Interesting project! As it happens, I just finished programming an Arduino-based shutter tester. It uses a laser emitter and sensor. The "scaffolding" is done with Lego bricks ;-) With the bundled light and the well-defined sensor area I can measure the curtain speed at specific points, principally in the middle and the opening and closing side. As far as absolute values go, I am quite satisfied with tests up to 1/250: very plausible and repeatable. I am more interested, however, in making sure that the opening speed matches the closing speed at 1/250 and 1/500. The shutter tester seems to measure the relative difference reliably. I still have to verify by film testing whether the tester serves the purpose of balancing opening and closing speed ... // Next project will be a shutter tester based on a reflected light sensor that could be used for screwmount Leicas without taking off the shell. I have a prototype. But it only works so-so because the working distances of these sensors tend to be very small.
@@atf2940 awesome! The legos to allow for pretty much any configuration. That's certainly a big advantage. If you check the links posted in the description you'll find everything needed for a super complete 3 sensors tester that will give you that precise information you're after. As for the reflective issue, some recommend sliding something thin but very shiny where the film should be. Sometimes the pressure plates are quite dull and won't reflect enough light back to the sensors.
@atf2940 Hi, I am the 'inventor' of the device that Alin is demonstrating. It is designed to only give a guide. It was in response to the discussion on Photrio of how Leica used the television scan lines to give an indication of shutter speed. There is now improved firmware available based on Alin's feedback. For accurate measurement, build my full ESP32 three sensor or Arduino two sensor shutter tester. As you already have Arduino, you should be able to get my earlier Arduino 2 sensor version up & running easily, but I would always recommend building the ESP32 version. I did jokingly suggest to one builder to use Lego & he did :o) Photos of this build and others are in my documentation You are correct, home-brew testers will be accurate up to around 1/250 and then the issue of sensor width to curtain slit width will start to give increasing errors, almost 50% error reading at 1/500s. The reasons for this are discussed in the Photrio thread. My shutter tester auto-calibrates for these errors and will show the true shutter speed. Using a reflective sensor is straightforward & my tester will do it, but not documented. It is a little more tricky to make the hardware as the Laser & tx have to be mounted one above the other and angled to converge on the camera backplane. Of course the camera always has to be the exact distance. github.com/billbill100
Well, I have my Arduino-based shutter tester up and running. The suggestion of masking the laser and the sensor with a narrow slit (see one of the comments above) was brilliant: I have run tests up to 1/1000 with repeatable and plausible results. The downside of the tester: It's depressing to find out how unevenly my Russians expose. (I should add that I rarely run film through my Russian cameras, I just use them for repair entertainment.) Worse, there is apparently near to nothing one can do about it by changing the curtain tension. Unlike with Leicas and Japanese Leica clones, exposure on opening and closing cannot be significantly adjusted individually. It is as if the two curtain were coupled: they accelerate together and there is not sufficient margin to compensate for that by widening the slit as it moves (Leica etc: very responsive to tension change on the curtain springs). Over the last two days I had the very same frustrating experience with a Zorki 1, 3M, and a FED-2 (all recently CL'd, two with new curtains, running smoothly). The ANSI norm says: at most half a stop difference between opening and closing. I found no way to get any of the three even close to that tolerance across all speeds. If you have been more successful with balancing exposure in Zorkis and FEDs, a video about your approach would be fantastic!
I'm still struggling with my ESP32 tester (the light source is extremely important as it seems) but overall my initial tests show the same thing. I'm still trying to understand if this might be inherent to the soviet design. On the bright side, I've never seen any major issues in the photos I've taken with the soviet cameras I serviced so far, even those adjusted just by using my CRT monitor and slow motion videos taken with the phone. And the results are what actually matter in the end. Unless you're shooting slides, in which case I'd stay away from these cameras anyway :)
@@AlinCiortea If you use a laser emitter and sensor (they sell cheaply in pairs), ambient light below and above 650nm (roughly) will not influence the result. I definitely can recommend that. // Yes, you are absolutely right about the bright side: Surprising as it may sound, you'll be hard put to notice an imbalance of 1 f-stop in an ordinary picture 🙂
@@atf2940 yeah.. the only issue is that aligning the emitters and receivers is a bit of a pain. And since I intend to build several sensor boxes (for different cameras), a film gate sensor box makes more sense for me.
@@AlinCiortea Today I ran the shutter tester on three more Zorkis. Let me try to put it in a positive way: The speed adjustments I had done before by purely visual inspection (basically B, 25/30, 100 and the fastest speed) could not be significantly improved upon by repeatedly fiddling with the tension screws and checking with the tester. It just is what it is, as you like to say ;-) Perhaps those Russian roller springs wear out in 60+ years, perhaps the cameras never did achieve truly even exposure -- impossible to tell now. The most problematic speed is always 1/200.
@@atf2940 I'd have said the most problematic (as in far from the truth) is 1/1000... I'll certainly make good use of my tester for the next CLAs and, fortunately, I'll have the chance to test head to head a Leica IIIf and a Zorki. It will be quite interesting to see how they compare :)
That is so cool. Ingenious reinvention of the principle of line testing.
Yeah! It takes a bit to get used to "reading" it but it's very helpful.
Interesting project! As it happens, I just finished programming an Arduino-based shutter tester. It uses a laser emitter and sensor. The "scaffolding" is done with Lego bricks ;-) With the bundled light and the well-defined sensor area I can measure the curtain speed at specific points, principally in the middle and the opening and closing side. As far as absolute values go, I am quite satisfied with tests up to 1/250: very plausible and repeatable. I am more interested, however, in making sure that the opening speed matches the closing speed at 1/250 and 1/500. The shutter tester seems to measure the relative difference reliably. I still have to verify by film testing whether the tester serves the purpose of balancing opening and closing speed ... // Next project will be a shutter tester based on a reflected light sensor that could be used for screwmount Leicas without taking off the shell. I have a prototype. But it only works so-so because the working distances of these sensors tend to be very small.
@@atf2940 awesome! The legos to allow for pretty much any configuration. That's certainly a big advantage. If you check the links posted in the description you'll find everything needed for a super complete 3 sensors tester that will give you that precise information you're after.
As for the reflective issue, some recommend sliding something thin but very shiny where the film should be. Sometimes the pressure plates are quite dull and won't reflect enough light back to the sensors.
@atf2940 Hi, I am the 'inventor' of the device that Alin is demonstrating. It is designed to only give a guide. It was in response to the discussion on Photrio of how Leica used the television scan lines to give an indication of shutter speed. There is now improved firmware available based on Alin's feedback.
For accurate measurement, build my full ESP32 three sensor or Arduino two sensor shutter tester.
As you already have Arduino, you should be able to get my earlier Arduino 2 sensor version up & running easily, but I would always recommend building the ESP32 version. I did jokingly suggest to one builder to use Lego & he did :o) Photos of this build and others are in my documentation
You are correct, home-brew testers will be accurate up to around 1/250 and then the issue of sensor width to curtain slit width will start to give increasing errors, almost 50% error reading at 1/500s. The reasons for this are discussed in the Photrio thread. My shutter tester auto-calibrates for these errors and will show the true shutter speed.
Using a reflective sensor is straightforward & my tester will do it, but not documented. It is a little more tricky to make the hardware as the Laser & tx have to be mounted one above the other and angled to converge on the camera backplane. Of course the camera always has to be the exact distance.
github.com/billbill100
I love it
Well, I have my Arduino-based shutter tester up and running. The suggestion of masking the laser and the sensor with a narrow slit (see one of the comments above) was brilliant: I have run tests up to 1/1000 with repeatable and plausible results. The downside of the tester: It's depressing to find out how unevenly my Russians expose. (I should add that I rarely run film through my Russian cameras, I just use them for repair entertainment.) Worse, there is apparently near to nothing one can do about it by changing the curtain tension. Unlike with Leicas and Japanese Leica clones, exposure on opening and closing cannot be significantly adjusted individually. It is as if the two curtain were coupled: they accelerate together and there is not sufficient margin to compensate for that by widening the slit as it moves (Leica etc: very responsive to tension change on the curtain springs). Over the last two days I had the very same frustrating experience with a Zorki 1, 3M, and a FED-2 (all recently CL'd, two with new curtains, running smoothly). The ANSI norm says: at most half a stop difference between opening and closing. I found no way to get any of the three even close to that tolerance across all speeds. If you have been more successful with balancing exposure in Zorkis and FEDs, a video about your approach would be fantastic!
I'm still struggling with my ESP32 tester (the light source is extremely important as it seems) but overall my initial tests show the same thing. I'm still trying to understand if this might be inherent to the soviet design.
On the bright side, I've never seen any major issues in the photos I've taken with the soviet cameras I serviced so far, even those adjusted just by using my CRT monitor and slow motion videos taken with the phone. And the results are what actually matter in the end. Unless you're shooting slides, in which case I'd stay away from these cameras anyway :)
@@AlinCiortea If you use a laser emitter and sensor (they sell cheaply in pairs), ambient light below and above 650nm (roughly) will not influence the result. I definitely can recommend that. // Yes, you are absolutely right about the bright side: Surprising as it may sound, you'll be hard put to notice an imbalance of 1 f-stop in an ordinary picture 🙂
@@atf2940 yeah.. the only issue is that aligning the emitters and receivers is a bit of a pain. And since I intend to build several sensor boxes (for different cameras), a film gate sensor box makes more sense for me.
@@AlinCiortea Today I ran the shutter tester on three more Zorkis. Let me try to put it in a positive way: The speed adjustments I had done before by purely visual inspection (basically B, 25/30, 100 and the fastest speed) could not be significantly improved upon by repeatedly fiddling with the tension screws and checking with the tester. It just is what it is, as you like to say ;-) Perhaps those Russian roller springs wear out in 60+ years, perhaps the cameras never did achieve truly even exposure -- impossible to tell now. The most problematic speed is always 1/200.
@@atf2940 I'd have said the most problematic (as in far from the truth) is 1/1000... I'll certainly make good use of my tester for the next CLAs and, fortunately, I'll have the chance to test head to head a Leica IIIf and a Zorki. It will be quite interesting to see how they compare :)