Simple DIY Shutter Speed Tester

SilverDog · Jan 30, 2023

I built this shutter speed tester and it works quite well. As far as accuracy goes, I'll probably take it to my local photo store and have them compare it to their tester.

My intent in building this was to have a tester for several Pentax cameras I'm working on. Some of them have slow and fast speeds that are way off. Getting them at least in "the ballpark" is better than where they are currently.

Links to parts and code for the Arduino are in the video descriptions on YouTube. I'm fully open to suggestions and critique on the tester.

There are two videos. First one is about the basic circuit assembly and the second covers building an enclosure/fixture for the parts.

Part 1:
Part 2:

VinceInMT · Jan 30, 2023

Thanks for sharing. I love these types of hacks. I’ve had a couple of mine featured on Hack-a-Day.

ic-racer · Jan 30, 2023

That is nice, but I'm surprised you only made it with a single cell and not 2 cells like the Pentax shutter tester schematic below.

Also, you can test it yourself like this ( https://www.photrio.com/forum/threa...speed-tester-calibration.196226/#post-2629453 )

I was browsing your videos, looks like you are a Mercedes mechanic? I'm restoring a 560SL with a leak near the steering box. Not sure the best way to get to the steering box. From below on a lift?

Mamiya_Repair · Jan 30, 2023

For a shutter speed tester to be useful with a focal plane shutter, you really need two sensors, one for the opening edge and one for the closing edge. And, first thing to do is adjust curtain travel time, then shutter speeds. You can't do either with only one sensor.

SilverDog · Jan 30, 2023

It shouldn't be to difficult to add another sensor and give two read outs.

SilverDog · Feb 1, 2023

I measured speeds yesterday on the far left and right of the film back and they measured the same as in the middle in all fast speeds on a Pentax Spotmatic SP II and an MX. On the MX all speeds were within tolerance based on this chart.
The SP II needs a CLA on the slow speed escapement.

Now, I know that all I have verified is that the slit opening is acceptable. A dual sensor tester would tell me that the travel speed of the curtains is correct so that exposure across the entire frame is even. I may build another tester at some point to do this.

I'm pleased with this tester and the results. No, it's not a professional caliber tester but it at least verifies that the camera is in acceptable range.

I also put together a quick tester, for the tester, consisting of a second Arduino pulsing laser LED at all speeds one at a time and my tester reads dead on.

madsox · Feb 1, 2023

Perfect timing,!I was just wondering yesterday (to myself) about how I could check my old cameras' shutter speeds. None of them have been used in years, but I don't want t send *all* of them out for CLA if I don't have to. This looks like a great answer for one big question.

Also looks like something I could handle technically, and not even needing a big cash outlay - all good stuff.

ic-racer · Feb 1, 2023

You could also shine two lasers at the single source without modifying the whole contraption. I did this a few times just to see if the curtain speed was ok on a few cameras. On the SL35 I work on, the 1/60 does hang up on the second curtain cam (on purpose) so the curtain travel speed is spec'd at faster than 1/60th, so the second curtain needs a little delay before releasing.

BHuij · Feb 1, 2023

This is way cool. I've gotten by so far by using a cheap lavalier mic clipped directly to the shutter mechanism and making audio recordings in Audacity. I usually record each shutter speed firing three times, then take an average and standard deviation to match the actual "shutter open" time to the nearest nominal standardized shutter speed. Works well with leaf shutters, but the method starts getting pretty imprecise once you get above 1/100th or 1/200th of a second or so. I'm guessing this will be accurate well above those speeds, and probably works much better for focal plane shutters. Might build one next time I feel like I have a camera that isn't behaving.

tom williams · Mar 2, 2023

Silverdog, thanks for posting this. At times longer than 1/2 second your code works better than the tester I made a year or so ago, also arduino based. That tiny oled was a strain for me though, so I modified your code to accomodate a 16x2 LCD. Happy to share the code if it interests you.

Niglyn · Mar 4, 2023

Mamiya_Repair said:
For a shutter speed tester to be useful with a focal plane shutter, you really need two sensors, one for the opening edge and one for the closing edge. And, first thing to do is adjust curtain travel time, then shutter speeds. You can't do either with only one sensor.

Indeed it does. I made one using two Arduino laser modules. They have the advantage of the receiver module already having the Schmitt trigger built in (gives a clean sharp on/off)
Some camera manuals specify the distance the two sensors must be apart (20mm for example) and then give the shutter curtain travel speed in mS.

I have seen many home-adjusted shutters (where peeps have been misguidedly told to blindly teak one of the springs) which then gives uneven exposure across the frame.

I posted a few photos of my setup on another post in this forum, but only one person requested the code.

I started a thread on learncamera repair facebook group, with details of how to build it, but got much hate.

Thinking of starting a thread here to post details.

Niglyn · Apr 2, 2023

Niglyn said:
Thinking of starting a thread here to post details.

Replying to myself, )

Started a thread to build a two sensor shutter tester, you will find it here

Build a shutter tester for Focal Plane shutters - Cheap, Easy & it Works

Hello Everybody, #1 There are many home-brew shutter testers out there, some use audio to try to detect the speed, others use an Arduino and one sensor (so will not work correctly) and there are better ones that use two sensors. A problem seems to be a misunderstanding of how a focal plane...

www.photrio.com

It is all up & working, links to parts are in the thread. Measures shutter 'speed', exposure, first & second curtain travel times.
Checks for shutter bounce & blanking. Running average & standard deviation. Not bad for under £20 in parts )

Simple DIY Shutter Speed Tester

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