Nikon F3 metering issue

Discussion in 'Modern Film Cameras' started by fred_bailey|1, Jan 5, 2018.

  1. Hi all - apologies if I’ve posted in the wrong place.

    Just wondering if anyone can help - finally acquired a gorgeous F3 recently, everything works except the meter. I’m aware that it only reads 1/80 before the frame counter hits 1 etc etc, but regardless of my film speed setting, f number etc, the meter reads underexposure regardless of what shutter speed I choose, if I go over to aperture priority, the LCD reads an 8 second exposure that doesn’t actually end until I change shutter speeds (like T mode).

    I know I probably need to get a CLA, but I just wanted to know if anyone could point out me doing something silly!

  2. It's not somethng silly but rather serious. The camera either lost the input signal from the sensor or the input from the FRE. But it's more likely to me it's a no signal from the sensor rather a broken FRE. Not a cheap repair I don't think so.
    On second thought, it could possibly that the secondary mirror is stuck in the up position and thus delivering no light to the metering sensor.
    Last edited: Jan 5, 2018
  3. Vincent Peri

    Vincent Peri Metairie, LA

    The Nikon F3 is not a digital camera. It doesn't have a sensor. And what is an FRE?
  4. The sensor is a light sensor to measure light. The FRE is Nikon term for the "Functional Resistor". Actually there are 2 of them. On is in the aperture coupling and the other is in the ISO dial. They are used to send signal to the metering circuit about the ISO and aperture in used. The sensor for the light meter of most camera before the F3 is in the viewfinder but with the F3 it's at the bottom of the mirror box. The main mirror has many tiny holes that light can go thru and then reflected by the secondary mirror down on to the sensor.
  5. Out of curiosity, is this a camera that you've received in the mail-like within the last few hours?

    If that's the case, with the current temperatures over much of the US, I'd leave the camera out and try it again this evening or tomorrow. Be sure the batteries are fresh also.

    Even if that "fixes" it, the camera is likely in need of a CLA. Otherwise, I agree that there's likely something more serious wrong.
  6. Note that if the F3 LCD is working then there is sufficient battery power. The F3 would shut itself off with low battery before the battery power drops to a level that could cause it to malfunction. According to the F3 service manual the problem is likely a bad solder joint on the circuit board.
    If this is a camera that you just bought then seriously consider returning it.
  7. Vincent Peri

    Vincent Peri Metairie, LA

    Thanks for your explanation. In my 43 years in photography, I have never referred to the light meter in a film camera as a "sensor" LOL.
  8. To me the light meter is a whole thing which includes many parts.
    1. The light sensor to sense the light.
    2. The amplifier to amplify the signal from the sensor and scale the signal.
    3. The display to display the meter reading.

    The problem with your camera is related to the signal from the sensor and not its amplifier or display.
  9. If you ever move into late AF stuff, you get sensors all over the place. Even the most basic phase-detect AF system usually uses a small CCD under the mirror for focus.

    Nikon made a big deal on the F5 about the "1005 pixel 3D Color Matrix Meter" that of course carried over into the digital bodies(and of course the F6 also).

    The F5 meter is amazing, though.
  10. Absolutely, terminology evolves along with the technology.

    One of the clearest examples of that is the change in the meaning of "automatic camera" from the 50s (when it meant a lens aperture that would stop down on its own instead of presetting it) to today when it means auto-exposure and auto-focus...
  11. Fortunately Nikon has at least been consistent with the use of the word "auto" in reference to lenses.

    Pre-AI lenses were often marked as below


    i.e. NIKKOR-S Auto meaning that the lens this is a 7-element lens with automatic stop-stop down to the taking aperture.

    It's also fun when you get into SLRs that advertise "instant return mirror" as a feature. Granted 10 years ago you could still buy newly produced cameras without an instant return mirror.
  12. See your non-AI Nikkor S 55mm f/1.2

    The fact that it and other non-AI lenses worked fine in stop-down mode on Canon EOS at the time I switched to digital, explains my present "in-between" status.
  13. The F3 light meter is inactive until the film counter has been wound to frame zero (two blank shots). Until then, the otherwise electronic shutter defaults to it's mechanical speed, 1/80.

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