Oil on blades?

[Brad Bireley]

Oil on blades? What does this mean?

Thanks,
Brad

[BillBingham2]

Brad,

Let me add to Freds post, in a rangefinder lens it is not a earth shattering thing. In an SLR lens, it is a very bad thing. Auto-return diaphragm must be 100% in order to close down quickly to the right aperture and then open up again. I had a lens shipped over from Australia once that was fine when it got shipped, but it took so long (I thing the proverbial slow boat) that I think it got fried in transit. Had to spend some bucks getting it CLAd. Cost more than I wanted or expected to spend but I have a wonderful lens now.

In rangefinders, as you are not viewing through the lens, there is no need for it to stop down and open quickly. There is no linkage on most mounts (Not sure about the Contax G1/2). You should get the lens cleaned as it will make it smoother and less likely to be troubles down the road (wd-40, who knows where else it went!) but it's will not stop you from using it.

B2 (;->

[FallisPhoto]

Originally Posted by Brad Bireley

Oil on blades? What does this mean?

Thanks,
Brad

There are two sets of blades in a leaf shutter camera (one set acts as the shutter and one acts as the aperture control). There is one set in the lens of an SLR (aperture control). Neither should have oil on them. The shutter blades in a leaf shutter camera will not work if they are oily. The oil causes them to stick together. This will, at very least, cause your shutter speeds to be sluggish. In the case where the oil is old and has dried up and become thick, it can jam the shutter solid, rendering it entirely non-functional. Fortunately, it is fairly easy to fix.

In leaf shutter cameras, if the oil is on the aperture blades, it can (at very least) cause your shutter/lens to have a stiff f/stop adjustment. At worst, it can become stiffer and stiffer until trying to force it breaks something. In leaf shutter cameras, this is an easy fix. In SLR lenses, it is quite a bit more difficult to fix, requiring a lot of disassembly. Also, the consequences can be far more dire, with the aperture blades and escapement virtually exploding as they try to stop down quickly and open again.

In any of these cases, the fix is the same: You either flush the parts (several times, thoroughly) with naptha, dissolving the old lube and washing it away, or (better method) you disassemble the shutter/lens and hand clean each part (again, with naptha).

In addition to the causes that nikonhswebmaster listed, let me add another common one: With vintage cameras, in the vast majority of cases, the factories just simply over-oiled their cameras. It takes VERY little oil to lube a shutter. Ideally, in a whole leaf shutter camera there should be less than one drop. I never put in more than will wet the point of a sewing needle when lubing pivot points, for instance. Using more oil than absolutely needed will cause more problems than it solves. You see, the thing about oils is that they don't stay where they are put. Oil spreads. Over decades, as in a vintage camera, it can spread pretty far, into places you don't want it to go. For example, if you put a drop of oil on a penny, and then look at it an hour later, the whole penny will be oily -- so will the table under it. If you put just enough oil on it to wet the point of a needle, it will still spread, but not as far and it will be thin enough not to cause problems.

[FallisPhoto]

Originally Posted by nikonhswebmaster

One of the reasons that whale oil and grease was used in a lot of older cameras is because it does not migrate. Olls like sewing machine oil which are used in Copal shutters migrate like crazy.

More modern lubricants are now very tenacious, and do not migrate, since they were designed not to. When possible do not lubricate, many cameras like Nikon have many parts that use bronze bushings which were self-lubricating.

I have cleaned a lot of shutters over the years, and it is hard to resist over-oiling them, you really need almost no oil as "FallisPhoto" notes.

Oh, it all migrates. With the better oil choices, it just does it a lot slower. In a 50-year-old camera it doesn't much matter what they used though, because it will be everywhere. They really did use too much back then.

[myoptic3]

You have gotten some good advice here. There are several options. Use the lens as it is (assuming the oil problem is not that bad) and make a point to keep it from high temps and ck it now and then to see how things are going. Or you could send it out to have it cleaned. What the lens is worth, weighed against what one w/o this problem would cost is important, as well as what you are willing to spend. Or you could try and sell it as it is and use the money towards another lens. If the lens was one that someone really wanted, and if they had been looking for one at a good price, that might work. If it is an expensive repair to an inexpensive lens, this won't work. You will have to throw it in the drawer and start lens shopping.

[jlw]

Originally Posted by nikonhswebmaster

Bill is right.

No, he's not. Not really. An RF lens with oil on the blades is not as much of a problem as an SLR lens with oil on the blades, but it's still a problem.

It's just not a "gotta fix it right away" problem... more of a "be careful until the lens needs servicing or until it gets worse, then be sure to get it fixed" problem.

Of course, if you plan to put the lens up for sale, then it becomes more of a problem, because nobody with sense will pay as much for a lens with oily blades as they will for an equal-condition lens with clean blades.

Old grease/oil gets like glue.

And that's why it's a problem. When you operate the aperture ring and the blades have to drag against the extra friction of this gluey residue, the extra force required is transmitted through the pivot pins of the diaphragm blades. These pivot pins are usually brass, and extra pressure accelerates the wear on them.

Also, if the blades are too "glued," the pins can be sheared off! Or they'll pop out of their locating holes, requiring a service to reassemble the diaphragm (and get all the goop cleaned out.) Or they can flex and arch, which can put a crease in the blade and, if it arches far enough to touch the adjacent lens elements, can damage the coating.

So yeah, you can usually use an RF lens with oily blades if you're very careful to move the aperture ring slowly. Keeping it out of cold weather would be a good idea as well. And if it gets stiffer, or if you can notice any sign of blade flexing when you change it, get it cleaned right away. Otherwise, get it cleaned as soon as you conveniently can.

[FallisPhoto]

Originally Posted by nikonhswebmaster

Well true, you are both right.

But oil is often a sign of subtle gassing (deposit of oil on the inner lens elements) which is really awful on a lens. You should inspect any lens carefully, that is internally covered in oil. But usually, as jlw point out, you can use the RF lens, with an SLR you can't.

True. You can glue a peanut to the front element of a lens and it won't have much effect on it's photo taking ability, but spread a quarter of a drop of oil on it and that will have a really drastic impact.

[wolves3012]

Originally Posted by nikonhswebmaster

More modern lubricants are now very tenacious, and do not migrate, since they were designed not to. When possible do not lubricate, many cameras like Nikon have many parts that use bronze bushings which were self-lubricating.

Maybe I'm being a bit pedantic here, but bronze (actually phosphor-bronze) is NOT self-lubricating. It's actually a porous metal, meaning that it soaks oil up like a sponge. Once oiled it'll go for a long time but it will need re-lubing eventually. If it does dry out it's actually going to wear rapidly, since it's also quite soft.