Old Nikon SLRs consistently overexposing, but only in strong light?

[albireo]

I don't have many older SLRs as I tend to like using electronic SLRs from the 90s or newer. My Nikon F90X, Canon EOS3 etc are my favourite class of 35mm cameras.

On occasions I dust off a Nikon FG and a Nikon FE - both in great condition, visually mint, great mechanics etc etc.

My last two rolls with the FG and FE however produced extremely overexposed negatives. I was surprised, as I used film and developers I have standardised on, and I use the same film+dev combo with the F90X and EOS3 with spot on results every time.

I had never noticed dense negatives from the FG and FE before but interestingly I had mostly used them in Winter, with poor lighting, and never in full sun. This time, I was taking pictures in bright conditions and just shot away expecting good results.

The negatives are borderline unusable for my standards. I decided to make a quick check

-Same lens, tripod, swap lens between FE, FG and F90X - bright sunny day, measure bright walls, bright skies; exposure meter in the F90X set to centre-weighted.
-Repeat test against EOS3, set to centre weighted meter, and use a Canon EF prime lens of the same focal length as above. Same tripod.
-Compare FE and FG against 'sunny sixteen' guess in simple bright light frame, iso set to 250 (so expect 1/500 f/11). Same tripod position, same lens.

Results: Nikon F90X and EOS are in complete agreement with each other, and +/-1/3rd stop wrt sunny 16 guess (depending on scene, discrepancy ofc due to wrong guess on my side). FE overexposed by 1 and 1/3rd stop. FG overexposes by 2 stop.

I repeated the above test in an indoor setting. Same ISO setting. Overexposure error of the FE and FG reduces to 1/3rd stop.

So it would appear that the meters in these two cameras are not to be trusted anymore, which is a shame. What is even more worrying is that it seems they can kind of be trusted when the light is low, but become essentially useless with strong light?

My questions

• Has anyone else encountered this kind non linear metering error in these Nikon cameras?
• Any other checks you would recommend I should try to make sure I'm not wrongly interpreting what I'm seeing?
• How common is it in similar photodiode cell meters of the same age?
• Is it worth attempting to have them fixed?

 

[albireo]

Interesting bit of info I didn't know, from https://camera-wiki.org/wiki/Nikon_FM

The FM used a match-diode metering system with the then-new gallium-based photodiode system that was supposed to be better than the earlier cadmium sulfide or selenium-based metering systems that came before

Emphasis my own. Does the above suggest it turned out not to be better than the older selenium based type?

 

[Chan Tran]

I had a couple of FE and I don't remember how accurate the meter were. My EM meter is overexposing by about 1 stop. My FM and FM2n are perfect. My F3 before I broke the shutter was perfect but the meter was not good before. I had to have a chip replaced and I did the calibration.

 

[Disappointed_Horse]

I have two FEs, one of which I've had for over 15 years. I haven't had any problems with the meters of either of my FEs, so I can't offer much assistance with regard to your problem. However, I do think the FE is an excellent camera and well worth having serviced. I last had mine serviced about four years ago, and the cost was reasonable and it came back functioning perfectly.

 

[koraks]

So it would appear that the rudimentary meters in these two cameras are not to be trusted anymore

The question is whether they were to be trusted to begin with, under the specific (challenging) circumstances mentioned. I think not.
The issue is also not so much semiconductor type, but metering pattern. The cameras you pitted these old ones against all feature highly intelligent, complex metering systems that have decades of R&D incorporated into them exactly to deal with the kind of challenge you've thrown at them. The somewhat unsurprising conclusion is that the R&D paid off in better performance.

Use your old cameras with confidence within the reasonable boundaries the technology permits.

 

[Chan Tran]

The question is whether they were to be trusted to begin with, under the specific (challenging) circumstances mentioned. I think not.
The issue is also not so much semiconductor type, but metering pattern. The cameras you pitted these old ones against all feature highly intelligent, complex metering systems that have decades of R&D incorporated into them exactly to deal with the kind of challenge you've thrown at them. The somewhat unsurprising conclusion is that the R&D paid off in better performance.

Use your old cameras with confidence within the reasonable boundaries the technology permits.

The OP compared the meters with the new cameras on center weighted and not on Matrix or Evaluative. Center weighted is a well defined metering pattern R&D has nothing to do with the reading. My FM's , F5 Df and D850 read the same.

 

[koraks]

Center weighted is a well defined metering pattern R&D has nothing to do with the reading.

The optics of the metering systems in these newer cameras are far more resistance to extraneous influences as well. Besides, do you know for sure that the center-weighted metering system on a matrix meter is a straight-through conversion? Fact of the matter is that you don't know this, and it most likely isn't and it's a mathematically weighted average, not an analog/electrical average as it would be in an old meter. So yeah, R&D has a lot to do with it.

 

[Nitroplait]

My first thought was LR44 batteries on the wrong side of the depletion curve.
I have seen it on other cameras, but have always used silver oxide and lithium in my FE.

 

[albireo]

The question is whether they were to be trusted to begin with, under the specific (challenging) circumstances mentioned. I think not.
The issue is also not so much semiconductor type, but metering pattern. The cameras you pitted these old ones against all feature highly intelligent, complex metering systems that have decades of R&D incorporated into them exactly to deal with the kind of challenge you've thrown at them. The somewhat unsurprising conclusion is that the R&D paid off in better performance.

As far as I know progress in metering has converged into 'evaluative' Matrix metering for Nikon. Centre weighted has always been a 60% to 40% ratio of the frame (perhaps 80% to 20% in some models, I can't recall which).

 

[albireo]

My first thought was LR44 batteries on the wrong side of the depletion curve.

I thought about that - the batteries were replaced last month, and I only took 2 rolls of pictures since. The battery test in the FG suggests plenty of charge.

 

[koraks]

My argument doesn't revolve around the formal spec, but the actual implementation.

Anyway, I've made my point; I don't really feel like doing a thesis on metering systems at this point so let's just say "holy cow, it's a miracle!".

 

[runswithsizzers]

Same lens...

Is it possible the lens is sluggish to stop down and therefore at a wider-than-wanted aperture at the time of the exposure?

Nevermind, after re-reading that post, you are reporting the metered results differ in your test, and not the actual exposures on film, right?

 

[albireo]

My argument doesn't revolve around the formal spec, but the actual implementation.

I think if the issue was evolution in implementation this would make it such a common issue with people owning various incarnations of centre weighted meters that there would be a lot of online discussions about such huge divergence in cameras of different vintage using 'on paper' the same centre-weighted style of metering,

 

[koraks]

there would be a lot of online discussions about such huge divergence in cameras of different vintage using 'on paper' the same centre-weighted style of metering,

You've never seen people mention metering inaccuracies with older type center weighted metering systems under high-contrast conditions, conditions involving light sources along the edges or just outside the image frame etc?
AFAIK such metering systems are notoriously unreliable under such conditions. At least each and every one of them I've used over the decades turned out to be. Maybe I just had dozens of duds, though.

The way I see it you've just determined a specific set of conditions under which these specific meters (ie yours) give this specific anomaly. So you can take this into account when using these cameras and live happily ever after. Personally I wouldn't be inclined to make more of this than meets the eye.

 

[Chan Tran]

The optics of the metering systems in these newer cameras are far more resistance to extraneous influences as well. Besides, do you know for sure that the center-weighted metering system on a matrix meter is a straight-through conversion? Fact of the matter is that you don't know this, and it most likely isn't and it's a mathematically weighted average, not an analog/electrical average as it would be in an old meter. So yeah, R&D has a lot to do with it.

The better center weighted system should be more closely to definition. The old analog is close enough to the definition so being closer doesn't make much of a difference. (less than 1/3 stop with all my cameras). I know the new one is always a multi spot metering system.

 

[albireo]

Is it possible the lens is sluggish to stop down and therefore at a wider-than-wanted aperture at the time of the exposure?

Nevermind, after re-reading that post, you are reporting the metered results differ in your test, and not the actual exposures on film, right?

Hi. Yes in the tests outlined above I was just observing the shutter speeds I read in the viewfinder when setting the aperture as needed (I used Aperture priority on all cameras).

 

[Chan Tran]

Good exposure doesn't mean accurate meter. I want the meter to be accurate but how you interpret the readings is important. I have the Yashica Lynx 14 and the shutter speeds were slow about 1 stop and more. The meter doesn't work so I guess the exposure. Took a roll last week and the images are all OK and many are in the slight underexposure category. None was overexposed.

 

[BrianShaw]

Like others, it seems, the explanation isn't apparent but I can assure you that it isn't the "rudimentary meter" at fault; at least not because of hte design or implementation. Nikon isn't toy cameras and never has been. This thread may have been more productive had it not beeen for these kind of incindiary words. Thank you for letting me get that off my chest.

Something is going on, I'm sure. You might want to try 2 things: first, evaluate your negatives to see if flare could be the source of hte incorrect metering and second, set up another test using a very consistently lit wall rather than a natural scene. And try using a lens hood/shade.

I've been using the Nikon center-weighted meter, very often in A mode, since the 1980's with both F3 and FE. Never had a problem like that. It's not a design issue. Look for the other sources of error.

 

[argent_negre]

Just to add something to the discussion, I find difficult to believe that overexposing by 1 stop is going to give "extremely overexposed negatives".

 

[BrianShaw]

Interesting bit of info I didn't know, from https://camera-wiki.org/wiki/Nikon_FM



Emphasis my own. Does the above suggest it turned out not to be better than the older selenium based type?

That's hilarious. It's the only opinion offered in the entire Wiki, and it's poorly stated. It should read, "The FM used a match-diode metering system with the then-new gallium-based photodiode system that was supposed to be better than the earlier cadmium sulfide or selenium-based metering systems that came before." As originally written, it leads to interpretations that are completely incorrect.

 

[albireo]

Like others, it seems, the explanation isn't apparent but I can assure you that it isn't the "rudimentary meter" at fault; at least not because of hte design or implementation. Nikon isn't toy cameras and never has been. This thread may have been more productive had it not beeen for these kind of incindiary words. Thank you for letting me get that off my chest.

Something is going on, I'm sure. You might want to try 2 things: first, evaluate your negatives to see if flare could be the source of hte incorrect metering and second, set up another test using a very consistently lit wall rather than a natural scene. And try using a lens hood/shade.

I've been using the Nikon center-weighted meter, very often in A mode, since the 1980's with both F3 and FE. Never had a problem like that. It's not a design issue. Look for the other sources of error.

Thanks. I see nothing incendiary in 'rudimentary', but I agree it was not the right word choice, given in principle a centre weighted averaging meter should be a centre weighted averaging meter.

I regularly use hoods on all my lenses so I don't think that's the issue.

The scenes I used for the test were very simple frontlit scenes so I see no issues there.

I'm not claiming there is a design issue at play. I'm wondering if there is decay or time-related inaccuracies at play which generalise to meters of the same vintage, or if my two cameras are simply faulty.

 

[albireo]

Just to add something to the discussion, I find difficult to believe that overexposing by 1 stop is going to give "extremely overexposed negatives".

In my workflow more than 1 stop - 2 stops in the case of the FG - leads to visible issues I like to avoid.

 

[4season]

Was the test scene (usually a wall or something similar) evenly illuminated, and filling the entire frame?

Did shielding the viewfinder eyepiece against stray light have any significant effect?

 

[BrianShaw]

I'm wondering if there is decay or time-related inaccuracies at play which generalise to meters of the same vintage, or if my two cameras are at fault.

I've paid attention over the years and never seen a hint of time-related inaccuracies other than light leaks and broken FREs for that era of Nikon camera. It's most likely not a generic issue and probably something you're not currently looking at regarding your technique. Give some consideration to the more recent suggestion of "light leak" through the viewfinder. The F3 addressed that issue with a viewfinder shutter built into the prism.

 

[Chan Tran]

Thanks. I see nothing incendiary in 'rudimentary', but I agree it was not the right word choice, given in principle a centre weighted averaging meter should be a centre weighted averaging meter.

I regularly use hoods on all my lenses so I don't think that's the issue.

The scenes I used for the test were very simple backlit scenes so I see no issues there.

I'm not claiming there is a design issue at play. I'm wondering if there is decay or time-related inaccuracies at play which generalise to meters of the same vintage, or if my two cameras are at fault.

simple backlit scene? Can you describe in more details? Unless backlit is something like a light box otherwise it should be an evenly front lighted and the the entire scene should be the same brightness. This is necessary to eliminate the different weighing. The FE and FG has 40/60 weighing the F90 has 25/75 weighing.