Oil On Aperture – Johnny Martyr Thought & Photography

I thought it would be useful to blog about a lens I just sold on eBay this week. It was a Nikkor 135mm 2.8 AIS that I owned and used sparingly for about 15 years. It’s a useful lens but nothing I’ve ever really liked about it, which is why it’s rarely used. Recently, I picked up a 180mm 2.8 AIS ED (which I I fell in love with and will post soon) and since I’m a fan of overselling camera gear I decided to free up space for the 180 by selling my Pre-AI Nikkor 135mm 2.8 Q or the newer, smaller, more expensive AIS version.

I removed both 135s from my camera cabinet to go through them and decide which one to drop out of. Pre-AI lenses were huge and heavy. My copy isn’t AI yet so I can only use it on my Nikkormats and F2sb, not my FM2n. I thought this lack of versatility would be a reason to say goodbye to my old friend. But when I checked the AIS copy, my mind changed.

When I removed the lens cap and looked at the aperture blades on the 135/2.8 AIS, I saw some visible smears of oil, I don’t remember seeing this before, but it’s probably been about two years since I used this lens.

The dark smudge in the middle of the opening is oil. Some of the blades have spots of similar size but reduced in size after the initial rotation of my aperture ring

I take very good care of my camera gear from a maintenance standpoint. I have everything I use regularly, professionally serviced when necessary. And sometimes even when it’s not needed. I also only buy from retailers who repair their equipment and offer a warranty. Nothing has entered my camera cabinet that has not been serviced in recent history.

But, let’s face it, old is old and even well-maintained equipment will occasionally peel at us. Despite being bought from KEH under an old warranty and seeing maybe a hundred rolls of film behind it under my care, this lens is no longer in working condition.

When I turn the aperture ring, the blades do not open and close in sync with setting changes. Oil, which has migrated from the aperture diaphragm blade pivots, is now causing the blades to stick. So if the lens is set to f5.6 and I open it to f2.8, the blades open but stop at, say 3.5 and a moment later, open themselves to 2.8. Then from 2.8, I set the ring to f22 and it stopped at about 11 and didn’t even hit 22.

Oil on the aperture blades is a common age-related problem with nearly all camera lenses. Often with rangefinder lenses this isn’t a problem as it usually doesn’t cause the blade to stick. But especially with SLR lenses featuring open aperture metering capabilities, oil on the blades is a real problem.

Because cameras like the Nikon FM2n hold the aperture blades at their widest position until the moment of exposure, they have to move back and forth from full aperture to set aperture very quickly. They can’t do this when they are sticky.

Sticky, greasy aperture blades on open aperture-measuring SLR lenses can cause incorrect exposures as well as dark viewfinder images.

The solution is pretty easy and I’ve done it with a few of my Olympus lenses that seem more prone to problems than my Nikkor or Pentax lenses for some reason. I will tell you how I have resolved the sticky aperture blades, however, I am a photographer by trade, not repair technology. So maybe there is another, maybe even better way to do it. I’m just showing what I’ve personally done as an illustration of the nature of the problem. My intention is not to replace comprehensive repair advice from a well-researched book or service from a professional. The latter is what I recommend if your goal is to concentrate on your photography instead of covering your dining room table with disassembled lenses that your cat is bound to drop, flinging the tiny, almost irreplaceable screw into oblivion.

Someone needs to disassemble then the lens to the aperture blades. The blade does not need to be removed and no further disassembly is required, however, you will also need to clean the glass surface on both sides of the blade – there is likely fog on it from migrating oil as well.

Carry on. wipe excess grease from the blades using something like an alcohol-soaked lens wipe. I like the lens wipe because it doesn’t leave any lint and the alcohol helps dry out the blades. The idea is to remove as much of this excess lubrication as possible as it loses viscosity (resistance to flow) with age. Lower viscosity oil will leak onto things it wasn’t meant to be lubricated. So you want to get as much of that old oil out of there as possible.

You know you’ve cleaned the blade thoroughly when it’s hard to open and close because it’s so dry.

Next, I added the smallest and most conservative drops of lighter fluid to each of the aperture blade pivot points. This kind of reactivates the remaining lubricant. You’ll need to train the blades to get the grease working again, but before you do that the aperture blades need some attention as they are very dry now.

With the blade fully closed to its smallest opening, I rubbed the tiniest graphite across its surface. There should be no visible specks of excess graphite. You only need a very small amount and it should be rubbed evenly throughout the aperture assembly. It doesn’t have to be done on both sides, just the open side.

Now you can train the blades using the aperture ring. Make sure not to lose those little silver ball bearings to stop the clicks! Work the bar back and forth from one extreme to the other at first, then stopping at the settings in between. They should now work as expected. If not, you can repeat the steps above as necessary.

Wrap by cleaning the glass surface as mentioned, before reassembling.

So like I said I mentioned the basic repair procedure of oiling the aperture blades not necessarily so you fix all your sticky lenses but just so you know roughly what’s going on here if you look at the oil. I imagine that a professional repair technician will completely wash the old grease off the pivot blade by taking the diaphragm apart and re-lubricating it completely. If you want to fix your sticky bar yourself, I highly recommend reading some good repair manuals and joining some online camera repair communities. Doing so fills in the details on a specific project and helps you get the necessary tools and suitable workspace.

But for me, I decided to sell this lens because I already have a pre-AI version of this lens and a hard drive full of wedding and family photos to edit now. I’d rather have a relatively small clutch with well-functioning, well-functioning equipment than pile on projects for another day when I want to shoot, edit, or write about shooting and editing!

The big fat lens mounted on a chrome FTn is the 135/2.8 Q I’ll be holding.

I described the lens very accurately, including the oily blade issue, and priced the 135/2.8 accordingly. Lenses sold quickly because I wasn’t trying to make a big profit; just pass it on for the next man to enjoy.

As a side note, I believe I paid around $60 for this lens about 15 years ago when everyone was screaming “death to movies!” It comes with a 6 month warranty and works flawlessly. I was able to sell it for $50 with aperture problems and see that working examples sell for more than twice that price. One of the great things about older film gear of reasonable quality is that it has increased in value since I got into photography so I rarely have to sell at a loss, even taking inflation into account. We’ll see how long it continues this trajectory.

Understanding some of the basic age-related issues that can occur with older camera lenses is useful for buying and selling equipment and understanding how things work to make an informed decision. During shooting, for example, I can continue shooting with this lens, provided I only shoot at full aperture. And of course, when buying a lens that is new to us, checking the blades for oil is an important factor in whether we should buy it or skip it. It’s great to see that good deals can still be had, and there is a strong market for serviceable vintage camera gear.

Thanks for reading and happy shooting!

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