I'm not sure if I'm asking a stupid question or not, so here goes.

When I take a close-up picture (6 feet or nearer) with my SL the photos they invariably aren't in focus the way I thought I focused it. It's usually a little bit out. At first I thought it might be to do with me needing new glasses. So I got a nice new pair, new prescription, nice new Kodak lenses with a very high refractive index.

So today I take some photos and they're a little bit out of focus. As an example, I shot a group of bottles from a range of 4 feet, focused on the centre bottle but the bottle behind it was the sharper, and before anyone asks I do know how to focus and it's never been a problem until a few months ago.

Is it possible for an SL (or any SLR camera) to become out of focus? What might be wrong? I can't see any fault or damage, I've always looked after my SL and despite its 32 years (on 14-1-2002) it looks perfect just very minor wear on the body.

My only thought is that the prism housing must be perfectly placed with the focal plane to be sharp, can they become slightly wrong?

I hope I've made sense and I desperately hope one of you lovely people can tell me whats wrong.

Thanks in advance

-- Philip Woodcock (phil@pushbar.demon.co.uk), December 13, 2001

Answers

The focusing screen has to be at the same virtual distance (after the light bounces off the mirror)as the film plane, and at exactly 90 degrees to it. If it has somehow shifted or the screen warped, that could account for the problem. I've changed screens on some cameras with non-interchangeable focusing screens (like the Hasselblad 500C and Pentax 67)and there are adjustments at the 4 corners to collimate the screens. I've never strip-searched an SL but I would be surprised if it didn't have a similar setup, and the screws might have loosened. This is guesswork. Best to take or send it to a repair shop for a checkup.

-- Jay (infinitydt@aol.com), December 13, 2001.

It's possible that something is loose, either the viewscreen or mirror. I had a similar problem with my first SL. The focus shifted when I changed from horizontal orientation to vertical. This should be simple for a qualified technician to repair.

-- Douglas Herr (telyt@earthlink.net), December 13, 2001.

The same happened to me. In my case it was my eyes/astigmatism/age.Just thought I'd pass that along.

-- peter mcdonough (31416@mediaone.net), December 13, 2001.