Flash Zoom Settings for Digital

Studio Photography, Flash, Daylight and Studio Lights, Flash equipment and use
  
29 Jan '13 Tue Jan 29, 2013 10:20    
layingback
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Post Flash Zoom Settings for Digital

Question: On an older pre-digital flash with variable zoom feature - eg. a Vivitar 285 - do you set the zoom factor (tele - wide) to match the numeric f/l printed on the lens, or to the 1.5x APS-C factor of it, ie. the 35mm equivalent?


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29 Jan '13 Tue Jan 29, 2013 12:18    
cardiff_gareth
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Post Re: Flash Zoom Settings for Digital

As the flash is using lens focal lengths from film ie full frame then I would use the 35mm equivelent of what your lens is so a 18-55mm lens is a 28-80mm in old money so:

18mm = 28mm (wide)
35mm = 50mm (normal)
55mm = 80mm (tele)

Test a few shots off and see how it looks Wink


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29 Jan '13 Tue Jan 29, 2013 12:28    
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Post Re: Flash Zoom Settings for Digital

Or is it that the angle (FOV) is the same for a given lens and thus the sensor size is irrelevant? Wink

Or is it neither? Shocked

I know I could test Smile But only real test would be at night in total darkness with long zoom which means outside and it's cold. Laughing


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29 Jan '13 Tue Jan 29, 2013 16:40    
Algernon
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Post Re: Flash Zoom Settings for Digital

The flash sets the FOV to suit 35mm film, so on APS-C you could set it to the equivalent length so for
35mm you could set 50mm.


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2 Apr '13 Tue Apr 02, 2013 19:20    
Anvh
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Post Re: Flash Zoom Settings for Digital

- layingback

Or is it that the angle (FOV) is the same for a given lens and thus the sensor size is irrelevant? Wink

Or is it neither? Shocked

I know I could test Smile But only real test would be at night in total darkness with long zoom which means outside and it's cold. Laughing

FOV is not an angle you know, photography is the only one doing it differently because they have a focus point.

FOV is the length measurement of the frame at the focus point and AOV is the angle of view
Photography 101 Wink

use equivalent is indeed the right answer.
Some pentax flashes have scale for 645 and 6x7 on them.

 
 
 
 
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