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Old 17-01-2017, 02:32 AM
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luka
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Join Date: Apr 2007
Location: Perth, Australia
Posts: 1,126
Rowland, as I said any suggestions are greatly appreciated, thank you. You are probably predicting the problems that we will soon have, once the cooling comes on

Pat, I had a look at your images at the Ukrainian website and mine are slightly different. My images show vertical noise and the StdDev is higher than yours, I believe within the expected range (see image 1). But the lines in images are common. I did not have time to check the 15V power yet but I have a feeling it is not a hardware issue (at least not for my cam86).

Now, I made some progress with my tests. On one of my laptops I took 1000 images and all were 100% line-free. Then while taking images I started copying large files over WiFi and bang... see the attached image 2.

The issue was easily reproducible every time I started copying files over WiFi. I think WiFi card inside the laptop is connected to the internal USB hub and the bandwidth is shared. Hence simultaneous copying and imaging puts load on the USB bus and we get corrupted images.

Of course if you are using a desktop PC there may be multiple USB controllers and connecting the camera to a different USB port may give different results.

Gilles, this was all on Windows. The latest code still gives lines/blocks here. I actually tried a different USB port and it is worse, much much worse
I started working on new code to use ftdi_readstream as it may improve the reading performance but it is not working (yet), I just get blank images. Not sure if I am using it correctly, there is not much documentation out there.
Happy to be listed as an author, thank you.

I will do more tests tomorrow, need to stop now. Need to fix the power supply for my cooled 450D... can't wait for this build to be fully working
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