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01-14-2010, 12:37 AM   #1
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What are problems with old lenses?

I plan on hitting a few flea markets this summer, in hopes of finding a few lenses. I've seen descriptions on ebay like "no fungus", "no oil" etc.

Since I've never seen these things, I was wondering if anyone had pictures of lenses with these (or any other conditions) to watch out for.

01-14-2010, 01:20 AM   #2
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Fungus - just search for lens fungus online. It looks like spiderweb or thin strands of cotton on the periphery of the lens. You can check for it by looking through the lens. It's bad and I wouldn't bother with such a lens, unless it's a very special rare one.

Oil - it's not necessarily visible, but its symptom is that the aperture blades close slow. Sometimes you may see a hint of oil on them, but it's not always that obvious. You can check for it by rapidly changing aperture settings - if there's any hesitation, you have a problem. It can be fixed by cleaning the blades, so it's a reversible problem. Had to do this recently for a lens and the cost was about $50.
01-14-2010, 06:26 AM   #3
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Oil is the result of breakdown of the grease in the focusing helix, seeping into the aperture blades.

It causes slow operation of the aperture, or the blades may be stuck totally (usually stuck open)

you can see oil usually on the blades, or at least the impact.

fungus looks like growth of crystals on the lens elements (almost like frost on the windows in winter). fungus can be cleaned if it is not between cemented elements

you also need to check for separation of cemented elements, dust, and smoothness of focusing operation. and aperture detents
01-14-2010, 07:13 AM   #4
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Look through the lens, with the aperture set to a small opening, and move the aperture lever in the mount with your finger. The aperture blades should close down rapidly, and when you release the lever, should spring back fast as well.

Try the focus ring, it should be smooth and with a pleasing amount of resistance. Too much resistance - or stuck focus - isn't good. If you have your camera with you, check that the lens goes to infinity.

Simply looking through the lens will show any fungus or other dirt inside. Look through a good lens to see what's normal

Is the lens otherwise solid, or is there some play in it - and are there strange noises if you shake it a bit? Often a loose lens is easy enough to tighten...

01-14-2010, 09:06 AM   #5
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QuoteOriginally posted by Nesster Quote
Is the lens otherwise solid, or is there some play in it - and are there strange noises if you shake it a bit? Often a loose lens is easy enough to tighten...
Yes. Although a slight rattle can in some cases be normal... See this thread.
01-14-2010, 11:53 AM   #6
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QuoteOriginally posted by jeryst Quote
I plan on hitting a few flea markets this summer, in hopes of finding a few lenses. I've seen descriptions on ebay like "no fungus", "no oil" etc.

Since I've never seen these things, I was wondering if anyone had pictures of lenses with these (or any other conditions) to watch out for.
I really should take a photo of fungus. I haven't seen many that represent fungus very well. Here are two from one recent eBay purchase. (It's extremely rare that fungus is visible in eBay photos at all. The description said "may need cleaning".) Look at the front element, next to the serial number, for gray spidery lines. Sometimes fungus is in denser splotches.



Oil on the aperture blades. Aperture blades are nearly always a uniform color. Oil shows as darker blotches, usually on the edges, sometimes only visible at mid-apertures. It's easy to see oil here because the lens is apart. An LED flashlight is handy for lens inspection in the field. Other causes of discoloration are wear and rust, seen very infrequently.



Here's element separation on a Pentax-M 40mm f2.8. Coating issues also resemble this rainbow look. A few lenses are known for element separation, such as the Pentax-FA 28-70/4 zoom and some Sigma 400mm f5.6 primes.



Scratches on the rear element can really affect image quality. You'll probably notice it quickly if it's this bad :

01-14-2010, 12:10 PM   #7
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QuoteOriginally posted by Just1MoreDave Quote
Oil on the aperture blades. Aperture blades are nearly always a uniform color. Oil shows as darker blotches, usually on the edges, sometimes only visible at mid-apertures. It's easy to see oil here because the lens is apart. An LED flashlight is handy for lens inspection in the field. Other causes of discoloration are wear and rust, seen very infrequently.

this wouldn't be a kiron / vivitar lens by any chance would it.

Looks suprisingly like my viv 24mm F2 and kiron 28mm F2 lenses inside.

Just a note, vivitar and Kiron lenses from the early 1980s seem specifically prone to oil, which migrates out of the focusing helix, to stick the aperture
01-14-2010, 12:33 PM   #8
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QuoteOriginally posted by Lowell Goudge Quote
this wouldn't be a kiron / vivitar lens by any chance would it.

Looks suprisingly like my viv 24mm F2 and kiron 28mm F2 lenses inside.

Just a note, vivitar and Kiron lenses from the early 1980s seem specifically prone to oil, which migrates out of the focusing helix, to stick the aperture
Funny, I have the opposite pair: Vivitar (K12) 28mm f2 and Kiron 24mm f2. I had to clean the 24mm but not the 28mm.

This happens to be a Super-Multi-Coated Takumar 50mm f1.4. It's pretty rare for these to ever have oily apertures. This oil is actually my fault. The aperture was really slow and I haven't figured out why. They had no oil on them, but they seemed to have too much drag. As a last resort I put what I thought was a very tiny drop of oil on the mechanism itself, away from the blades. At first, this fixed the problem, but the oil migrated onto the blades and it's slow again.

01-14-2010, 12:41 PM   #9
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+1 Nesster reply

and take along your camera & a few different lens adapters...
01-14-2010, 01:31 PM   #10
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QuoteOriginally posted by Just1MoreDave Quote
Funny, I have the opposite pair: Vivitar (K12) 28mm f2 and Kiron 24mm f2. I had to clean the 24mm but not the 28mm.
you mean "........but not the 28mm yet"

From the two that I own, they get really saturated in oil all arounf the aperature mechanism and even the setting ring.

I have cleanse both mine. Note neither was pentax mount origonally, but I have swapped out the stock MD and Nikon mounts in favor of a flanged adaptor.

the viv 24 was free the kiron 28 cost a whopping $5 and the 2 flanged adaptors cost a total of $16. As of now, I have a 24mmF2 and 28mmF2 (stop down lenses only) for a total of $21.
01-14-2010, 07:29 PM   #11
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QuoteOriginally posted by Just1MoreDave Quote
I really should take a photo of fungus. I haven't seen many that represent fungus very well. Here are two from one recent eBay purchase. (It's extremely rare that fungus is visible in eBay photos at all. The description said "may need cleaning".) Look at the front element, next to the serial number, for gray spidery lines. Sometimes fungus is in denser splotches.
Fungus can also look like a "puff". I had a photo of some on a S-M-C Takumar 50/1.4 that unfortunately deleted just last week.

Here is my "old" lens field checklist:
  • Focus action smooth lock-to-lock
  • Aperture ring action smooth lock-to-lock
  • Aperture size changes appropriately for different f/stops
  • Aperture opening essentially symmetrical at all settings (the key word is "essentially")
  • A/M switch works at all apertures (Automatic diaphragm M42 lenses having this switch)
  • Preset ring/switch works at all apertures (Pre-set diaphragm lenses)
  • Aperture actuator action snappy and without hesitation at all apertures
  • Mount free of dings and obvious damage to threads or bayonet tangs as well as coupling lever(s) and electrical contacts
  • Filter ring not bent and with clean threads
  • Front element free of scratches (minor are acceptable but only with reduced price)
  • Rear element free of scratches (essential)
  • No gross internal contamination (dirt, dust, fungus, or water spots)
  • Undamaged coatings (a problem on some Russian lenses)
  • No evidence of having been dropped, botched repair or other physical abuse (bent rings, big dings, stripped/missing screws)
If you have a small penlight (torch) with you and a dimly lit space, here is how to do a fine evaluation of the lens innards:
  • Set the aperture to fully open
  • Looking from the rear of the lens, shine your penlight at oblique angles through the front element
  • Move the light to various positions while changing your angle of view
  • Repeat with you looking from the front of the lens and shining the light through the back element.
You will see more than you want to using this technique. Every spec of dust should be visible. More importantly, any fungus, internal scratches (from botched repair), and/or element separation will be very obvious.

Have fun!

Steve
01-16-2010, 03:26 PM   #12
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Here is a Super Takumar 50/1.4 I just bought on fleaBay. Has the spidery fungus on the front element and the puffy fungus on an internal element. It also has yellowing. I will never buy another used lens from Florida again.




Last edited by boriscleto; 01-16-2010 at 04:02 PM.
01-16-2010, 05:25 PM   #13
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An abundance of good hints already, found one pic of terminal fungus



Looking through with strong light is key I guess. The tinkerer would try to disassemble and clean (did not really help in this case).
Best of luck, Georg
01-31-2010, 10:23 PM   #14
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Havent been on for a little while, but thanks for all of the great photos and tips.
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