DIY shutter-speed tester: Informed opinions?

[nitroplait]

Can you tell if that's happening with my Nikon N6006, samples below. They seem OK to me.
https://www.flickr.com/search/?sort=...N05&view_all=1

If you can't see it in the results, there is not much point in speculating if there is a problem.
I mostly see non-uniform issues with horizontally travelling focal plane cloth shutters, not often with otherwise functioning electronically controlled vertically travelling shutters like in your N6006.

[Havoc]

Isn't it just easier to get a cheap oscilloscope and just measure it that way? I usually do it tat way. For the optical side I use a TOSLINK receiver and a short piece of plastic audio fiber. Makes it easy to measure at different places.

[tomwilliams]

"cheap oscilloscope" - is that an oxymoron?

[reddesert]

Several years ago I assembled an inexpensive mini storage oscilloscope from a kit (a JYE Tech DSO150) for about US$20-30. I did a writeup of it on a guitar pedals forum, you can find it at the madbeanpedals.com forum (although you'd have to be a member to see the attached pictures). It works remarkably well, within the limitations of a single channel oscilloscope with a few-button interface.

An oscilloscope is a wonderful and flexible tool, but likely to frustrate a total electronics newbie. You have to gain at least some understanding of triggering to even see the signal you're interested in.

I keep harping on this, but the Shutter-Speed app is a good introduction because you can actually see the audio or light-signal (with Photoplug) waveform and there is an easy interface to measure the time from it. One needs to be able to handle at least that before venturing into building a more complex instrument.

[Tin Can]

No

I used to buy an airplane seat for my scope and Ultrasonic

The stuff was $100K

For a shutter tester there are $25 O Scopes

all day long

"cheap oscilloscope" - is that an oxymoron?

[ic-racer]

Certainly there are many ways to measure the output of a light sensor (oscilloscope, sound-card, Arduino, etc.) but most importantly the sensors have to be setup correctly to measure properly. For example, leaf shutters need a measurement at the center and the edge.

Also, focal plane shutters need a sensor each end of the film gate.

[tomwilliams]

Several years ago I assembled an inexpensive mini storage oscilloscope from a kit (a JYE Tech DSO150) for about US$20-30.

For a shutter tester there are $25 O Scopes

all day long

I checked around and found a number of kits and assembled units, cheap! That does change the picture for me.

[Havoc]

"cheap oscilloscope" - is that an oxymoron?

It was, but it all depends on what you want to do and need to measure. You really don't need a 6GHz 4 channel one if it is only for shutters, then the max speed is 1/8000s or 0.125 milliseconds. For the price of a box of 4x5 you have a standalone 2 channel 25MHz scoop these days. Ok, you still need to know or learn how to work with it but if you can manage a modern digital camera or a smartphone then that should work.

[jimskelton]

I adapted a shutter tester on GitHub to work autonomously (instead of requiring a computer) using existing code and it seems to work accurately at least until 1/250, though I did get measurements of around 1/950 when testing an OM-4's shutter at 1/1000, which to me indicates it may be only 5% off at high speeds, though the shutter may be off...

I did another project which converts an automatic Polaroid camera to use manual shutter speeds with an arduino and the shutter tester was consistent with this project until around 1/250. I'm thinking at higher shutter speeds, the opto-isolator which shuts off the Polaroid shutter when the time is complete may cause a lag which resulted in around a 10% lower reading than the tester at 1/500. I compensated for that, as well as a 30% lower reading at 1/1000 and the tester reads speeds up to 1/1200, but it's hard to tell how accurate it is. The real test will be trying the faster shutter speeds out with film.

The shutter tester I did was very cheap around $7--using an arduino nano and laser as it posted at https://github.com/hackaninstant/Shutter-Speed-Tester

My github page also has the Polaroid shutter control project.

[Jim Andrada]

Well, we used to use oscilloscopes to do performance analysis on IBM mainframes in the early 60's. I remember one setup that had a scope and a film camera that would take photos of the scope screen on 100 foot rolls of 35mm film. So we'd figure out where to put the probes, load up a few rolls of film and let it run a sort of standard routine at a standard memory location - then spend the next week or so looking a the films and tying hard to figure out what the squiggles were really telling us - It cost $12 to get a 100' roll developed IIRC.