Canon and lens not focusing to points

[PeterEde (Peter)]

I've a problem. It never used to do it but last night I mounted my 60D with 100mm Macro and tried to focus. All I got was ellipses. I could not get it to sharp focus. No filters, tried various stops.
I tried my 100-400 and the same issue. It never did it before.

Thoughts?

[skysurfer]

Was the AF on ?
And were you taking the stars ? In that case the AF will not work as it is too dark. Current generation of cameras cannot autofocus in the dark, so switch off the AF and focus manually using the optical viewfiinder.

[PeterEde (Peter)]

Originally Posted by skysurfer

Was the AF on ?
And were you taking the stars ? In that case the AF will not work as it is too dark. Current generation of cameras cannot autofocus in the dark, so switch off the AF and focus manually using the optical viewfiinder.

AF was off. I was manual focusing using live view. I've used it before. I've taken widefield before without this problem.

I'll put a lens on my 40D tonight and see how that goes

[Marios (Marios)]

Originally Posted by PeterEde

AF was off. I was manual focusing using live view. I've used it before. I've taken widefield before without this problem.

I'll put a lens on my 40D tonight and see how that goes

Be sure to turn off Image stabilizer as this can also work against you..

[PeterEde (Peter)]

No IS on the 100mm not sure if it was on or not on the 100-400.
I just don't get why this issue has arisen. I've used it before for WF without issue

[raymo]

The chances of both lenses getting the same problem at the same time are vanishingly small, and connection camera/ lens problems wouldn't cause
ellipses, so very high likelihood the problem is in the camera. You can eliminate the lenses easily by seeing if the camera will focus when the body is
held up to a scope focuser, and the focuser adjusted. Easier still if you have a T-ring to attach the camera to the scope properly. I just had an
improbable thought: the diopter adjuster on the viewfinder hasn't got accidently moved a long way from it's normal setting by any chance. If you have
some astigmatism, this could cause ellipses.
raymo

[PeterEde (Peter)]

the camera focuses fine using the telescope via a T adapter.
Maybe I need to clean the lens interface

[raymo]

Definitely worth a try.
raymo

[REVEREND (Raymond)]

I had a similar problem . I gave the lens and camera contacts a clean with isopropyl and it solved the problem
Cheers Reverend.