Home · Register · Join Upload & Sell

Moderated by: Fred Miranda
Username  

  New fredmiranda.com Mobile Site
  New Feature: SMS Notification alert
  New Feature: Buy & Sell Watchlist
  

FM Forums | Sony Forum | Join Upload & Sell

       2       3              6       7       end
  

Call for help - building sensor readout speed database

  
 
snapsy
Online
• • • • • •
Upload & Sell: On
p.1 #1 · p.1 #1 · Call for help - building sensor readout speed database


I've published a GitHub project that seeks to compile sensor readout speeds for all cameras on the market. I've added a bunch of cameras myself, including some I bought/sold on B+S for this purpose but that's getting expensive so I've come up with a much cheaper strategy but it requires a little help from my fellow FM'ers

The technique is simple - photographing/video recording a small LED on a $17 Arduino board, then measuring the resulting light bands in the photo/video to calculate the sensor readout speed. Nothing groundbreaking here - the technique to photograph light and count the bands has been used by many, including Jim Kasson and FM'er dclark. The idea to use the LED on an Arduino came from a1ex at Magic Lantern, who also wrote sample code that blinks the LED at a known high frequency to assist in the measurement.

The advantage of using the Arduino board is that 1) it's programmable, so we can set a known universal light frequency, 2) it's dirt cheap at $17, and 3) it's portable and easy to photograph - it only needs access to USB power.

The help I need from FM'ers is to crowdsource the measurement of all the cameras I don't own, ie acquire the Arduino board and follow a simple set of instructions to photograph the board's LED in various settings and send me the resulting photographs and video.

Here's how I think the process will work:

1) PM me if you own one or more of the cameras I'm seeking to add to the database of measurements

2) If you are the first to inquire for that model, I'll buy the Arduino board from Amazon and have it shipped directly to you

3) After you receive the board you'll follow the instructions on configuring your camera and taking the photos/video of the board's LED, then send me the resulting photos/video via your file sharing method of your choice, after which I'll do the analysis and add the camera to the database. If you'd like attribution I'd be happy to add you to my GitHub project's wall of fame. If you prefer to remain anonymous that works too.

4) The Arduino board is yours to keep

Here's the home page of my GitHub project:

https://github.com/horshack-dpreview/RollingShutter

And the specific section on the instructions, if you'd like to get an idea of what's involved:

https://github.com/horshack-dpreview/RollingShutter?tab=readme-ov-file#camera-submission-how-to-guide

I estimate it will take about 45 minutes for your first camera. If you have additional cameras the process should be much faster after you've done it once.

Here are the cameras I'm interested in adding:

All Sony APS-C Bodies (that have an electronic/silent shutter mode)
Sony A7S, A7S II, A7S III
Sony A7r II, A7r III
All Canon RF bodies, both APS-C and FF (RP, R3, R5, R6, etc...)

Updated 3/15/24: Camera's pending testing by FM'ers:

Sony A7r III
Sony FX3
Sony A9 II

Thanks!


Edited on Mar 15, 2024 at 07:51 PM · View previous versions



Mar 03, 2024 at 07:49 PM
ironfur
Offline

Upload & Sell: Off
p.1 #2 · p.1 #2 · Call for help - building sensor readout speed database


I ran into your post while I was looking for a way to test my A7iv and also my Fuji X-S20. It would be interesting to see what other cameras and even what modern phones can do.


Mar 04, 2024 at 03:13 AM
newdom
Offline
• •
Upload & Sell: Off
p.1 #3 · p.1 #3 · Call for help - building sensor readout speed database


This is a brilliant project! I can't see any results for A7C - be happy to do that?


Mar 04, 2024 at 07:06 AM
j4nu
Offline
• • • •
Upload & Sell: Off
p.1 #4 · p.1 #4 · Call for help - building sensor readout speed database


Ordered my very first Arduino ... I'll try to complete the test set with my A1 this week.


Mar 04, 2024 at 07:49 AM
jcolwell
Offline
• • • • • • •
Upload & Sell: On
p.1 #5 · p.1 #5 · Call for help - building sensor readout speed database


Great project. I'll contribute, once I get my first RF or Sony body. I'm holding out for the high res RF unicorn, I mean camera. I already have the LED. ;




Mar 04, 2024 at 08:25 AM
kirbic
Offline
• •
Upload & Sell: Off
p.1 #6 · p.1 #6 · Call for help - building sensor readout speed database


I can do the R5 if you still need data on it.

Edit, looks like you have someone on the R5 already.



Mar 04, 2024 at 10:45 AM
snapsy
Online
• • • • • •
Upload & Sell: On
p.1 #7 · p.1 #7 · Call for help - building sensor readout speed database


FYI, I've changed the GitHub project name from "CameraSensorReadoutSpeeds" to "RollingShutter", which required creating a new project. I've updated the links in the OP. I'll be deleting the project associated with the old name.

"CameraSensorReadoutSpeeds" lol. Engineers shouldn't be trusted with naming projects



Mar 04, 2024 at 10:50 AM
Cnyphotoguy
Offline
• •
Upload & Sell: Off
p.1 #8 · p.1 #8 · Call for help - building sensor readout speed database


Readability is low the way the data is all on a single page without any sorting ability. Interesting concept.


Mar 04, 2024 at 01:01 PM
snapsy
Online
• • • • • •
Upload & Sell: On
p.1 #9 · p.1 #9 · Call for help - building sensor readout speed database


Cnyphotoguy wrote:
Readability is low the way the data is all on a single page without any sorting ability. Interesting concept.


Yep, right now the GitHub Pages-hosted html page is a simple export from the LibreOffice Calc spreadsheet where the results are calculated. Improvements are planned once I finish all the infrastructure of the repository.

In the meantime you can use the spreadsheet from the project if you'd like to sort or arrange the data.



Mar 04, 2024 at 01:08 PM
rscheffler
Offline
• • • • • •
Upload & Sell: Off
p.1 #10 · p.1 #10 · Call for help - building sensor readout speed database


Anyone doing the a9III?







Great project and super looking forward to the results.



Edited on Mar 04, 2024 at 02:02 PM · View previous versions



Mar 04, 2024 at 01:56 PM
 


Search in Used Dept. 

snapsy
Online
• • • • • •
Upload & Sell: On
p.1 #11 · p.1 #11 · Call for help - building sensor readout speed database


rscheffler wrote:
Anyone doing the a9III?




Great project and super looking forward to the results.


I've already done one global shutter - no LED banding on the Nikon D40








Mar 04, 2024 at 01:58 PM
rscheffler
Offline
• • • • • •
Upload & Sell: Off
p.1 #12 · p.1 #12 · Call for help - building sensor readout speed database


Not sure how relevant this is and if it just adds a lot more work, but wondering if it's possible to test for differences between single and continuous frame advance settings (all if there is more than one continuous advance option). I've read posts by some who anecdotally believe that some cameras change sensor scan speed based on fps rate in stills mode.


Mar 04, 2024 at 02:02 PM
snapsy
Online
• • • • • •
Upload & Sell: On
p.1 #13 · p.1 #13 · Call for help - building sensor readout speed database


rscheffler wrote:
Not sure how relevant this is and if it just adds a lot more work, but wondering if it's possible to test for differences between single and continuous frame advance settings (all if there is more than one continuous advance option). I've read posts by some who anecdotally believe that some cameras change sensor scan speed based on fps rate in stills mode.


Yep, single vs continuous shooting is part of the test plan. And several cameras I've tested exhibit this behavior, including the Panasonic S5 II/IIx and the Sony FF models. Some cameras also change their readout speed at high ISO, including the Olympus E-M5 III and OM-1.



Mar 04, 2024 at 02:05 PM
rscheffler
Offline
• • • • • •
Upload & Sell: Off
p.1 #14 · p.1 #14 · Call for help - building sensor readout speed database


rscheffler wrote:
Not sure how relevant this is and if it just adds a lot more work, but wondering if it's possible to test for differences between single and continuous frame advance settings (all if there is more than one continuous advance option). I've read posts by some who anecdotally believe that some cameras change sensor scan speed based on fps rate in stills mode.

snapsy wrote:
Yep, single vs continuous shooting is part of the test plan. And several cameras I've tested exhibit this behavior, including the Panasonic S5 II/IIx and the Sony FF models. Some cameras also change their readout speed at high ISO, including the Olympus E-M5 III and OM-1.


Thanks for confirming. I had a look through the results and noticed some of this but good to know it's in the plan.



Mar 04, 2024 at 02:11 PM
newdom
Offline
• •
Upload & Sell: Off
p.1 #15 · p.1 #15 · Call for help - building sensor readout speed database


rscheffler wrote:
Not sure how relevant this is and if it just adds a lot more work, but wondering if it's possible to test for differences between single and continuous frame advance settings (all if there is more than one continuous advance option). I've read posts by some who anecdotally believe that some cameras change sensor scan speed based on fps rate in stills mode.


Yes agreed - Sony FF bodies change from 14-bit to 12-bit depending on the shooting mode:
https://www.sony.com/electronics/support/articles/00229990

The scan rate is faster in 12-bit, and faster again in APSC/crop mode. Would be great to get data on all these modes



Mar 04, 2024 at 05:40 PM
snapsy
Online
• • • • • •
Upload & Sell: On
p.1 #16 · p.1 #16 · Call for help - building sensor readout speed database


Cnyphotoguy wrote:
Readability is low the way the data is all on a single page without any sorting ability. Interesting concept.


I've added sorting and searching to the results page...

https://horshack-dpreview.github.io/RollingShutter/



Mar 05, 2024 at 03:07 PM
newdom
Offline
• •
Upload & Sell: Off
p.1 #17 · p.1 #17 · Call for help - building sensor readout speed database


Thanks for such a great writeup in github readme. Buying the hardware and setting up the software is very straight forward, and the procedure for taking the samples is simple and easy to implement.

I got 29 bands (34.5ms) in single shot mode and 16 bands (62.5ms) in continuous-Hi mode which is the opposite of what I'd expect, so I'll do a full set of tests you have listed tomorrow and upload somewhere.

Great project



Mar 05, 2024 at 05:35 PM
snapsy
Online
• • • • • •
Upload & Sell: On
p.1 #18 · p.1 #18 · Call for help - building sensor readout speed database


newdom wrote:
Thanks for such a great writeup in github readme. Buying the hardware and setting up the software is very straight forward, and the procedure for taking the samples is simple and easy to implement.

I got 29 bands (34.5ms) in single shot mode and 16 bands (62.5ms) in continuous-Hi mode which is the opposite of what I'd expect, so I'll do a full set of tests you have listed tomorrow and upload somewhere.

Great project


Thanks, looking forward to the images. Btw fewer bands translates into a faster readout rate rather than slower, since the sensor is reading for a shorter period of time and thus will capture fewer of the light cycles.



Mar 05, 2024 at 05:40 PM
newdom
Offline
• •
Upload & Sell: Off
p.1 #19 · p.1 #19 · Call for help - building sensor readout speed database


snapsy wrote:
Thanks, looking forward to the images. Btw fewer bands translates into a faster readout rate rather than slower, since the sensor is reading for a shorter period of time and thus will capture fewer of the light cycles.


Ah see this is why I'm not an engineer

The README says:

"For example, if we know the light source is 60Hz (120 transitions/second) and the sensor captures 6 bands, we can calculate the sensor readout time via 1000/120*6, which is 50ms"

and

"The readout speed in milliseconds is simply (500 / number of full bands), since the LED is being toggled at 500 Hz, so 500 / 25.2539, which comes to 19.79ms."

These confused me - I don't see how either of these make sense?



Mar 05, 2024 at 06:02 PM
snapsy
Online
• • • • • •
Upload & Sell: On
p.1 #20 · p.1 #20 · Call for help - building sensor readout speed database


newdom wrote:
Ah see this is why I'm not an engineer

The README says:

"For example, if we know the light source is 60Hz (120 transitions/second) and the sensor captures 6 bands, we can calculate the sensor readout time via 1000/120*6, which is 50ms"

and

"The readout speed in milliseconds is simply (500 / number of full bands), since the LED is being toggled at 500 Hz, so 500 / 25.2539, which comes to 19.79ms."

These confused me - I don't see how either of these make sense?


Your engineering skills are fine - it's my writing skills which failed you I flubbed that section, reversing the ms vs time calculations.. I've just published a correction to the readme.



Mar 05, 2024 at 07:14 PM
       2       3              6       7       end






FM Forums | Sony Forum | Join Upload & Sell

       2       3              6       7       end
    
 

You are not logged in. Login or Register

Username       Or Reset password



This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.