Nikon F w/FTN meter solution

[User_4754088]

<p>Not sure how many of you have a Nikon F with the FTN finder like mine, but I made a discovery this week that I wanted to share.</p>

<p>I've read that many of the FTN finders are dead, as the resistor ring can have issues and none of the repair shops I've talked to have parts for these anymore. I've also read that many FTN finders had issues with the contacts in the battery chamber making good contact with the two batteries. Mine worked great for the first three weeks I had it, with two old PX625 mercury batteries I had around since the late 1980's.</p>

<p>But then it developed an issue where it would just stop working. I would take off the battery cover, try to pry the top contact out from the wall of the battery chamber to make better contact with the batteries, then drive myself nuts with my big gorilla fingers trying to get the battery door back on. With the door off and me holding the batteries perfectly in the middle of the battery chamber, the meter worked fine. Then I'd struggle to get the door back on and by the time it was finally in place, the meter no longer worked.</p>

<p>I was ready to give up on it, when I saw this auction on the evil eBay:</p>

<p>I can't put a link to eBay on this forum, so just look up Auction #151718676694 or search for: Nikon F Photomic FTN TN Meter Prism Battery Adapter.</p>

<p>I have no affiliation with this seller aside from buying one of his adapters. He recommends using a 1/3 N battery with the adapter. I put in a 1/3 N and naturally the meter, which is calibrated for 2.7 volts, was inaccurate with the 3.0 volts of the 1/3 N. Although there was no more problem with the meter not getting juice from the batteries.</p>

<p>Then I discovered the 675 size hearing aid batteries at the local Walgreens (at 75¢ each), which are 1.4 volts, and two of them fit perfectly into the above adapter, giving you 2.8 volts. I found that with my FTN, it is now as accurate as it was when I first got it and it was working with the old mercury batteries.</p>

<p>So I wanted to pass this along to others who might be having similar trouble with their FTN finders. The thing I like most about this solution is that the 675 size hearing aid batteries are plentiful and inexpensive. So hopefully I'll be able to use them for a long time.</p>

<p>Best,<br />-Tim</p>

[User_5050610]

<p>Tim--thanks for the tip! I've ordered a couple and can't wait to see how they work. Thanks again....<br>

Paul</p>

[bob_flood1]

<p>I used this same solution in my Nikkormat FTNs until I went completely digital some years back. Let me add two points:<br>

First, the hearing aid batteries are smaller in diameter than the mercury battery and the battery compartment. If the battery sits off-center in the compartment, the electrical contact may be troublesome. I found that a trip to my local hardware stored solved this. A decent hardware store will have O-rings in an assortment of sizes. I got a couple that are just a little larger in diameter than the hearing aid battery but small enough to fit in the battery compartment. This keeps the battery centered in the compartment for good electrical contact.<br>

Second, keep a supply of hearing aid batteries in your bag - they are air activated (hence the peel-off cover) and only last about a month, whether you use the battery or not. So you need to have some around. With the low low cost and easy availability, the short useful life is no problem.</p>

[User_4754088]

<p>Paul, glad to help out.</p>

<p>Bob, the adapter I mentioned from eBay (which costs about $12 dollars) takes care of the centering issue in the battery chamber. It holds two 675 cells and does a great job of making contact with both spots in the battery chamber. It also makes it much easier for me to get the battery chamber cover screwed back on. And I agree with you, I've read a number of places about the short life of the hearing aid batteries, so I bought a 24 pack last night.</p>

<p>Best,<br>

-Tim</p>

[Matthew Currie]

<p>I have also had good luck with metal rings around the smaller batteries. Unfortunately, though some holders can use O-rings the FTN cannot because its feeler is on the side. In a pinch you can use aluminum foil too, but that's kind of rickety.</p>

<p>As for voltage, I think there are still some resources if you hunt on the net for them that will tell you how to recalibrate an FTN meter for modern batteries. I did all three of mine for silver oxides, and they worked well. There is only one variable resistor for meter sensitivity, and another for battery test needle centering. Some sources will tell you that this is not accurate throughout the range, but I adjusted mine for a middle range exposure at ASA 100 and they were just fine for the real world. I found that adjusting mine to match a very accurate Minolta meter (featureless wall, constant light, 50 mm. lens and tripod so they both matched), mine was accurate enough to use for slides, within about 1/3 of a stop, which is closer than you can usually get with the stepped shutter and full stop apertures anyway.</p>

<p>You can find one link for adjusting on http://arcticwolfs.net/</p>

[bgelfand]

<p>When the meter on my FTn failed - about 15 years ago, two different repair facilities said, "it is the Ring Resistor; there are no replacements."</p>

<p>Then I found Robert Decker. He said it usually is not the Ring Resistor but the photo cells that fail. I sent my FTn finder off to him.</p>

<p>Mr. Decker:</p>

<p>1) Replaced the failed photo cells.</p>

<p>2) Recalibrated the resister network for A76 cells rather then the mercury cells that were originally used.</p>

<p>The meter worked beautifully after that - until my camera was stolen a few years later.</p>

<p>Here is a link to a photo.net article that cites Mr. Decker and gives his contact information:</p>

<p>http://www.photo.net/classic-cameras-forum/00OhSi</p>

<p>If he is still in business, I highly recommend him.</p>

[Sandy Vongries]

<p>I order Duracell PX625AB by the box (6 batteries) through Radio Shack. Can't recall what I paid last time, not inexpensive, but I think under $30 for 6. They work just fine in my Nikon F with FTN finder, which I have owned since '68 or '69.</p>

[Matthew Currie]

<p>People get all bent out of shape over alkaline cells because the voltage tapers as they age, but they do work adequately in a Photomic meter, which has a check button. It's still a good idea to recalibrate the meter and the check button, and the voltage of an alkaline is a wee bit lower than that of a silver oxide, but if you calibrate to either one, the difference is small enough to compensate easily.</p>

[bgelfand]

<p>I made a mistake in my post above. I should have written 625 battery rather than A76.</p>

<p>I guess I am getting old. <grin></p>

[robert_bowring]

<p>I have found that when FTn meters stop working properly it is usually because the resistor rings are dirty and need to be cleaned. They are easy to take apart and clean the resistor ring if you are careful. As for batteries I have successfully used the MR-9 adapter from CRIS camera repair. They have a built in resistor that will allow you to use 1.5 volt silver batteries. I have used them in my Nikon FTn and Nikkormat Ft and FTn and they seem to work well.</p>