Spectral sensitivity om BW films and perceived sharpness

pkr1979 · Oct 22, 2024

Just an update from me on this. I shot a couple of sheets with Ortho Plus last week using a UV-filter and a yellow filter... I cant say for 100 % its what makes the film sharper, but these shots are as sharp (or sharper) as T-Max 400 - especially the one with a yellow filter.

Nicholas Lindan · Oct 22, 2024

Filtering light to a narrow spectral band will, obviously, remove chromatic aberration. Using a #25 red filter produces very sharp photographs by eliminating almost all chromatic aberration, though a UV filter may sometimes be needed in the mountains. (For a really black sky with a #25 combine it with a polarizer.)

A #25 doesn't work with Ortho film. A minus-blue variety of yellow filter leaves only the green component that the film is sensitive to, and again the lens' chromatic aberration is removed.

Andrew O'Neill · Oct 22, 2024

Nicholas Lindan said:
Filtering light to a narrow spectral band will, obviously, remove chromatic aberration. Using a #25 red filter produces very sharp photographs by eliminating almost all chromatic aberration, though a UV filter may sometimes be needed in the mountains. (For a really black sky with a #25 combine it with a polarizer.)

A #25 doesn't work with Ortho film. A minus-blue variety of yellow filter leaves only the green component that the film is sensitive to, and again the lens' chromatic aberration is removed.

Well, the #25 does in fact work on Ortho film... but one must apply a 512X factor. Impractical, but doable. I've tested the #25 on green latitude XRAY.

_T_ · Oct 22, 2024

Changing your shutter speed by 2.3 stops is an increase in time of 500%. A 500% increase in time can definitely have a large affect on sharpness. Especially when shooting landscapes.

Things like wind in the trees will show 500% more motion blur.

pkr1979 · Oct 22, 2024

_T_ said:
Changing your shutter speed by 2.3 stops is an increase in time of 500%. A 500% increase in time can definitely have a large affect on sharpness. Especially when shooting landscapes.

Things like wind in the trees will show 500% more motion blur.

2.3 stops? Its buildings and rocks - not trees

Spectral sensitivity om BW films and perceived sharpness

pkr1979

Nicholas Lindan

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Andrew O'Neill

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_T_

pkr1979

Spectral sensitivity om BW films and perceived sharpness

pkr1979

Nicholas Lindan

Advertiser

Andrew O'Neill

Moderator

_T_

pkr1979

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