Camera Electronic Shutter

camera

I have close to zero experience with cameras modules. I need a global electronic shutter camera for my application.

While I was browsing I see that the shutter speeds that are 1/1000th of a second.

Is it possible to control these modules for: (in general, I realize each module has its own mechanism)
– Turn on/off the shutter from software at the desired speed? (i.e. turn on the shutter for 1/500th of a second although frame rate is 50fps. I know the image will have a lot less light but that is ok). (The idea is to make sure the camera is no longer integrating the light when the electronic shutter is off)

Start a frame conversation on demand as opposed to a fixed FPS. (i.e. convert two consecutive images only but do that such that the speed is controlled by the uP)

Best Answer

The kind of CMOS camera modules you are asking about all have global shutters (electronic shutters, not focal plane shutters). You control them through their bus, typically some sort of serial bus like e.g. I2C.

You can find modules where you have control over both frame rate and shutter speed.

I very much doubt any camera module has a separate shutter pin. You need to implement the bus protocol anyway, or there would be no way for you to get the image data...

Related Solutions

Electronic – Testing camera framerate variability by filming clock time

A binary count is going to be very hard to read in the image; if the exposure time is long enough to capture more than one displayed value, the reading will be very ambiguous.

I recently had a need to measure both shutter delay (latency) and exposure time for various DSLR cameras. I set up a microprocessor to drive an array of 40 LEDs (NOT multiplexed!) counting at a 10 kHz rate. The display is arranged such that each digit is represented by a column of 10 LEDs, where each column only has one LED on at a time.

100ms 10ms 1ms 0.1ms
   o    o    o    o  9
   o    o    o    o  8
   o    o    o    o  7
   o    o    o    o  6
   o    o    o    o  5
   o    o    o    o  4
   o    o    o    o  3
   o    o    o    o  2
   o    o    o    o  1
   o    o    o    o  0

Looking at the resulting images, it's actually quite easy to estimate both the starting and ending times of each exposure.

ADDITIONAL

A variation of this idea might be more appropriate for your application of evaluating the accuracy/stability of the video frame rate. Simply put the 40 (or whatever number) LEDs in a straight line (or maybe in a circle) and turn them on one at a time at 40× the nominal video frame rate. Viewing the resulting video directly will show you in real time whether the rate is correct and how much it is varying.

Electronic – Genlock two OV5642 camera modules on Arduino with ArduCam

Looking at the User Guide, it looks like pin 8 on the "alternative connector" is the trigger input. I assume if you drive a 3.3V active-high signal into the trigger pins on your two modules, they'd fire at (relatively) the same time.

However, I don't see anything on ArduCam's web site to indicate this thing is capable of shooting streams of video -- and I don't know how fast you can shoot still photos. They're basically using a CPLD to read out the DVP's data, buffer it a bit, and shove it on the SD card. No idea how fast it is.

Best Answer

Related Solutions

Electronic – Testing camera framerate variability by filming clock time

Electronic – Genlock two OV5642 camera modules on Arduino with ArduCam

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