Set shutter speed of D455
Hi there,
I have the D455 and I want to set a specific exposure time for it, meaning not to use the global shutter.
Few problems:
1. I couldn't find anywhere the exposure time of the fixed global shutter. I know that the highest FPS of this model is 30fps, but fps and the exposure time are not necessarily the same, and I'm almost positive that the exposure time is not 100/30=33.3ms. So does anyone know what is that the actual value of the fixed exposure time?
2. I only found a way to control the fps with config.enable_stream(), but is there any way to control the exposure time of the sensor to light?
Thank you all in advance for your help :)
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Hi Yehonatan
1. If depth auto-exposure is enabled then the exposure value is not updated, so you can instead obtain the 'real' depth exposure value from the camera metadata. References for retrieving the metadata exposure value can be found at the links below.
C++
https://github.com/IntelRealSense/librealsense/issues/1624#issuecomment-389085387
Python
https://github.com/IntelRealSense/librealsense/issues/3717#issuecomment-481584222
A difference between depth and RGB exposure metadata is that when RGB auto-exposure is enabled, RGB exposure metadata is not accessible. So you would have to set RGB exposure to manual to retrieve exposure metadata. A RealSense team member advises about this here:
https://github.com/IntelRealSense/librealsense/issues/2549#issuecomment-431863920
2. You can use set_option to set a manual exposure value for depth or RGB exposure.
C++
https://github.com/IntelRealSense/librealsense/issues/10239#issuecomment-1040104921
Python
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Hi MartyX Grover!
Thank you very much for the quick reply :)
First, I looked into getting the metadata in python from the image, but I couldn't understand how to get the info after the fact
(after saving the image) it looks like from that link that it's how to set the values, and not to retrieve them after from the image metadata. unless I misunderstood or looked in the wrong place.
Second, I understand that once I'm using auto-exposure with RGB, it impossible to know what was the exposure time for every image? am I right?
Regarding setting manual exposure for depth or RGB - Thank you!
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If you are aiming to extract metadata from an image file that has been saved then that would not be practical as the camera metadata would not be embedded into the image file. You may be able to save the metadata separately as a textual file such as the .csv format, as referenced in the Python discussion at the link below.
https://github.com/IntelRealSense/librealsense/issues/10480
And yes, you would not be able to retrieve the real metadata exposure values for RGB whilst RGB auto-exposure is enabled.
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