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Appropriate shutter speed tester
Old 06-18-2018   #1
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Appropriate shutter speed tester

So after wanting a screwmount Leica (or a rangefinder in general), purchasing bodies from keh that didn't work and sending them back, i have purchased a broken Leica iiic for next to nothing. Anyway, I didn't plan for after restoring the entire thing, that now I need to set the times of the shutter agh. Idiot. So. For those of you who have used good shutter speed testers, what can you recommend? I shoot slides, and black and white with low exposure latitude. So I need a very accurate one. But price is also a thing.. I'm a student so I'm trying to do this cheaply, and so I can keep buying film. But you get what you pay for.. Anyway, I saw the "photo plug" which seems sketchy, and I saw the sk grimes Leica rotary box thing. I also saw a cool Kickstarter shutter speed tester. Anyway advice on what you all have used would be nice. Thank you all a lot.
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Old 06-18-2018   #2
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The photo plug type (or the kind you can build yourself for next to nothing) is fine for leaf shutters but for a curtain shutter you have the problem of light hitting the sensor at an angle i.e. not only the light coming straight at it. You can solve this by using a laser (e.g. spirit level) as the light source, but this is very much a budget tester. Fine for checking out a camera but if you want a good one, it's going to cost money, so you can get more info e.g. curtain synchronisation or whatever it's called, adjusting to prevent capping, bounce etc. things that are beyond me to be honest! I use a DIY one for checking out (including curtains, but it's basic timing only) and leaf shutter adjustment.
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Old 06-18-2018   #3
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Never wanting to actually buy a shutter speed tester, I have used both sound and analyzed the waveform to check shutter operation as well as using a CRT with a known refresh rate. I calibrated a few shutters this way, my favorite one was a Speed Graphic which I got to within about 3% of nominal at 1/1000 second. With that shutter, after adjusting spring tension and braking, the time itself is just how wide the slits in the continuous curtain are. Quite a bit of fun, those are.

Phil Forrest
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Old 06-18-2018   #4
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Quote:
Originally Posted by johnnyrod View Post
The photo plug type (or the kind you can build yourself for next to nothing) is fine for leaf shutters but for a curtain shutter you have the problem of light hitting the sensor at an angle i.e. not only the light coming straight at it. You can solve this by using a laser (e.g. spirit level) as the light source, but this is very much a budget tester. Fine for checking out a camera but if you want a good one, it's going to cost money, so you can get more info e.g. curtain synchronisation or whatever it's called, adjusting to prevent capping, bounce etc. things that are beyond me to be honest! I use a DIY one for checking out (including curtains, but it's basic timing only) and leaf shutter adjustment.
https://www.ebay.com/itm/Camera-shut...0AAOSwtGlZBIVH

Something like this?
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Old 06-18-2018   #5
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Quote:
Originally Posted by Phil_F_NM View Post
Never wanting to actually buy a shutter speed tester, I have used both sound and analyzed the waveform to check shutter operation as well as using a CRT with a known refresh rate. I calibrated a few shutters this way, my favorite one was a Speed Graphic which I got to within about 3% of nominal at 1/1000 second. With that shutter, after adjusting spring tension and braking, the time itself is just how wide the slits in the continuous curtain are. Quite a bit of fun, those are.

Phil Forrest
Hi Phil,

i was just reading a thread you were involved in. Did you find that this method was accurate/consistent enough for high and slow shutter speeds calibration?
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Old 06-18-2018   #6
Sarcophilus Harrisii
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Quote:
Originally Posted by Soder View Post
Hi Phil,

i was just reading a thread you were involved in. Did you find that this method was accurate/consistent enough for high and slow shutter speeds calibration?
Hi,
it tends to be most useful for speeds above a focal plane shutters synchronisation speed because it enables you to see the amount of the film gate actually being exposed at various parts of the gate if you cycle the shutter enough to examine right across the gate. Once you hit the sync speed (which could be anything from 1/30 to 1/125 on the majority of "classic" focal plane shutters, depending on age etc) you should be seeing the whole gate exposed simultaneously anyway. In this sense it will be of less help in comparing, say, 1/60 with 1/30 if the shutter, for example, has a 1/60 sync speed.

That's not necessarily as big a problem as it seems. Yes, there can be exceptions: but if most shutters are well adjusted for their top speed (often, 1/1000) down to 1/60, slower speeds will only usually be much off spec if there's an issue with the escapement. Again, usually, this will be easy enough to detect (slow speeds stalling, pallet sticking, etc).

Using a CRT screen can, if you're observant enough, even offer some very basic insights into curtain acceleration. Because of the essentially fixed refresh rate of the picture, increases in the slit angle across the gate can let you know which curtain is running fastest at the end of the gate and to a lesser extent in the centre (less acceleration by then, so, harder to spot). The faster the curtain velocity = the steeper the slit angle. Of course any significant degree of taper in the slit across the gate informs which curtain is gaining on the other.

Ideally, because the curtains accelerate as the traverse the gate, there should be a very slight increase in slit width across it, to balance the reduction in exposure which would occur if the slit was truly constant (same slit width x increased curtain speed = less exposure, right?). Not everyone is aware of this point: conventional wisdom (and even some text books) discuss shutter function in terms of constant shutter velocity and slit width at each speed. This is OK in a general "getting a basic handle on how fp shutters work" context. But it is not truly accurate. The curtains, on being activated, do not instantly attain optimum velocity.

Physics has other ideas about that: mass; inertia; mechanical friction; etc all dictate that the curtains begin to run, have accelerated up to a usable speed as the laths pass the beginning of the gate, but, being spring powered, continue to accelerate as they move across the gate. For this reason the dimensions of the shutter drums, the shutter release system and spring tension are set up so that, when everything is to spec, they all conspire to bias a little gain to the first curtain, in order to maintain consistent exposure despite the faster curtain velocities towards the end of the gate.

Anyway, yes, you can use a CRT screen to adjust the fast/medium speeds with a fair degree of accuracy. But it's much more time consuming than using a dedicated tester, which will be easier, more accurate, and less dependent on skilled interpretation of the visible information. The biggest problem with using a CRT is that, whereas a neophyte can, indeed, get an approximate idea of shutter behaviour quickly, getting the most out of one involves a solid theoretical understanding of fp shutter operation, a good eye for spotting minute differences, and a great deal of practice. And I say that as someone who has used a CRT a lot.

I still keep a small CRT television receiver on a corner of my repair desk even though I now own an older model, but professional quality Kyoritsu camera tester. It still comes in handy for some situations. Initially dialling in the spring tension on a pair of curtains from zero for instance, the quick and dirty visual check will get you into the ballpark (at which point I'd switch over to the tester for the more subtle final balancing of springs). But despite the above, whilst a CRT receiver is a whole lot better than nothing, an electronic tester (particularly one that records curtain travel speeds) is certainly even more useful, and a guaranteed time saver.
Cheers,
Brett
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Old 06-19-2018   #7
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whatever you choose, always get one with an opening and closing sensor otherwise it's a waste of money
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Old 06-19-2018   #8
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Hi,
I appreciate the reply and information about the CRT Television method. I was actually inquiring about the use of the photo diods/plug things phill mentioned. Do you have any experience with this type? I'm willing to spend a hundred or so dollars, but simply not 400 for the calumet SST i saw on ebay... So i'm really interested to hear from people with some experience what they'd recommend me to buy/make.
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Old 06-19-2018   #9
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Quote:
Originally Posted by richardHaw View Post
whatever you choose, always get one with an opening and closing sensor otherwise it's a waste of money

Hi Richard,

I'm not quite sure what you mean? Would you care to elaborate?
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Old 06-19-2018   #10
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Found this app:

https://www.lomography.com/magazine/...or-your-iphone

This:

http://www.photoplug.de

I did download the app and will give it a try.
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Old 06-20-2018   #11
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Quote:
Originally Posted by Soder View Post
Hi Richard,

I'm not quite sure what you mean? Would you care to elaborate?
for focal plane shutters (leica, contax, nikon, etc) in short anything that travels along a plane, X or Y. you will want your tester to read the opening and closing shutter speed. having one at the middle is a bonus. each sensor records how fast your shutter is at that point.
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Old 06-21-2018   #12
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You can get a cheap shutter tester from a Romanian supplier on Ebay. I bought one many years ago when he started making and supplying them. The sensor is a phototransistor and you have to download free software to analyse the signal. Mine included a simple light source and was designed for cameras whose back could be opened. For my Leica screwmount I bought a laser pointer and worked through the front of the camera. I placed a white card in the film plane and pointed the laser. It worked fine. I improved the accuracy using two pieces of tape over the end of the pointer to make a slit. Of course I had to keep the slit vertical. The big advantage of this technique is that you can point the laser right-centre-left to get an idea of the variation in exposure across the film plane (e.g. because the shutter slit width varies as it moves across).
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Old 06-22-2018   #13
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Hi Richard,

I highly appreciate the information. How can i know if a shutter speed tester records opening and closing? I am sorry for the stupid questions.. I just have never known much about electronics (evidence being i shoot 80 year old cameras..), and so learning about them is difficult..

Here is the one i've been looking at.

https://www.ebay.com/itm/Camera-shut...0AAOSwtGlZBIVH
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Old 06-22-2018   #14
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Quote:
I did download the app and will give it a try.
How did it work?
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Old 06-22-2018   #15
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Again Richard,

Sorry for asking so much
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Old 06-22-2018   #16
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Originally Posted by jcb4718 View Post
You can get a cheap shutter tester from a Romanian supplier on Ebay. I bought one many years ago when he started making and supplying them.

I think we are thinking about the same ebay seller.

Does this method work quite well? Accurate, and easy? Its just i shoot chromes, and if it's not in that 30% accuracy margin... They just don't turn out well.

Can you measure curtain opening and closing with this method?
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Old 06-22-2018   #17
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Quote:
Originally Posted by Soder View Post
Hi Richard,

I highly appreciate the information. How can i know if a shutter speed tester records opening and closing? I am sorry for the stupid questions.. I just have never known much about electronics (evidence being i shoot 80 year old cameras..), and so learning about them is difficult..

Here is the one i've been looking at.

https://www.ebay.com/itm/Camera-shut...0AAOSwtGlZBIVH
That will do everything you need. It will give you both the actual exposure across the film gate and the physical speed of each curtain. The latter is of little consequence to those who do not repair cameras but can be a big help when diagnosing why exposure across the gate is not correct. It lets you know exactly what each curtain is doing across the gate, so that if there is a consistency issue over the image frame you can see which curtain is running fast or slow. Some manufacturers helpfully included the optimum velocity for the curtains with their service manuals. When this is available simply adjusting the curtain spring tensioners to the correct figure will often get the shutter close to optimum (assuming the timing mechanism is in good repair and adjustment of course).

I have an older professional Kyoritsu tester that is very good but it only reads exposure time at the beginning, centre and end of the gate: it doesn't inform curtain velocity. Meaning I have to use my experience and judgement to work out whether, say, the last part of the gate is overexposed because: the first curtain is running fast; the second curtain is running slow; or sometimes, both. I can do this, but when the velocity of each curtain known, it does make fine tuning a shutter both simpler, and quicker. So eventually I suspect I will buy one of the linked items or a similar one myself, simply to save time.

Of course there is more to adjusting a focal plane shutter than just tuning the curtain springs. Actual designs vary but if, for instance, there's an issue with the timing gears for the curtains and/or their release latches, the accuracy of the shutter may be poor for reasons not directly related to the curtain condition and adjustment. But the final result all comes down to those curtains, and getting them to traverse the gate at the right velocity, and in the correct relationship to each other for the various speeds. If you don't know what they're doing, correctly adjusting the shutter becomes that much more time consuming, and harder.
Cheers,
Brett
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Old 06-23-2018   #18
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like what I previously mentioned, you will need to have a tester with at least 2 or 3 sensors. a tester with only a single sensor is not very useful. probably OK for small things but is near-useless for real repairs.

in my experience, a tester that only works with sound is not what you would want.

1) the real testers made by kyoritsu are not cheap, they are the best but is kind of overkill for people who just wanted to do DIY repair from home.

2) the cheapest ones (that operate on sound) are a waste of money.

what you want is something in-between the 2 types mentioned above.

I will not give recommendations for this as much as I want to.
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Old 06-23-2018   #19
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Quote:
Originally Posted by Soder View Post
Hi Richard,

I highly appreciate the information. How can i know if a shutter speed tester records opening and closing? I am sorry for the stupid questions.. I just have never known much about electronics (evidence being i shoot 80 year old cameras..), and so learning about them is difficult..

Here is the one i've been looking at.

https://www.ebay.com/itm/Camera-shut...0AAOSwtGlZBIVH
Soder,

When I looked at the listing this morning, there were 19 units sold and 1 left. Now the listing has ended. I got the last one. The seller has great feedback, the unit looks ideal, and I've got a bunch of cameras I would like to test. Sorry if I rained on your parade by getting the last one.

Sid
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Old 08-20-2018   #20
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It took 8 weeks to get the tester in the mail from Romania, but now I have it, and it's a great little device. The tester unit itself is a little bigger than a pack of King size cigarettes. The display is easy to read. It supports an SD card, so all the shutter and curtain speed test data can be put into a spreadsheet if your computer has an SD card reader.

Now that I have all this curtain and shutter speed data, I am not sure how to interpret it.

What is a good reference for shutter curtain speeds? I need something that will help me interpret the data.

For example, if the first curtain goes across the frame 25% faster than the second curtain, does that mean one end of the picture gets a quarter stop more exposure than the other end?

I can recommend the tester. The seller, vfmoto, was excellent to work with (the first shipment got lost in the mail, and he sent a second one after it was obvious the first was not going to arrive). Because he re-listed the tester, I didn't get the last one. He just sells them in batches of 10, apparently.
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Old 08-20-2018   #21
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Originally Posted by sreed2006 View Post
It took 8 weeks to get the tester in the mail from Romania, but now I have it, and it's a great little device. The tester unit itself is a little bigger than a pack of King size cigarettes. The display is easy to read. It supports an SD card, so all the shutter and curtain speed test data can be put into a spreadsheet if your computer has an SD card reader.

Now that I have all this curtain and shutter speed data, I am not sure how to interpret it.

What is a good reference for shutter curtain speeds? I need something that will help me interpret the data.

For example, if the first curtain goes across the frame 25% faster than the second curtain, does that mean one end of the picture gets a quarter stop more exposure than the other end?

I can recommend the tester. The seller, vfmoto, was excellent to work with (the first shipment got lost in the mail, and he sent a second one after it was obvious the first was not going to arrive). Because he re-listed the tester, I didn't get the last one. He just sells them in batches of 10, apparently.
Hi
Curtain velocity is helpful information to have—but it has to be interpreted in conjunction with the actual amount of exposure at the various parts of the gate.

As I think I may have mentioned in a previous comment, some manufacturers, particularly some of the Japanese ones, would actually advise a curtain velocity that should achieve good shutter accuracy when the camera involved was new, in their service manuals. This information isn’t universally provided, (and you should always make a note of the number of turns or clicks etc when de-tensioning the springs for reference, anyway). But if, for instance you’ve just fitted new curtains to a shutter and have to adjust the tension from scratch, if the amount of adjustment the springs previously had, as noted, does not produce good accuracy to start with, then—dialling in the required tension to get each curtain travelling at the recommended velocities, should see the actual exposure times looking fairly close (assuming, of course, that all else is well with the mechanism).

That said—the curtain velocities and relationship between them (timing of their release, which establishes the slit width at the beginning of the gate) together combine to determine the actual exposure on the film. Achieving the correct actual amount of light hitting the film at the various settings is always your ultimate goal, follow? The velocity of each curtain is helpful information but is a means to an end, the end being accurately calibrated shutter speeds.

If you take a look back over my last 50–100 posts on this forum you will find another one that mentions the Leica screwmount shutters, and how the dimensions of their drums are designed to give the first curtain a bit of an edge as both curtains run across the film gate, thus, offsetting the effects of curtain acceleration.

In your shoes, if you do not have an absolute number for the curtain velocity of your camera (and whilst that can be helpful it’s not absolutely critical, usually), I would dial in a couple of turns of initial tension for each curtain, and then start checking the relevant exposure times according to the accepted wisdom for adjusting Barnack shutters. With many cameras this may be the fastest speed Ie 1/1000, however some designs have individual timing adjustments available for various speed ranges and in some instances, the best speed for initially fine tuning the curtain tensions might be Eg 1/60. Whilst the information I’ve relayed is accurate overall, as far as how focal plane shutters function, I prefer Contax rangefinder to Leica and have successfully avoided having to work in Leica cameras to date. So if the repair manuals dictate a certain procedure for adjusting the shutter accuracy or other experienced repairers have informed comments about how to dial your shutter in, I would defer to their wisdom about the order in which any adjustment(s) ought to me made.
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Brett
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Old 08-21-2018   #22
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Thank you, Brett. I have never seen curtain velocity data before, which makes me a newbie to understanding the information (and prone to asking simple questions).

It appears that the curtain velocity data is valuable if one has the tools to make adjustments - and has data as to what the velocities and accelerations should be. I don't have either. So right now, I am just trying to understand what the numbers mean as far as what to expect from the camera's ability to expose properly.

If curtain velocity data are not normally published then I will regard it as information that is nice to know, but not totally needed. It's something that can be useful once I learn more.
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