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alliedvision / VimbaPython

Old Allied Vision Vimba Python API. The successor to this API is VmbPy
BSD 2-Clause "Simplified" License
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Latency of Camera.ExposureTime.set() #54

Open mkisantal opened 3 years ago

mkisantal commented 3 years ago

I'm trying to compose HDR images, from frames recorded in short succession at different exposure times. The goal is to finish this acquisition as fast as possible. At the moment I'm following the asynchronous grab examples for capturing.

I plotted my results below, dashed red lines indicate the time when Camera.ExposureTime.set() was called (around 2, 4, 6 and 8 sec), and the subsequent step in the average intensity shows the delay.

image

I've found that it takes about 0.4 sec to change the exposure time to a new setting, and even longer if the frame rate is low. Is there a way to speed up exposure time changes? An alternative approach maybe? Or is it a hardware limitation?

BernardoLuck commented 3 years ago

Hello mkisantal,

can you tell which camera do you use?

mkisantal commented 3 years ago

@BernardoLuck The ALVIUM 1800 U-500c

BernardoLuck commented 3 years ago

thank you! This particular camera uses a rolling shutter sensor. When changing the exposure time on a rolling shutter sensor, internally the sensor needs to stop the acquisition, change the exposure time and restart the acquisition. This procedure introduces some delay. However, this delay should not be so big. I think we should move this Issue to support system to evaluate this deeper. Please navigate to the following link and fill in the formular to create a support ticket: https://www.alliedvision.com/en/support/contact-support-and-repair.html