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Tutor
Posts: 20
Member Since: ‎11-19-2016
Message 1 of 5 (983 Views)

how big is the influence of the aperture?

Hi guys, has anybody tested in how far the lenses aperture takes effect to the scanning quality /

how sensitive are the results in regards aperture (DOF)? Is there a aperture you roughly recommend?

 

regards, spark

 

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Intern
Posts: 41
Member Since: ‎11-04-2016
Message 2 of 5 (951 Views)

Re: how big is the influence of the aperture?

I follow the basic photographic rule:

Try to scan at the optimal aperture (often found in lens reviews).

Low f-stop and you have lens aberration, too high and you have light bouncing on the blades of the diaphragm.

On DSLR, I usually stay between 11 and 16.

Each lens has it's sweet spot.

Since we are scanning, the higher the f-stop the better until your image quality drops.

All the above is unrelated to David. I don't know if something else comes into play.

Jeff
Tutor
Posts: 20
Member Since: ‎11-19-2016
Message 3 of 5 (930 Views)

Re: how big is the influence of the aperture?

Thank you, this is in between the settings i use anyway.

But i havent found lens reviews for the industrial c-mount / cs-mount lenses. Do you have a source?

 

regards, Spark

Intern
Posts: 41
Member Since: ‎11-04-2016
Message 4 of 5 (925 Views)

Re: how big is the influence of the aperture?

I don't have a specific site with lens reviews for industrial camera lenses.

 

I would download this chart:

 

http://img15.hostingpics.net/pics/714472ISO12233reschart.jpg

 

Print and take pictures with your camera and different f/stops.

 

You will quickly find the usuable range for you lens.

 

Jeff

Intern
Posts: 48
Member Since: ‎11-05-2016
Message 5 of 5 (896 Views)

Re: how big is the influence of the aperture?

Small aperture setting also introduce distortion from diffraction around the blades, I try not to use an aperture smaller than f11, F16 max. Use an ND filter if you need to stop down the image.

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