What are these spots?


Mu-43 Regular
I got this Pentax M42 50 1.4 in today and, although it is in great shape, it has a bunch of tiny black spots in the lens. I've attached a picture and they show up blurred, but to the eye they look just like tiny black dots (kinda like small metal flakes or something similar). I've gotten a couple of these legacy lens and don't know a lot about them. This one came off Ebay.

Can somebody tell me if this is dust, fungus or something else? Thank you in advance for your help and sorry the picture isn't better.



Administrator Emeritus
Sometimes it's actually paint from inside the barrel, sometimes it's dust. Unless it's really a large spot, you probably won't notice it in your images....


Mu-43 All-Pro
It's probably some kind of dust. Oil drops seem less likely, but you might want to check the aperture blades for oil; if they are oily I'd return it straight away. AFAIK fungus doesn't show up as isolated spots. If the lens doesn't show haze or fungus I wouldn't worry about the spots, I've had many older lenses with some dust inside and it's inconsequential unless there's something like a layer of dust on one or more elements.


Mu-43 Regular
Thanks guys. It looks like little specs of paint. It kinda irritates me cause the guy said the glass was clean. It is other than these spots but they are pretty numerous. I don't see any oil on the aperture blades.

Ulfric M Douglas

Mu-43 Hall of Famer
It is almost certainly little specks of paint/metal. The seller may well have been truthful, as they can hide in the edges or threads and pop onto the lens when ... kicked about in a postie's bag ... or something.
Don't worry about them UNLESS you see a problem with the images it takes. (They are easily cleaned out of an old manual lens anyway)