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IQ180 as digital pinhole

PostPosted: Tue Oct 07, 2014 10:09 am
by Shau
I made several test using an IQ180 with a pinhole camera built around a Sinar P1. The images I produced under different light condition show strange artifact. Could someone explain me what are those big amount of colored and black pixel around the trees in the image below?


Re: IQ180 as digital pinhole

PostPosted: Wed Oct 08, 2014 4:36 am
by Digital Transitions, Doug
You need to cover the pinhole BEFORE ending the exposure.

If light hits the sensor after the exposure is ended then you'll get these weird artifacts.

1) Start Sensor Exposing
2) Open Lens
3) Close Lens
4) Stop Sensor Exposing
5) Wait for Dark Frame Calibration and Write-to-Card
6) Enjoy Pretty Images

In this case "close the lens" could mean putting a piece of tape over the pinhole, or even just covering it with your thumb. But for steps 4 and 5 the back MUST be in complete (or very very close to complete) darkness.

Re: IQ180 as digital pinhole

PostPosted: Wed Oct 08, 2014 8:11 am
by Shau
Thanks for your help. Yesterday, after several attempts, I finally managed to produce "normal" pinhole picture by closing the lens after the exposure time. I am glad to read this morning your precious advice. It is exactly what has to be done! Thanks a lot.