Nikkormat FT3 vs early Minolta SRT102 which is better?

[Chan Tran]

I took out my SRT-101 last night. Hooked it up to a lab power supply and dialed in 1.35V and when the BC is switched on the needle is slightly above the mark. To center the needle on the mark it took 1.55V. Strange.

 

[xkaes]

I took out my SRT-101 last night. Hooked it up to a lab power supply and dialed in 1.35V and when the BC is switched on the needle is slightly above the mark. To center the needle on the mark it took 1.55V. Strange.

I have several SRTs and the needles don't always point at the exact same spot during the Battery Check. Plus, the uaer manual says that as long as the needle is in the black BC box, the battery is OK.

 

[GaryFlorida]

So maybe it doesnt even matter then since both batteries put the needle within factory parameters

 

[GaryFlorida]

I took out my SRT-101 last night. Hooked it up to a lab power supply and dialed in 1.35V and when the BC is switched on the needle is slightly above the mark. To center the needle on the mark it took 1.55V. Strange.

This is awesome Chan. Superbe effort! Did you notice any difference in the meter readings? Maybe the camera itself has circuitry that only takes what it needs. My understanding is that silver oxide batteries fail suddenly like mercury batteries and not a gradual depletion. Currently i have a lr44 that has been depleted to 1.36v. So long as it passes tge battery test it should be ok. Also if the mercury battery fails suddenly and not gradually, why did they put a battery test function on the camera? It should either work or it doesnt. Did they make non mercury 1.35v batteries back in the day?

 

[Chan Tran]

This is awesome Chan. Superbe effort! Did you notice any difference in the meter readings? Maybe the camera itself has circuitry that only takes what it needs. My understanding is that silver oxide batteries fail suddenly like mercury batteries and not a gradual depletion. Currently i have a lr44 that has been depleted to 1.36v. So long as it passes tge battery test it should be ok. Also if the mercury battery fails suddenly and not gradually, why did they put a battery test function on the camera? It should either work or it doesnt. Did they make non mercury 1.35v batteries back in the day?

I didn't do the reading check. I will when I have time. I need to fix my variable light source first. I did it before and found that at 1.35V and 1.5V the camera did give different readings but neither was correct. Also there is significant non linearity with both voltage. I don't remember correctly but at low ligh (LV9) and bright light (LV14) the degree of error was more than a stop. As I said I used the SRT-101 for about 15 years in the period when I didn't have any good camera and I used it without the meter and the result were fine. (in fact the exposure were better with me guessing than the F5 when I bought it in 2002 using its matrix meter).
I am not faulting the F5 but its matrix meter is very good for slide but not good for color negative which I used often.

 

[Chan Tran]

I just checked my 2 SrT. One is the 201 and the other is the 101. Both of them read low (the needle is above the circle) by about 2 stops at EV15@ISO100. At EV9@ISO100 the 101 read 3 stops low and the 201 is a lot more like 4 stops or so low.
I made the adjustment by turning the potentiometer at the base of the camera and got both of them read correctly at EV15@ISO100. But the 101 is still 1 stop low at EV9@ISO100 and the 201 is about 2 stop low. I am using alkaline battery.

 

[GaryFlorida]

I just checked my 2 SrT. One is the 201 and the other is the 101. Both of them read low (the needle is above the circle) by about 2 stops at EV15@ISO100. At EV9@ISO100 the 101 read 3 stops low and the 201 is a lot more like 4 stops or so low.
I made the adjustment by turning the potentiometer at the base of the camera and got both of them read correctly at EV15@ISO100. But the 101 is still 1 stop low at EV9@ISO100 and the 201 is about 2 stop low. I am using alkaline battery.

can you just change the film speed? would that work to compensate? When you talk potentiometer are you talking about removing the bottom plate?

 

[Chan Tran]

can you just change the film speed? would that work to compensate? When you talk potentiometer are you talking about removing the bottom plate?

Yes the potentiometer I do mean to remove the bottom plate. You can change the film speed which move the circle up to compensate. But either case if it's correct in bright light it will overexpose in low light. On the SrT only the intensity of the light moves the meter needle. Adjusting the aperture, shutter speed and ISO just move the circle. So the electronic is simple. I don't have the Nikkomat but I think the Nikon way if the light intensity changes or you move the aperture, shutter speed or film speed they all move the needle.

 

[MattKing]

can you just change the film speed? would that work to compensate?

Only if the error is linear.
If it differs depending on light level - which an incorrect battery can make happen - it won't be a solution.

 

[GaryFlorida]

so then adjusting the potentiometer under the bottom plate is a viable option which preserves the non linear output of the needle? I have to re read what you wrote about that Chan.

 

[Chan Tran]

Only if the error is linear.
If it differs depending on light level - which an incorrect battery can make happen - it won't be a solution.

I think part of the problem is that the Cds cell got old and not as sensitive and loses the linearity. I can try it with the exact 1.35V which I would have to readjust but the non linearity is still there. So having the right voltage isn't any better. What is better if I have mercury battery is that the reading won't change as the battery run down. Using silver oxide even with the diode the reading will change as the battery run down.

 

[GaryFlorida]

I think part of the problem is that the Cds cell got old and not as sensitive and loses the linearity. I can try it with the exact 1.35V which I would have to readjust but the non linearity is still there. So having the right voltage isn't any better. What is better if I have mercury battery is that the reading won't change as the battery run down. Using silver oxide even with the diode the reading will change as the battery run down.

So its not a battery issue, its a cds issue. I can only use my nikon fe as the gold standard. What are you using as your standard for what the reading "should" be?

 

[Chan Tran]

So its not a battery issue, its a cds issue. I can only use my nikon fe as the gold standard. What are you using as your standard for what the reading "should" be?

I use my Minolta Flashmeter VI but it agrees with my Nikon F3, FM2n, FM, F5 and even my digital cameras. Even the Pentax KX, Minolta XD-11. Just the Srt isn't good.

 

[GaryFlorida]

I use my Minolta Flashmeter VI but it agrees with my Nikon F3, FM2n, FM, F5 and even my digital cameras. Even the Pentax KX, Minolta XD-11. Just the Srt isn't good.

I ordered a bunch of sr44 silver oxide batteries. Arriving today. Im going to replace all my old lr44 in all my cameras today and see how much they agree with each other with fresh premium batteries.