Nikon F3 Meter Weirdness at Particular Apertures

[rulnacco]

Hi! I've got a nice second hand F3 I bought several months back and am only now getting the chance to play around with daily. It seems to be in very good shape, but has one really irritating quirk, and I'm hoping someone here might be able to advise me on it.

The meter needs a bit of calibrating, but what's prevented me from doing that thoroughly is some strange behaviour the camera displays at F4 or F5.6.

At any other aperture on either side of those two, the meter tracks just fine (although I'm not always in agreement with what it's telling me is proper exposure) as you change shutter speeds, or set it in aperture priority. However, when the lens--any lens--is set to either of the two apertures above, the camera will tell you that you are way underexposing, no matter what. If you are in manual, you can set the shutter speed all the way to 8 seconds, and it will still show a minus exposure. And in aperture priority it defaults to 8 seconds while still showing a minus indication.

Any idea what the problem might be, and if it's something I could deal with myself? Or is this the symptom of a problem that really needs the hand of an expert? (Yes, I'm generally in favour of leaving complex things to trained hands, but it turns out frequently that well-known problems with lots of things can be fixed with a bit of tweaking by those who don't mind delving into the innards of whatever device is in question, so please don't suggest a CLA if you're not 100% sure from experience that that would sort the problem--I don't mean to be crotchety, but I do often see that handed out as well-meaning but blanket advice when really, it's not the solution. I'm hoping for some more expert and specific input in order to make an informed decision about how to proceed, thanks!!)

 

[BrianShaw]

Clarification question: how are you determining the reference exposure that you believe is “proper/correct “?

BTW, I quite agree that the blanket “needs a CLA” isn’t useful advice in the absence of knowledge regarding the failure. Like rebooting a computer, though, it often cures problems.

 

[rulnacco]

Clarification question: how are you determining the reference exposure that you believe is “proper/correct “?

Basically, Sunny F16. The camera seems to want me to overexpose by a stop or so fairly regularly. I want to get the *obvious* problem sorted out and see if I can get some consistency in the meter readings across the aperture range, and then I can see if and how I need to set my ISO dial for the films I use to give me proper exposure--which really isn't a problem, so long as the readings are off by a stable, consistent amount.

 

[Sirius Glass]

Calibration can be approximated with Sunny 16 but it would be much better to have the light meter calibrated in a lab to a known source.

 

[BrianShaw]

Yes, the difference between Sunny and F3 isn't really you problem, and discussing it is kind of a red herring, but could be the difference between "apples and oranges" metering since the F3 is center-weighted and Sunny is not.

As you already know, the shutter speed should change in 1-stop increments for each aperture stop change. How far off of that 1-stop change are you seeing at f/4 and f/5.6?

 

[rulnacco]

Oh, and here's another data point: I just found that the behaviour does differ by lens. On my 50mm/1.8 and my 35mm/F2.0, the aperture weirdness does happen at F4 & 5.6. However, I just stuck my 75-170 Series E on, and it's at F8 and F11 that the problem happens. I have a buttload of other MF lenses, I'll try some more of them and see what happens.

It appears that at some point in the camera metering ring's travel, it experiences the problem. I know about the FRE under the flash attachment that is frequently a source of problems if the camera has taken a jolt in that area, but isn't there another one coupled to the metering ring? Would that be a potential source of the problem as well? Or is this something that likely doesn't have to do with either FRE?

Thanks in advance for all the help!

 

[Nicholas Lindan]

Does the problem always show up at f4/5.6 even with lenses of different maximum aperture?

The reason I ask is that the AI indexing tab doesn't indicate the f-stop set on the lens but rather how many stops down from maximum aperture the lens has been set at: f4 on a 50mm/1.4 lens will have the AI tab in the same place as f8 on a f2.8 lens.

 

[BrianShaw]

Does the problem always show up at f4/5.6 even with lenses of different maximum aperture?

The reason I ask is that the AI indexing tab doesn't indicate the f-stop set on the lens but rather how many stops down from maximum aperture the lens has been set at: f4 on a 50mm/1.4 lens will have the AI tab in the same place as f8 on a f2.8 lens.

That brings up what was about to be my next comment... check the indexing ring to ensure that it's moving smoothly and consistently through the range and not sticking.

 

[rulnacco]

Calibration can be approximated with Sunny 16 but it would be much better to have the light meter calibrated in a lab to a known source.

True. But that involves expense, and when you're *mostly* shooting black and white film (I use my F4 if I want to shoot E-6, on those rare occasions), Sunny F16 works fine.

As you already knoiw, the shutter speed should change in 1-stop increments for each aperture stop change. How far off of that 1-stop change are you seeing at f/4 and f/5.6?

As I mentioned, at the problematic apertures, the camera acts like there's simply not enough light to make a photo. In manual, you can set it to 8 seconds and it will still indicate underexposure. And in aperture priority, it defaults to 8 seconds and still indicates underexposure with a minus sign.

Does the problem always show up at f4/5.6 even with lenses of different maximum aperture?

The reason I ask is that the AI indexing tab doesn't indicate the f-stop set on the lens but rather how many stops down from maximum aperture the lens has been set at: f4 on a 50mm/1.4 lens will have the AI tab in the same place as f8 on a f2.8 lens.

Yes, I added that in later, above--good question. I just found that on my 75-150 Series E (3.5 maximum aperture), the problem happens at F8 and F11. I haven't had a chance to try other lenses yet, but given what you said, it appears that the problem happens in a consistent spot on the camera metering ring's travel.

Thanks, all for the input!

 

[rulnacco]

That brings up what was about to be my next comment... check the indexing ring to ensure that it's moving smoothly and consistently through the range and not sticking.

It doesn't *seem* to be sticking--the meter just goes haywire at a certain point. In fact, just now I took the lens off the camera and manually pushed the metering tab along its arc of travel with a finger, while looking through the viewfinder. Once I reached a certain point (just before 12 o'clock) the same thing happened--the shutter speed (in aperture mode) jumped to 8 seconds with a minus sign--and once I passed that interval, it went back to displaying "logical" shutter speeds. I didn't notice any kind of change in resistance as I reached that point.

 

[Nicholas Lindan]

Ah, your latest update came in just as I was posting the above.

It seems the problem is in the F3 body's aperture resistor - it likely has some dirt on it. Servicing the part isn't for the faint of heart. Heck, it isn't for the brave of heart either.

 

[rulnacco]

Ah, your latest update came in just as I was posting the above.

It seems the problem is in the F3 body's aperture resistor - it likely has some dirt on it. Servicing the part isn't for the faint of heart. Heck, it isn't for the brave of heart either.

Haha! Not good news. Here's another bit of information: I put the 35mm/F2.0 back on the camera. I have been shooting with the ISO set at 80 (I'm shooting Delta 100 right now, and I like to overexpose slightly). When I set the ISO to a higher setting, the aperture at which the meter does its madness shifts along with it. So for instance at ISO 400, it shifts to F11 and F16. *And*, at that setting, it will sometimes briefly display 8 seconds, and then shift back to something that makes sense (I'm in aperture priority, so I can easily see how the shutter speeds change). So I'm beginning to think maybe I have a bit of crud in the FRE area under the ISO dial, since I'm getting the shifting *and* it seems that the meter *wants* to try to work now that i've jiggled the ISO settings a bit.

Does that sound like I'm getting close to the nature of the problem?

 

[rulnacco]

Well, I'm not sure if we'll completely sort the problem, but there is some comfort--I rarely shoot 100 speed film, I tend to favor HP5+. And when I set the camera at ISO 250 (my normal exposure index for shooting HP5+, it seems to need just a bit of overexposure to give the negatives a bit of the "meat" I like coupled with my developing routine) the problem, when it does happen, shifts over toward F11-16--which apertures I'm not going to use, as most of my shooting is between F4 and F8. So that's why I hadn't noticed there *was* a problem with the metering, until I started using the slower film.

Once I switch back to faster films--HP5+, I've got a couple of slightly expired bulk rolls of Delta 400 I got for a bargain that I'm about to load up--it won't be so irritating.

But is there a consensus here, based on the camera's behaviour? Is it likely that it may only need a, yes!, CLA, or would a cracked FRE display this same set of symptoms, and so be a more extensive repair job?

Again, thanks for all your input--it spurred me to try different things to try to diagnose the problem, which I simply hadn't had time to do with my work schedule lately on my day gig.

 

[BrianShaw]

Ah, your latest update came in just as I was posting the above.

It seems the problem is in the F3 body's aperture resistor - it likely has some dirt on it. Servicing the part isn't for the faint of heart. Heck, it isn't for the brave of heart either.

There's, also, another potential internal problem... the physical connection between the aperture ring and the resistor. These cord-driven connections and their pulleys sometimes get gummy and glitchy.

And I'm with Nicholas, ecsept that I'll just say it... probably a candidate for a CLA.

 

[rulnacco]

And I'm with Nicholas, ecsept that I'll just say it... probably a candidate for a CLA.

Haha! To quote Clint Eastwood in The Outlaw Josey Wales, "I reckon so." I also have a Leica, and ohmigod, you'd sometimes think, reading forums, that if you don't have it CLAed at least every five years, camera and lenses, it's going to self-destruct in your hands and cause collateral damage as well.

That seems such a primitive system in an "electronic" camera, the pulley and cable thing--very interesting! The nice thing about old, mostly mechanical, cameras is that quite often, if you use them regularly, they start loosening up a bit (in a good way). My F3 shows signs of doing that--and at the ISOs I normally shoot at, even if there is a more severe problem, it looks like I can work around it.

It would be nice to know if I am looking at having to *replace* the FRE at some point though, as I still have a bunch of 50- and 100-speed E-6 film in the freezer, and when I started photography I *loved* doing macro work on slide film. One thing that attracted me about the F3 was that the meter is in the body, so even with a magnifying chimney finder you still have full metering capabilities (unlike, say, the F4). So at some point, I'm hoping to get out in a field and shoot flowers/bugs with slide film and the F3, and before I do that--especially given the prices of processing today--I want to make sure that the metering in the camera is "locked in" in terms of calibration, accuracy, and consistency. I never slavishly follow the meter's indications, I know how to interpret them based on what I'm shooting--but it definitely helps, and takes out some mental calculation steps, to have a good, dependable, working meter in camera as a starting point for certain things.

Thanks Brian, and everyone else!

 

[BrianShaw]

If/when you have your F3 CLA'd, they should "lock in" the exposure to the factory specifications. Those specs and the process/tools are denoted in the repair manual. For me, that camera is most often dead-on, even in A mode, except in unusual lighting situations. Whether they agree with your desired exposure is possibly a different situation, but that what the ISO offset and manual mode is useful for. It really is a great camera and worthy of being in 100% operational condition. (I never worry about the FRE breaking... I just keep using mine and every once-in-a-while spin the ISO dial all the way in both directions a couple of times just in case that helps keep the contacts clean.)

 

[rulnacco]

If/when you have your F3 CLA'd, they should "lock in" the exposure to the factory specifications. Those specs and the process/tools are denoted in the repair manual. For me, that camera is most often dead-on except in unusual lighting situations. Whether they agree with your desired exposure is possibly a differnt situation, but that what the ISO offset and manual mode is useful for.

Absolutely! If I can get it calibrated to factory standards, that would be really wonderful. Again, one of the things that made me grab an F3 when I found a good one at an incredibly cheap price at a camera swap meet was that I'd read many instances of people praising the accuracy of the metering system (too bad the display of the metering information isn't quite so grand), especially for a somewhat older camera. And as I mentioned, the F3 seems particularly suited to macro photography.

In fact, if you can get your hands on a copy of John Shaw's book Closeups in Nature, I would highly recommend it. He was using an F3 for his work at that time, and that book is one of the simplest, most direct, and most useful books I've ever seen about macro photography in, yes, nature. It contains a lot of photos that I personally quite liked (they show why I miss film so much), and a whole lot of meat without a lot of frippery. It's a great addition to anyone's photo library--not only for the practical knowledge to be gained (much of which is still extremely useful on digital), but simply for the pleasure of flipping through it and reading random sections. Especially if you enjoy using old Nikon film gear.

Some of the things he discussed are the fact that there frequently is a disparity amongst camera meter readings, how to calibrate your own camera's meter, and how to adjust your exposure to what you are shooting, given an accurate, calibrated meter reading as a starting point.

 

[Chan Tran]

The F3 has one single FRE (Nikon called it Functional Resistor Element) it is located under the rewind knob and is moved by the ISO dial and the aperture coupling on the lens mount via string/pulley. I think there is one bad spot on this FRE. Sure finding the replacement part as well as taking if apart is not an easy task. If you move the aperture ring and ISO dial a lot it may (or may not) fix the problem. I am pretty sure that this is the problem but I wouldn't know how to fix it though.

 

[rulnacco]

The F3 has one single FRE (Nikon called it Functional Resistor Element) it is located under the rewind knob and is moved by the ISO dial and the aperture coupling on the lens mount via string/pulley. I think there is one bad spot on this FRE. Sure finding the replacement part as well as taking if apart is not an easy task. If you move the aperture ring and ISO dial a lot it may (or may not) fix the problem. I am pretty sure that this is the problem but I wouldn't know how to fix it though.

Thank you! Yes, I've learned a lot about how the metering system works today. I had heard about the problem with the FRE on the F3--particularly how it can be broken by an impact, or when overstressed when a flash is mounted there and it takes a bang. (Good lord, I know that was a long time ago in technology terms, but having the rewind, a fairly delicate bit of the metering system, and the flash mount all crammed together concentrically *doesn't* seem the wisest of design and engineering choices.)

I'm hoping that with a bit of exercise, the problem will clear itself up (as it shows signs of maybe doing) and the FRE isn't permanently damaged. And even if it doesn't resolve on its own, it appears that I can use the camera with medium speed or fast film and it won't cause a problem, as he "bad spot" won't be in my favoured range of aperture settings.

 

[RudyMerz]

Perhaps the following video gives you a bit more inside of the inner working of the F3. It is in 4 parts.

F3 Disassembly Part 1

The video is from James Holman (ITCamera), where I send my camera's for CLA.

I myself have an F3HP and F3P and also have several books from John Shaw. I have learned so much from those books in the last 25 years that he became my favorite photographer.

 

[BrianShaw]

Excellent link to really interesting video! I’m now certain that I’ll never fiddle with the innards of a F3.

Part 2 addresses the specific concerns of this thread

 

[John Earley]

Excellent link to really interesting video! I’m now certain that I’ll never fiddle with the innards of a F3.

Part 2 addresses the specific concerns of this thread

Great video! Thanks.

 

[Chan Tran]

I can see soldering those 3 wires would be tough.

 

[rulnacco]

Part 2 addresses the specific concerns of this thread

Awesome, thanks! That does indeed look like the probable source of my problem. I'll probably, when I'm a bit more flush with cash, send the camera off to James Holman. He's quite active on the Facebook Learn Camera Repair group.