markwilliam1

I was shocked when I took a look inside my Minolta AF 100 macro lens! The most beautiful lens I own. Dust! Everywhere! The lens takes Gorgeous pictures with no evidence of dust. Knowledgeable Hoggers how does this work and how does dust enter a fixed focal lens?

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

S_ _ t happens. Especially to a lens that has seen some years. But fear not, a little dust should not effect the final result.

Blurryeyed Loc: NC Mountains.

It is more of an irritant than a real problem, like you said, it takes gorgeous pics. I have seen dust in new lenses, but if the front of your macro lens moves in and out to achieve close focus this may be a bigger problem for you than for folks who use macro lenses that internally focus.

DanCulleton

The dust focuses out.

rond-photography Loc: Connecticut

I bought a lens on E-bay that had a small spider (dead) inside. It was a film lens, Olympus 50/1.4 and cheap, plus I did not notice it right away. Googled "stuff inside a lens" and lived with it. It didn't seem to be noticeable in the photos. Eventually I disassembled it and cleaned it. Not noticeably better. As you say, it focuses out.

olemikey Loc: 6 mile creek, Spacecoast Florida

Dust is much preferred to fungus/mold!

markwilliam1

Very True!

IDguy Loc: Idaho

You might lose contrast if there is too much.

amfoto1 Loc: San Jose, Calif. USA

Without seeing the lens ourselves, it's impossible to give a very useful opinion...

"Dust! Everywhere!" inside a lens could mean a half dozen specks... or hundreds or thousands of them.

Lenses are NOT built in "clean rooms" and typically aren't particularly well sealed against dust getting inside.

Some dust inside is common... As are other "imperfections". In fact, some optical glass has tiny bubbles (my Canon 100mm macro has one or two). A lot of people actually think those bubbles are sign of extremely high quality glass and seek out lenses with it!

In general, it doesn't matter. It takes something really large.... or a whole heck of a lot of small specks... before there's any effect at all on image quality.

Be sure it's dust and NOT fungus. If it's fungus, the lens urgently needs to be cleaned but may already be ruined. Some fungus etches glass or the coatings on it. Fungus usually looks like spider webs or a the roots of a plant growing inside a lens. But there are many different varieties of it. Using a lens with fungus in your kit can "infect" other lenses or the camera itself.

If in doubt, take the lens to a camera repairer and have them look at it. They can tell you if it's a lot... or just normal.

I don't know about the Minolta 100mm macro, but some lenses tend to accumulate more dust than others. For example, the original Canon EF-S 17-55mm f/2.8 IS USM lens was known to gather dust under it's front element... probably something to do with how the lens "breathed" during use. There were a lot of concerned postings about it, the first few years (intro'd in 2006). Cleaning it was relatively easy (only the front group needed to be removed, just a few screws)... It used to be pretty common, but apparently Canon made some changes because it's been years since I've read or heard of any "dust" problems with the lens.

markwilliam1

Thanks no fungus just dust.

rook2c4 Loc: Philadelphia, PA USA

But only if the shop owner is a personal friend you can fully trust to give you an honest assessment. It would be a shame to spend money on an unnecessary service.

nadelewitz Loc: Ithaca NY

Internal dust is part of the aging process. Internal dust or even mold/fungus does not show up distinctly in the finder or on images, because it is far from the focal plane. What it CAN do is affect contrast & sharpness by scattering light. Whether it is noticeable/objectionable to you is the question.

markwilliam1

Thanks! Focal plane. Now I understand.

aellman Loc: Boston MA

If you don't see it on the print, don't worry about it.