Olympus OM-1 CLA and meter circuit upgrade

I've been Googling around for a good repair person to handle a few of things for me. My OM-1 is working fine. I got it around 6 months ago, the previous owner obviously cared for it, and it's in perfect working condition. I have several rolls through it with no problems. The meter is accurate when using a 1.4v zinc air cell.

What I'd like done is:

1. Normal CLA. Just want to keep up on standard maintenance of this camera so it can continue to provide years of happy service.
2. Shutter speed ring is a bit on the stiff side. I'm hoping a standard CLA will resolve this, but figure it's worth calling out specifically.
3. Removal of any foam around the pentaprism if this hasn't already been done - so far no signs of rotting, and I haven't disassembled to see if the foam is still there. But I want it gone if it is still there.
4. Installation of diode or resistor in meter circuit so I can stop using zinc airs and instead pop an in SR44 with a MUCH longer lifespan.

I have reached out to:

* Garry's Camera in IL. He is happy to do the standard stuff, but recommends against modifying the meter circuit because "1.35 and 1.5v batteries are readily available". He wants instead to calibrate the meter for a 1.5v battery, without actually changing the circuit. That sounds like the wrong answer to me, my understanding is that simply re-zeroing with a 1.5v battery introduces significant nonlinearity at the lower and higher ends of the EV scale. Perhaps someone can confirm or deny this? Garry's price seems very reasonable, but I've read enough concerning reviews of his work and business practices to be wary.

* John Titterington. He quoted me $80 for a standard "overhaul" including light seals. I replied asking specifically about how much more it would cost to do the meter circuit upgrade and pentaprism foam removal, since he didn't address that specifically.

* John Hermanson/Camtech - He says he is trying to retire and only works on a short list of OM bodies these days (which doesn't include the OM-1, unfortunately)

* Lezot Camera - They want $150 and seem to be confident they can do all of it, but $150 is their standard CLA fee, and I'm not convinced they're factoring in the meter circuit upgrade in that quote.

* United Camera - haven't heard back yet

* Jim Holman/International Camera Technicians - haven't heard back yet

* Dean's Camera Repair - Called him, he seemed to really know his stuff. He said he could probably do the CLA and meter upgrade as well as foam removal and replacement of all light seals with felt, for about $150. Seemed a bit more concerned about the front ring stiffness, apparently the disassembly on that ring involves some finicky cam timing during reassembly. And he was also very up-front that the $150 quote could go up if he found the shutter speeds needed adjustment.

Anyone have other recommendations? I'm relatively handy and have done some rudimentary repairs on some of my simpler cameras (Zeiss Ikoflex, various folders). I have experience with soldering too. Has anyone done the diode installation on their own who can speak to how complicated it is? It looks a bit intimidating with how tightly packed-in all the wiring is.

Jim Holman at International Camera Technicians should be able to help you out: https://ictcamera.com/.

Thanks, submitted an inquiry on their website too. Original post is updated.

BHuij said:

* Jim Holman/International Camera Technicians - haven't heard back yet

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Good luck to you. I was told I was put into their repair queue in April 2023. I checked in a couple of months later to see where I was in the queue and was told that they'd get back to me by the end of the week. I waited a month without a reply and sent another email inquiry. Never heard back. Maybe you'll have better luck than I did.

I'd contact Dean's Camera repair in Torrance, CA at (310) 782-8619. I don't know if he works on the OM-1 but he did a great job with my Nikkormat FT-3 when few others would touch it.

John Hermanson of Camtech worked on my Olympus Pen FT and he installed a germanium diode inline with the battery as it has a 0.3V voltage drop to correct the meter for use with currently available batteries. Very easy and cheap if you're handy with soldering.

BHuij said:

* John Hermanson/Camtech - He says he is trying to retire and only works on a short list of OM bodies these days (which doesn't include the OM-1, unfortunately)

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Les Sarile said:

John Hermanson of Camtech worked on my Olympus Pen FT and he installed a germanium diode inline with the battery as it has a 0.3V voltage drop to correct the meter for use with currently available batteries. Very easy and cheap if you're handy with soldering.

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See Bhuji's reference to John Hermanson's status.

MattKing said:

See Bhuji's reference to John Hermanson's status.

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Saw that and why I suggested if you want to DIY that part . . .

I recently did the diode replacement on my OM-1 and it seems to be metering quite Well. I just ran 2 rolls of Ektachrome 100D through it and everything came out great. It had the plastic screw on the negative battery terminal which broke off. I had to do a repair anyhow so I figured I would do the diode.

OM-1 with Ektachrome

Another idea on the light meter diode- just get a battery adapter with the integrated diode. Very simple, you’ll probably be out $30-40 and you can use it on any other device (light meter, Leica M5, etc) that needs the mercury battery.

btaylor said:

Another idea on the light meter diode- just get a battery adapter with the integrated diode. Very simple, you’ll probably be out $30-40 and you can use it on any other device (light meter, Leica M5, etc) that needs the mercury battery.

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Germanium diodes are probably a dozen or more for $5 and that's paying too much just for convenience packaging. I haven't looked in my OM-1 but I'm thinking it involves removing the bottom plate and soldering it inline to the wire going to the battery connector. And of course there is even a youtube video on how to do it . . . Fix Old Cameras: OM-1 Dead Meter / Diode Modification
Since the brown wire looks long enough, I would cut it somewhere convenient and splice the diode inline. Easier then removing the holder and soldering onto the pin. Either is perfectly fine.

logan2z said:

Good luck to you. I was told I was put into their repair queue in April 2023. I checked in a couple of months later to see where I was in the queue and was told that they'd get back to me by the end of the week. I waited a month without a reply and sent another email inquiry. Never heard back. Maybe you'll have better luck than I did.

I'd contact Dean's Camera repair in Torrance, CA at (310) 782-8619. I don't know if he works on the OM-1 but he did a great job with my Nikkormat FT-3 when few others would touch it.

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That's odd. I had Jim service one of my cameras in, I think, 2021, and he was very responsive and turned the project around quickly.

btaylor said:

Another idea on the light meter diode- just get a battery adapter with the integrated diode. Very simple, you’ll probably be out $30-40 and you can use it on any other device (light meter, Leica M5, etc) that needs the mercury battery.

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This solution, if acceptable as a personal decision, works quite well. Only caution to mention is that not all adapters available actually lower the voltage so make sure that the difference is understood before buying (and getting disappointed). I used adapters and haven’t yet had a problem with meter accuracy or adapter fit provided when the correct battery is used.

AAlfano said:

That's odd. I had Jim service one of my cameras in, I think, 2021, and he was very responsive and turned the project around quickly.

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I'm not sure what happened. Perhaps it was a particularly busy time for them and I slipped through the cracks. I should note that it was Jim's wife who was initially responding rather than Jim himself so maybe she made the error. It all worked out in the end as I was introduced to Dean's Camera Repair and I had a great service experience with him.

btaylor said:

Another idea on the light meter diode- just get a battery adapter with the integrated diode. Very simple, you’ll probably be out $30-40 and you can use it on any other device (light meter, Leica M5, etc) that needs the mercury battery.

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I went with this solution on my OM1 as well as other cameras that use the same battery (Konica T4, Canon F1,Rolleiflex SL35M,etc.

Just be sure to use Silver oxide batteries, since you will get weird lectures with alkaline batteries. I suggest SR43 since SR44 will not fit correctly on camera.

Honestly those $150 quotes must be more than you paid for the camera surely? I'm a great believer in "if it ain't broke don't fix it" and personally I would just live with the battery issue, it's not as if they're expensive.
As far as the shutter speed ring is concerned you should try gently feeding in either some pure alcohol or lighter fluid from a cotton bud and keep turning it and see if it frees up - obviously don't drown it. You certainly can't hurt anything and it may well fix your main problem.

Good luck!

Thanks all for the advice.

I believe I'm going to have John Titterington take care of the CLA and seals, as well as foam removal from the pentaprism if it's still in there. He said he usually recalibrates the meter for a 1.5v battery unless specifically asked not to.

At this point I'm not sure. On the one hand, I'm worried that simply recalibrating the meter and skipping the diode will not give me accurate and linear readings with a silver oxide battery. On the other hand, maybe I'm misunderstanding, and there's some technician magic he can do that will completely solve my problem and allow for perfect exposures at 1.55v without needing to solder in a diode. The official OM-1 repair manual I've glanced through makes it seem like properly calibrating the meter has to do with 3 different resistors, which is significantly more complicated than splicing in a single diode on the brown wire.

Anyone here have an OM-1 serviced by John Titterington who can speak to whether or not it's working correctly at 1.5v? Unless I can get a solid confirmation that his recalibration is better than adding the diode, I'm going to have him leave it at 1.35v and put the diode in myself when the camera comes back. Having watched a video it looks pretty easy, especially since my battery terminal screw is metal and not broken, so I don't need to mess with it.

John is particularly known for Minolta brand cameras some of which also uses the mercury battery so I would believe he is aware and has addressed this problem many times. I would think he also already does the diode mod as part of the meter calibration. It wouldn't hurt to ask for confirmation.

John actually told me he almost never puts a diode in, but he can set the meter to work with a 1.55v battery all the same as part of his normal calibration.

I'm unclear on whether his procedure for adjusting the calibration to use the higher voltage is as good as adding the diode. Everything I know about these meters (which isn't very much compared to a professional repairperson) is that they were designed from the ground up for 1.35v, and the circuit needs to be modified to use a higher voltage.

Since I can't really undo whatever John does, I'm going to play it safe and have him leave it set for 1.35v, then add the diode myself when the camera comes back.

BHuij said:

John actually told me he almost never puts a diode in, but he can set the meter to work with a 1.55v battery all the same as part of his normal calibration.

I'm unclear on whether his procedure for adjusting the calibration to use the higher voltage is as good as adding the diode. Everything I know about these meters (which isn't very much compared to a professional repairperson) is that they were designed from the ground up for 1.35v, and the circuit needs to be modified to use a higher voltage.

Since I can't really undo whatever John does, I'm going to play it safe and have him leave it set for 1.35v, then add the diode myself when the camera comes back.

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There is another choice. stable625px@gmail.com sells tiny little chips that take 1.5V or 3V in and produce 1.35V or 2.7V out. These are small enough they they can typically be wired in line with the battery somewhere in the camera cavity.

I have not permanently installed one, but I've checked the devices I bought and they do what he says.

Isn't that the same end result as using a diode to lower the voltage from the battery before it hits the meter circuit?

BHuij said:

Isn't that the same end result as using a diode to lower the voltage from the battery before it hits the meter circuit?

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this is an exact voltage regulator.

the diode voltage drop varies slightly at different currents.


as a practical matter, once you calibrate your shooting to either solution, either is fine, though the regulator is probably better for two battery situations

Just to add to the list, I follow a guy that goes by @omcameras on Instagram and he seems to do great work, but he is located in Georgia (country), so the shipping might be a bit outrageous but I don't know for sure.

Good to know. I ended up sending it to Mr. Titterington. When it gets back, I'll test the meter against my known-good baseline spot meter at several different EVs to see if whatever black magic he does to the circuit has resulted in reliable readings with an SR44 battery.

Just to close the loop, I ended up sending the camera to John Titterington.

He had excellent communication and a very fast turnaround time (less than 2 weeks after receiving the camera, after subtracting out the vacation he was on and informed me about when I sent it). His prices were more than fair. He replaced the light seals, removed the prism foam, and cleaned/lubricated the shutter speed ring, which is now buttery smooth and clicking like a dream. He also confirmed my shutter speeds were accurate (which checks out as I've never had exposure issues with that camera when using zinc air batteries in the meter).

Only oddity is that he said the meter was accurate even with a 1.5v battery. He returned it to me with a complementary 625A alkaline battery. I checked it against my baseline meter and... found it to be off by a fair amount, as expected. Popping my 1.4v zinc air back in, it matched.

Well, since I was never able to get a very clear answer on whether the adjustment/calibration he offers without using a diode was able to not only properly zero the meter at something like EV12/EV15, but also keep linear/accurate readings at significantly lower and higher EVs using a 1.55v battery, I asked him to just leave the meter alone, which he did.

So the camera itself is fantastic and I can't wait to get out and shoot with it again. I easily got my money's worth and won't hesitate to send things to John in the future.

But I still need to decide what to do with the meter circuit. I have a pack of 1N-6263 schottky diodes on the way to my house now. I'm going to attempt the conversion on my Canon FTb first (which has both less monetary value and less sentimental value than the OM-1 for me). If all goes well and I can get meter readings I'm satisfied with using an SR44 after the fact, then I'll try it on my OM-1. It doesn't look that hard. It things go south with the FTb or I'm just not happy with the result, then I dunno. Maybe I'll finally shell out $40 for a CRIS MR9 or something. Maybe I'll just keep using 675 Zinc Airs that last 29 minutes after peeling the sticker off.

BHuij said:

Just to close the loop, I ended up sending the camera to John Titterington.

He had excellent communication and a very fast turnaround time (less than 2 weeks after receiving the camera, after subtracting out the vacation he was on and informed me about when I sent it). His prices were more than fair. He replaced the light seals, removed the prism foam, and cleaned/lubricated the shutter speed ring, which is now buttery smooth and clicking like a dream. He also confirmed my shutter speeds were accurate (which checks out as I've never had exposure issues with that camera when using zinc air batteries in the meter).

Only oddity is that he said the meter was accurate even with a 1.5v battery. He returned it to me with a complementary 625A alkaline battery. I checked it against my baseline meter and... found it to be off by a fair amount, as expected. Popping my 1.4v zinc air back in, it matched.

Well, since I was never able to get a very clear answer on whether the adjustment/calibration he offers without using a diode was able to not only properly zero the meter at something like EV12/EV15, but also keep linear/accurate readings at significantly lower and higher EVs using a 1.55v battery, I asked him to just leave the meter alone, which he did.

So the camera itself is fantastic and I can't wait to get out and shoot with it again. I easily got my money's worth and won't hesitate to send things to John in the future.

But I still need to decide what to do with the meter circuit. I have a pack of 1N-6263 schottky diodes on the way to my house now. I'm going to attempt the conversion on my Canon FTb first (which has both less monetary value and less sentimental value than the OM-1 for me). If all goes well and I can get meter readings I'm satisfied with using an SR44 after the fact, then I'll try it on my OM-1. It doesn't look that hard. It things go south with the FTb or I'm just not happy with the result, then I dunno. Maybe I'll finally shell out $40 for a CRIS MR9 or something. Maybe I'll just keep using 675 Zinc Airs that last 29 minutes after peeling the sticker off.

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You could always get the MR9, but a much simpler hack is to just adjust the ASA downward until the meter matches a known standard, note how much (1/3, 1/2, 2/3, 1stop ...) and apply that correction every time you load film with a different ASA. You can also do this with an exposure compensation setting, but I cannot recall if the OM-1 had this sort of thing.

The one thing you have to watch for it that alkaline batteries lose voltage an a steady decline and you will get slightly worse and worse readings over time. One of the advantages of an MR9 is that it can take silver oxide batteries which hold full voltage until they fail suddenly. I have a location in my darkroom that has a known exposure at ASA 200. I aim meters and cameras there now and then to make sure they are approximately the same, to catch failing batteries.