How much does fungus effect the images? Check this out!

As i often buy fungus infested lenses as fixer-uppers i just thought i'd show just how much (or how little!)effect fungus has on the actual images.
Of course most lenses have only tiny traces of fungus -not the large amounts this lens has ,so it's quite an interesting example.
One thing i should say though -wide angle lenses do tend to show effects from optical flaws more than tele lenses such as this one.Any flaws on the front element of a superwide lens may show slightly ,simply because they are less out of focus than with tele lenses

Here is the shot of the lens with it's fungus infested second element.The front element has a large patch as well.It's all not QUITE as bad as it looks here -it shows so well because i've got strong light shining on it.

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Thanks, that's very interesting. The moon shot is very sharp.

Do you ultimately disassemble the lenses and clean them? How do you get rid of the fungus? Ever have to replace parts?

Your example reminds me that lenses don't have to be perfectly clean to get great images. My wife was a wedding photographer for about a dozen years and I was always shocked at how dirty she let her gear (Nikon)get. But she always got good results. It always seemed her only concern before a wedding was batteries.

Dude, that is COURAGE... putting a fungus infested lens on a digital camera and risking contamination! But I commend you for doing this for all of us. I'm surprised how little impact it has.

Looks like a nice lens too, 500/4.5 Pentax M42? Bet you got a discount for it!

PS: Just checked up on the specs of the lens. What a beast.. 3.37kg, demands a tripod that's for sure. How much did you pay for yours?

So it should be pretty good once you have cleaned it.
Makes worrying about a single speck of dust look a llittle silly

Haha,the fungus can't get to the camera from there, wouldn't do any damage if it did....and fungus spores are all around us anyway

Some lenses are easily damaged by fungus,some not so much.So far i've had very good luck with any pentax lenses which is why i took a risk on this one.The type of multicoating pentax used on their old lenses seems to be resistant to fungus damage.
I still haven't managed to disassemble this one yet,one of the threads is very tight.Basically one has to have access to the lens surface.From there it's a simple matter of cleaning it off with normal lens cleaning products

Interesting there...looks like a sharp picture still. And it'll perhaps be even sharper when the fungus is gone. I'm seeing splotches of red on the moon...possibly CA caused by fungus?

Ron,

Would you attempt disassembling a IS or VR lens ?

Thanks for the informative post.

fWord wrote in post #2119156
.... I'm seeing splotches of red on the moon...possibly CA caused by fungus?

Not in this case but fungus can indeed give colour cast effects.
That red fringing is caused by the lens itself,it's not fully apochromatically corrected so gives red or green fringing in the highlights (depending on wether they are in front of or behind the focus point i've noticed)
Oddly i've never once seen purple fringing when using these lenses on digital cameras,just the red/green type

shaunknee wrote in post #2119173
Ron,

Would you attempt disassembling a IS or VR lens ?

Thanks for the informative post.

Er....if i had to,lol.
To be honest i probably wouldn't buy an IS lens with fungus unless it was super cheap.I've seen none so far.

Has your IS lens got some fungus? I've seen at least one such lens taken apart on the net.The IS parts tend to be in modules so are not that difficult to deal with (....but don't quote me on that!)

ron chappel wrote in post #2119178
Not in this case but fungus can indeed give colour cast effects.
That red fringing is caused by the lens itself,it's not fully apochromatically corrected so gives red or green fringing in the highlights (depending on wether they are in front of or behind the focus point i've noticed)
Oddly i've never once seen purple fringing when using these lenses on digital cameras,just the red/green type

I see...so that's why the moon was giving off all those colors. CA comes in different colors, if I'm not mistaken, so the red/ green that you've seen while using the lens on a digicam might actually be CA. In some lenses known to be prone to CA, such as the 18-55mm kit lens or the 17-85mm, I've seen anything from purple down to ruby-red CA.

Nice post Ron - yesterday I posted a similar experience in a thread titled "17-40L scratch!", showing that scratched on the front element don't affect the image. So between us, we've shown that all of the glass in a camera lens is dispensable!


D

ron chappel wrote in post #2119193
I've seen at least one such lens taken apart on the net.

Probabely here

huh? you mean that's not the Planet Fungus?

Nice to see a picture of a Southern Hemisphere moon !

Interesting also to see how pointless it is worrying about a few flecks of dust in a lens, or a few little scratches. Are filters fungus resistant?

That's the one Rene' !
Thanks for that link ,it's been ages since i've looked in on that.It's nice to see he finished the project

Steve are you asking wether filters can keep fungus out? If so the answer is no .Fungus spores get everywhere ,unless the lens manufacturer specifically sterilizes and seals the lens groups.Even then it's not very successfull judging by the sealed groups i see with fungus.
It's not one big horror story though,there is an absolute sure fire way to completely eliminate fungus problems -just store the lens at humidity of less than 75%