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

OAPOli · Oct 20, 2024

Thanks @Niglyn.

My DEV values don't seem to match your description (5.6ms S1 vs 4.1ms M is 1.5ms difference or +0.45EV). I'll check the manual when it comes out.

I think the labels S1/M/S2 would be better. L/R can be confusing if you turn the tester 180 degrees, or for vertical shutters.

I understand that because the curtains are accelerating, the slit naturally widens from start to finish. However the total travel time should be the same (like two apples falling from the same height) and exposure time should also be the same (larger slit but faster = smaller slit but slower). It seems the 1st curtain in my camera is accelerating more between M-S2, hence the shorter exposure on S2.

Maybe it's not overly significant. Here's the output for 1/30.

OAPOli · Oct 21, 2024

You can find the ISO tolerances here:

https://cdn.standards.iteh.ai/samples/70966/31d970b16eef4559ae381cb450d46a99/ISO-516-2019.pdf

It seems the tolerance for uniformity (max vs min) is 0.2 EV at 1/125s and slower, 0.6 EV for faster speeds.

Tolerance for each setting is +/-0.3 EV and +/- 0.45 EV each side of 1/125s, vs. the 1/(2^n) series.

I think that showing the EV deviation in decimal expression would be better than an approximate fraction.

ic-racer · Oct 21, 2024

For reference, the values are calculated here in the table "Annex A," referred to in the above ISO 516:

Niglyn · Oct 21, 2024

Hi all,

Checked the code, Dev is indeed in decimal stops, or EV.
Then also expressed as a fraction in 1/3 stops.

There is a slight error on the TFT as it does not display the sensor 1 Dev value correctly.
It is fine on the PC screen.

It has been corrected for version V4.0,0.1 beta.

I also found another bug, that has been bugging me (no pun intended) where the light-meter looses it's calibration setting.
Also fixed.

Have also changed the display for curtain travel as per OAPOli's suggestion.

LIK · Oct 24, 2024

Niglyn said:
Hi all,

Checked the code, Dev is indeed in decimal stops, or EV.
Then also expressed as a fraction in 1/3 stops.

There is a slight error on the TFT as it does not display the sensor 1 Dev value correctly.
It is fine on the PC screen.

It has been corrected for version V4.0,0.1 beta.

I also found another bug, that has been bugging me (no pun intended) where the light-meter looses it's calibration setting.
Also fixed.

Have also changed the display for curtain travel as per OAPOli's suggestion.

Hi. Could you give me the access key to V4? I put on an enconder today and forgot to ask for the key in advance

Niglyn · Oct 24, 2024

LIK said:
Hi. Could you give me the access key to V4? I put on an enconder today and forgot to ask for the key in advance

Hi, yes, flash the V4 firmware & send me the authorisation code that will be displayed. I will then send you the user key.

The authorisation code is unique to your device, as is the user key I will send.

V4 4.0.0.0 beta is on github

V4.0.0.1 will be available soon. This build will require re-entering your user key, for various techy reasons.

User guide for V4 is on github

VirtualFeature · Oct 25, 2024

I'd love an access key too, if you don't mind

Niglyn · Oct 25, 2024

VirtualFeature said:
I'd love an access key too, if you don't mind

Hi, yes, no problem.

Load V4 firmware. First one has to test the encoder following the on-screen/TFT prompts
then an authorisation code will be displayed.

PM me that code & I will send you back the user key.

The above process is detailed in the new V4 user guide, available on github.

Note, the new full release is almost ready, which will require re-authentication, but the same key sent to you will work.

User keys are free and always will be. They will work for the lifetime of your shutter tester.

LIK · Oct 25, 2024

Hi. Can you tell me what the problem might be? Sometimes this error pops up, but not every time. I didn't see any pattern in it. That is, for example, I do 3 tests and everything is fine. I do not change anything and do the 4th test and for some reason an error comes out

LIK · Oct 25, 2024

The assembly was almost completed. It remains to finish a little and solve this error.
By the way, I found one error in the connection diagram V4. When I'm done, I'll tell you where to fix it

LIK · Oct 25, 2024

This error did not appear on V3 version, it seems, it appeared only in V4 version.

Niglyn · Oct 25, 2024

LIK said:
The assembly was almost completed. It remains to finish a little and solve this error.
By the way, I found one error in the connection diagram V4. When I'm done, I'll tell you where to fix it

Yes please tell me of the error in the diagram.
I changed the colours & layout from V3 but have not actually followed it to build a V4 tester. I am planning on doing so this coming week, to take photos and update the build documents.

The error you are seeing is because sensor 2 was triggered for some reason and as no other sensors were triggered within 32 seconds, it shows an error.

Currently, the tester takes a reading & goes straight back to looking for the next sensor inputs without delay. This can cause some errors, if the sensor sees a reflection, for example, so thinks a new test has started.

The new version is about to go onto gitbub, should be within the hour. It now has a delay between readings and checks that all sensors are blocked before proceeding.

I like your case )

LIK · Oct 25, 2024

The building is beautiful. I also like the main thing is not to look at what's inside
I also "cleaned up" the wires

OAPOli · Oct 25, 2024

Niglyn said:
It now has a delay between readings and checks that all sensors are blocked before proceeding.

That's a good idea. I have to lift the big 6x6 camera to cock the shutter and I get that error often.

BTW @Niglyn, what sort of camera are you testing for the examples in the manual? The curtain times are very long!

LIK · Oct 25, 2024

Niglyn said:
Yes please tell me of the error in the diagram.
I changed the colours & layout from V3 but have not actually followed it to build a V4 tester. I am planning on doing so this coming week, to take photos and update the build documents.

The error you are seeing is because sensor 2 was triggered for some reason and as no other sensors were triggered within 32 seconds, it shows an error.

Currently, the tester takes a reading & goes straight back to looking for the next sensor inputs without delay. This can cause some errors, if the sensor sees a reflection, for example, so thinks a new test has started.

The new version is about to go onto gitbub, should be within the hour. It now has a delay between readings and checks that all sensors are blocked before proceeding.

I like your case )

Okay, then I'll wait for your new firmware and see what the problem might be. Maybe I somehow hooked the wire and its output contact is constantly working

LIK · Oct 25, 2024

LIK said:
Okay, then I'll wait for your new firmware and see what the problem might be. Maybe I somehow hooked the wire and its output contact is constantly working

I checked the new firmware and the problem with the 2nd sensor seems to be gone

LIK · Oct 25, 2024

I'm finally done. It took me 7 days to make my own portable mini version of the tester. Special thanks to Niglyn. What you did is a very cool and necessary thing. I am glad that you are still working on the tester and improving it. A real hero for analog photography in the field of repair. And there are no words to express my gratitude to you for this device. Thanks x100000000

LIK · Oct 25, 2024

Regarding that error in the scheme. Everything is simple. The output of the encoder and buttons are not connected to GND. The fix is very simple

LIK · Oct 25, 2024

And regarding the fact that the sensors read the same value in different ways - Everything is cool. Everything is fine with the new firmware version. This problem is no longer there

Niglyn · Oct 25, 2024

LIK said:
A real hero for analog photography in the field of repair. And there are no words to express my gratitude to you for this device. Thanks x100000000

Thanks for your kind words.

Your case looks really good, thanks for posting the photos.

I still have some work to do with the firmware, it was a little rushed.

I have noticed 'Ready' overwrites some of the data on the screen, so need to look at that.

Niglyn · Nov 2, 2024

Firmware Update 4.0.0.3
latest firmware & documents now now on Github.

billbill100 - Overview

billbill100 has 8 repositories available. Follow their code on GitHub.

github.com

Most significant change is a new Simple screen (shown below), giving basic results but in a much larger typeface.
Toggle between the Detailed & Simple screen by pressing the Blue Button.

Now checks that sensors are blocked before allowing a new test to be performed.
If sensors are seen for longer than 40 seconds, will report error & wait, as above, before allowing a test.
Automatically resets once sensors are blocked. The word 'Ready' appears, to indicate this.

The above stops the strange reading that sometimes appeared when performing a test, or after a failed test (sticky shutter, for example).

Sticky shutter testing has been removed at the moment.
Should the shutter curtain not complete it's travel after 2 seconds, a warning was given.
Not sure if it is needed or not?

General tidying of screen, updating text & PC output where needed..
New routine written to centre highlighted text correctly.
(This was a fault of the font library & graphics driver, not my coding).

Documents Updated
Updated user guide with latest firmware changes.

Updated Parts List document.
This reflects the change from Dupont to JST HX connectors and other improvements.

New 'Wiring & Hardware' build document.
Combined two documents into one, making it easier to follow, with new photos.

New 'Build a Box' document.
All new photos showing improvements to build over V3 and using new parts as
specified in the parts document.

Note: - Users of the V3 tester are encouraged to add the rotary encoder and update to v4 firmware.
No other hardware changes or additions are required.

How much does this cost?
I still get asked this question. The answer is simple. It is free. All firmware and documentation is free and always will be.

All you need to do is to buy the parts. These are standard cheap off-the-shelf parts. No need to make pcbs.
You can spend between £15-£30, depending on which options are chosen. Can be even cheaper if you have an electronics scrap-box.

Passkey
Whilst a one-time passkey is required, it is issued free upon request. This is only to protect my intellectual rights & stop piracy.
It has the benefit of me knowing how many users there are.

The passkey will always work and will never expire. Even if using the board for another project and then reloading the Shutter Tester firmware, the same passkey will work.

As always, I welcome feedback, suggestions for improvements & extra functionality.

Niglyn · Nov 3, 2024

LIK said:
I'm finally done. It took me 7 days to make my own portable mini version of the tester.

Hi, had you mentioned you wanted a battery operated version, I would have said to use the Lolin D32 board.

The pinout is almost identical to the NodeMcu32, just missing the six pins that cannot be used anyway & the pin that is labelled 'GND' which is in fact CMD'

The Lolin D32 board has an on-board LIPO charger and connector for the lipo battery. Just connect to USB & the battery will charge.

Look at my Developing Timer, where this board is used. The idea here is for the lipo to give backup power in case of a mains fail. One does not want the timer to stop working whilst developing film!.

Synthon · Nov 3, 2024

Hi everyone, especially Niglyn.
Just signed up to the forum as i am diving deeper and deeper into the thematic.
Trying to build a shutter "time" tester for an evening school project and i will try out the Arduino version first because i already got most of the parts, but i already ordered the esp32 a well.
I am interested in seeing where this goes, it took me quite a few hours to catch up with this thread, an exciting project! I will try to post an update somewhere down the road.
Is everything i need on github, or do i still have to pm you, Niglyn? Can't send PMs yet because i just signed up, but i already found other areas of interest like solargraphy. This is a nice forum!

Niglyn · Nov 3, 2024

Synthon said:
Hi everyone, especially Niglyn.
Just signed up to the forum as i am diving deeper and deeper into the thematic.
Trying to build a shutter "time" tester for an evening school project and i will try out the Arduino version first because i already got most of the parts, but i already ordered the esp32 a well.
I am interested in seeing where this goes, it took me quite a few hours to catch up with this thread, an exciting project! I will try to post an update somewhere down the road.
Is everything i need on github, or do i still have to pm you, Niglyn? Can't send PMs yet because i just signed up, but i already found other areas of interest like solargraphy. This is a nice forum!

Hi,
Well you are in luck. ) I have actually removed the Arduino firmware from Github (and version 3 of the ESP32) as it is easier for me to support just the newest & best ESP32 Version 4.

However, there seems a lot of interest in building the Arduino version as many people are more familiar with this than ESP32 and, like you, have many of the parts required.

And so at this very moment, I am updating the Arduino version, with new firmware and new build documents.
There will be a new Arduino V2 directory on Github, where I will post the firmware and documents as I finish them.

I will get the beta version of the firmware up on github for you now, as well as the schematic (same as existing one, but neater) so you can start playing with it.

Details on how to load the firmware is in the existing Arduino directory. This is slightly different on how you are used to doinf it with Arduino IDE.

If you need any other help, please just ask. You will also be the first user of version 2 and the documentation, so please let me know any errors, omissions or areas of improvement that can be made.

Synthon · Nov 3, 2024

Niglyn said:
Hi,
Well you are in luck.

Oh thank you so very much! It's primarily for a school project after all and doesn't need to be top notch.
But i definately have some pracical use for it, as i am connected to lot's of analog photographers in my town who may want to use it.
And as i am just now getting my education as technician, i may as well do the esp32 build after that to get further into the matter.

And i have to say, i already learned a lot from this discussion here. Didn't know there were so many shutter types and how they operated, nice. Thanks for sharing!

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

Privacy & Transparency

Privacy & Transparency