Bemerkung zu der Kiev 60 Kalibration-Seite:
Am 12.11.2001 schrieb ich ein e mail an den Verfasser der Anleitung, die meines Erachtens fehlerhaft ist:
11/12/2001 I wrote an e mail to the writer of the Kalibraition Manual, which in my eyes contains a severe mistake:
Hello,
thank you for your nice manual in the web. But in my eyes there is a severe mistake regarding adjustment of shutter speeds:
"The first curtain determines how fast your shutter opens and the second curtain determines how fast your shutter closes" is what you write and which is correct. BUT:
It is not the right way to control shutter speeds! Why?
Let us have a look at the 1/30 flash synch speed. The slit formed of the two curtains is just as wide as the frame ( or a little bit more ). Now let´s look at 1/60: the slit is half of the frame, but the speed of both curtains remains the same! The movement of the second curtain is started later, that is what determines the width of the slit and thus the shutter speed.
What would happen, if the speed of one of the curtains is varied? If the speed of the second curtain is set to slower by loosening its spring, it indeed would start to close the film aperture a little later. But the main effect is, it travels slower than the first curtain, that means that the slit at the end of the frame is wider than the slit at the beginning of the frame. Exposure would increase towards the end of the frame! The smaller the slit ( with 1/1000 it is just 2-3mm) the bigger the effect if you have not accurately the same speed of the two curtains.
Imagine what would happen, if the second curtain is just 2-3mm fast at the end of the frame: No exposure anymore. (This case actually occured with my first Kiev 60...).
Well, how do we adjust correctly?
In the way you described, we adjust the curtain speeds of both curtains to get them exactly the same. For that purpose we have to measure the short shutter speeds at the beginning and the end of the frame.
To adjust the fast speeds from 1/1000 to 1/125 there is a spring which determines how fast the shaft rotates which starts the first, and with delay, the second curtain. It can be adjusted from top of the camera with the cover taken off.
To adjust the slow speeds from 1/60 to 1/2, the position of the clockwork-escapement can be varied. Its distance to a rotating cam attached to the above mentioned shaft determines how long it delays the start of the second curtain.
Best regards
Rolf-Dieter Baier
www.baierfoto.de