Re: Another FED question

[P3D Joel Alpers <joel.alpers@xxxxxxxxxxx>]

Edward I. Comer  wrote:

> While I have no current problems, does anyone know where I could obtain (a)
> a detailed description on disassembly/reassembly of a FED; (b) diagrams or
> exploded views of a FED to enable disassembly/reassembly ? Thanks in advance!

Sorry, I don't know of anything of the sort available.

> I have anticipated one potential modification that I may undertake should
> the rumers prove true. I'm referring to the rumers that FED's light meters
> never turn off, and can quickly exhaust the battery.

No rumor, that's a fact, Jack. The FED metering circuit is very simple, consisiting
of a battery, a series resistance, a light cell, and a meter movement with a 
parallel resistance. Nothing turns it off, but the key is the "light" vs. "dark"
resistance of the light sensor. The dark resistance is fairly high (sorry, I 
haven't measured it), so if the camera is stored in the case or in the dark,
very little current flows. If stored so that light can hit the sensor, it can
exhaust the battery fairly quickly.

This seems to be the same setup as in my Pentax K1000, in that the battery will
go dead after some time of storage whether being used or not.

Obviously a switch would help.

> I had a though of how
> to install a switch that would turn off the FED light meter when the camera
> was stored, yet require no mechanical linkage, holes, etc. Assuming that
> there was physical room within the body, place a small mercury switch in
> series with the light meter circuit. When the camera was stored, store it
> upside down. At all times, except when the camera was upside down, the
> mercury switch would be closed enabling the meter circuitry. Turn it upside
> down, and the battery is disconnected.

As long as you don't ever want to take pictures with the camera upside down ;)
There is plenty of room in the top to add a mini slide switch, but I can understand
if you don't want to carve the top of the camera.

> I'll wait to see if the rumers are true before I crack open my perfectly
> functioning FED. I'd also like the requested info before wielding my
> screwdriver.

While "the rumors are true" I think you can get acceptable results by careful
storage of the camera (i.e. in the case) when not in use.

Tip: Since the FED doesn't have a "battery low" indicator, I'd advise doing the
battery check described in the manual if the camera has been stored a while, 
before shooting film: Set the ISO dial to 800, point the camera at a bright 
scene (out a window or towards a lamp). If the shutter "low light" interlock
engages, the battery needs replacement.

Joel Alpers
Rocky Mountain Memories - Equipment and Supplies for the 3D Photographer
rkymtmem@xxxxxxxx
http://www.frii.com/~rkymtmem


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