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Entry  Mon Sep 11 23:31:50 2017, johannes, Update, Cameras, post-vent camera capture comparison 13x
    Reply  Tue Sep 26 22:11:08 2017, johannes, Update, Cameras, post-vent camera capture comparison lens_distance.pdfImage__2017-09-26__18-54-29.jpgIMG_20170926_190157222_HDR.jpgIMG_20170926_185649325.jpg
       Reply  Mon Oct 2 12:44:45 2017, johannes, Update, Cameras, Basler 120gm calibration calib_20170930_152.pdfcalib_20170930_153.pdf
          Reply  Mon Oct 2 23:16:05 2017, gautam, HowTo, Cameras, CCD calibration 
             Reply  Tue Oct 3 01:58:32 2017, johannes, HowTo, Cameras, CCD calibration gige_calibration.pdf
                Reply  Thu Oct 12 01:03:49 2017, johannes, HowTo, Cameras, ETMX GigE side view IMG_20171011_164549698.jpgImage__2017-10-11__16-52-01.pngGigE_lens_position_helper.py.zip
                   Reply  Thu Oct 12 07:56:33 2017, Steve, HowTo, Cameras, ETMX GigE side view at 50 deg of IR scattering Image__2017-10-11__15-29-52_15k400g.pngImage__2017-10-12__15-50-18wipedRefocud2.pngcamCan16cm.jpg
                      Reply  Wed Oct 18 11:37:58 2017, johannes, HowTo, Cameras, ETMX GigE side view at 50 deg 
                Reply  Wed Oct 18 15:26:58 2017, johannes, HowTo, Cameras, Revision: CCD calibration calib_20170930_152.pdfcalib_20170930_153.pdf
Message ID: 13354     Entry time: Tue Oct 3 01:58:32 2017     In reply to: 13352     Reply to this: 13375   13391
Author: johannes 
Type: HowTo 
Category: Cameras 
Subject: CCD calibration 

Disclaimer: Wrong calibration factors! See https://nodus.ligo.caltech.edu:8081/40m/13391

The factors were indeed enormously off. The correct table reads:

Camera IP Calibration Factor CF 85.8 pW*s 78.3 pW*s

I did subtract a 'dark' frame from the images, though not in the sense of your point 1, just an exposure of identical duration with the laser turned off. This was mostly to reduce the effect of residual light, but given similar initial conditions would somewhat compensate for the offset that pre-existing charge and electronics noise put on the pixel values. The white field is of course a difference story.

I wonder how close we can get to a white field by putting a thin piece of paper in front of the camera without lenses and illuminate it from the other side. A problem is of course the coherence if we use a laser source... Or we scrap any sort of screen/paper and illuminate directly with a strongly divergent beam? Then there wouldn't be a specular pattern.

I'm not sure I understand your point about the 1.5V/A. Just to make sure we're talking about the same thing I made a crude drawing:

The PD sees plenty of light at all times, and the 1.5V/uW came from a comparative measurement PD<-->Ophir (which took the place of the CCD) while adjusting the power deflected with the AOM, so it doesn't have immediate connection to the conversion gain of silicon in this case. I can't remember the gain setting of the PD, but I believe it was 0dB, 20dB at most.

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