Slightly embarrassing question about t-mount...

[aprecelton]

Dear SGL

Please feel free to put me in the stocks and hurl rotten veg at me after this post, but I need to ask!

I have a t-adapter to mount my Pentax DSLR onto the back of my Celestron SCT for some AP. There were no instructions with the tube of the adapter. I know how to mount the adapter onto the camera and place the adapter into the hole where the eyepiece goes in tHe back of the scope.

However my question is, do you insert an eyepiece inside the adapter tube? The EP seems to fit into the tube, and there is a small screw on the side of the tube that is suggestive of retaining/locking an EP into place inside.

Am I barking up the wrong tree, or just barking?

Thanks everyone. Please form an orderly queue to throw the veg......

Adam

[The Sailor]

Hi Adam, know what you are on about, it's up to you if you wish to insert an eyepiece but it can be done and does work. The eyepiece I used was a 5mm, I think it was the only one I got to fit at the time, insert it barrel first and hold it with the screw. Problem you will have will be getting on traget but once there it's focus and shoot, I only used it for Nebuals. Hope that helps, maybesomeone can give you a better answer.

Jim

[Bizibilder]

Normally you just place the camera, with the adapter, into the focusser tube. The telescope acts like a fixed focus "telephoto lens" for your camera, that is your image is focussed directly onto the sensor of the camera - sometimes referred to as "prime focus".

Just to confuse things there is a method of imaging where you have the eyepiece mounted normally and place a camera so that it can pick up an image in the same way as your eye would if placed normally at the eyepiece - this is called "eyepiece projection" or "afocal" and is used sometimes with "point and shoot" cameras where there is no facility to remove the lens from the camera.

Have fun - and if it is clear post some pictures of the Moon! - It should be out tonight if only it would clear.....

[aprecelton]

Cheers Jim

Glad some else has tried it! Looks like its going to be a clear night so I suppose it would be rude not to try it.

Thanks again,

Adam

[aprecelton]

Thanks Bizibuilder

I take it that it isn't wrong to just mount the camera direct without an EP in the adapter. Lets hope the sky is clear, and I will try it!

cheers,

Adam

[chrissealuk]

I can take good pictures with nothing in the T adapter, but when I put an eyepiece into the tube, there isn't enough space in the camera to re-attach the T adapter. Has anyone else had this problem & solved it?

I am using a Nexstar 6SE with a Canon EOS 550D.

Thanks in advance, Chris.

[The Sailor]

The EP I use is small enough to fit inside and when secured it sits inside the adapter without protruding, as said I use a 5mm.

Jim

I am comming back in here after reading the next post, the only solution I can think of is for you to get or cut a shorter barrel. The barrel is required to hold the EP in place so just enough could suffice.

[atmenterprises]

I can take good pictures with nothing in the T adapter, but when I put an eyepiece into the tube, there isn't enough space in the camera to re-attach the T adapter. Has anyone else had this problem & solved it?

I am using a Nexstar 6SE with a Canon EOS 550D.

Thanks in advance, Chris.

I've had that problem (550D user here but this was when connecting to a dob). The 25mm Plossl supplied with my scope wouldn't fit because it was too long. But I had a 10mm Plossl that was short enough that I could put it in the tube and still connect everything back into my camera.

Don't really have a solution for you except to find a shorter eyepiece. This was more of an empathetic response to let you know I had the same problem.