[Marc Sabatella]

what this one indication of use compare with 1.7 : '' wide-angle prime 28mm 1:2.8 ''

As I said above, "i definitely recommend you do a search on the terms aperture, shutter speed, and ISO to learn how these relate and why aperture is important. Or get a book on photography." I'll add, I recommend you do that sooner rather than later, and that you add "focal length" to your search. Actually, search on that term separately; it doens't really have anything to do with the other three, but they are intimately related. Once you understand those terms, you're set.

will this lens ''Ricoh Rikenon P 50/1,7 ''(withaut P pin ) will work on my k-x ?

Once again, Google is your friend. Look up "Ricoh lens Pentax" and find the many, many references to lenses getting stuck on the camera because they have a different pin configuration. Once you've read through some of that, you'll be able to figure out if this particular lens will work or not. Hint: the phrase "without P pin" is a good thing in this context, but you will want to read up on the subject to know why.

[crossing]

I just found it a very cheap FA 50mm F1.4 , please tell me , i understand is fully automated - in that case what is the purpose of aperture ring present ?? Will I need to set it manually ?

[Rondec]

The FA 50 has an "A" setting on the aperture ring which allows the camera to set the aperture and you don't have to change it on the ring. The aperture ring would let you use this lens on an older camera that didn't have that capability or, to use it with macro extension tubes that don't allow the camera to set it.

Anyway, the FA 50 is a great lens, go for it.

[Alfisti]

Anyone taking bets we get a thread because of 'blurry pictures' and it's just a DOF thing?

[Ex Finn.]

Chances are high.

Cheers, Mike.