There is no problem from the Ad on PU either. Perhaps your software is being over-zealous?

I've just tried accessing SRS and there was no problem.

You've answered the question, basically the EXIF in PU isn't working properly. IT are aware of this and it's on the list of Things to Do, but for some reason it's never been successfully solved. There may be technical issues, or maybe other more urgent things have kept leapfrogging the issue to claim their attention.

The usual relevant figures are the f/stop used to calculate exposure with still cameras and the T/stop which measures the actual transmission of light for video/film movies.

Think of an uncoated and a multicoated lens. The lenses may well have the same physical aperture and the same nominal f/stop, but the muticoated lens will transmit a lot more light and therefore have a different T/stop value. The depth of field will still be determined by the f/stop.

Uncoated glass loses quite a bit of light, about 5% per surface. Multicoating takes that down to 0.1 - 0.2 per cent per surface, so a very dramatic difference. This was originally noticed when very old uncoated lenses that acquired a natural "bloom" had less flare than a new lens.

I've only had a brief look at the DPR thread, but it's full of misconceptions from what I can see, likely to confuse rather than enlighten.

I need to look at the EXIF in detail and work out what it does mean, but I wonder whether or not it's simply referring to set and actual apertures on variable aperture zoom lenses.

This is still available. One pristine K-5 body, boxed with accessories, 17,690 actuations.

The lens has a good reputation. The review in Photo Technique in the 1970s was positively glowing.

Nothing wrong with that at all. I think you should just do what you feel comfortable with.

The only counter argument I have to that is that sometimes it's good to stretch ourselves outside our "comfort zone". This can lead to improvement and honinbg of skills, or discovery of skills that we didn't know we had.

An exposure meter will tell us that the ASA/ISO figures are just as applicable to film as to digital in terms of setting the exposure. So we could use a Weston Master meter (selenium cell) to gauge exposure for a new K-1.

As regards grain/noise there are two totally different worlds. In black and white, ISO 400 film is grainy. In colour, likewise. On digital we can now expect to be able to use our cameras up to ISO 1600 with no problem, and I frequently and happily go up to ISO 3200.

However, given that my favourite black and white film was Kodak Tri-X (ISO 400) developed in FX-39, clearly I like sharp, crisp grain structure in an image. So when making monochrome images I sometimes Add Noise in Photoshop.

Messages stay in the outbox until the recipient opens them, then they become sent messages.

Messages that disappear usually do so because the sender has deleted them after they are sent but before they are read.

I've not had any particular problems with PMs, but if it keeps happening do please make a report.