Is dust bad?

[DCB]

How much internal lens dust is to much?

Does it really make that much of a difference?

Thanks

Peace

 

[lynnb]

I have some dust specs in an I-61 and it doesn't seem to make any visible difference to the images. I would expect a lot might create some diffraction problems.

 

[Brian Legge]

There is a big difference between dust-to-the-point of-haze and single specs/strands on the front element.

this is what haze will do:

Now, I'm not saying the aestheic is subjectively bad or unusable but it does can have a large impact on images which may or may not be desirable.

 

[truefriendship]

It only seems to make a difference to the resale value

~Rif

 

[x-ray]

It only seems to make a difference to the resale value

~Rif

That's odd but I understand how enthusiasts think. A small amount of dust internally is no big deal. Even new lenses have some dust as as time goes on dust has a way of working itself inside almost every lens. On the front element it would have to be pretty dusty to be a problem. On the rear element it would have to be more than moderate dust to be a problem.

Odd thing, my 85 tilt shift lens has a tiny piece if internal dust that is in a location where it shows in the photo if stopped down more than three stops and becomes a problem. I'm going to have to get it cleaned I guess.

 

[kuuan]

so far I have not noticed any optical degradation caused by dust, nor by fungus, really. what i am weary about and what does degrades optical perfomance, causes blooming and hazy image, is milky / etched glass and faults on coating, specially if on the rear lens and more so if on a wide angle

 

[DCB]

It will definitely effect the resale value even though it does not make any difference.

Thanks

Peace

 

[Paul Jenkin]

I think I can remember reading somewhere that the nearer to the film plane dust, marks, etc are, the more likely they are to degrade the image. This might be the reason why dust on a sensor or a hair across the film gate can cause such disastrous results.

A couple of my lenses have tiny, almost un-noticeable specs of dust (which might actually just be on the front element) and they've never caused me any grief. I don't buy lenses with the thought of re-selling them but I must admit that I would pay a few £ extra to get a lens with clean(er) optics rather than saving a few £ by buying one with optics with which I'm not confident.