Well you've discounted choice 1 so it's down to whether or not you want the 50-200mm or the 55-300mm to add to your standard zoom.

Both are excellent, the longer zoom perhaps slightly better performance-wise, but either would be entirely satisfactory.

Maybe you need to handle both and see what you think, but the longer zoom will be very handy if you ever decide to photograph wildlife.

It's all done in Photoshop, the original was shot at a Halloween Party on a humble Pentax T30 compact. It's a combination of Hue/Saturation, Diffuse Glow, Motion Blur, Levels....

The lines I left in rather than try to remove them and are actually part of a rather strange wall clock.

Here's my version of a Night Vision shot for Most Haunted. They never seem to catch the action quite like this:
[IMG]http://i240.photobucket.com/albums/ff250/johnriley1uk/033-Night-Vision-Most-Haunt.jpg[/IMG]

I read a lot.....

GPD cells are Gallium Arsenide Phosphate (GAsP) and are a variant of silicon cells (SPD) that are less sensitive to exposure errors from IR light.

They are also more expensive and therefore have largely been dropped.

As with any lens, it's important to know what it has been designed for.

The f1.2 has a very wide aperture to enable manual focusing in very low light. It also has superb control of coma distortion, so point light sources are well under control, more so than any other 50mm Pentax lens.

f1.2 DOF is very, very shallow, so close ups at open aperture are not really the intended use. The curvature of field would also preclude this, although in some circumstances this could be used to advantage.

Stopped down to a normal working aperture of f8 and beyond it behaves as well as any other 50mm for general subjects. Focusing will still be very, very precise though, or very, very tricky if you have problems with MF.

At ADAPS we have a much higher than usual percentage of Pentax users. There are equal numbers of Pentax, Nikon and Canon users, with a few using Sony, Olympus and Leica.

It's not something we normally notice or talk about.

It will be an education for them that's for sure.

And it would be a shame to miss the magic of seeing a black and white image appear on a piece of photographic paper for the very first time.

Seriously, any students will be the wrong age to have used any film SLR at all. I think we're now at the point where new, young photographers have always been digital in one way or another.

Mature students maybe, but not young ones.

Well they wouldn't would they. If they chaged to a Pentax DSLR then they wouldn't be on a Canon or Nikon forum, they'd be here....