Mamiya TLR lenses: Slow speed repair tips?

[andyfalsetta]

A couple of the Mamiya TLR lenses do have compound elements, andyfalsetta, but since the optics modules are completely removable by simple unscrewing from the shutter barrel and/or lens board, you can totally eliminate the risk of solvent contaminating the glass. An advantage of Mamiya's somewhat jurassic TLR and Press engineering.

 

That's good info and helps justify the extra effort to get the glass out before a flush.

[orsetto]

About 18 months ago, I posted some pics of a partially disassembled Mamiya 80mm TLR lens in a thread about repairing its gritty rough-turning aperture ring. It shows how the front taking lens cell simply unscrews from the shutter barrel, providing access to the shutter. The smaller rear taking lens cell (not shown) unscrews the same way, but tends to be tight if never before removed (use of a latex glove for extra grip helps). The viewing lens set also unscrews from its shutterless mount the same way, so if desired one can work on the lens mechanism with no fear of optical mishaps.

 

Mamiya C330 lens repair

 

The lens pictured is a later black barrel version: these have a more complicated multi-part aperture control system. The chrome faced lenses have simpler aperture controls that stay out of the way when working on the shutter. Both versions use a similar segmented retaining ring around the lens cell thread that must be unscrewed to gain complete access to the escapement (as do the chrome face Press lenses).

[conrad_hoffman]

When I clean or flush, I use two jars of naptha, one dirty, one clean. OK, they both start out clean! I get the bulk of the oil and grease off in the dirty bath, then use the final one to be sure there's little or no film or residue left. I use compressed air to get things dry- you want to remove the remaining solvent, not let it dry and leave deposits. Obviously you have to be careful with aperture and shutter blades as an air blast will destroy them. I dry those no closer than 2 feet away from the nozzle.

 

As for focusing helicoids, the lens I've done the most is the 55mm f/2.8 Micro-Nikkor. It has two, one of which drives the compensating lens, so any dried grease will really bind the whole thing up. Normal greases are way to heavy and I usually lube them with a small amount of Superlube oil with PTFE. The inner always has to be fully disassembled, but I don't always disassemble the outer. Sometimes adding a couple drops of oil will rejuvenate the grease and it will work fine. Other times I've immersed the whole outer section in naptha and gently rotated it to get it clean. Bad ones get the ultrasonic cleaner. When clean and dry, they get a couple drops of Superlube. Never had a problem, just don't rotate a dry one! What will cause a huge problem is trying to reassemble a helicoid with excess force. Ding it up and it will never be smooth again. Regular helicoids can usually be lubed with a #1 or thinner grease like Molycote PG-30 or similar. Superlube now makes greases from #2 down to #000, which I've yet to try but could be very useful.

[andyfalsetta]

Now that we've pretty much veered off into helicoid cleaning, it really makes a difference if you scrupulously clean each helicoid thread after givning it a bath. I have a needle mounted in a pinvise that has a tip that I ground down to a flat tip. I then "chase" each thread (both sides) on each set of threads. It doesn't take long to go through all sets and you might be surprised at how much comes out of a "clean" helicoid. A good set of helicoid threads (especially Zeiss) leave no room for debris so get all of that out before applying your lube of choice.

[timlaux]

Interesting discussion!

 

An update on my project. Yesterday, I disassembled the 65mm for the 4th time. I noticed, after my 3rd reassembly, that the shutter leaves were getting stuck about 10-20% of the time, and that they were most likely sluggish...so no good for fast shutter speeds.

 

I started with thoroughly flushing the shutter leaves with 99% "electronics grade" IPA. I found that using Q-tips/cotton swabs just resulted in strands of cotton getting caught on the edges of the shutter leaves. So, I opted to use Kimwipes (popular in electronics and chemistry labs). I cut them into smaller pieces so they would fit in the lens barrel. I use the Q-tips to apply light pressure to the Kimwipes. Kimwipes are virtually lint free.

 

This seems to work okay, but still jamming occasionally. So, I went against my better judgement and sprayed a little CRC QD electronics cleaner (from auto parts store), and worked the shutter several dozen times. According to some other forum discussions, this stuff is safe on plastics and lens coatings. (We'll see when I develop the film.) The QD stuff is definitely a much better solvent than IPA. However, it still seemed to leave a few rainbow splotches, so I did one final round of IPA and Kimwipes.

 

It's now firing 100% again!

 

Next, I removed the slow speed mechanism (also for the 4th time), threw it in a container of Naphtha, agitated it for about 2-3 minutes. Then I removed it, liberally sprayed it with CRC QD, hoping the compressed air might dislodge any final pieces of grit. Then, finished off in IPA bathe. I applied a miniscule amount of oil to the pivot points, though I feel that if any of you were to see my work, you'd still think it was too much.

 

I reassembled and...same thing, still running about 1.6-1.7x marked speed. I tried twiddling with the mechanism's two set screws (mainly the top one), but really could not get much change at all. I also experimented with varying the pressure applied from the brass-colored retaining ring upon reassembly, but that didn't seem to have an effect.

 

---

 

In the process, I some how knocked a "straight spring" (I think) on the left-hand side, near the shutter release lever. I think I moved it back into the right position, but my confidence is not that high. All I know now is that sometimes the shutter will refuse to cock, but once I partially depress the shutter release lever, it sets it loose, and the shutter cocks fine again. Not sure what I might have goofed up there.

 

Regarding oiling the shutter cocking ring, I did not oil it...Where should it be oiled? I suppose the only real option is on the teeth?

 

I'm a little bit hesitant to crack it open again, since it seems to be in a relatively good working state, with a quirk or two, and needing exposure compensation. I just want to shoot now!

 

Thanks everyone.

[kmac]

Regarding oiling the shutter cocking ring, I did not oil it...Where should it be oiled? I suppose the only real option is on the teeth?

 

The cocking ring needs lubrication on the inside diameter. The mating part of that inside dia. is the inner housing of the shutter body. They need a thin film of non-running grease between the mating parts, but since yours is already assembled, one drop of 15-50w engine oil spread around where the parts meet will do the trick, and once again different oils come up for debate and I read all arguments but that cocking ring definitely needs lubricating because excess friction when it's dry will slow it down on it's return journey, and if yours is dry, it could be the reason why your speeds are reading slow, or maybe not, but the ring does need to be operating smoothly and freely, achieved with lubrication.

 

For the gear teeth, lubrication is simply done by rubbing a lightly oil dampened cloth over the top of the teeth. The thin film of oil will find it's way down to the working faces of the teeth.

[andyfalsetta]

Use restraint when lubing a shutter. They like to run dry. The only caveats for me are:

- pivots on slow speed controllers - Heat the head of a needle cherry red and then flatten it with a hammer against an anvil. This tip will now retain a small drop of oil. Once cool you can dip it into watch oil or your oil of choice and apply a small drop to the pivots.

- cocking cam. As KMAC said, the inner circumference of the cam has a lot of stress on it as it rotates around its mating/bearing surface. A thin film of oil here might be enough but I tend to use a heavier lube here.

- springs. Since I can't find replacement springs for most of my cameras these days, prevention of broken springs is paramount. I apply a small drop of oil to every spring so it can spread over the entire length of the spring over time preventing rust and eliminating rust related breakage.

If you have a manufacturer's lube schedule, use it. Otherwise, that's it. If you have to lube anything else, chances are there is something else wrong.

 

As for CRC electronics cleaner, if it works for you, that's great. I find that it's not the cheapest solvent and it emits noxious fumes. I don't like using it at my workbench. It does seem to not affect plastics or painted lettering or glass though. The one thing I dislike most and the main reason I stopped using it in favor of naptha is that its an aerosol, it leaves the parts cold due to the propellant and rapidly evaporating fluid (remember those noxious fumes?). This causes condensation and a thin film of rust to develop anywhere that the parts are not plated.

[timlaux]

Thanks kmac and andy. My ignorance is glowing. I "cleaned" off the greasy stuff on the cocking ring the first time I opened it. 2 of 4 set screws that hold the front elements in place, into the figure-eight plastic piece, no longer have any plastic to thread into. I'm a little worried I'll have no set screws left if I open it again!

 

Sounds like I ought to.

 

I took my first roll of 12 exposures yesterday. They are in the Paterson tank now, will develop later. I feel like I'm messing up something with the order of operations for the film advance, shutter, and single/multi switch. A few times the shutter lever seemed locked and/or I couldn't cock the shutter and I wonder if I goofed up something. I don't know. Hoping it's operator error and not the lens.

 

If the pictures come out alright, I think I'll open it one more time and put a little 15-40W oil on the ring. Fingers crossed.

 

Still feel like I put too much oil on the pivots!

 

Interesting ideas about the aerosol cleaner. Anything I hit with CRC, I cleaned with IPA after, hopefully removing any residue or oxidation layer..hopefully..

[orsetto]

Don't worry about the set screws for the plastic figure eight brace: 9 out of 10 Mamiya 65mm lenses are completely missing these set screws by now. The brace is held in place perfectly well from friction fit and the front barrels both being screwed into it.

 

Film can be advanced with the C220 body before or after shutter speed selection and/or shutter cocking: makes no difference. The single/multi switch is normally left on single, only set it to multi if you want to make a multiple exposure on the same frame of film. Usually if you cannot cock the shutter it means you already did it: if the knob is in the lower position the lens is cocked. There is no mechansm in the C220 body that can stop you from cocking an uncocked shutter, unless perhaps you attempt to do so while the shutter button is held down.

 

Normally, with the film advance set to "single", the interlocks work to prevent an accidental double exposure (after you press the shutter button to take a photo, the shutter button will lock until you advance the film again, preventing a double exposure). Some Mamiya TLRs have a bit of a "hair trigger" to the shutter button: it can be hyper-sensitive. If you're in the habit of keeping your thumb on the button in readiness to take the shot, the weight of your resting thumb can be enough to trip the double exposure lock before you actually take the intended photo.

 

Positioning your thumb near but not on the the shutter release button (or the bar its attached to) will help avoid this. If you discover the lock has been triggered before you can make your planned exposure, you can override the lock by switching from "single" to "multi", take the shot, advance the film, then switch back to "single" to reactivate the protection. You can also just leave the camera permanently set to "multi" to defeat the auto lock, but then you will need to remember to advance the film immediately after every shot to avoid unintentional double exposures.

[timlaux]

Don't worry about the set screws for the plastic figure eight brace: 9 out of 10 Mamiya 65mm lenses are completely missing these set screws by now. The brace is held in place perfectly well from friction fit and the front barrels both being screwed into it.

 

Film can be advanced with the C220 body before or after shutter speed selection and/or shutter cocking: makes no difference. The single/multi switch is normally left on single, only set it to multi if you want to make a multiple exposure on the same frame of film. Usually if you cannot cock the shutter it means you already did it: if the knob is in the lower position the lens is cocked. There is no mechansm in the C220 body that can stop you from cocking an uncocked shutter, unless perhaps you attempt to do so while the shutter button is held down.

 

Normally, with the film advance set to "single", the interlocks work to prevent an accidental double exposure (after you press the shutter button to take a photo, the shutter button will lock until you advance the film again, preventing a double exposure). Some Mamiya TLRs have a bit of a "hair trigger" to the shutter button: it can be hyper-sensitive. If you're in the habit of keeping your thumb on the button in readiness to take the shot, the weight of your resting thumb can be enough to trip the double exposure lock before you actually take the intended photo.

 

Positioning your thumb near but not on the the shutter release button (or the bar its attached to) will help avoid this. If you discover the lock has been triggered before you can make your planned exposure, you can override the lock by switching from "single" to "multi", take the shot, advance the film, then switch back to "single" to reactivate the protection. You can also just leave the camera permanently set to "multi" to defeat the auto lock, but then you will need to remember to advance the film immediately after every shot to avoid unintentional double exposures.

 

Thanks orsetto. I wonder if I have the "hair trigger" problem that you suggested. In general, yes, I usually do apply light "pre"-pressure to shutter release on all cameras I've shot on, mainly to avoid camera shake. It is tempting to leave it on multi, but obviously we know the potential problem with that.

 

I developed the roll today. So far the negatives look promising. I took 3 at 0.5sec and 1sec, 4 at 1/30 and 1/60, and 3 at 1/250 and 1/500. Hopefull that's a good test. Oh...and I got 2 blank exposures! I think that was from me tricking the camera into thinking I took a shot, when I didn't.

 

Exposure looks pretty good so far. We'll see when I scan them.

 

Thanks!

[orsetto]

In general, yes, I usually do apply light "pre"-pressure to shutter release on all cameras I've shot on, mainly to avoid camera shake.

 

Yep, this is a common habit which is fine and desirable with most cameras. But it can be problematic with Mamiya TLRs due to the very wide tolerances in the very crude "Erector Set" connection between shutter button, double exposure spring and lens trigger lever. With practice, you can develop a different way of keeping your finger in ready position with a Mamiya: each individual example is slightly different so this varies.

 

The most important thing to un-learn from other cameras is to not try to take up the slack in the button: that slack is what keeps the double exposure lock from kicking in. You can keep your finger on the button but don't press on it: if anything, try to put pressure in the up direction by pushing up on the metal strut the shutter button is attached to with the side of your shooting finger.

 

Since the entire linkage is external and exposed, you can easily experiment with varying thickness of tape or perhaps a piece of adhesive velvet between the sliding bar the shutter release is attached to and the side frame of the lens panel it rides against. Adding some slight additional friction will permit you to rest your finger on the button more casually with less chance of the lock accidentally engaging. The camera is heavy enough and the leaf shutter almost vibrationless compared to an SLR, so theres a lot of leeway to avoid shake. The loud ping sound some of the lenses make when fired is entirely after the shutter has closed: its just the snap back of the cocking knob after exposure, amplified by the bellows bed and front standard.

[timlaux]

Thanks again everyone. Well, I think the few photos I took came out alright, for not knowing what I'm doing...and especially with my "slow" lens.

 

[kmac]

I think the few photos I took came out alright

 

Looks ok, a little underexposed perhaps, and the focus is a little too close to the camera. But I like the story, it reveals what must have been a more prosperous era from the past.

 

Here it is with the magenta color cast removed and sharpened ....

[timlaux]

Thanks kmac. I played with the colors and black point a little in Lightroom. (This is a DSLR scan.)

 

i think this is at f/8, thought a little more would be in focus but ultimately I don’t mind the soft background so much.

 

Always appreciate a critique.

 

The real exposure is actually lighter. I kind of liked the look of darker shadows. Usually I like light shadows, but thought it was a little more interesting darker. But my style of edit is constantly in flux, so who knows how I’ll re-envision this in the future.