Elektrojänis
Established
I think this is (or hopefully, was) a leak during cocking. I checked it by holding a flashlight in the lens side (lens removed) and looking from the film side in a dark room. When looking straight from the back I could see no light when cocking, but when I tred looking from the right side of the film port I could see a really thin stripe of light. I had to look in a very low angle to see it.
I moved the second curtain so it will overlap the first a bit more. After this I could still see the light the same way than before, but it seemed to intensity seemed lower. I could make the curtains overlap even more, but I think it might stop the 1/500 shutter speed working (I already had thet problem earlier when I glued the curtains a little carelessly).
I have test roll in it now. I mostly cock it with a lens cap on now, but I will try a few times without.
Well on this one I have everything a bit slow. Mostly not more than half a stop... 1/25 is a bit more than half a stop slow. I tried to get them faster, but it always ruined the balance between the sides. I did not get the balance perfect either, but I think it's good enough for me.
I'm probably using this mostly with cheap colour print film so half a stop doesn't matter too much... Especially when I know it.
Most sources seem to say that within third of a stop is fine.
Elektrojänis
Established
This thread is a bit old, but I'll add my final results/thoughts now... Better late than never.
The biggest problem was actually a bit of second curtain bounce combined to a bit too loose curtain tension. The second curtain bounced a bit (mostly on the fastest speeds) and I had the tensoin so loose that it did not close properly after the bounce. The "too little curtain overlap when cocking" -thing might have had some effect too, but the bounce thing was the main problem.
I tightened the curtains a bit and now it works good enough for me. The balance between left and right side exposure is a bit worse now acording to my measurements, but it's good enough that it I can't see it with regular print film (at least on the prints I get).
There is still some second curtain bounce, but it affects only on a very tiny stripe on the negative (less than 1mm). On the prints thet the regular labs do, they crop enough that it does not show. Secondly... With the internal wievfinder the framing will be so loose that usually nothing from the original framing will be on the problem area anyway.
This has been a very nice learning experince for me. Actually the learning experince is still going on, as this is my first meterless camera and now I'm learning to guestimate the exposure without a meter (with print film it's not too hard though, at least on daytime/outside).
The biggest problem was actually a bit of second curtain bounce combined to a bit too loose curtain tension. The second curtain bounced a bit (mostly on the fastest speeds) and I had the tensoin so loose that it did not close properly after the bounce. The "too little curtain overlap when cocking" -thing might have had some effect too, but the bounce thing was the main problem.
I tightened the curtains a bit and now it works good enough for me. The balance between left and right side exposure is a bit worse now acording to my measurements, but it's good enough that it I can't see it with regular print film (at least on the prints I get).
There is still some second curtain bounce, but it affects only on a very tiny stripe on the negative (less than 1mm). On the prints thet the regular labs do, they crop enough that it does not show. Secondly... With the internal wievfinder the framing will be so loose that usually nothing from the original framing will be on the problem area anyway.
This has been a very nice learning experince for me. Actually the learning experince is still going on, as this is my first meterless camera and now I'm learning to guestimate the exposure without a meter (with print film it's not too hard though, at least on daytime/outside).