Dust Bunnies lens crazing

[thegrump]

I was just informed by AM that I had dust bunnies. On cleaning and close inspection of my lens, I noticed one of the internal lenses looked like it had grazing on it. There is also a small segment on the inside of the outer lens. What does this mean.

[I @ M]

The "dust bunnies" that Am was referring to are small particles of dust or lubricant on the filter that covers the sensor in the camera .​ Any dust or marks that you see in a lens may or may not impact on image quality depending on the severity of said dust or marks. Generally marks or dust towards the front elements of a lens will never be seen in an image and it takes a fair amount of dust, fungus or scratches on the more rearward lens elements before you have issues with image quality. If you are worried about those deposits or marks in the lens, have it examined by a service company and likewise, removing dust from the sensor filter can be done by a service company or by your self when you have learned the relatively simple process involved to clean a sensor.

[ameerat42]

TG. Can you point me to this post? Definitely get your lenses looked at (cheaply, of course, like at a local photo store).
If you can, post some pictures of the offending marks on your lens. It would involve a bit of close-up work, but you could try.
Am.

[thegrump]

any clue on the lens. Here is a shot of white paper OOF f11. to see if anyone can spot anything.

DSC_2245a.jpg

[ameerat42]

Nope! That's for checking your sensor. That has a few blemishes that you can see with an
"Auto Levels" adjustment, but for just about everything they shouldn't matter.

For your lens you need to photograph the surfaces. Open the aperture to maximum and put a macro
(you've started macro haven't you?) lens on and focus on the different surfaces that have the blemishes.

[thegrump]

am...Not sure if this is what you meant, but, set the camera to macro, f4.


DSC_2250a.jpg

[ameerat42]

Basically, just take a photo of the surfaces of your crook lens using macro gear. Just like any close-up object.
The trick is to get the blemish to show up. You might need to have a brightish background. OK, do you have a webcam,
camera phone...? Do something like below.

Back of lens (roughly with smartphone camera).
DSC_0251c.jpg

[thegrump]

Ok.. I might have to wait until daylight. Thanks

[thegrump]

It looks worse than it is, with the light, and being out of focus, but still is it an optic or something more sinister.

DSC_2252a.jpgDSC_2254a.jpg

[ameerat42]

Yep. Eventually you'll get light scattering through that as it gets worse. Does it respond to any cleaning?

I would still use it though. And which lens is it, the one you recently bought?

[thegrump]

It is the lens I just bought, 70-300. It was second hand and pretty cheap. Now I know why. I will try to get my money back. HA HA. What is it ?. Can I disassemble the lens and try and clean it ?

[davidd]

It looks like a fungus. Keep that lens away from your other ones, it can spread.

[mpb]

I would still use it though. And which lens is it, the one you recently bought?

I personally would not use it. You run the risk of the spores getting into your camera and transferred to another lens, especially if its a zoom lens.
If it looks worse than those photos, I would say its a pretty back case of fungus.

I don't suppose there is a good case of fungus on a lens, only on the BBQ with a nice piece of fillet steak.

[ameerat42]

Mark, David. This is the coating surface that's crazing, not spores from a fungus.

TG. To be sure, take it to someone reputable - got a local photographer handy? - to give it an "eyeball".

Or, take it with you to one of the meets and let some others have a good look at it.

[arthurking83]

Mark, David. This is the coating surface that's crazing, not spores from a fungus.

TG. To be sure, take it to someone reputable - got a local photographer handy? - to give it an "eyeball".

Or, take it with you to one of the meets and let some others have a good look at it.

I think that's definitely fungus. Lens isn't worth cleaning, as it's value is less than the cleaning cost.
Like David said important to keep it away from your other lenses.

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[arthurking83]

But, this has nothing to do with the dust bunnies that Am referred too in the other post.
It's high on impossible to get anything remotely captured in an exposure from within the lens.
Maybe if you had enough extension tubes... But other than that, remote!

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[thegrump]

I could take it to TEDS they are local and handy.

[Cage]

That is very definitely fungus !

I bought some used lens years ago from Queensland, the home of lens fungus.

A couple were quite good lens so I tried the UV treatment. You pick a nice sunny day with a high Slip, Slop, Slap reading, and put the lens in the sun so that direct sunlight gets onto the glass for an hour or so. It wont remove the fungus but it sure kills it and stops it getting any bigger. This wont kill spores hiding in the lens barrel away from the lens glass.

It is almost impossible to remove as some fungus actually eats into the lens coating.

Definitely isolate the lens from your other gear, and if you do use it, be aware, as Mark said above, that the spores could get into your camera and spread to your other lens.

Personally, I'd recycle it, and write the loss off as part of the learning curve.

Be very, very wary of buying any camera lens from Qld, NT and the northern half of WA.

[ameerat42]

TG. I could well be wrong. Be cautious with it. Get it checked.
Am.

[arthurking83]

....

Personally, I'd recycle it, and write the loss off as part of the learning curve ......

This is the best post in this thread so far .. but with a bit of explanation as to why.

One thing I've learned over the years, is that it never hurts to know more about something that to know less about that something.

Take lenses for example, I'm assuming that TG doesnt' know much about the inner workings of a lens(as most folks don't), nor how to pull one apart(but not so much to "tiny bits" ) .. and this situations now presents itself as a great opportunity to learn.
The lens is basically junk now .. as already said(and it can't be stressed too highly here) .. do your best to keep it away from the other gear whilst stored.
During the day tho, there isn't all that much of a chance for the fungi spores to really move about too much(but it's possible). So you could still use the lens on the odd occasion, but try to keep it on the camera for a short a time as you can(ie. don't pack the camera away with this lens attached!!!!)

So the learning process Cage mentioned could be .. pull it apart, try to clean it yerself try to get it back together again and see what happens.
Personally I wouldn't sell it(a personal philosophy) .. so it's really a paperweight now .. but a teaching aide type of paperweight, I guess!

Note that IF(big IFF here) you do try to disassemble the lens, that the screws on the rear mount are NOT philips head screws no matter how identical they look.
The actual head type is called JIS(Japanese Indsutrial Standard or soemthing) .. is a particular Japanese design.
Philips screws appear to slot in nicely, but this is only an illusion. There's a 101% likelyhood that if you use a well fitting philips driver it will slightly damage the head on the screw.
Those drivers can be had on ebay and suchlike .. but pretty much impossible to get at any local shops here in Aus(that I've tried) .. and I've tried some fairly specialised screw/tool shops they hadn't even heard of JIS!

Anyhow .. if this were mine(ie. I was in your situation!) .. the lens has finally revealed it's usefulness and the fun has just only begun!