It's best not to get too complex and confused with this, but basically whatever is behind a lens (film, sensor, any size) that does not change the characteristics of the lens. A 50mm lens will always be a 50mm lens and have the DOF of a 50mm lens.

However, on 135 format 50mm is a standard lens. On APS-C it is a telephoto lens. To get the same field of view without moving the camera, we need a 35mm lens (approx) for the APS-C. The smaller the format, the greater the DOF for a given aperture. At the extreme, a Minox uses a 15mm lens as its standard and has the immense DOF that you would expect, even wide open. 10" x 8" plate cameras would have miniscule DOF.

Now if we move the camera things change. The perswpective changes for one thing. But let us suppose we fill the frame with a 50mm macro on our K-5. Now we put on a 100mm macro, but we have to move twice as far away to get all the subject in. However, the magnification remains the same and the DOF with the two lenses will be identical.

Hope that helps rather than confusing it further!

Moved to General Chat.

Thread tidied up and PMs sent where appropriate.

People's experiences with other marques are off-topic for this forum, please stick to Pentax-related subjects. Many thanks.

It's a fair comment that anyone entering the weekly competition should be prepared to have a go at setting and judging the nextr one.

I too can't see how uploading to the weekly competition could be any simpler. It makes the process quicker if the file size is reasonable, but that's the only thing to think about.

Linking into a forum is by necessity more complicated, but not too onerous if we follow the instructions.

It's only speculation, but perhaps it means current stocks are indeed dwindling and something new is imminent?

Anyway, we know the answer - pick up the telephone!

You could always hire a studio and some models and maybe some of your friends have girlfriends?

Otherwise, have a look around the various galleries here on PU, over on ePHOTOzine and anywhere else. Books on various subjects will also give plenty of ideas.

I shoot everything, as the mood takes. I often suggest choosing a project to get people started.

Try this: The project is Red. Shoot 12 pictures in 1 hour, all of which should contain something red. Then see how well you have done and post us some examples?

It strikes me that a WR lens will be an enormous advantage and increase the possibilities. I was at Whitby on Sunday and the camera and 18-135mm lens were saturated. They were much happier than I was.

The 18-55mm and 18-135mm WR lenses are both an excellent introduction and the price of either as a kit is better than buying a separate lens.

The Pentax 18-250mm is also excellent, but no WR and no QuickShift.

The best market for cameras and lenses is overseas. There isn't really much of a problem sending to Europe and even beyond, and the price will be much better than just sticking to the UK.

It depends why the lens has stuck, so the first question would be what lens exactly is it? Then the second is was there any particular event that might have caused it to stick?