Is perfect metering with mechanical 35mm SLRs pie in the sky?

Paul Howell said:

Not sure if we can buy from a Russian address.

Click to expand...

It depends where you live, I guess.

I think Mexico (my country) don't have any issues with Russia so I guess we can buy from them. Not that I agree or disagree, simply a fact.

Not sure if there is any short of restrictions on the shipping companies though.

In the U.S we have a couple of issues, sanctions, batteries might be an issue, could have duel uses but could only apply to exporting. Second is mercury being sent though the mail.

It occured to me that todays photographer is perhaps spoiled. In the mid 90s cameras did appear where you could select the exposure time in thirds. I know my Nikon F90 does have only full stop settings and the F90x can set time in thirds of a stop. (The funny thing is you could now go by the old scale or the new, eg. old 1/10s vs new 1/15s, 1/25-1/30, 1/50-1/60, etc.)
My childhood and youth was photographed by my father with a Praktica MTL 3 which could do only full speed stops and the Pentacon 50/1,8 that can do half stops. On slides. (ORWO that he developed at home.) They are perfectly exposed. Before that he did the same with a Chaika II and the Leningrad 4 exponometer.
So I advocate to renounce the fear exposing slides. It is not as difficult as the reputation it got from the influencers. (The bad thing is those expose maybe one roll and have to say something lurid, but by that they stop potential real users from trying the medium.)

In the interest of reporting back, I'll link to another thread that I intended mostly as a public journal of my experience chasing "perfection" here.

I'm happy to report that I now have an OM-1 and FTb with diodes in the meter circuits, giving me readings that match within less than 1/3 of a stop to my trusted spot meter at EVs 8, 12, and 15. The diode installation was easy in the FTb even for my inexperienced hands on the soldering iron. The OM-1 diode installation was even easier: when I opened it up I found the previous owner had already done it.

The meter calibration adjustments for both cameras are also fairly easy. Big thanks to this YouTube video I followed to get near-perfect results with my OM-1, and this thread on another forum that pointed me towards the potentiometers on the FTb.

Now to get out and shoot these beauties!

I sell all the cameras i end up with that have problems like this and use slightly newer cameras that don’t have these problems

Good for you. The newer cameras I have like the AE-1, AT-1, and OM-G are great, and I love shooting them. They will also all die an electronic death someday, while my mechanical bodies will hopefully still be kicking.

There are fully mechanical cameras that don’t have these problems.

But a camera being fully mechanical doesn’t mean it’s going to outlast an electronic camera. It’s a crapshoot and you can’t predict what will happen over time.

I had a Nikon fm2 where the shutter jumped track and kinked. Cost more to repair than replace. And a canon ftb where the shutter would open but not close. Again more to fix than replace.

It’s just a fact of life for these old cameras. They’re all going to die someday and there’s no knowing when for any particular copy.

_T_ said:

There are fully mechanical cameras that don’t have these problems.

But a camera being fully mechanical doesn’t mean it’s going to outlast an electronic camera. It’s a crapshoot and you can’t predict what will happen over time.

I had a Nikon fm2 where the shutter jumped track and kinked. Cost more to repair than replace. And a canon ftb where the shutter would open but not close. Again more to fix than replace.

It’s just a fact of life for these old cameras. They’re all going to die someday and there’s no knowing when for any particular copy.

Click to expand...

Aside from mechanical cameras bound to die due to wear/malfunction, camera repair technicians are becoming scarcer. Fewer people being trained. Also parts are becoming scarcer as well.

No warranty mechanical would outlive electronics.

The FM2n has an improved shutter. Mine will long outlast me. But there are some people who could manage to break a stainless steel bowling ball. The model of camera makes very little difference if you drop it off the edge of the Grand Canyon. But as far as I'm concerned, the less electronics, the better.

DREW WILEY said:

The FM2n has an improved shutter. Mine will long outlast me. But there are some people who could manage to break a stainless steel bowling ball.

Click to expand...

That’s what I had. The fm2n with the titanium shutter.

Never dropped it. Never banged it around. Worked flawlessly for 4 years and then one day during totally normal use the shutter jumped track and kinked itself.

Obtaining a fancy titanium shutter and installing it cost more than buying a new fm2n. In the end it was the fact that the shutter was so much improved that killed my camera.

The meter problem associated with cameras with CdS cells. Fully mechanical cameras like the Nikon FM, FM2, FM2n the meters are very accurate. I have several and the meters are all accurate.

It's the titanium shutter which they REPLACED with something better aluminum - much more robust - in the later version of the FM2n. Overall, the improved model is much more common. These had titanium shutters only the first six years of manufacture, then aluminum the following eleven years.

When I owned a Konica T, 1969 I was in a Camera Shop in South Cal, the Konica rep was making his rounds. I asked him why Konica did not make a motor drive. He said that the Cds meters had issues with memory when moving from light to dark and a motor drive would make this issue more noticeable. He said it was the reason that Minolta motor drive body did not have a built in meter. He then said that the shutter speed auto exposure of the T and A were it's selling point so that Konica had no plans at that time for a motor drive model. When I bought a Nikon F with motor drive I did not experience any issues with memory with a FTN head. In the late 70s I met a guy who had an T3 with a custom motor drive added on. His father worked at Northrup design division and on slow work days he and his co workers cobbled together a motor drive from a Canon F1 motor drive.

ic-racer said:

The voltage regulator (above) requires a camera with a negative ground. Maybe someone can re-configure one for a positive ground camera like the OM-1. Of course one could try to place the regulator between the battery and the cap or incorporate it into the cap somehow.

Click to expand...

I was doing some routine maitinance on my OM-1 and thinking about my post above from a while back. I re-examined the wiring of the camera and indeed it would be possible to install the voltage regulator. I drew up a layout below.

The galvanometer receives the positive charge from the battery through a jumper to the chassis (+). The voltage regulator can be placed between the galvanometer and the chassis by removing the jumper.

The ground connection for the voltage regulator can go to the on-off switch where the red wires connect.

Brown wire: from voltage regulator ground to on-off switch, (-) from battery.
Light Blue wire: from the voltage regulator output to the galvanometer.
Red wire: from the voltage regulator input to the chassis (+).

There is just enough room under the hot shoe connector, right over the viewfinder, for the voltage regulator device.

Wow! You implemented Filip Dee’s 1.35v regulator in OM-1!!!!

Very cool! I am finding that the diode in my OM-1 and a bit of calibration with the brass cam on the galvanometer is giving me dead-on accurate readings at EV9, EV12, and EV15 (or at least perfectly matching my spot meter), so I don't have immediate plans to modify the camera further. But I've been thinking about grabbing an SR-T 101... maybe I'll finally get a batch of those voltage regulators.

This is very late in this fascinating thread but I've never been able to think of cameras with through the lens metering as being precision exposure devices. Well, maybe if a camera has a "hard", sharply defined, flare free, narrow angle spot meter in the viewfinder it could be possible but I don't know of such a camera.

I see a fundamental problem in TTL metering being that the meter reading depends on how the subject is framed in the viewfinder. A landscape framed with 1/3 sky, or 1/2 sky, or 2/3 sky will deliver three different meter readings with a perfectly calibrated TTL meter. Which, if any, of those meter readings is correct remains uncertain. On the other hand a good hand-held spot meter will enable the separate sky and land readings to be placed on predictable tonal renditions; no uncertainty.

As an aside, the Minolta SRT-101 is a particularly interesting case. The TTL metering for this camera featured the CLC (contrast-light-control) design which biassed the meter reading to the lower part of the focussing screen. This was to avoid under-exposure because of too much bright sky influence. In practice this worked ok until the camera was turned to portrait mode orientation. Then the metering bias was either to the left or the right depending on how you held the camera.

All my grumbling aside I think TTL metering can be a very convenient camera feature that enables quick access to acceptable results. The lack of precision is hidden in the exposure tolerance of photographic materials and in user tolerance for minor exposure errors.

Posts #3 & #4 nailed it. If you're shootin' slide film, use an incident meter -- preferably one with a spot attachment (which can be handy at times, like if you are in the shade and can't get out of it).

But having an "accurate as possible" TTL camera meter is handy at times. For that, go with the MR-9.

Maris said:

This is very late in this fascinating thread but I've never been able to think of cameras with through the lens metering as being precision exposure devices. Well, maybe if a camera has a "hard", sharply defined, flare free, narrow angle spot meter in the viewfinder it could be possible but I don't know of such a camera.

I see a fundamental problem in TTL metering being that the meter reading depends on how the subject is framed in the viewfinder. A landscape framed with 1/3 sky, or 1/2 sky, or 2/3 sky will deliver three different meter readings with a perfectly calibrated TTL meter. Which, if any, of those meter readings is correct remains uncertain. On the other hand a good hand-held spot meter will enable the separate sky and land readings to be placed on predictable tonal renditions; no uncertainty.

As an aside, the Minolta SRT-101 is a particularly interesting case. The TTL metering for this camera featured the CLC (contrast-light-control) design which biassed the meter reading to the lower part of the focussing screen. This was to avoid under-exposure because of too much bright sky influence. In practice this worked ok until the camera was turned to portrait mode orientation. Then the metering bias was either to the left or the right depending on how you held the camera.

All my grumbling aside I think TTL metering can be a very convenient camera feature that enables quick access to acceptable results. The lack of precision is hidden in the exposure tolerance of photographic materials and in user tolerance for minor exposure errors.

Click to expand...

Maris, i think you nailed it. In decades of working with kodachrome, i had success with many different cameras with built-in meters. Now after a long time of working in LF and black & white, i prefer to use handheld meters either spot or incident, and have no use for in camera meters.

I have always used hearing aid batteries in my FTb and F-1, and have a lot of perfectly exposed slides to show for it.

With that said, the title of the original question referred more generally to metering with mechanical SLRs.

There are cameras out there that both are able to tolerate voltage differences(Pentax K1000 is most notable among the "cheap" cameras) as well as ones that use silicon metering cells that tend to have held accuracy/linearity better after ~50 years than any of the CdS cells out there.

For Canon FD, your best option is probably a New F-1. It's not a pure mechanical camera but a hybrid, and can work from 1/90 to 1/2000 without a battery. It uses a silicon photocell, allows you to change the metering pattern(with a focusing screen change) and uses the fairly easy to find PX-28(4LR44) battery. There's also the T60 for a more modern pure mechanical camera, albeit one made by Cosina and badged as Canon.

The Nikon F2 uses 2x LR44 batteries(or the 3V extra tall battery whose number escapes me as I'm typing this), as do a lot of the other Nikon mechanical SLRs like the FM and FA series. You have silicon metering options in the F2 like the F2SB and F2AS. I don't remember what the FM uses, but the FM2(n) is silicon and is fully mechanical. If you want to spend a pile of money, the FM3a both is fully functional at all speeds without a battery and offers aperture priority.

I think perhaps my approach to metering with my in-camera TTL meters is different from the "default." I'm not hoping for a meter that will look at any scene, understand what it is, and spoon feed me the singular perfect exposure every time. Really all I wanted was a camera with a metering area I understand (whether that's full frame, biased towards the bottom, partial, center-weighted average, or spot), that matches my spot meter. And when I say "matches my spot meter" I mean if I fill the entire metering area with an evenly-illuminated, homogeneous subject (a concrete wall on a cloudy day or what have you), then the camera will give me the same recommendation to expose the whole thing at Zone V as my spot meter.

I believe I have achieved this with my favorite two 35mm SLRs (an OM-1 and an FTb) After soldering in diodes to both meter circuits to allow for SR44 batteries, and then using the built-in calibration tools (a brass cam on the galvanometer of the OM-1, and a couple of potentiometers on the FTb), I got excellent and reliable matches (less than 1/4 stop) between the cameras and my spot meter at EV9, EV12, and EV15.

When I actually go out and shoot slide film in my FTb, I'm using its well-defined rectangular "partial" metering area in the center of the frame to check a shadowy area in the foreground, the sky if there is a sky, etc. to get a good idea of the subject brightness range of the scene, and then placing the most important shadow or highlight where I think it ought to go. Not just pointing it somewhere and centering the needle in the lollipop.

The OM-1 is trickier since so far as I can tell, it uses the entire area visible in the viewfinder to get an averaged meter reading, with no bias that I can detect towards the bottom of the frame (such as the bias found in my XA). Often I end up walking closer to an area of shadowy foreground so I can get a meter reading where the entire frame is filled with only shadowy foreground. I can repeat the same exercise by filling the frame with sky, in order to understand scene brightness range, if I intend on including sky in the composition.

Or, basically, I'm using these meters as imprecise spot meters. Imprecise in the sense that it's more difficult to isolate a single area of tone that I want to place on, say, Zone III, but not imprecise in the way that the readings themselves, properly understood, are inaccurate. I believe that the exposures I am choosing for a given scene are the same with my built-in meter as they would be if I happened to use my external spotmeter to make the decisions. That was my goal, and my definition of "perfect metering."

Sometimes, in trickier scenes that have a lot of smaller areas of different brightness, where it's hard to fill the metering area with something I considered a good representation of what I'd want to put on Zone III or Zone IV, I will set my composition, take my best educated guess at what the actual "average" brightness of the entire scene is (perhaps the entire scene, if averaged together into a gray rectangle, would land somewhere around Zone VI instead of Zone V, for example), and expose accordingly.

So far results have been great since I got the metering circuits in these cameras modified and calibrated.

xkaes said:

Posts #3 & #4 nailed it. If you're shootin' slide film, use an incident meter -- preferably one with a spot attachment (which can be handy at times, like if you are in the shade and can't get out of it).

But having an "accurate as possible" TTL camera meter is handy at times. For that, go with the MR-9.

Click to expand...

Agree wholeheartedly with both incidents metering and Mr-9 recommendations. But never heard of an incident meter with spot capability; can you give an example, please.

I don't have a complete list, but several meters fall into this category. A few have an incident dome AND a spot meter built-in, but most simply allow the incident disk to be removed and a spot attachment to be attached instead. These spot attachments vary in coverage from 10° to 1°. Gossen, I think, even had one with a zooming spot.