Thanks for this. Can't say I'm surprised. I'll look into getting it fixed. I'd taken some shots of the moon before it bust, and one of them had come out quite well. Realising the lens had bust spoilt my feeling of triumph, it has to be said.

It's been a fab lens... and I was looking forward to it remaining so, especially as with the K10D's anti-shake I can now hand-hold the thing even in not terribly bright light.

Any recommendations as to repairers?

Calamity has struck

My slow but still useful A-Series Sigma 400mm F5.6 has broken after years of faithful service. I was taking pics of the moon with it, and noticed that the aperture hadn't opened up again after the shutter closed.

I didn't bash it - it seemed to happen quite spontaneously.

On inspection, one of the iris blades seems to be swinging loose, rather than opening and closing as you move the lever at the bayonet end. So the shape of the aperture is unpredictable, and sometimes it jams the mechanism.

Is this repairable? Expensively? Would I be better off looking for another one on eBay? I hate to think of chucking it out.

TIA

Before my 400mm lens broke, I took this shot the other night:

http://www.ephotozine.com/gallery/showlargepic.cfm?photoid=808104&start=0

Look closely at the top and bottom edges of the moon; there's a green and red tinge respectively. They're a lot more obvious on the bigger version of the file that I resized for the gallery.

Can anyone shed any light on the origin of these tinges?

This style of screen is what I've been used to for years (Super A and ME Super), and initially I missed it on the K10D.

However, with a slow long lens, it can be very dark, and getting anything but a black splodge in the middle is extremely sensitive to precise eye positioning. Sometimes it took longer to get my eye in the right place than it did to focus.

I think the plainer screen that comes with a stock K10D is ultimately going to be better for me. I'm already a lot better at seeing when it's sharp, and I reckon I'm nearly as fast at MF now, and will become faster, especially, as I say, with long slow lenses.

Yep, definitely set to A.

Spot on guys, thanks very much.

All is now clear, and I've got it to fire in AF-S mode several times. Catching it with the AF indicator on can be tricky, so I'll probably leave it in MF with my A lenses.

I thought my K10D was faulty the other day, when I took the AF 18-55 off the front and replaced it with one of my A-series lenses.

It was only when I switched from Auto to Manual focus that the shutter would fire.

It's reproducible with other A lenses (both Pentax and Sigma) - if it's in AF mode it won't fire. Even set to A (and FWIW with the "Use Aperture ring, shutter release permitted" option in the custom menu).

I'm guessing this behaviour is by design, but I can't find it documented anywhere.

Have I missed a menu option to override this anywhere?

This is the sort of thing I had in mind.

Which one did you use? How did you deal with dust?

I've found some ads for the Nikon Coolscan V ED - at about £450 it's quite pricey, but if it's as good as the brochure (http://www.nikonusa.com/fileuploads/pdfs/2004_coolscan.pdf) says I'd probably be prepared to find the money - especially since I'd probably end up scanning my family's negs too, and I expect they'd chip in.

Has anyone used one?

It's a nice idea, and one I hadn't thought of (duh!), but we're talking 6000 frames here!! I have no idea what most of them look like anymore, and I want to capture them all.

I have an album full of negatives (strips of 4-6), taken over the last 20-odd years. The ex-wife took the prints as part of the split, and I'd like to scan the negs, cos there are a lot of memories in there.

Probably 200 rolls, so maybe 6000 frames.

I tried scanning a few strips with my (now quite old) Epson Perfection 1640SU - the resolution was acceptable but the dust that the negs inevitably acquired drove me nuts, and the project got put on hold.

Can anyone recommend a device that removes dust as it takes the strip in to scan? One or two of the newer Epson flatbed scanners seem to have motorised neg strip transports, but I'm wondering if a dedicated negative scanner would be better.

If dust-free scanning isn't possible, I'd appreciate ideas about software too... I don't want to have to manually edit the dust spots off 6000 frames - I want the quality to be reasonable straight off the scan.

TIA.