Ok thanks David. I'll give that a go and see if I can spot anything wrong with the images.

The only other lens I have is the 18-55 kit lens that came with my K-x, probably not the best comparison! Should be ok though. I can open the kit lens up a bit wider and get in close.

Am I best testing the 50mm at the widest aperture do you think?

Hi David

Thanks for the reply. The lens is a SMC Pentax-A 50mm F1.7 prime. Not sure of the age. It cost me £47.50 including postage.

I have taken a couple of shots with it but not in great light. I'll need to test it more properly in daylight.

The only thing is that I have never used a fast prime lens like this before so I am not sure what results to expect.

If the dust is bad will it be immediately obvious in photos? What kind of effect on the images would it have do you think?

Thanks for your help.

I just bought a second hand lens from the auction site and it was listed as being in "very good condition".

It has arrived and does look to be in a reasonable state externally but examining the inside it looks like there is a fair amount of dust.

I managed to take a photo which illustrates it fairly well:



What do you guys think? Will this affect image quality? Should I send it back?

I'm new to SLR so I don't know how much I need to worry about this kind of thing.

Very sorry. Good luck with the sale.

Were you also on the ebay auction this evening?

Sorry. Offer withdrawn.

Found a different one.

I will offer £45 inc postage.

Just missed a Buy It Now for that this morning.

Hi there,

Is the smc pentax-A 1:1.7 50mm still available?

Are you willing to sell it separately?