FM2n meter - can it be calibrated cost-effectively?

[b_c12]

I have an FM2n that I love. However, it has always underexposed about a stop when the meter reading is observed.

It's not a huge problem, as I generally overcome it by shooting at 1/2 the ISO of the film I'm using...or simply

increase F stop by one. I'd love to get it "zeroed in," however, if it can be done without too much hassle or

expense. Any suggestions?

[leicaglow]

I had one CLAd for $125. I would think just the meter adjustment might not run that much.

[User_276104]

I have a Nikkormat FT2 that underexposes by 1 stop from my other bodies. I bought it used in 1999 and wondered if I should return it, but then I read a John Shaw book in which he discussed calibrating the meter to your own liking (moving the ISO around) and I never worried about it again.

[lex_jenkins]

BC, how did you determine that your meter needs to be calibrated? What testing methodology did you use?

[b_c12]

Lex - I determined the error by a couple of means:

 

1) Underexposed B&W negatives when set at desired ASA relative to my other camera bodies.

2) I develop my own B&W film and did a few test rolls with consistent times/processes between the bodies. Shot several different conditions with each camera at the same time and same settings. B&W negs from FM2n came out underexposed. Others were fine.

3) Full stop meter discrepancy between the FM2n's and FG's + D40's meters. Even my Rolleiflex.

[lex_jenkins]

Have you identified the metering patterns for each camera or handheld meter used in these comparisons?

 

Are you metering off an appropriate, continuous tone surface under even illumination?

 

Have you compared the Nikon's TTL meter against a calibrated meter or other meter known to be reliable, using the above described scenario?

 

Have you eliminated mechanical variables such as lens diaphragms and shutter speeds as possible problems?

 

Have you tested using color slide film processed by a reliable lab? There are many variables involved in using b&w negative film, and it would be very difficult to determine a 1/2 stop variance with any reliability without methodical testing and a densitometer?

[b_c12]

It's a one-stop difference, not 1/2. I used the same lenses for each comparison...namely a 50mm F1.8 set at identical apertures and shutter speeds.

 

You bring up a great point, though...I do not know the accuracy of the shutter speeds on the FM2n. That could very well be a factor. The speeds compare favorably at low shutter speeds as compared to my FG, that's for certain. Higher speeds I can't say other than by "sound and feel" but that's probably irrelevant.

 

I have run some Velvia through the FM2n and have seen the same phenomenon. Reputable lab here in Dallas. I have not compared this vs. my other bodies in exact same circumstances, however. I have of course run slide film through my other bodies with good results at indicated metering.

 

I've used HC-110, but perhaps more controllably, Diafine, in the B&W comparisons. I think Diafine may be about the best I can do in terms of level playing field in B&W development.

 

The subjects taken were things like brick walls under shadow conditions, sun-splashed, sky scenes, total shadow, white walls, and high-contrast situations (black dog against bright lawn). Same and consistent results with regard to the stop difference.

 

No use of densitometer, I don't have access to one.

 

Thanks again for your help.

[photo5]

If you develop your own film, how do you know your film developing is calibrated correctly? Try increasing the development time or the dilution of your developer. I've rarely heard of any Nikon with a meter consistently off by 1 stop. I say it's your development, not the camera. Also try printing with a stronger filter to get your blacks true black. I used to totally nuke my black and white negatives during development. Scanning them nowadays isn't easy!!

 

Use the Sunny 16 rule. On a sunny day, your exposure with 100 film is 1/125 at f16 or any equivilant (1/500 at f8 works too). Shoot a test like this and see how it comes out with your normal development routine. If they are still under, increase your development time by one stop and you're there.

[b_c12]

Dave - that's why I commented that I used Diafine for some of the comparisons. I figure, perhaps incorrectly, that it's the most consistent way of development since it's not very temperature or time dependent. In fact, I developed both rolls of 35mm (one from FG, one from FM2n) in the same tank at the same time using Diafine...so that's about as close as you can get to consistent times/temps/etc. For what it's worth, I'm using Arista Premium 400 for these trials.

 

Thanks again....

[cabrabesol]

I used to calibrate it based on tests on a grey cardboard keeping exposure values fixed and varying the iso/asa value on it's own dial.

 

Once you have determined the exact (for you and your film chain) simply dial in the iso value of your film plus (or minus) the delta form your findings. If it helps, use a stiker in the film cover holder on the back and write down the most common values es: 100=160 and so on. That I found is a very effective way to correct and uncalibrated meter.

 

Be careful with the sunny 16 it applies to slides. If i remember well (from kodak's exposure strips) for a color negative you must use f11 and not f16.

[b_c12]

Thanks Mauro, that's what I've been doing more or less. I was just hoping there was a way to get the meter calibrated accurately without having to adjust ISO. In other words, make it like it was supposed to function. Get the 0 to light and press the shutter = correct exposure @ box ISO or preferred EI.

 

Thanks again

[lex_jenkins]

<i>"Get the 0 to light and press the shutter = correct exposure @ box ISO or preferred EI."</i><p>

 

Unfortunately, that's not how it works. That approach will give only an approximation of a correct exposure for some, probably not even half, of all exposures. There are far too many variables for a single type of metering tool to deliver 100% satisfaction with all types of film or digital sensors, of all scenarios in all types of lighting, all of the time.<p>

 

While it's possible your FM2N meter has indeed deviated somewhat what factory specs, it's far, far more likely that the variations you're seeing are due to the metering pattern and at least half a dozen other variables.

[b_c12]

Could be Lex.... like you say, lots of variables...but I'm pretty sure that the meter is indeed off based upon a good

amount of experience with this and other cameras...particularly with B&W and associated darkroom processes.

It's more of a "wish it would" than a "need it." I've been working around it in the manner prescribed in my initial post

for a long time. Wish there was a variable resistor (pot) I could fine-tune it with.... oh well, like I said, no big deal.

It's a great camera regardless and I continue to enjoy it. If there's no practical way to adjust, I'll still be content.

 

Regards to all who made suggestions....

[photo5]

I still say the camera is on, and your processing is not. If you're really sure the camera is off, why not take it into a good camera repair shop. They can tell you in 5 seconds if they have a good tester if your meter is accurate. I worked at a camera repair shop for a few years, and we never found a Nikon with a meter that was off by a stop. Maybe a third of a stop, but that is "within factory tolerances." Of course when we'd do a CLA we'd get it in a lot better tolerance than that! My friend is in Spokane, Washington now (he was in Issaquah, Washington before that) and he still has a store and uses a very expensive Kyoritsu shutter tester to calibrate camera meters and shutters. It can display the timing of the first and second curtain as well as the overall shutter speed and meter.