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accurate long exposure control with tech

Wayne Fox

Workshop Member
Anyone using some type of timer/controller to the cable release of a tech so exposures over 1 second are consistent?
 

Ken_R

New member
Anyone using some type of timer/controller to the cable release of a tech so exposures over 1 second are consistent?
I was going to ask the same thing a while back. I have learned to time it pretty good by looking at the shutter time counter on the back. Would love an integrated electronic shutter on the lenses that do not require a large controller or usb connection.
 

gerald.d

Well-known member
Hi Wayne -

Just wondering how accurate the consistency you're looking for?

For shutter times of a second and over, it's relatively simple to get them accurate to within a tenth of a second simply by using a stopwatch (one on a phone is good enough). Just start the stopwatch with one hand and fire the shutter with the other at the same time, then close the shutter when the watch gets to the time you want. With a little practice, I guarantee you can get to at least 0.1 second accuracy, if not a lot better.

Obviously the longer the exposure, the more accurate - with regards exposure - your time becomes, but even at 2 seconds, if you're out by 0.1 seconds then that's only 0.07 of a stop. I'm not exactly sure how reliable and accurate Copal shutters are, but that could well be more accurate than regular shutter speeds and possibly even the aperture setting.

Kind regards,

Gerald.

/edit

Found some data for Copal shutter accuracy here (scroll to the bottom)

http://www.largeformatphotography.info/shutters.html

At 1/60th of a second, the test timings ranged from 0.01520 to 0.01455, which is about a 5% difference - roughly the same that 0.1 second accuracy at 2 seconds would be. Based on this I reckon you should be absolutely fine just timing your exposures manually with a stopwatch.
 

GrahamWelland

Subscriber & Workshop Member
+1 to Gerald's approach. I use the chrono on my watch or if it's short enough the timer on the IQ back display. I'm pretty sure that my reaction times are about as good as any shutter would be, even if it shot long enough.
 

jotloob

Subscriber Member
+1
Like Gerald & Graham I do the same and find it accurate enough.

Like Gerald & Graham & Dan do , I do the same.

When I was still shooting LF I used the Prontor Professional Timer .
It works perfectly good .
Not that it is more accurate than your watch , but many times bypassing people tried to involve me into a chat and than I forgot my counting .

There is also a smaller Prontor Timer , but I do not know , where I have hidden that smart little thing .

View attachment 81138
 

Steve C

Member
I use either the timer on the back of the IQ (make sure display is active for the entire exposure) or as an homage to Ansel, a metronome app on my iPhone. It clicks each second and I just count. Don't have to worry about starting it and the exposure at the same time.
 

Paul2660

Well-known member
Problem is on using the phase LCD as about 1/2 of the time the screen stays blank. I used to think it was because I has let the screen time out but the other day I was doing some 6 sec exposures and 1/2 of the time the screen timer did not come on.

I too use watch stopwatch.

Paul
 

Ken_R

New member
Like Gerald & Graham & Dan do , I do the same.

When I was still shooting LF I used the Prontor Professional Timer .
It works perfectly good .
Not that it is more accurate than your watch , but many times bypassing people tried to involve me into a chat and than I forgot my counting .

There is also a smaller Prontor Timer , but I do not know , where I have hidden that smart little thing .

View attachment 81138
That should do the trick. Very very cool.
 

jotloob

Subscriber Member
Here is the little brother of the PRONTOR PROFESSIONAL TIMER .
Total length of the housing is just 5cm .
That timer was adapted to a mechanical machine . It was a present for me and is now part of my collection .
View attachment 81160
 
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