcher 130P.

[Merlin66]

Robzy,

Welcome to the black magic circle!!!!

From what you say you're trying to do "prime focus" imaging ( no eyepiece or other lenses) this is basically using the main mirror as a giant telephoto lens!

The nosepiece and T adaptor to the camera sound OK.

Setting at 200 ISO is probably enough.

How do you focus the camera? What object were you trying to photograph?

Start with something simple like the moon; a setting of 1/30 sec exposure will get you a pretty good image and give you the practise in focussing the camera.....

[Parallax]

It seems like you have got everything setup correctly, and you just need to sort out the focus. I say "just", as this is a very tricky, but necessary, part of the procedure.

As Merlin has said, try something simple to start with. Unfortunately, the moon isn't about at the moment so maybe try focusing on Jupiter (nice and bright in the south). Pop an eyepiece in, centre the target, then replace with the camera. You only need a short exposure (say, 1 second or less) then review the image. Adjust the focus a little and repeat. It may take a little time but you'll soon get the hang of it.

Good luck.

Steve

[Robzy]

Thanks Steve.

I'm heading out now to give it a try.

If I get anything other than white/black I'll be sure to upload them!

[barkis]

The 450D has Live View doesn't it? You should see a bright object on the LCD screen. that should enable you to get close to a decent focus.

Ron.

[Robzy]

Just been out with no luck.

I focused the scope on Jupiter then switched to my camera, lined everything up again but I couldn't see anything. I saw nothing through the view finder or through live view.

All I can see is the cross section at the end of the scope. I tried blindly attaching the focus very slightly and taken a photograph each time. That didn't work either.

On a seperate (possibly related) note; when I look at jupiter through the scope with my wide angle eye piece in it doesn't appear any bigger than what it does without the eye piece...

I'm either being extremely stupid or I've bought a crud scope.

[adamsp123]

Just been out with no luck.

I focused the scope on Jupiter then switched to my camera, lined everything up again but I couldn't see anything. I saw nothing through the view finder or through live view.

All I can see is the cross section at the end of the scope. I tried blindly attaching the focus very slightly and taken a photograph each time. That didn't work either.

On a seperate (possibly related) note; when I look at jupiter through the scope with my wide angle eye piece in it doesn't appear any bigger than what it does without the eye piece...

I'm either being extremely stupid or I've bought a crud scope.

When you say I focused my scope and then switched to my camera could you explain step by step what you are doing.

Are you trying to image by focusing with an EP and then swapping to the camera?

[themos]

It could be that your focuser is too fat and doesn't allow the camera's sensor to get to the focal plane. Start by racking the focuser all the way in and attaching the camera. Do this during daylight but not pointing near the sun. What image do you get? Then rack the focuser out bit by bit and try again.