Why do older camera lenses have faster F-stops?

Started Apr 14, 2013 | Discussions thread
The Davinator
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Re: f1.8 equivalents...
In reply to Joseph S Wisniewski, Apr 17, 2013

Joseph S Wisniewski wrote:

Dave Luttmann wrote:

Joseph S Wisniewski wrote:

EinsteinsGhost wrote:

Joseph S Wisniewski wrote:

Yes, because it's micro four thirds, and the DOF and you need f0.9 to have the light gathering and DOF equivalent of the "plastic fantastic" $100 f1.8 lenses on FF. So, some old "cine" lenses get reincarnated.

DOF yes (at same FOV), exposure no.

Exposure yes.

Cut the sensor area into a quarter of what it was, and you have 1/4 of the photons in the picture, so you need to throw 4x the light at it to get the same results. Just like in the film days, when tri-x was probably my most shot film on the 4x5, while tech pan was one of my favorites on 35mm.

Physics is a bear.

Exposure...no.  I get the same shutter and aperture rating using a FF camera at iso 100 and f8 as I do on an m43 body.

exposure...no.

Exposure... yes.

Come on Dave, you've shot many different film formats and different digital formats. Do you shoot the same ISO in all formats?

That isnt the question.  If you are correct, then if I take my Fuji x10, use the 50mm equivalent, and set iso 100 and f5.6.....i'll get a different shutter speed than I would with my Nikon D700.  As the shutter speed is identical between the two, you are mistaken.

And yes, I use the same iso on my 4x5 rig as I do my FF DSLRs and Mf and point and shoots....but that wasnt the question, was it?

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Rahon Klavanian 1912-2008.
Armenian genocide survivor, amazing cook, scrabble master, and loving grandmother. You will be missed.
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