View Full Version : Old Shutter Times

29-Dec-2009, 22:13
So, I just got an older shutter and noticed the times were 1, 1/2, 1/5, 1/10, 1/25, 1/50, 1/00, 1/200 and 1/400. What gives?

I'm wondering why it deviates from the normal shutter speeds I'm used to seeing - 1/15, 1/30, 1/60, 1/125, 1/250, etc.?

And how do I use this with my spot meter which has the "common" speeds?

thanx much

30-Dec-2009, 00:26
You have found one of the complex conundrums of the parallel photographic universe. You will need to spend thousands of dollars and have Grimes convert the shutter to "common" speeds. Of course you could try to use your spot meter but again the inconsistency of speeds and f stops will drive you crazy. It may not be a long drive.

There is another solution but it depends on how a##l you are. One of the sets of shutter speeds is about 1/4 of a stop different to the other. I'm not sure but I think there is an ISO compensation on most modern exposure meters.

Ok it is very hot here today and you haven't done much of a search to really help yourself but the answer is contained in the second paragraph.

30-Dec-2009, 01:01
This is a case where a light meter with analog readout comes in handy. Shutter speed of 1/5 sek obviously is just a little faster than 1/4, so closer to 1/4 than to 1/8. You just read from your meter's scale the apropriate aperture setting for a point about 25-30 % away from the mark for 1/4 sek. On a digital readout you may have to use the 1/4 sek setting and compensate by opening the aperture a little (about 1/3 of a stop).

For most applications a difference of 1/3 stop will hardly be noticeable. If you regularly do very critical work and do it for a living, you would hardly use an old shutter like this. How clean and well maintained it is will probably influence more on the pictures than the difference between shutter speed scales. If the shutter is consistent, have the actual times measured. Then you would know what you have.

Good luck!

30-Dec-2009, 01:21
Never had an issue using an older shutter with a Spotmeter, the speeds are so close to the modern scale taht you can just adjust to the nearest 1/3 of a stop. as Svein says.

As these shutters came first it's the new ones that deviate :D

The beauty of these shutters is you can set intermediary speeds as well, except with the top 2 speeds.


Steve Hamley
30-Dec-2009, 04:42
Of course, you're assuming that those speeds are actually what's marked, which is actually your biggest error and problem when speaking of a mechanical leaf shutter.

The most likely scenario is that neither the vintage not the modern shutter is within 1/4 stop of what's marked, at least at all speeds (and certainly the two fastest marked speeds).

Cheers, Steve

Ivan J. Eberle
30-Dec-2009, 08:08
Ummm... Because they were visionaries looking ahead to the day when virtually all films would have ISOs in denominations of 100 rather than 8, perhaps?

30-Dec-2009, 10:22
if the shutter is a betax you can just move the shutter speed thingy
to something you are comfortable with. the betax does not have indents
but a sliding thingy, like the fstops ... so you can adjust for the marked speeds
or anything inbetween.


13-Jan-2010, 19:50
Allright Steve, I give..

Robert Hughes
14-Jan-2010, 12:03
Um, was it because they had converted to metric? Wait a sec... What is 1/100 of a minute, anyway, a centi-minute? :confused:

Richard K.
14-Jan-2010, 12:08
Darn, I thought this was an announcement for the first issue of a new, arcane interest journal!

Ole Tjugen
14-Jan-2010, 15:34
Um, was it because they had converted to metric? Wait a sec... What is 1/100 of a minute, anyway, a centi-minute? :confused:

I don't know - but in the early days of my oilfield career (insert long convoluted connection) I came across the microfortnight. That works out to be about 1.2 seconds...

14-Jan-2010, 15:59
Yeah, what Ivan said
So after ASA and ISO straightened out film speeds, and shutter designs got to neatly match, why did "they" come up with 100 speed films????
Gee if only Kodachrome 10 were still available