Fungus on a Beautiful Lens

[terry_scott]

I've just bought (eBay) a Pentax SP1000 with a 55mm f/2 SMC Takumar.

But the lens has a bit of fungus creeping in from one edge of the

front glass. How can I clean the stuff off?

 

The lens seems in great mechanical condition and cosmetically it's

good. Moreover, it's an 'F' type - so would give full-aperture

metering with a Spotmatic F or ES/ESII (I plan to add an F to my

collection one day). I'll know about its optical qualities when,

tomorrow, I process a test roll of Ilford Pan F.

 

Your wise words of wiz would be much appreciated, folks.

[nicolas_douez]

<p>A picture please ! There is fungus... and many phenomenas that look like

fungus, but are not fungus. Under a front lens... well, it's rare. But if it's it, you are something lucky as the front lens is not the hardest to remove.<br>

Even regarding the actual fungus, there are several types of fungus which are at

different levels regarding the possible medicine. <br>

Some folks here might be aware of that. <br>

With a picture (several pictures are preferred) it will be easier to at least

determine if it's actual fungus or not.</p>

<p>Anyway click <a href="http://cesarigd.club.fr/photo2.htm#fungus">here</a> for

more info (grasp, in French, I'm... I'm... I'm sorry).</p>

[conrad_hoffman]

First, you need access to the surface with the fungus. If it's outside, great. If inside, assume that the facing surface also needs to be cleaned. Windex or a 50/50 mix of ammonia and hydrogen peroxide have been recommended. Some also use cold cream, but I haven't tried that. If the fungus isn't well established, it should come off easily. If it's been there a while, it may have eaten away some coating or etched the glass. You won't know until you try to clean it. After cleaning, breath on the lens to fog it and look at the fog pattern. A perfect lens will have even fog. If you see swirls, your cleaning technique needs work. If you see the pattern from the fungus, either the surface is damaged, or all the fungus isn't gone yet. Don't do more damage trying to clean something that can't be cleaned than the original problem! Hopefully someone else can tell you how to get it apart, if that's necessary. Some lenses can be partially disassembled to reach the central area without removing individual elements. If you have to remove individual elements, be sure you have a good spanner. "The mark of a good repair person is that they leave no marks." Think of it like camping. When you leave the site, there should be no trace that you were there.

[jonathan_stark]

Why not just get another example? I think the 55mm f1.8 and f2.0 Takumars are pretty common, even the SMC versions. I've got a couple of 55's sitting around at home with gummed up diaphrams that aren't worth fixing. The last 55 I bought cost $10, and probably that much only because the dealer thought he had to charge at least something.

[nicolas_douez]

<p>Also read <a href="http://www.chem.helsinki.fi/~toomas/photo/fungus/">this</a>

!</p>

[terry_scott]

Thanks for your suggestions.

 

I'll post a couple of pictures over the weekend (here, it's late evening, Friday, right now). And yes, there is always the possibility of another lens - just seems a good idea to work on this one first.

[david_m]

I have a 55F1.8 SMC Takumar with unbelievable fungus. It looks really bad when you look thru the lens. However, the lens takes pictures as sharp as you could possibly want. The only thing is that there is slightly more flare when shooting into the sun. So I would not even worry about it.

[terry_scott]

Here's the foto of the fungus.

 

It looks like dust - but that's what it is not.<div></div>

[james_ogara1]

Terry I agree that you are probably fine. Also the coating on an older lens like that is not going to stand up to a lot of polishing.

[nicolas_douez]

Terry, it seems to be "usual" aerobe fungus because it has the typical look of fine filaments growing towards several directions and following a kind of anarchic way. So it might be removed once the front lens is taken apart - if the glass has not been etched yet.

 

The other form of fungus, anaerobe fungus, is the most aggressive one and looks more like a sole little white tree with branchs growing from the edge towards the lens center. Some nice examples can sometimes be seen on German 1940-1950's lenses for sale on auction at high prices on the main auction site...

 

Good luck with your Takumar.

[john_chambers]

I have to disagree with the comment that this lend probably isn't worth fixing. My opinion is that this is one of the great under-appreciated lens of the past and produces beautiful images. It has the same cross section as the more sought after 50/1.4.

 

Here's a link that will show you how to open it up for cleaning.

 

http://retina.topcities.com/pentax50mmf1.4.html

 

Also, Matt Denton on his website recommends cold cream for removing fungus.

 

Good luck with your lens.

[gary_turner1]

As far as cleaning off the fungus, this Pentax lens is a perfect candidate to practice on. A low cost, high quality lens. Really easy to access front lens element and not a difficult repair. Understandably some prefer not to tinker; in that case just pass it on to someone who will. Professional repair is certainly not worth considering as so many good ones are on the used market at very low cost. There's a lot of Internet sites via search engine that detail cleaning such lenses. Good luck!

[john_chambers]

Sorry for the bad URL. Here's a good one..

 

http://homepages.ihug.co.nz/~Srawhiti/pentax50mmf1.4.html

[kelly_flanigan1]

The fungus in the later stages creates an acid. This acid etches the glass; and creates micro potholes; divots; micro rivers; ie surface defects. All the magical chemicals can sometimes remove the fungus; but the damage is still there. The chemicals remove the fungus; or parts of it; but the damage is still there. The chemcials do NOT fix the surface defects. There seems to be a myth that fungus can magically be fixed with chemicals. In extremely bad cases; the entire surface is crazed looking; and contrast is radically dropped. Lenses that are used; see daylight; usually dont get fungus. To create fungus; get the lens dirty; then damp; then store it away in a leather case; in a dresser drawer; and wait a few years. :) Many cameras and lenses on Ebay that are "discovered" in Estate sales tend to have fungus problems. Brushing ones teeth one time in a decade may make them clean; but it doesnt remove the cavities.

[gary_turner1]

In my opinion fungus in a lens need not be considered the 'kiss of death'. Probably depends on the degree and duration. On relatively recent lenses from the 70's on up maybe the usual cure yields fully satisfactory results? I know I have bought several lenses with fungus that were dirt cheap. Why? Just to see if I could remove the fungus effectively. On some lenses the fungus appeared to literally melt away with not a whole lot of rubbing and visually I could not detect any residual damage (did not use a microscope). Obviously on a few real oldtimer lenses that were heavily infected the results left the noticeable tell-tale etchings. For a collectible shelf camera maybe that's still good enough? On a user camera I wonder if that cleaning will still yield still fine photos, even good enough for a perfectionist? In some respects lenses seem to be rather forgiving about scratches on front elements other than some flare potential. Scratches can also create a pleasant soft portrait effect. I'm sure there's a lot Leitz lenses still in use with frosted or cloudy front elements. Some individuals will still use an old Sonnar lens with a bit of separation. I know I have used several such premier brand lenses with assorted defects and the photos sure looked quite nice to my eye. Maybe the minute tell-tale marks from a thorough cleaning on the lesser infected lenses will actually have little or no negative impact on a photo? Maybe significant marks create some flare potential? Anyway, an interesting topic that I'm sure will illicit a lot of divergent opinions.

[red_buckner]

Some of my 1950s Voigtlander lenses suffered from fungus when I bought them. A little work by a repairman erased the problem, and the lenses have remained razor sharp. One of them is susceptible to flare, but that may be a design, not a fungus, problem.

[jonathan_stark]

John Chambers- my comment was directed at the relative ease of finding another example of this lens, not it's intrinsic worth. I've been shooting 55/1.8 Takumars for 35 years - obviously I think they're worth using.

[terry_scott]

Thanks for your good advice, folks. I shall take it gently and carefully and try to clean 'er. What I was most worried about was the fact that this lens, of course, has multi-coating - and I didn't want to mess that up.

 

Still, as has been said (and it's a valid point), it's not as if 55mm SMC Takumars are especially rare. I could indeed get another through eBay. It'd just be fun to clean this one and that I shall now attempt to do, taking into account all your comments.