Nikon FA Meter Ofby 3-Stops

[jmseight]

Hi,

I have an FA that I bought used around 20 years ago. It worked very well then. Few years ago I shot some film and the exposures were all off.

I recently took out the FA and found that the meter works perfectly, EXCEPT it is OFF by 3 stops. I calibrated the meter using a digital camera and the sunny day f/16 rule.

Basically, if I am using ISO100 film, I have to set the camera to ISO800 to get the correct exposure readings. This is very consistent and is true for both center weighted and matrix metering modes.

Does anyone know what the issue is? The metering photodiodes getting old? Or something dirty or a film got on the metering diodes?

I found the TTL flash diode but cannot find the metering diode. Can anyone tell me where it is?

Thanks,
James

 

[agnosticnikon]

Did you check your exposure compensation dial? It may have gotten moved when setting your ISO speed. I did this once with my F3, but only by one stop.

 

[jmseight]

Yep, I checked it and it was correct.

I just recalibrated my camera in indoor lighting and found that for indoor lighting it is off by 2 stops - ISO400 film needs to be set at ISO1600. So in daylight it is -3 stops form actual reading and in tungsten it is -2 stops.

Thanks,
James

 

[Lamar]

I know this seems obvious but are you using correct batteries? Are the voltages correct?

 

[gleaf]

Ditto on battery thoughts. Modern 'replacements' are not mercury cells and have slightly lower voltage.

 

[Chan Tran]

Hi,

I have an FA that I bought used around 20 years ago. It worked very well then. Few years ago I shot some film and the exposures were all off.

I recently took out the FA and found that the meter works perfectly, EXCEPT it is OFF by 3 stops. I calibrated the meter using a digital camera and the sunny day f/16 rule.

Basically, if I am using ISO100 film, I have to set the camera to ISO800 to get the correct exposure readings. This is very consistent and is true for both center weighted and matrix metering modes.

Does anyone know what the issue is? The metering photodiodes getting old? Or something dirty or a film got on the metering diodes?

I found the TTL flash diode but cannot find the metering diode. Can anyone tell me where it is?

Thanks,
James

The 5 photodiodes for the FA metering system is inside the viewfinder.

 

[fstop]

Ditto on battery thoughts. Modern 'replacements' are not mercury cells and have slightly lower voltage.

The FA uses standard SR44 batteries.


Its possible the ASA base plate under the rewind knob needs adjustment.

You really should use a light meter for comparisons.

One trick I use on older electronic cameras is to turn the ev adjustment back and forth a few times and the ASA dial a few times along with the aperture ring. Contacts although gold can get a film of foreign material on them causing eratics readings.

 

[Lamar]

Another thing you might consider is the lens type you have mounted. I've never had an FA but it may not play nice with G type lenses and/or pre-AI lenses. I honestly don't know how issues related to non-compatible lenses would manifest themselves on the FA. It may not matter. Have you checked for damage to the AI follower.

 

[jmseight]

Hi,

Thanks for the suggestion. I tried to remove the oxide by rotating the ASA knob and it did not work.

Is there a way I can adjust the ASA plate myself?

There are 2 photodetectors - one for the TTL flash facing the film and one in the viewfinder for the regular metering, correct?

Thanks,
James

 

[fotch]

Have you tried shooting film using the meter as is? And or comparing it to sunny16 vs camera metering on a 16% Gray card?

 

[benjiboy]

When was the last time the camera was C.L.A'd ?

 

[benjiboy]

Ditto on battery thoughts. Modern 'replacements' are not mercury cells and have slightly lower voltage.

The FA takes 2 SR44 1.55 Volt Silver Oxide batteries, not Mercury..