All camera screens are an approximation, so what you see on them is only a guide. You can change the brightness of the K20D screen but I'm not sure about the colour balance or hue. Check the manual to see what's in the menus.

If the graphs seem the wrong way round, it's been known before now for exactly that to have happened. It happens in magazines as well.

As gartmore said, infra red light focuses at a different point to the visible sepctrum and lenses are not usually corrected for this. The point of focus changes and old manual focus lenses have an IR mark to move the lens to after focusing.

As IR photography needs a very measured approach, usually on a tripod, then I'd suggest the purchase of some inexpensive manual focus lenses. Focus, move to the IR mark, put the IR filter on and expose the image, a slow process but it will work.

http://www.srbfilm.co.uk/ is the link for all thing Adapter!

There are all sorts of bird watching scopes other than Nikon, in fact I see quite a few Leica ones about in particular.

You probably need some sort of eyepiece adapter and the place to find adapters of all kinds is a company called SRB. (Not SRS!) If needs be they can make you virtually any adapter that you can imagine, but a Pentax K adapter for your purposes will probably be "off the shelf".

Telescope adapters are also used widely by astonomers. There are also microscope adapters.

I think I'm right in thinking that the standard diameter for these items is 25mm.

Yes of course. I did my own tests for my own purposes and if you do the same you will find out if, in your hands, there's a significant difference.

My conclusion was that the 18-55mm is very good, but the 16-45mm has the edge when making large exhibition prints. It is also better when used wide open. When I say better I mean in ano overall sense, the balance of optical properties, not just MTF values.

Orwell's conclusion was that eventually we'll love Big Brother. It will save us from thinking for ourselves.

The problem with film cameras was that if left for a while the film would kink where it passed over the rollers, so the first frame or two would be out of critical focus.

Things improved dramatically as camera design became more sophisticated and these problems were addressed by looking again at the film path through the camera.

Old 35mm cassettes also caused film kinking where the film left the canister. Later design modifications made this exit path tangential to the wound film.

Rolleiflexes and other TLRs also suffer from this problem, because of the complex film path.

The good old days never existed!

Telephoto lenses can often disappoint if higher shutter speeds are not employed. Camera shake becomes a major factor over 150mm or so.

The 50-200mm should be as sharp as your 18-55mm. The 55-300mm is a better lens, but in ways other than just sharpness. The 18-250mm is just as sharp as all the otheres mentioned.

Sharpness is crispness, the appearance of being sharply in focus. Resolution is the ability to resolve (delineate) very fine detail and is not the same thing as sharpness. A high contrast lens of low resolution will appear sharper than a low contrast lens of high resolution. This is one reason why Japanese lenses ousted German ones in the 1950s and 1960s.