Nikon Metered Finders/Prisms

[david_clark10]

Hello I have recently come across two older metered Nikon prisms.

Firstly I am trying to find out what batteries they take and secondly

how to test them.

The first is a Photomic T finder, the second a Photomic FTn finder.

Any information would be of use, because if they work I may consider

buying a body for one of them as I have always fancied one of the

older F series. Also what is their approximate value, they are in

good condition boxed.

[mskovacs]

<a href="http://www.mir.com.my/rb/photography/hardwares/classics/michaeliu/cameras/nikonf/index.htm">Here is a great place to start.</a> They take the (now banned in the USA) 1.35V mercury button cells. Do a search in google of photo.net links for gobs of info on suitable replacements.

 

<p>As for valuation, are they chrome or black? "Good condition" means how close to mint? I'd say no more than $50-100 unless they are truly mint, 50% more for black or something special about them to make them collectable.

 

<p>You'll need an F body to test them beyond installing batteries and trying the battery check button. The photomic FTn won't fit on early bodies without modifying the hole for the prism eyepiece (very early) or the name plate (I think prior to serial block 69*****). Get a later body to be safest (mine is from the 73***** serial block).

[robert_byrd1]

I assume those old finders can be altered to take currently available batteries. Does anyone know who does this kind of work?

[fred_sun1]

Try these:<br>

<a href="http://members.aol.com/_ht_a/drwyn/myhomepage/">http://members.aol.com/_ht_a/drwyn/myhomepage/</a>

<br>

<a href="http://www.cameraquest.com/repairs.htm">http://www.cameraquest.com/repairs.htm</a>

[dave_hickson]

I have a Nikon FTn, and have finally purchased the adapters from CRIS, and can use inexpensive 1.5v batteries. Exposure is still right on. http://criscam.com/mr9.htm

[mskovacs]

David H: Your CRIS observations seem to be at odds with the info on Robert Decker's site (refer to Fred's first link).

[craig_bridge]

I use PX625 silver oxides in my Photomic FTn (unless I can't find them when I need them). The Wheatstone bridge type meter circuit cares more about the internal battery resistance than the voltage if you are trying to judge how far off the exposure is based on needle displacement. The PX625A alkalines internal resistance changes with current draw as they age so they are second best and need to be replaced before they show as dead.

 

The variable resister wipers for the shutter speed and aperture sensors are better off being used than left unused so don't count on the finders working straight out of the box. This is one of the reason why the non-metered finders are worth more to a collector than the Photomic's.

[lex_jenkins]

An ordinary, cheap zinc air hearing aid battery, size 675, will meter just fine to within 1/2 EV or better accuracy with most older metering systems. Unless you're shooting Velvia or possibly Kodachrome 64 you'll never notice any difference in metering accuracy.

 

The only trick to using the 675 zinc air batteries is their smaller diameter may cause them to rattle around a bit inside some battery compartments, tho' in every case I've seen there's enough spring pressure from the contacts to keep the battery in place.

 

Also, the batteries should be checked at least every three months - they don't least long after the tape is removed from the air holes, which activates the cells. Fortunately a pack or half a dozen or so cells costs no more (often less) than many silver oxide, lithium and other camera batteries.