Dust

Just bought a used lens, looked fine in the shop and got it home to find three dust specs on the inside of the lens. the condition of the lens was apparently mint.
My questions would be
- would I notice the dust in the pictures?
- how frequently do lens get dust inside of them. None of my other lenses have this issue?
- if it is not that common and this lens already has dust inside then is it more likely to get more dust inside?

I am thinking about taking the lens back but as i've never had dust inside a lens before thought i'd find out a bit more about it first.

Its quite common, normal in fact for zoom lenses to accumulate dust, zooming or even focusing on primes can suck air into the lens along with dust, it should have no adverse effect on you images.

Sealed lenses are less prone to it as they are...sealed

Without knowing what lens it is it would be hard to say any more.

its the pentax 60-250mm

The 60-250 is a sealed lens although it is still a zoom and could theoretically still pull some dust in, it depends how old it is, it's even possible there's some wear on the seals.

If you got it for a good price I would forget it, I don't own the 60-250 so can't offer anything else, no doubt there will be some 60-250 owners along with their expertise

Just ignore it i have an 18-250 with a couple of dust specks in and it makes no difference to the image

The best reassurance I can offer is this link: it helped banish my lens cleanliness OCD and allowed me see them for what they are - tools to be used, but not abused, and not treasures to be cleaned and polished endlessly

Jon

Ooops! link

Jon

The 60-250 is a sealed lens although it is still a zoom and could theoretically still pull some dust in, it depends how old it is, it's even possible there's some wear on the seals.