Adjusting Compur/Copal shutter speeds
Testing the shutter speeds on my (small) collection of shutters, I find the speeds faster than 1/100 sec are way out. For example, Copal:
1/125 measured at 1/83
1/250 measured at 1/166
1/400 measured at 1/166
1/100 measured at 1/86
1/250 measured at 1/123
1/500 measured at 1/117
1/10 measured at 1/15
1/100 measured at 1/80
1/200 measured at 1/107
1/400 measured at 114
Most of the other speeds were within 10%, and a few, spot on. Apart from the fastest speed on each shutter, I'd kinda hoped for reasonably accurate timings - Not wanting to send the mechanisms away for a CLA, is there anything that I could do to improve the speeds ?
The Compur is fully adjustable. The manuals are out there, here is one http://cgi.ebay.com.my/Rolleiflex-TL...mZ120362946347 If I had the PDF I'd sent it to you.
Sometimes bad results implicate the test and not the subject. Are you certain that your test method is reliable?
Repeated the tests again this morning, and the results are within 2% or so.
Originally Posted by jon koss
Seems there are quite a few places selling the Rollie manuals. Reluctant to shell out $35+$13 without knowing if the required information is included. Looks like ebay #360153020687 would cover two of the shutters in question.
Originally Posted by ic-racer
Googling with a better search parameter, I found http://www.suaudeau.eu/memo/rep/Comp...ir-manual.html.
I would imagine Copal shutters would be similar in terms of cleaning and adjusting.
When you measure high speed leaf shutter opening time, you need to think about the effective opening time. For that, I think you need to integrate the amount of light that pass through and not just looking at the opening and closing time.
When calibrating my shutter using a phototransitor and my sound card, I realized that the highest speed are off quite a bit. About 0.20 stop at 125, 0.5 stop at 250 and about a full stop at 500. The other speeds are within 0.10 of a stop. Since I'm not able for now to get the DC component of the signal, I can't validate my assumption. As soon as I can get my hands on a DAQ card, I will check if integrating the signal make a more sense.
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