View Full Version : changing shutter speed

brian reed
15-Jul-2005, 17:53
a quick question. after I cock the shutter on any lens and I decide to change shutterspeed, will I need to trip the shutter and recock or could I just set the new speed? On some of my lens I could hear buzzing when I turn the shutter speed ring after I cocked it. don't know if thats good or not.

David A. Goldfarb
15-Jul-2005, 17:58
It's okay to do that on Copal shutters, but on some older shutters it's possible to strip something. Best just to get in the habit of changing the shutter speed before cocking the shutter.

tor kviljo
16-Jul-2005, 11:41
The synchro Compur have a strong booster-spring being tensioned only on the one or two higher speeds (easy to feel the difference in tension needed when setting the shutter at 1/30 sek compared to highest speed). I understand that You put a unhealty high strain on shutter mechanism if you set a compur at f.ex. 1/30, then force (you have to use an amount of pressure turning the ring) the shutter-speed ring to highest shutters speed. In older books, this is emphasized as "dont-do!", as is the information that the shutter is subjected to a lot more wear when running on highest shutter speeds than on slower ones (which is to be expected, as the acceleration the steel-blades/mechanism have to withstand on max- speed - booster sping tensioned is much higher than on lower speeds), so you're not to use the big compurs at max speed other than during picture taking. I have bought a few lenses with defect (compur) shutters, and sometimes, when opening the shutters, I find that the timing-pins (steel pins being moved by cams on shutter-ring to different positions when selecting shutter-speed) is broken of close to rivet-point - which might be due to extra strain being put on rivet-point when turning the timing-rim of an allready set shutter.