Shutter Speeds - More accurate than we often suppose?

[David Karp]

Over the years, I have read on many occasions that our shutters are less accurate than we would like to believe, especially older shutters.

A while back, I purchased the Shutter Speed app for my Android devices. This is the one created by Lukas Fritz (http://www.photoplug.de). I first used it without his PhotoPlug accessory and was very surprised that most of the tested shutters were quite accurate (assuming, as I do, that the app is accurate). Below 1/125, most of them are almost right on.

I was worried that using the app without the PhotoPlug was leading me to bad results, even though my results were repeatable.

So, I purchased the PhotoPlug and it sat around for months and months. This weekend I pulled it out and started making some measurements with my Nexus 7 tablet. I tested older style (jagged edge shutter speed ring), silver block style, and all black style Copal shutters. It did not seem to matter how old they were. I also tested versions used by Rodenstock, Nikon, and Fuji. Again, it did not matter which ones I chose. They are all mostly right on target. Of course, the higher speeds (above 1/60) are all off. However, they are not off by much. Usually, 1/125 and 1/250 are off by 1/3 or 2/3 of a stop. The top speed, 1/500 or 1/400, are, as expected, off by much more. Usually 1 1/3 stop.

All but one of my lenses are used. I have not yet tested the one I purchased new. None have been serviced since purchased by me! The one I sent to Carol, she sent back after making a minor fix for free!!

Based on what I have read, I expected more deviation from the marked speed, but I found that with the PhotoPlug the shutters were more accurate than I expected after using the app without it. So, I am wondering what others have experienced. Am I lucky in the shutters I have tested so far? Or is this a typical experience?

I have yet to test some Seikos, an Ilex, and some Wollensak shutters. We will see how that goes.

[Jac@stafford.net]

Based on what I have read, I expected more deviation from the marked speed, but I found that with the photoPlug the shutters were more accurate than I expected after using the app without it.

Your assertion certainly has my attention and I look forward to more comments from our readers. I've worked for forty years by finding a couple shutter speeds I could trust, and adjusting aperture or film speed to accommodate the one or two shutter speeds that work.

[photog_ed]

Over the years, I have read on many occasions that our shutters are less accurate than we would like to believe, especially older shutters.

A while back, I purchased the Shutter Speed app for my Android devices. This is the one created by Lukas Fritz (http://www.photoplug.de). I first used it without his PhotoPlug accessory and was very surprised that most of the tested shutters were quite accurate (assuming, as I do, that the app is accurate). Below 1/125, most of them are almost right on.

I was worried that using the app without the PhotoPlug was leading me to bad results, even though my results were repeatable.

So, I purchased the PhotoPlug and it sat around for months and months. This weekend I pulled it out and started making some measurements with my Nexus 7 tablet. I tested older style (jagged edge shutter speed ring), silver block style, and all black style Copal shutters. It did not seem to matter how old they were. I also tested versions used by Rodenstock, Nikon, and Fuji. Again, it did not matter which ones I chose. They are all mostly right on target. Of course, the higher speeds (above 1/60) are all off. However, they are not off by much. Usually, 1/125 and 1/250 are off by 1/3 or 2/3 of a stop. The top speed, 1/500 or 1/400, are, as expected, off by much more. Usually 1 1/3 stop.

All but one of my lenses are used. I have not yet tested the one I purchased new. None have been serviced since purchased by me! The one I sent to Carol, she sent back after making a minor fix for free!!

Based on what I have read, I expected more deviation from the marked speed, but I found that with the PhotoPlug the shutters were more accurate than I expected after using the app without it. So, I am wondering what others have experienced. Am I lucky in the shutters I have tested so far? Or is this a typical experience?

I have yet to test some Seikos, an Ilex, and some Wollensak shutters. We will see how that goes.

I bought Lucas's app and photocell and tested all my shutters a couple of months ago. I got a similar result; they were all very accurate at 1/30 and slower. Performance degraded at higher speeds, usually about one stop slow at 1/400. They are all Copal shutters, and just as I received them, no CLA on any of them. A total of six shutters, I think.

Ed

[Leszek Vogt]

Most of my shutters seem OK....till they were properly tested. One Ilex didn't work at all (I bought the lens at v. reasonable), couple of them seemed slow at 1/2 and 1 second. Decided to CLA (all 6), so I wouldn't have to look over my shoulder. Only one Copal seem perfect, so I didn't send it. Each person will likely will have a different story.

Les

[morecfm]

I use the app with the photoplug. I don't think in terms of speeds being off by x/y stops but rather matching a real speed vs. an indicated speed. That way I just meter to the real speed of the shutter and don't bother with the additional math after to make adjustments to the marked speed. I make a chart for each lens. I also do this on my mechanical medium format leaf shutter lenses.

[David Karp]

I am making charts for each lens in Excel. I will put them on labels or tape them onto the lensboard with each lens. I may also make note cards and laminate them.

[drew.saunders]

I am making charts for each lens in Excel. I will put them on labels or tape them onto the lensboard with each lens. I may also make note cards and laminate them.

I have a Calumet shutter tester (bought new long ago), and used it to test every lens and create a cheat sheet that's taped to each lensboard with the shutter speed corrections. I also have the bellows extensions corrections for each lens as well on the sheet (i.e.: infinity at Xmm, 1/3 stop at Ymm, etc.), all of these created in Excel. I made a master sheet that I printed small and carry with my grey card (which came with a nice ziplock plastic bag, so it stays dry and easily found without needing lamination).

[David Karp]

Drew,

Did you find your shutters were accurate? Inaccurate?

[pjd]

I use that shutter speed tester app with the photo diode widget, it showed that an Ilex Universal I've got is fast at slow speeds and the top speeds are all 1/25th. That Ilex is the shutter type that SK Grimes won't attempt to repair according to their site, by the way.

I've got a few old dial set compurs that test consistently accurately. Also a couple that are less reliable, and a couple of outright dogs. I use a couple of Volute shutters one of which has speeds a bit slower than the dial speeds, but consistently so. The other Volute runs nicely most of the time but is a bit awkward in cold weather.

Compound shutters are generally pretty good in my experience, usually a bit fast at 1 second, accurate through most of the mid range and then a bit slower than claimed at top speed.

[IanG]

I tested quite a few of my lenses 3 or 4 years ago and found all the shutter speeds on Copals, Compurs and Compounds were well in tolerance with little deviation less than 10%, not enough to compensate for. What surprised me most was the smoothest were the early Dialset Compurs and Compounds. I was most interested in the shutter speed range I was typically using 1 second to 1/30, although I do use faster when working hand held.

The Ilex and Wollensak shutters showed much greater variability while just in tolerance which is +/- 1/3 stop they aren't as accurate.

Ian