astro imaging using radial SCT guider

[Mark at Beaufort]

I am thinking of buying the celestron radial (off axis) guilder to take astro photos through my SCT using my Canon 10D DSLR. If you focus the eyepiece side of the guider can I assume that the camera is in focus as well?

[SteveL]

If you focus the eyepiece side of the guider can I assume that the camera is in focus as well?

Sadly, nothing could be further from the truth

[Tim]

Well, there's a thing.

I have one of these gizmo's but havent really had the patience to test it properly.

The guy at David Hinds shop, not David himself, says that the trick is to get the camera focussed first, the old fashioned way, however you usually do it. Then, by dropping the eyepiece in the slot and adjusting how far you insert it (which is how you focus it anyway), you can get the two appropriate focal wotsits (plane, length? dunno) matched.

Next step is to mark the EP at that setting. Next time you should be able to drop that EP in first, use it for focussing (easier than camera) and then the camera should also be focussed.

I dunno if this is true, haven't had chance to test it, am just passing on what I have heard, but it seems to make sense. The celestron instructions dont mention it, apart from saying that you need to adjust the position of the EP in the holder to attain focus in line with the camera.

Of course, if you take pics with and without focal reducers etc, then each setting would need marking I guess.

Do you live nearby? (Coventry) You can come over and have a look if you like. (If you happen to be a leggy busty redhead with dreamy green eyes, then please dress as a man with a beard. I'm on my final warning........)

Cheers

TJ

[Mark at Beaufort]

Thanks TJ but sorry Coventry is not nearby and the other bad information for you is that I am not a leggy busty redhead with dreamy green eyes!!!!

Anyway the advice you have given seems logical so I might give it a go.

Thanks again and behave yourself

Mark