Cropping a 35mm shot to 50mm in post

[SsSsSsSsSnake]

How would one calculate the crop to simulate a 50 mm,?
Thanks

 

[AndrewFlannigan]

Perhaps this will help...

https://www.pointsinfocus.com/tools/depth-of-field-and-equivalent-lens-calculator/#{%22c%22:[{%22f%22:13,%22av%22:%228%22,%22fl%22:50,%22d%22:3048,%22cm%22:%220%22}],%22m%22:0}

 

[Nod]

I'd shoot 2 frames with a zoom, of the same subject. Ideally something like a brick wall (so I could get an easy sense of scale to compare between the 2 shots) then use those shots as a template to do the crop.

 

[alfbranch]

50mm on what format?

 

[SsSsSsSsSnake]

50mm on what format?

Fuji APSC

 

[sk66]

Pretty simple, *double the FL is approx half the horizontal/vertical field of view (or double the subject distance for the same FOV). 50mm is close enough to double as to be negligible... especially considering neither lens is likely to be exactly the FL stated; especially if not focused to near infinity. The resulting DOF in the crop will also reduce and be reasonably accurate (assuming enlarged to the same output size).


*doesn't work for UWA FL's

 

[alfbranch]

Pretty simple, *double the FL is approx half the horizontal/vertical field of view (or double the subject distance for the same FOV). 50mm is close enough to double as to be negligible... especially considering neither lens is likely to be exactly the FL stated; especially if not focused to near infinity. The resulting DOF in the crop will also reduce and be reasonably accurate (assuming enlarged to the same output size).


*doesn't work for UWA FL's

Unless of course the question is aiming for an equivalent of 50mm on 35mm format.

 

[sk66]

Unless of course the question is aiming for an equivalent of 50mm on 35mm format.

Did the title change? I'm pretty certain it said 28mm to 50mm originally??? If not, I wouldn't say 50mm is "close enough" to double the 35mm FL, and my previous answer is a bit off. But the same kind of SWAG can be applied...

E.g. 2x FL is 50% FOV. 50mm is ~1.5x of 35mm, so ~ 75% FOV. A 35mm has an ~ 38˚ FOV on Fuji APS, 75% of 38˚ is 28˚... actual 50mm FOV on Fuji APS is 27˚.

I keep a link to this page of photography calculators in my favorites... https://www.tawbaware.com/maxlyons/calc.htm

 

[Woolsocks]

Errr? Crop and enlarge.

 

[snerkler]

50/35 = 1.43. I would then reduce each side by 1.43x, so a 6000 x 4000 image becomes 4196 x 2797.