Nikon N80 Question

[Bruce Butterfield]

Ran out of battery about halfway through a roll of 36; I removed the dead batteries but wasn’t able to replace them for a few days. When I finally put in the new ones, lo and behold the film counter was automagically set to 22 which seemed right to me. My question is what is the technology that allows that magic to occur? As far as I know there isn’t an underlying mechanical counter — or is there? Inquiring minds want to know…

 

[MattKing]

Many cameras have two battery systems - one to do things like wind film and meter scenes and power built-in flashes, and a second, extremely long life semi-permanent battery that is designed to power the systems that retain information even when the other batteries are out of the camera.
That second battery is often designed to require the involvement of a service technician to replace it.
The Nikon experts will know better than I whether the N80 is set up that way.

 

[Andreas Thaler]

Data/Date Back (Application for F80D, N80QD and F80S) …

… Power Source: (Common to Simple and Between Films QDs)
The power is supplied from the camera body. The super-capacitor is mounted so that the date
is not reset when the battery in the camera body is replaced.

Nikon N80 Service Manual

Factory service manual. Also covers the F80 and F80s

learncamerarepair.com

This applies to the version with data back.

Accordingly, a (high-capacity) capacitor is installed, which is charged by the main batteries and supplies voltage to the settings when the batteries are removed.

I suspect that this solution is also implemented for the camera settings, but I couldn't find anything about it in the service manual.

 

[blee1996]

Yes most likely a high capacitance capacitor for the EPROM that hold essential settings.

 

[Bruce Butterfield]

Interesting, thanks

 

[Daniela]

Good question, OP. I've noticed that too and wondered about it. I've had mine for 24 years....Long live the N80!

 

[Sirius Glass]

Ran out of battery about halfway through a roll of 36; I removed the dead batteries but wasn’t able to replace them for a few days. When I finally put in the new ones, lo and behold the film counter was automagically set to 22 which seemed right to me. My question is what is the technology that allows that magic to occur? As far as I know there isn’t an underlying mechanical counter — or is there? Inquiring minds want to know…

I have has similar experiences with the NIkon N75 and N80.

 

[koraks]

My question is what is the technology that allows that magic to occur?

The N80 is from 2000. By this time, EEPROM technology was already readily available at least in the sizes needed to store settings like those in a camera. EEPROM is a non-volatile memory (i.e. contents are retained even without power to the chip) that can be programmed many times over (typically thousands of times or more). It's relatively fast and durable. Data retention rates are typically well above a decade. It's likely that most cameras from this era leverage EEPROM technology to be effectively independent from any battery at all to store settings, frame count etc. So if you open up the N80, you may find that there's no auxiliary battery as you would find in cameras from 10-15 years earlier (e.g. Canon T90).

Yes most likely a high capacitance capacitor for the EPROM that hold essential settings.

Supercaps suitable for applications like these became available much later than EEPROM. I'm not aware of supercaps being used in film cameras for this purpose. That doesn't mean they don't exist, but it doesn't seem plausible to me for a variety of reasons.

Also, 'EPROM' is definitely NOT what's used here since that is the kind of memory that typically requires UV exposure to erase it. It had gone out of fashion several years before the Nikon N/F80 was introduced, and it's inherently not suitable for this particular application.

 

[PurpleCat]

Some Nikon cameras (like my F5) will also log the exposure information for the entire roll in the EEPROM and it can be retrieved using a cable. If you plug the camera into the PC and use Softtalk 2000 you can even see the exposure information of the roll currently in your camera. That's on top of the CSM settings being stored there as well. So on the F5 at least, I'm highly confident it's stored in the EEPROM.

 

[Sirius Glass]

Some film cameras are able to store the number of the last exposed frame in a data register, electronics designed to save that data when the battery run out. As long as not too much time has passed, the data register will hold on to that value as long as it can.