Build a Camera Shutter Speed Timer

If you're into film photography using vintage mechanical cameras, you might expect that after 50 years of existence they don't often work as well as they might have originally.  Lubricant dries out, dirt seeps into the mechanisms and eventually things start to go wrong. 

When the delicate timing mechanisms of the shutter begin to deteriorate, the shutter times can change, and this results in incorrect image exposures.  Sometimes  the inaccuracy iis substantial and clearly noticeable, but at higher shutter speeds, it is difficult to tell the difference between 1/500th of a second and 1/1000th of a second.  However, to the film that difference is substantial.

When doing camera shutter repair, having a way to measure the timings can help give you insight into what might be wrong, and also lets you test as you tinker with things to see if you're making things better or worse, and how close you are getting to your desired shutter accuracy.  It's an invaluable tool for any aspiring camera repair tinkerer to have.

This project is based on the PIC18F2525 microcontroller, and an HD44780 16x2 character LCD.  It uses an OPT101 photodiode with integrated trans-impedance amplifier for the sensor, and a 1 watt red LED for the light source.

Step 1 Tools and Materials

For this project I had access to some pretty elaborate tools, but its nothing that can't be done with simple hand tools, it just takes longer.

Materials:
- 6.5" x 4.5" x 2" Aluminum project enclosure
- Chemistry bolt-down retort stand base
- 8" stainless steel retort stand rod
- Retort stand clamp  x 3
-1/4" thick aluminum plate
- 1" length of 1/4" aluminum or steel rod
- 1.5" length of 1/8" steel rod  x 3
- 1/2" hole rubber grommet x 2
- Various screws, nuts, washers
- Epoxy


Circuit Components:
- 16x2 character HD44780-based LCD
- PIC18F2525 microcontroller
- 28 pin IC socket
- 10k trimpot
- 7805 voltage regulator
- 100nF capacitor x 3
- 10k resistor
- 4.7 ohm 2 watt resistor
- 8MHz crystal
- 15pF ceramic capacitor x 2
- Male header pins
- Female header pins
- Various lengths of wire
- OPT101 photodiode IC
- 8 pin IC socket
- 1W red LED
- SPST toggle switch
- Panel-mount pushbutton
- Panel-mount DC jack
- Heatshrink

Tools:

- Drill
- Various drill bits
- Mill (if possible)
- Soldering iron
- Solder
- Wire stripper
- Wire cutter
- File
- Center punch
- Hammer
- Tap and die set

Comments

[Konican]

This looks like a very interesting project and will be worth trying for all film camera users. I have attempted to make electronic timers based on infrared diodes as emitters and detectors, but without any success so I resorted to making a purely mechanical set-up based on the famous Leica Drum Tester. It uses a slotted drum rotating at a constant speed, and is still a quick method of spotting shutter bounce and fade.

[mattthegamer463]

A quick google finds some interesting information on that method of testing, it's quite similar to a method I saw using the scanning electron gun of a CRT television for the same effect. Quite interesting, thanks for sharing.

[seerixprojex]

This is absolutely amazing, great work. I created a far simpler version that uses a flashlight or laser pointer, phototransistor, 1.5 volt battery, a resister, and a mini-stereo audio plug to connect to a computer via the line input port. Then I use audio recording software to record the signal generated by the light hitting the phototransistor as a wave file that is very accurate. It's not nearly as good as this design because computer audio ports are not designed to read DC current so the signal gets dropped if it is too long, but it is accurate for most shutter speeds above 1/20 second. I should post an instructable for my simple version anyway because even though your design is far better, it may be a bit much in the way of electronics and programming for most people to tackle (including me).

[mattthegamer463]

I read a number of guides doing it your way, it's about the only other reasonable way to do it. I built this thing because I felt nothing available cut it for me.

[seerixprojex]

Yes, I know the guides you are referring to, and most of them are pretty thin on instruction or even misleading. Besides, the whole computer / audio method is very weak compared to your design. If I find the time I may even try to build your design because I think I have the skills to pull it off and I'm way, way, way into using old cameras, I have several of them. In addition, if you saw my instructable, you know that I made a home made camera so a shutter speed tester is a "must have" for me. Best, Rick

[mattthegamer463]

Thank you very much :)

[alanstarkie]

This is really good. I used to be a camera repairer and the Kyoritsu shutter testers were in the thousands of $$$. Well done!

[Nyanman]

will this device be able to check the timing for opening, full open, and closing on an iris shutter?

[mattthegamer463]

It will measure the time the camera takes for opening, full open, and closing, and display the total time. It cannot measure the time it takes to open, the time spent open, and the time it takes to close. You could measure that possibly by connecting the sensor to a digital acquisition oscilloscope and recording the pulse in an analog form. This pulse is only recorded in digital form, but the sensor delivers it as an analog voltage.

[nomadigin]

The shutters not fully opening isn't an error. Mechanically shutters can only move so fast so to get "faster" shutter speeds, only a portion of the frame is exposed at a time simulating a faster shutter speed. Read more here:
http://en.wikipedia.org/wiki/Focal-plane_shutter

[mattthegamer463]

I have taken the camera and looked through the shutter at a bright white wall in sunlight, when the shutter fires at all other speeds it is clear the entire frame lights up, but at 1/500 only 80% lights up and at 1/1000 it is clear that about 20% lights up. Even with this "scanning" exposure method, I should still see the entire frame light up.

This is a common problem with old shutters, it is a result of dried lubricant in the mechanism preventing faster motion. The first shutter is slow due to a malfunction, so the second shutter overtakes it mid-exposure, resulting in a partially-exposed image.

[Nano_Burger]

Wow, this beats the crap out of the shutter speed tester I cobbled together (the plug into your soundcard variety). You should go into business building and selling these things on Esty.com. I get the sense that photography with vintage SLR's is getting trendy with the young hipster crowd and there are enough DIYers to make this a high demand item. Reserve one of your first production runs for me!

[mattthegamer463]

Thanks. I would but the build time is too long, I wouldn't make any money and still sell it for a price that someone would actually pay, and wouldn't have time to build anything else. Plus it would be pretty expensive. Most of the stuff here I had lying around.

[Phil B]

This is very impressive. I believe the Pentax K1000 has a cloth focal plane shutter. I have a camera repair manual a guy published privately in the early 1970s. His method for testing shutter speeds was to photograph the screen of a cathode ray tube television set. It scans 528 lines per second. The user had to have the film developed to evaluate the test, but the percentage of the screen visible in the frame compared to how much was still black gave a pretty good idea of the speed of the shutter. It was low tech, but it worked. A lot depends on the requirements of the user. I had a Zenit SLR and did some work on its shutter. I was able to get it well enough adjusted by means of this television test that I got good exposures with Kodachrome II (ASA 64).

[mattthegamer463]

Thanks, I'm glad you like it.

I have read that and tried it myself once, didn't seem to work, all I saw was a blur of screen, not as it was demonstrated on the internet.

This method also works for any shutter type, such as leaf shutters.

[colin353]

This is too amazing, well done.