Nikon FM overexposing

Discussion in 'Nikon' started by arthur_smith|1, May 5, 2015.

  1. So, I have shot a couple of rolls with my newly acquired FM. After developing a couple of rolls, the shots seem to generally be over exposed by a stop. I have a roll of TriX in there now, and have my ASA set to 800. For times when I don't want all that speed, like outdoors with a wide angle or normal lens, does it make sense to reduce the light coming in with an ND filter? If so, which filter specs should I use? Thanks, Arthur
     
  2. Well, Tri-X only has a true speed of around 400 ISO, so setting your camera ISO to 800 doesn't make any sense. And are you sure it's overexposure you're seeing and not over-development? The two are easily confused unless you know what to look for.
    Overexposure will give you overall dense negatives with a fairly normal contrast and some detail in the highlights, while over development will give you negatives of high contrast with almost no printable detail in the highlights. Over development is common from too many commercial labs these days I'm afraid.
    "For times when I don't want all that speed, like outdoors with a wide angle or normal lens, does it make sense to reduce the light coming in with an ND filter?"​
    You shouldn't need an ND filter. The "Sunny 16" rule means you should need no more than 1/500th of a second @ f/16, well within the shutter speed range of the Nikon FM camera and the aperture range of most lenses. However, if you want a shallow depth-of-field then you will need to use a slower film or an ND filter. To use an aperture of, say, f/2 at the camera's top speed of 1/1000th in full sunlight you'd need a 5 stop (32x or 1.5D) filter. The focal length of lens makes no difference to exposure BTW.
    Edit: If your Tri-X shots really are overexposed with an ISO setting of 800, then I'd suggest that the camera meter or shutter are out of calibration. But try the Sunny 16 rule first, http://en.wikipedia.org/wiki/Sunny_16_rule as a rough guide to telling if the exposure reading you get from the camera is out of whack.
     
  3. It makes perfect sense to me. if the camera's meter is overexposing, a faster shutter speed may be called for. I may also try try shooting at 400, and going with the meter's underexposure indication. Yes, I would like to use shallow DOF on occasion. And I am familiar with Sunny 16, but it is not the end-all.
     
  4. If your meter overexpose for one stop, it certainly makes sense to set the ISO at 800 to halve that excess of light and expose the film correctly.
    But I agree with Rodeo... are you sure it is overexposure? Think that there are more possible reasons to get the film too dense; from a development failure (overdevelopment, something quite common in my experience), to an excessive contrast scene. Standard developing times doesn`t know about scene contrast. Camera meters can also get fooled with certain subjects.
    Meters could go out of calibration (mine have needed calibration a couple of times), but before any CLA I`d try what Rodeo suggests... compare your camera readings to the Sunny f16 charts. Or better to check it with another camera or hand held meter and a grey card.
    Which ND filter strength? Calculate it by yourself. If you shoot under good illumination (f16-1/500 with TX), a 8x filter will take three stops. So it will help you to shoot at f4 (1/1000).
    BTW, expect the exposure tolerances yo be as much as one third of a stop in a mechanical camera. Usually they are far more accurate, but one third is considered acceptable.
     
  5. I think RJ was suggesting using Sunny 16 as a guide to figure out if the meter is overexposing or if there is some other fault. A sluggish aperture can also cause overexposure. Scanning can also be a weak link and certain scanner presets can have an effect on the exposure in the final image.
    If you want to use wide apertures or longer shutter speeds in bright light, or if you are worried about diffraction at smaller apertures, then ND's or polarizers are required. My personal preference is towards polarizers since there is some flexibility in the amount of light loss and the overall effect.
     
  6. ShunCheung

    ShunCheung Administrator

    Over and under-exposure is frequently difficult to judge when you look at negatives, such as Tri-X, due to the reversal.
     
  7. I dont think its development- I have noticed on both TriX and TMax 100. and, my F3 exposes those perfectly. Different lenses also have produced overexposure. Meters can go out of whack- after all, we are talking circuitry that is over 30 years old.
     
  8. I have noticed the overexposure through the scanning process. And I do not notice overexposure on my F2, F3, FE2, F FtN, N80, or N65.
     
  9. Meters can go out of whack- after all, we are talking circuitry that is over 30 years old.​
    Lots of things can go out of whack, including the mechanism that closes the diaphragm down to shooting aperture. If it is overexposure, which is still not clear to me, it could be due to other causes than the meter. Are you experiencing this at all shooting apertures?
     
  10. If the question is whether the meter in your FM is off, there's no need to even shoot any film let alone look at negatives or scans. All you need to do is compare the meters.
    I would take your FM, F2 and F3 and set them up the first one on a tripod pointing at a fixed subject against a fixed background with fixed lighting. (Outdoors at mid-day with constant bright sun would probably be easiest). See what exposure reading you get. Then, using the same lens and without moving anything, see what exposure readings you get with the next two cameras. If the FM is consistently giving you a one-stop difference from the others, you know that it is off one stop. All you have to do is adjust the film speed setting accordingly to compensate (as it sounds like you've already done) and you'll have correct exposures. If you want to spent the money to have it fixed is up to you.

    The purpose of comparing the FM against two other cameras is to make sure the camera you're comparing it against isn't the other that's off. If two out of three say the same thing, those two are most likely the ones that are correct.

    As for an ND filter, this is a metering problem not something that requires an ND filter to fix. There are reasons to use an ND filter, but an out-of-calibration meter is not one of them.
     
  11. Yes, I would say at all apertures. I am going to take Craig's advise and compare the meters, and also, try to use Pocket Light Meter on my iPhone to meter half a roll, and see what I get.
     
  12. If it's the mechanical camera shutter that's causing overexposure, then comparing meters won't help. A slow shutter is more likely, since electronics are generally more reliable than mechanical clockwork.
    Quite frankly Arthur, with the collection of cameras that you have, I'm not sure why you're bothering with a troublesome FM. Just use one of the other Nikons at your disposal that you know are working fine.
     
  13. I love them all. Variety is the spice of life. I doubt there is a shutter issue. if there is, a few shoots might very well be what the FM needs.
     
  14. Lukas Fritz has been so kind helping us with that suspicious shutters:
    http://www.photo.net/classic-cameras-forum/00bdOI
     
  15. It's worth pointing out, if the meter is out of whack, using an ND filter is not going to be of any benefit.
     
  16. When in doubt, shoot sunny-16 and dial in your developer. Then, figure in the meter factor.
     
  17. I'm going to chime in and say that the mechanical parts which regulate the shutter speed are more likely to be "slow" than the light meter. Just a guess, but old oil and tired springs would slow things down. A shutter speed check would be a cheap way to confirm.
    Light meter problem should be diagnoseable by pointing a known accurate Nikon with the same lens at a wall. A whole stop off should be easy to spot.
     
  18. Important to note is that I did have a few nice exposures. But to my eyes, the light areas seemed very light, almost washed out. Out of all of my cameras, I think the F3 has a great light meter. I may use that one to compare, as well as Pocket Light Meter.
     
  19. In a 36 exposures film there are place for very different contrast ratios. And there is just one developing time for all of them... if you think there are some good shots, the developing time only suits this scene`s contrast.
    Shoot extremely bright scenes and the result will be underexposure. Shoot dark scenarios and the result will be overexposure. And it doesn`t matter if the scene is high or low contrast... despite of this, the ISO and developing time are always the same. Wrong from scratch, don`t shoot roll film... ;D
     
  20. Peter says: "I'm going to chime in and say that the mechanical parts which regulate the shutter speed are more likely to be "slow" than the light meter. Just a guess, but old oil and tired springs would slow things down."
    Peter, is it likely this is diagnosable by setting the FM at one second and listening to the shutter fire? I've found that many shutter timing problems can be identified that way. If 1 second is incorrect, the whole shutter is called into question. I've disqualified for purchase (or qualified for my own cheapskate CLA) several cameras this way.
     
  21. If you're going to compare the FM's meter to that in your F3, just beware that the F3 gives more weight to the center circle than most other Nikons. 80/20 for the F3 versus 60/40 for the rest.
     
  22. I guess it depends on how good your timing is.

    I'm an engineer, so I would probably build an optical shutter speed measurement gadget. :)
     
  23. You first make sure that your film is underexposed. If it is. Compare meter to known good meters. If meter is OK check shutter speed accuracy. Aperture can be wrong but very unlikely. If the camera isn't accurate buy another I am sure you can afford to buy another FM.
     
  24. Wow, shouldn't the camera be sent for a CLA and the meter can be checked as well.
     
  25. No! If the problem is serious enough a repairer can't make a living charging less than $100. Even a good CLA should cost more than that. Good used FM can be bought for less than $100.
    I know you're going to say that after the CLA the camera is certain to be good for a long time. I don't think so.
     
  26. I dont want to overengineer a solution for an otherwise great camera that I paid less than $40 for. But, I did have a few good exposures that I spotted in scanning last night. And they required very little, if any, adjustments to highlights. Sending it in for a CLA would cost more than I paid for it. I have replaced the seals, mirror dampener, light meter batteries, and a few cosmetic things. I am going to keep working the shutter and live with it.
     
  27. Might use the FE2 to compare metering. That meter is usually dead on.
     
  28. My mistake, you said it overexposed by 1 stop in that case if you shoot negative film either B&W or color isn't a problem at all.
     
  29. I see your point Bela, but what I'm going to say is if you can't figure out how to compensate for whatever the problem is on a consistent basis, assuming its camera related, than the camera is really worth $0. So what is the worth of having properly exposed photographs to you? I don't know how much a CLA or just a meter adjustment is. I imagine it depends.
     
  30. The DOF preview lever was not opened up all the way. Guessing this may have had some impact on proper exposure.
     
  31. the shots seem to generally be over exposed by a stop.​
    Since you already know that, it is not a problem at all, for whatever reasons there are. We should not try to solve the problem before the problem is described clearer. But in my experience, the mere fact that you purchased it recently at $40 suggests that the meter is bad and the shutter speeds are not accurate either. I do have a few FM in mint conditions not needed for a long time, but to sell for $40, the answer is "no way". I mean, if someone has been taken good care of his/her beloved FM, he/she would not sell it for $40.
    Again, with a little compensation, you can easily get perfect exposure. That would be a lot easier than using an old Leica.
     
  32. "The DOF preview lever was not opened up all the way. Guessing this may have had some impact on proper exposure."​
    Shouldn't have any effect on the actual exposure. The preview lever simply stops the iris down to whatever aperture has been set on the manual lens ring. However, partial operation may result in a slight viewfinder darkening, and hence will affect the meter readings to give overexposure. So it looks like the metering issue might be sorted.
    But I thought you'd tested the camera at all apertures Arthur? Setting the lens to maximum aperture would have over-ridden the preview lever and made the meter read correctly.
     
  33. I was hoping to get help on here, not have my purchasing or troubleshooting skills critiqued. This is far from my primary camera, and the good exposures I have taken have already helped the camera more than pay for itself.
     
  34. An update- I shot another roll over the weekend, and developed using Rodinal and semi-stand developing. Got some beautiful exposures, and the process seems to hold highlights beautifully. So, maybe it was my development. In any event, very happy! Still think the F3 meter might be the best out of the Nikon manual focus bodies.
     
  35. Congratulations! The F3 is a pro body, so there is no wonder it is better than the FM. Personally, among all Nikon film cameras, I like the F4 the most (for performance, not other characteristics like size, beauty, ...). It is not a manual camera by definition, but I turn off AF and slide the mode to M. There I have my perfect manual film camera. Its meter would be better than the F3 (not that I care about or need a meter)
     
  36. Ask 50 photographers what the best 35mm camera to use is, and you'll get over 100 responses. I don't think not using a light meter makes someone a better photographer. They are tools, and can be used nicely in the right hands. They are never 100% accurate, but it's always nice to have a guide that can make an accurate recommendation as to what exposure to use for most given situations.
     
  37. In ye olden days we'd use color slide film to evaluate the meter, shutter and aperture function. Negative film was so forgiving it wasn't useful for estimating those factors, unless it was a full stop off.
    I still use a copy of Fred Parker's Ultimate Exposure Computer charts to evaluate meters when I'm not sure they're quite right. Helps in tricky lighting when some simpler meters are easily fooled by strong backlighting, or light entering the eyepiece (the Olympus OM-1 was very vulnerable to stray light entering the eyepiece).
     
  38. Thanks- I have never heard of Fred Parker's Ultimate Exposure Computer charts- will have to look into that. I have been using my iPhone Pocket Light Meter, and Gossen Luna Pro F, and the more I compare now, the FM's meter looks to be within a half stop. Not bad for an almost 40 year old camera.
     

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