Hey, I have a couple of film camera's and a X100T which I use to check if the lightmeters on my film camera's are still working. My X100T gives the same reading as my Konica T3N (I tested at ISO1600 and a shutter speed of 1/250 with gave me f5.6 in both cases. I had the Konica T3N converted to use normal batteries (i.e 1,55V silver oxide batteries) but it used to run on PX675. Before the conversion I used 1.4V zinc-air hearing aid batteries (which are luckily also labeled 675) to replace the PX675. And they worked fine. Now I recently acquired a Konica TC. I wasn't actually going for the TC but for the three Hexanon lenses that came with it. So I thought the TC would make a nice birthday present for my 10 year old niece who told me she wants to be a photographer when she grows up (yay!). Been testing the light meter but at ISO1600 and 1/250 the meter reads f2.8. Two stops off. I tested it with film, I compensated for the two stops and the film turned out fine but of course this makes it a lousy present. I tested the TC with two 675 zinc-air batteries. I still have lots of 675's because I still use them in my Konica Auto S3 rangefinder. They have the same voltage, they're just smaller, so it didn't seem like a big problem. But because of the wrong reading on the lightmeter I am doubting this. Is it possible that they would give a different reading? Is the lightmeter faulty? Could there be another reason the lightmeter is 2 stops off? If I would put a couple of 1.55V silver-oxide batteries in, would it (partially) compensate or would it make it worse? Thanks!