View Full Version : Shutter Testing devices
Would like to hear your comments on shutter testers. Do you have one of these devices or do you bring your lenses to a repair shop when you feel the need to have them tested?
I guess a pro device for heavy daily usage would be overkill. Are there products in the market, which are targeted at photographers and not at professional repair persons?
Calumet (www.calumetphoto.com) sells a relatively inexpensive shutter tester (just under $100) called the Fidelity Calumet Digital Shutter Tester. It has the reputation of being simple to use and quite accurate.
Yes, the ZTS Tester Pro.
Tests shutter speeds, metering, AE system, flash synch and is also a hand held reflected and incident exposure meter and flash meter. Easily hand holdable and reads out on LCD screen.
I have the DCA-1 shutter tester - It came as a kit and was part of the old National Camera course. Works like a charm...
The tester that Eugene mentioned has been a trusted tool of mine for many years. Mine wasn't a "Calumet" branded one, but from the original maker (I think Delta?). I've got a spreadsheet that does a quick graph showing shutter accuracy at each speed and erratic behaviors, too. It's nothing fancy but it gives me a quick reference and visual image of the shutter's behavior through its speed range. I've got a copy at
If nothing else, it might be a good start for someone who wants to polish it up. The routine is to test from slow to fast, fast to slow and then slow to fast again. The right side of the graph shows the % variation within a speed setting and the left shows the f stop variation for that speed on average. The data and formulas in the master are for focal plane shutters and there is some "massaging" needed for leaf shutter numbers.
For what it's worth, I bit the bullet, spent the $100, and got a Calumet tester. I tested my modern Fujinon, Nikon, and Fujinon LF lenses and found them to be very very close to their marked speeds. I also tested my 1950's folding cameras: an Agfa Record and an Agfa Isolette. They too were so close to marked speeds, that there was nothing wrong. What a disapointment !
There is supposedly a problem with reliability of the Calumet tester due to its dependence on an incandescent light source, which can vary significantly in wavelength. Better testers have stabilized internal light sources. Bob, where is the ZTS Tester Pro unit sold?, and does have an internal stabilized light source?
ZTS is sold by ZTS. They are in Cincinatti. It uses a light panel like the Gepe Pro 4x5" box as a light source. It should be easily calibrated to any other evenly illuminated light source as well.
Martin, Do a serch on this forum and Photo.Net for shutter speed tester. Over a year ago I think. Somewhere in one of the two archives there is plans for building a shutter tester using materials available at Radio Shack (under $10.00.), and a cheap laser pointer. Very easy to build. Also needed is a program for your home computer named "Cool Edit" (available as freeware.) I built one and mounted it in a small cardboard box. It is limited in that you can't carry it with you unless you take your computer with you.
If you happen to be in the market for a darkroom timer, the Metrolux lamp controller as they call it can also be used to test shutter speeds. However, it's expensive (around $350) so you certainly wouldn't want to buy it just to test shutter speeds.
"There is supposedly a problem with reliability of the Calumet tester due to its dependence on an incandescent light source, which can vary significantly in wavelength. Better testers have stabilized internal light sources. Bob, where is the ZTS Tester Pro unit sold?, and does have an internal stabilized light source?"
Wavelength would have absolutley no influence on shutter speed testing with the Calumet. You're not measuring from one bulb to another, or even luminance. Just the duration of a light powered switch. Any light source that can turn the switch on and off will be 100% dependable. The only possible affect a light source could have would be a slow flourescent, that flickered, and _if_ the tester didn't use any damping at the sensor. Anyone who uses such a light source for testing shutters deserves what they get!
If you follow the instructions (necessary for the faster speeds), the Calumet tester is extremely accurate and simple to use. Just be carful measuring leaf shutters at high speeds. If not done right, you can easily be more than a stop off...
Michael S. Briggs
I have the Calumet tester and it works well. The directions supplied with it say to refer to several incandescent bulbs for the reasons that RichSBV alludes to. If the bulb is bright enough to trigger the tester, it is quite implausible that the wavelength of the light would have any effect.
The confusion may arise from the instructions that Calumet gives to adjust the distance of the bulb from the shutter tester. The problem with the simplest testers is that, if a bright light is used, they measure the total opening time, starting their measurement from when the shutter blades are just barely open. When the blades are first open, perhaps only light for f128 is passing through the lens, so if the aperture is set at f16, you really aren't getting an f16 exposure. What the user cares about, and what is marked on the shutter scale, is the effective opening time. This only matters for the fastest one or two speeds on the shutter, which I have never used with a LF lens, so the simplest advice is just to ignore the fact that the simple use of the Calumet tester will give long times for those speeds.
The directions supplied with the Calumet tester are intended to space the bulb at a distance that will cause the shutter tester to start measuring when the blades are about half open, thereby giving a truer measure of the effective opening time. Again, this only makes a difference for the fastest speeds of a between-the-lens shutter.
Other methods would be to adjust the intensity of the light with a control, or to have a built in light of the correct intensity, or to have a sensitivity adjustment on the shutter meter, or, with much more complicated circuitry, do a weighted average of the time profile of the light passed through the shutter. These methods lead to a more expensive shutter tester. Getting back to the original question, about products aimed at photographers vs professional repair persons, the Calumet tester and several others mentioned above are aimed at the photographer market and products with the more complicated designs to measure effective speeds are typically aimed at the professional repair person.
If all of your shutters are from the past two decades or so, you probably don't need a shutter tester. Recent shutters (typically Copals during this time period) are almost always accurate. If your films are correctly exposed expect when you make a mistake, you probably don't need to be concerned about your shutter speeds. If you have older shutters, then a tester can be useful to either determine the actual speeds for use in exposing, or to decide to have a CLA done on the shutter.
"extremely accurate and simple to use. Just be carful measuring leaf shutters at high speeds. If not done right, you can easily be more than a stop off.."
So it is simple and accurate but capable of being way off if not done right. Is that correct? Seems like a contradiction.
Thx for all your replies. Guess the Calumet tester is enough for me.
The ZTS (http://www.ztsinc.com/tpro.html) looks very neat, but according to the specs it can be used only for 35mm and MF and you need dedicated adaptors for different formats.
Craig, will definitely use your spreadsheet. Thanks a lot!
"""extremely accurate and simple to use. Just be carful measuring leaf shutters at high speeds. If not done right, you can easily be more than a stop off.."
So it is simple and accurate but capable of being way off if not done right. Is that correct? Seems like a contradiction.""
Almost anything can be used wrong, interpreted wrong, or just generally screwed up.
Yes, it is very simple and very accurate. Anything beyond that is operator error, and if you read anything about testing leaf shutters, you would ask such a question. As with anything else, the simpler something is, the easier it is to get things wrong.
The speed of the shutter is arbitrary to begin with. At what point, close-to-open-to-close do you measure and consider the exact speed? This can be argued indeffinitely with leaf shutters. Luckily there are some accepted standards.
If you follow the simple directions that come with the Calumet tester, the results will be very accurate at the fast speeds.
I read the directions, metally figured out what was going on, decided that the correct placement of a light bulb on one side and the tester on the other would come close enough for me. So I don't do the facier setup Calumet suggests. The trick is the placement of the tester light sensor in relation to one of the shutter leafs. For speeds over 1/100, you can easily get within 10% without doing any setup at all.
A quick look at the ZTS seems to indicate it works the same way the Calumet does. Although it may display directly in shutter speeds instead of time. This would indicate that the ZTS would have all the same problems of measuring a leaf shutter that the Calumet has. The only way to not have this 'problem' would be to use a diffused light source at one end shining through the shutter to another diffuser. Problem there would be that the measurment of the opened leafs would be different than the standard. You win & lose. But not if you follow the simple directions...
Since the ZTS would look to measure the shutter speed the same way the Calumet does, and it apparently does not come with the proper directions to accurately measure the faster speeds, I would wonder greatly about it's accuracy! And at 6 times the cost!
--Bob Fowler contributed, 2004-03-23 13:02:45
"I have the DCA-1 shutter tester - It came as a kit and was part of the old National Camera course. Works like a charm..." Bob, I would like to build a shutter tester. Do you have the kit instructions that came with your DCA-1 shutter tester? I could purchase the Calumet or make the computer card tester, but, I would like to also measure opening and closing shutter curtain speeds. I was thinking that I might be able to modify the DCA-l schematic, if you have one. A shutter speed tester that can measure opening and closing curtain times is critical if one is going to do repairs on focal plane shutters. Please contact me: pkmichaelis at yahoo dot com
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