F1.2 pro glass

[MikeOxon]

Re: F1.2 pro glass


I was surprised to read of such a large difference, so I checked with the Cambridge in Colour DoF calculator. Of course, DoF is not a 'hard and fast' calculation and depends a lot on how you define 'sharpness' but, using their rather strict criteria of viewing a 20" print from 25 cm (less than a foot away), the results I got were:


17mm at f/1.2, subject at 12': DoF= 2.95'

17mm at f/1.8, subject at 12': DoF= 4.5'



Significant, yes, but not as 'major' as you suggested. Also, if you were photographing a 'group' of people, might not the greater depth of field be considered more useful?

[drmarkf]

Re: F1.2 pro glass

I was surprised to read of such a large difference, so I checked with the Cambridge in Colour DoF calculator. Of course, DoF is not a 'hard and fast' calculation and depends a lot on how you define 'sharpness' but, using their rather strict criteria of viewing a 20" print from 25 cm (less than a foot away), the results I got were:


17mm at f/1.2, subject at 12': DoF= 2.95'

17mm at f/1.8, subject at 12': DoF= 4.5'



Significant, yes, but not as 'major' as you suggested. Also, if you were photographing a 'group' of people, might not the greater depth of field be considered more useful?

[MikeOxon]

Re: F1.2 pro glass

Since drmarkf mentioned an iOS App, I might also point out that the Focos App, which works far twin-lens iPhones, can produce the effect of a wide-aperture lens automatically.