Reducing an Atik 314L+ for use in C8 SCT

[gustavo_sanchez]

Hello to all,

I tried searching around in the forums, but I could not find a good answer for this:

How good is a 0.5x 1.25" reducer for use in a C8 and Atik 314L+, in comparison to the normal 0.63x SCT reducer? The problem arises from the fact that I like to use a flip mirror for the CCD, and the length of the imaging train using the flip mirror is about 140mm, much longer than the recommended reducer-to-sensor distance of the 0.63x reducer (about 84mm for the Antares 0.63x SCT reducer). On the other hand, since the 0.5x 1.25" reducer sits right in the CCD nosepiece, I could use it with the flip mirror, but I don't know how it would affect the image. What do you recommend?

I hope I am explaining myself correctly; if not, please let me know.

Thanks!

[Merlin66]

IMHO there's no comparison!

The original SCT reducer was designed for that purpose...

the x0.5 eyepiece reducer was an "aid' for webcams... not in the same league.

[red dwalf]

there is also a 3.3 reducer you can get for SCT scopes, not much good for visual but can was designed for ccd imaging

[Merlin66]

Correction: It was designed for webcam sized sensors...not full frame CCD's.

[Zakalwe]

Correction: It was designed for webcam sized sensors...not full frame CCD's.

The 314L is a long way away from being a full frame sensor though.

[Merlin66]

A webcam chip is 2.8 x 3.7mm - an ATiK 314L is 6.6 x 8.8mm - a very big difference!

[Zakalwe]

A webcam chip is 2.8 x 3.7mm - an ATiK 314L is 6.6 x 8.8mm - a very big difference!

Agreed.

But a "full frame" is 36×24 mm.

Has anyone ever gotten a decent result with the 3.3 focal reducers...I don't think that I have ever heard of anyone praising them.

[JamesF]

For the OP's information, my understanding is that these reducers produce a curved image field, so if the sensor you're using is too large it isn't possible to get it all in focus at once.

James

[Tim]

try and use the 0.63 reducer if you can.

If the spacing isn't optimal, it isn't critical, it just affects the f-ratio and the flatness, but i have brought a 0.63 reducer down to a 0.45 in an SCT on a chip same size as the 314 without major issues.

There's a link somewhere on the Celestron site about alternative spacings but I can't seem to find it now.

Cheers

Tim