Last night I resized the flange with a small saw.

First I unscrewed the flange to avoid any dust on the inside of the lens. Then it was easy going. (10 mins).

Second I checked for that famous pin to block my AF slot. Luckily it didn't had a pin.

I snapped the lens on my k10 - and it is now working - nicely.

Thanks all!

Thanks all - for replies and comments.

I found this thread on another site. Just to put it up here if anyone have similar problems.

Looks like Tyr's suggestin is the way to deal with it.

Cross my fingers now - I'm starting to trim the flange (I learn new things every day of my Dslr life )

http://forums.dpreview.com/forums/read.asp?forum=1036&message=19213773

Thanks Clarky...Where did you find this?

Could you post a link.

Sorry John - My english isnt to good - what is a flange?

Here are a few pictures I just made. The long tap seems to be the problem.

This is a picture of the bayonet. Can you see if its a Pentax fit? (picture from ebay)

I noticed the tap - is larger than my other lenses - and clearly pushes off the body - leaving a gap.

I got hold of a Vivitar 28-70 Macro lens 1:3.9-4.8 MC.

Im trying to get it on my K10D - but seems to be off some how. Just a tiny bit - like the mount is too high and wont get in deep enough.

On the mount it says P/K-A R-P/K.

It won't fit on my K10D - Should it? Or do I need an adapter of some kind.

Hope some of you can help me.

Well ya - better lenses.

Actually I'm quite pleased with the 75-300 but not so satisfied with the kit lens.

I ordered a Sigma 28-70 EX DG F2.8 to replace my kit lens. I think that will help a bit.

Really appreciate the time you guys used to reply my posts - thanks!

Ok - just to make sure I got it.

I can shoot F5.6 while he needs to do at least F2.8 to get the same result - because my shutter speed is better due to the shake reduction. He needs fast shutter speed to compensate for shake - while we can be slower with shake reduction...right?

How many steps in aperture?

Thanks guys - on the right track I see.

Regarding the aperture.

I was wondering about the difference is F-value on different lenses. My friend who was with me in the zoo took some pictures with his N****N D80 - using a sigma 70-200 F2.8 HSM EX DG....

Most of the time he used F2.8-3.5 and had some bright pictures...too bright in my opinion.

If we shoot with the same aperture - eg. F5.6 or so - would the images be similar regarding the light and DoF (same shutter and focal length) - or would his lens which is substantially wider be a better option than my FAJ 75 - 300?
(sorry for all these questions - trying to learn )

I sum it up to:
More experience with the camera - then I can move on to the post-processing.....

Thank you...

I'm just a bit fuzzed about how much you need to to think about in every picture

Experiments seems to be the only option - the Aperture is really tricky. I'm not sure when to use a large or a low one - except than just shooting the same shoot with different F-values. I figured the DoF is better with a high F-value - but my main problem is how to figure the exact value to the present light.

Do you measure the light or is it just experience that gives you an idea of which aperture you use?

Some of my other images or not super crisp - and I figured I used a too high f-value because i wanted a good DoF. Not enough light in the pictures to make the fur sharp on the animals. My lens might limit me as well

Thanks for any help - appreciated.