I suspect you zoomed for various exposures, and the aperture will change as you zoom unless the lens is a constant aperture design.

By all means you can suggest a refinement of the term, but how many people have seen your comments, and how many all over the world are using the term bokeh in the aesthetic sense?

I'm pretty sure now that if I talk to a group of photographers about bokeh then they will be expecting me to be discussing the aesthetic qualities of the out of focus areas in an image.

But things can change. As an example, in the 1940s and 1950s you will find photographic writers quite happily calling what we now know as depth of field by the term depth of focus.

Since then it has been drummed into one and all that depth of field refers to how much in the scene is within the boundaries of acceptable sharpness, whilst depth of focus refers to how much leeway there is in placing the film plane or sensor in the area where the lens focuses that image.

So by all means promote the scientific definition you suggest, but I suspect you will have a hard battle to persuade thw world that bokeh is anything else but the aesthetic.

This isn't an argument, it's a discussion that is slowly bringing out the information we need.

Although I suppose technically, as we might say, "So your argument is then....." then we all present our argument for a particular point.

Perhaps I should say it's not a confrontational argument, which is something else altogether and not a good thing.

Photo-Optix is a name I recognise, but I can't recall if it was a franchise.

When the new carpet is laid tomorrow and all the stuff moved back I'll be able to get at the magazines that would throw some light on that. At the moment the only free space is my computer.

Priorities...

That's OK, Stefan, we have to remember there is a wide range of ages on this forum.

I think that would be a bit too draconian, even if it were technically possible.

Proper questions from prospective buyers could assist all interested parties. What we don't want are uninterested parties clogging up the process with irrelevant or unhelpful comments.

Sorry Stefan, that was one step too far from the path.....

Neither of these things is the "whole point" of an SLR. They are both features of most SLRs and these plus many other things make up the raison d'etre for the SLR.

It is very rare that one feature of anything is the whole point of it!

Boof? Truly wonderful!

Martin, I'm very patient as long as things happen immediately...which is one reason that I like digital photography so much!