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Old 8th September 2009, 07:38 PM
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Barry Barry is offline
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Default Calculating the Hyperfocal Distance

I need to calculate the Hyperfocal distance of a large format lens at a particular aperture. Unfortunately my knowledge of optics leaves a lot to be desired.

I will be using the following formulae: -

H= F^2/fc

Where H is the Hyperfocal Distance
F is the Lens Focal Length
f is the Lens Aperture Stop
c is the Circle of Confusion

The Circle of Confusion appears to be very subjective and is also dependant on the film format. I shall use 0.013" as my starting point for 8x10" film.

My problem is that the lens in question has a Focal Length of 120mm, but has a Flange Focal Distance of 130.7mm. What value do I use for 'F', 120mm or 130.7mm.

Can anyone advise
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Old 8th September 2009, 07:47 PM
SteveB SteveB is offline
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barry

Try this......www.dofmaster.com/doftable.html. It might save you a lot of time.

steveb
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Old 8th September 2009, 08:01 PM
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Thanks Steve, useful link. It compares favourably with my own calculations, which gives me some confidence.
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