Micro Four Thirds Focal Reducer Shootout

Started Feb 20, 2014 | Discussions thread
MichailK Junior Member • Posts: 34
Re: Micro Four Thirds Focal Reducer Shootout

This thread has been hugely informative along the links posted to other threads of very basic information! Many many thanx! It is funny how things may not be what you expect from a great lens of the past if you take account the sensor glass stack and the adaptor's optical qualities into play. It seems like a trial and error bet depending on the combination of sensor-lens-adaptor. What's fun is that  a great lady portrait photo may be so exactly because of degraded performance...

Jay Turberville wrote:

Bonus related concept 2: The exit pupil of constant aperture (constant aperture by optical design, not by electronic control of the iris) zoom lenses does not move when the lens is zoomed. It will move for zoom lenses that change f-number when zoomed. If you think of the exit pupil as projecting the image onto the sensor, this begins to makes perfect sense.

Interesting - my thick head tries to fully understand the implications besides the hot spotting problem. Is the image circle width related to the exit pupil distance? Does it change as this distance changes? (Among the lenses friends lent to me to use on my E-PL5 there is a seemingly rare Nikon zoom 25-50mm constant 1:4 Ai-S and a "common" Nikon 28-85mm 1:3,5-4,5 AF. I suppose that I could see for myself of the image circle projection on a piece of paper or so?) Could a too wide image circle produce a reflection haze of not fully absorbed light by the adaptor barrel walls that degrades shadows on high contrast bright daylight scenes?

 MichailK's gear list:MichailK's gear list
Olympus PEN E-PL5 Olympus M.Zuiko Digital 14-42mm 1:3.5-5.6 II R Sigma 19mm F2.8 DN | A Sigma 60mm F2.8 DN Art Olympus M.Zuiko ED 75-300mm 1:4.8-6.7 II +6 more
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