500mm is a focal lenght and a focal lenght is a measure of an optical system of how strongly it converges (focuses) or diverges (diffuses) light. A system with a shorter focal length has greater optical power than one with a long focal length.
It doesn't matter on what camera it is, it stays 500mm or are you saying that the camera can change the focal point of a lens

The only thing that change is the angle of view.
You can see it a bit like printing a photo, crop it for 50% and then print the photo on the same size of paper. If you compare them you will say that the crop photo has a greater magnification as the non cropped photo.

they calculated that if you want the normall image to look like the cropped image you need a lens that is 1.53 times longer, atleast that's whit Pentax.
To make it more complicated Canon use a smaller sensor so there crop is 1.6x and nikon a bit bigger with a crop of 1.5x

ps. Amin I didn't knew you've bought a DA* lens, how is it so far?
I'm still very busy but will send you the photoshop stuff this weekend

Sigma is also coming with a 18-250 lens but with HSM, so it will focus faster (tamron and pentax are rather slow) and you have manual focus without using the switch on the camera.

I almost never use the DA 18-250, only when I need to range.
Just not a lens for me

if you're 100% perfect you aren't 100% human since humans make mistakes so if you're 100% human you can't be 100% perfect you see.

Prieni,
I already said that I didn't see a difference before I did the test.
Although I compared some profiles to the chart I've printed and there really are some differnces.

Michal,
Both of them and the preview jpg that is fitted into the RAW also get those settings but your software can or do change those settings when you upload them. Atleast that's my understanding of the matter.

I don't know those software so I've no idea how they work.

Since some post here about RAW files and me being busy with them.
I was wondering which colour profile has the most correct colours.
There are ways to calibrate and make your own profile maybe some of you like to share them or is that really so difference to each camera?

Just for my curiosity, there is also a poll about what colour profile you use.

yes in a way, if your focus is off you get the same effect of course.
Since manual focus realise on you and what you see through the viewfinder there is always a chance to get a fault somewhere, nothing in this world is 100% perfect afterall certainly not humans.

No difference what so ever in the photos, didn't upload it since it would be a waste of time.

About what John?
I'm with Prieni on this since I don't see any diference between the files. Except that in DNG there is also the information JPG development settings.

These are the settings in your menu of the camera about saturation, sharpness and brightness. These are saved with the raw and are used as standard when opening the raw (I think).
You can also have the software set as a standard preset when opening a raw file.

ps. I''ve printed a test sheet, it's now drying

That ask for a test Shim.
will download a colour card and test it.
I will be the one to say what RAW they are

No RAW is compressed its just lossless to the highest degree.
The camera doesn't compress DNG as much as PEF so the files are twice as big but the amount information in them is the same. you can see it when zipping a file the amount of data stays the same but you can compress it to a high degree but takes more time or a small degree that goes much faster.

With the DP review the program makes the difference not the file, its like comparing Photoshop with Gimp.

If you read the article you see this link.
So nothing to do with the camera, only the way the software handels the file.

The sharpening is very differend, the sharpning you aplied with a raw converter isn't fixed and can be adjusted without any lost, just like the white balance.

Read this for some more understanding of the RAW files link