35mm lens related question

[armisiano]

I'm not sure if this is a dumb question or not. I think it is, but I want to be sure. Here it goes:

Will the image produced by a (for example) 50mm f/1.4 lens set to f/2.8, look the exact same as that of a 50mm f/2.8 lens wide open? I know the light loss will be the exact same, but will the sharpness and level of depth match up as well? I'm very curious.

 

[bwest]

this would depend on the lenses optical scheme... number of elements, groups, etc.
you need to find the MTF for the lenses in question for comparison on the web. Im assuming your talking two lenses here... even by same manufacturer.

Some info on Nikons here... but not a complete MTF: http://www.photosynthesis.co.nz/nikon/lenses.html

 

[Dennis Wood]

DOF should be virtually identical. Sharpness at a given f stop, contrast, chromatic aberration, and falloff is another story.

The single best site I could recommend is Ken Rockwell's, particularly this review of 50mm lenses: http://www.kenrockwell.com/nikon/50-comparison/index.htm#index

Those pages are a must read IMHO

 

[Charles Lowthian]

yes, check the elements (bwest) to have a better prediction