Thread: Impact of lens dirt & scratches on image quality

i came across this article as a link on an eBay listing (clearly the the seller was sick of "hazeless lens" obsessives returning stuff) ... anyway, might be of interest ...

Dirty lens article

PS

This one too ...

http://www.lensrentals.com/blog/2008...ment-scratches

as I understand it - buy lens with scratches on front element really cheap as they have no or very little effect on IQ, (for us humans!)

Paul, Arne today, (in the rain), if I can persuade my wife!!!!

Internal haze is "IMO" the worst offender to image quality. It can cause color shift and loss of sharpness.

I had a Summarit with internal haze, sent it out to be cleaned. Big difference in quality.

Cleaning marks on the front element cause the least impact.

I have a 90/2 Summicron with a fracture in the second element a few millimeters long. No real problem on the image unless in direct sunlight. Pixel-Peeping, you can find a minute effect.

i was counting myself as one of the obsessives Brian ... though the seller in question was not the one I had returned a lens to because of severe haze ...

Bill - take your 10x bins if you're going to the hide although today the rain will make visibility a bit of a 'mare down there

Great article and test, I will certainly consider "bargain" lenses with a bit more confidence. I am with Brian though, haze does have a big influence on the optical performance of a lens.

wow I never expected those results to be so good!

This has been around for ever. It is true though. I personally am not one of those people that need to go into a clean room to clean off their lenses. I use my shirt. The qualifier to this I'll add is isolated bits of dust and dirt don't degrade IQ that much. Lots of fine scratches, like on the coating really do though. It's all just foggy.

Originally Posted by lenshoarder

This has been around for ever.

well, since 2009 anyway, but I hadn't seen it before and thought perhaps others hadn't.

The lens of my Ansco Memar Pronto lens is so hazed up the photos look like something shot with a pinhole, has a very dreamy effect. This favorable result is probably not the norm but I had several people want to buy the camera because of it. Nope I haven't sold it :D

I have a problem with little black specs on my photos, but I suspect it is bits of stuff between the lens and the sensor. I find it quite hard to keep everything clean and clear.