[Elphel-support] Help on short distance focusing

[Andrey Filippov]

Hello Norman,



I believe the problem is that the distance is too short for the lens so it can not be properly focused. The focus should be achieved with the iris completely open. The solution is very simple - you need to add extra 5mm adapter ring ( https://www.google.com/search?q=5mm+adapter+ring ) between the camera and the lens (there will be two rings if you already have one installed).



Andrey








Subject: [Elphel-support] Help on short distance focusing [SEC=UNOFFICIAL]
From: "XIONG, Norman"<nxi at ansto.gov.au>
Date: Thu, 25 Aug 2022 05:41:15 +0000
To: "Elphel Support"<support-list at support.elphel.com>

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 Dear Elphel Support team,



Can you advise on how to make the picture bright enough for a short distance focus?

We have a NC353L system with a 55mm F#1.8 lens. And we need to focus on an object that is 340mm away from the lens. When I expand the aperture to make the picture bright, I can't make it focus. If I make it focus, I have to change the depth and it becomes very dark. Is there a way to improve the brightness for such a short distance focusing,
 such as adding a spacer to the lens system?



The system configuration: 

FPS: 60

Manual Exposure: 250ms

Auto WB: OFF

Auto Exposure: OFF



Please see attached image snapshot and configuration files for detail.

Thank you.



Regards, 

Norman






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Subject: confirm d0b85f21876f30ad5718b130d75b55516fc607ed
From: <support-list-request at support.elphel.com>
Date: Wed, 24 Aug 2022 22:42:04 -0700

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