[Elphel-support] DC auto-iris

[Shane Sanford]

Thanks!  You just saved me a reasonable amount of work prototyping and testing to come to the same conclusion...

 

Shane

 

From: support-list [mailto:support-list at support.elphel.com] 
Sent: Saturday, October 13, 2012 11:42 PM
To: Shane Sanford; Elphel List
Subject: Re: [Elphel-support] DC auto-iris

 

Hello Shane,

I was thinking of adding lens control to the camera, but then I realized that with the 2.2 um pixels (and the modern sensors have even smaller ones) the usable aperture adjustment is very limited because of the diffraction - the maximal F# is just the ratio of the pixel size to the light wavelength, so in our 5MPix cameras it is about 3.5. If you close more - the resolution will be degraded. On the other hand - it is a strong side of the electronic rolling shutter sensors - there is no penalty for going to very short exposure time (something common for global shutter CCD and CMOS sensors).

So I would not recommend using of any motorized iris lenses, they woulld provide little if any benefit, while degrading the image sharpness.

Andrey





 

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