Camera Shutter Tester Cheap-Easy-it-Works

The Shutter Tester - ESP32 (Arduino) Version

Update:- This Instructable has been updated to version 4 of The Shutter Tester.

Version 4 adds extra functionality and user features.

Arduino ESP32 based shutter tester using three lasers. Based on the Arduino platform, but using a much faster processor, the ESP32.

Please note for a simpler build see my similar The shutter Tester - Arduino Version

The use of three lasers & three receivers allows for correct travel time measurement for each shutter curtain of a focal plane shutter, which is most important to ensure even exposure across the frame and detect shutter blanking & bouncing. Flash sync can also be confirmed.

DIY builds that use a single sensor or Audacity simply will not work. Both shutter curtains must be set to travel at the same speed, which is simply not measurable using just one sensor. Similarly there will always be an inherent error when measuring a single light point with a sensor, which of course will be wider than a single photon. This error can be mathematically calculated and corrected using a simple algorithm, if multiple sensors are used.

A shutter speed of 1/500s can have a shutter slot width of just 2mm. So a sensor of 1mm width, would measure 3mm, giving a 50% error!! This is why single sensors or designs built without an understanding of how a focal plane shutter actually works, will always have a very high reading error. This design, of course, calculates these errors, giving a true and accurate reading of shutter speed.

Just a note on 'shutter speed'. This is a misnomer. The shutter always moves at the same speed. It is the time of second curtain release that determines exposure. A camera with sync speed of 1/30s will allow the first curtain to fully open (flash fires) and then second curtain starts to close. Moving to 1/60s the second curtain starts to close when the first curtain is only half open. At 1/120s actual speed (it is just called 1/125 for human brains) the second curtain will start to close when the first curtain has travelled only a quarter. This halving continues all the way to the fastest 'shutter speed' yet the curtains always travel at the same speed.

The shutter tester is designed to use cheap, easy to obtain parts from Aliexpress.

A comprehensive build guide thread & user group can be found on on Photrio.

https://www.photrio.com/forum/threads/build-a-shutter-tester-for-focal-plane-shutters-cheap-easy-it-works.197756/

Latest versions of firmware and build documents can be found here.

billbill100/Camera-Shutter-tester-Cheap-Easy-it-Works: Arduino / ESP32 based shutter tester using three lasers. This allows for correct focal plane curtain speed adjustment & even exposure across the frame.

I would really be grateful if you start to build the shutter tester, that you go to the Photrio thread and say hi. Also please post photos of your completed tester.

Please refer to Photrio for further build help & to let us know you are building the tester..

Note the Firmware requires a one-time pass key. Each pass key is unique to to the tester itself. On first use, an Authentication Code is displayed. Forward this code (via Photrio private message is the quickest) and by return the pass key will be sent.

The Pass key is free. It will last the lifetime of your tester and never expire.

Parts to build the project come as ready built modules. This negates the need for little, if any, soldering.

The modules are connected together with pre-made JST XH (or Dupont wires), so again no soldering required.

The ESP32 a very fast microprocessor, comes pre-mounted onto a board, complete with power supply and USB interface.

There are various options the builder can choose along the way. The simplest build is without LCD, TFT display, or light-meter, with the the measurements displayed directly onto the computer screen.

The best (imo) version is with the TFT colour display. It gives all of the information required, including averages and makes it a stand-alone project.

There is a document describing how to make an enclosure using simple hand tools. There are may other options available. Some builders have made their own 3d printed designs.

The PDF file gives a list of all the parts required & links to AliExpress suppliers. Links, of course, could change & also check the supplier sends to your country.

The hardware_wiring document details how to wire each of the different modules together, with detailed photographs of each step. With tips, guidance & advise.

The schematic shows the wiring layout clearly.

Included are photos of other makers designs, showing how they have built their sensor frame, some even using Lego :o)

For the ESP32 processor board to connect to your computer, a suitable USB driver must be loaded.

If purchasing the recommended ESP32 board, the CP2012 driver used, is not normally pre-installed on a computer. The PDF guide shows how to load this driver to your computer.

To view the Shutter Tester output on a computer screen, as suitable serial monitor program must be used. The PDF document details how to load Arduinio IDE which has a serial monitor function.

Note:- If you are not planning to view the shutter Tester output on a computer, this step can be omitted.

The computer code that runs on the ESP32 microcontroller is called Firmware.

This firmware must be loaded onto the ESP32 board, using a USB cable and suitable computer software to transfer the firmware from the computer to the ESP32 board.

The software is called Flash Download Tool, from Espressif Systems. The manufacturers of the ESP32 microcontroller.

Details of where to download & how to install the software are found in the PDF document.

Instructables do not allow the hosting of the Flash Download Tool software, or the drivers or indeed the Shutter Tester firmware for this project. These can be found in the Github repository

billbill100 (github.com)

The ESP32 Shutter Tester is fully functional and has lots of features, as well and timing the exposure, it also diagnoses the results, highlighting any errors, like imbalanced curtains, for example.

It is also able to test the flash sync timing and detail exactly when, during the exposure cycle, the flash is fired.

The operating guide is the PDF below.

This guide details one method for cutting a hole in a project box for the TFT screen and a template for this & the buttons, if using the suggested project box.