T Piece and T mount camera adapters..

[jayjt29]

My 20D should be with me today, obviously aswell as normal photo's ill be dabbling in some very primative DSO's images.

Could someone explain the difference in using a 2" T mount camera adapter to a 1.25" one?

Am i also right in thinking that i need a T piece to initially connect the camera to the scope.

Thanks

Jay:D

[brantuk]

The 2" adaptor fits 2" eye pieces, the 1.25" one fits 1.25" eyepieces - it's that simple. You'll need a T-ring to attach the camera to, and the adaptors will thread onto that.

Here's some combinations fyi:

http://stargazerslounge.com/members/brantuk-albums-photography.html

Beware that some scopes and reducers/flatteners have direct T-ring connections - I think your 150P probably does. In which case you'll only need the T-ring and not the adaptors

[jayjt29]

Thanks bran, my scope has either a 2" or 1.25" eyepeice mounts, so i could have either was just wondering if there was any difference in the two sizes using a camera other than the filters etc will cost more for 2" as opposed to 1.25"

Jay

[brantuk]

Right - so your two inch adaptor presumably unscrews like mine to reveal a 1.25" T-thread?

Yes you'd save on filters (around £50 a time) using 1.25". I only have experience of webcams and dslr's - so maybe the 2" ones have implications when using the larger astro ccd's. Hopefully someone will comment on that for you.

I use my 2" T-adaptors for eyepiece projection mostly. I guess you get more light throughput when attaching 2" directly to scope

[jayjt29]

Think you have answered it, using the 2" will let more light in, but be more expensive.. Will check out what people usually use.

Thanks again

Jay

[Shibby]

Yeh, you might find that the 1.25" may illuminate all parts of the sensor, but you will get less vignetting at the edges with the 2" adapter.