Luminous Landscape Forum

Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: jrsforums on January 26, 2014, 05:23:28 pm

Title: Sensor size v. Lens image height
Post by: jrsforums on January 26, 2014, 05:23:28 pm

Canon patents for 85mm, 100mm, & 135mm lens show a height of 21.635mm
http://www.canonwatch.com/canon-patent-image-stabilized-85mm-100mm-135mm-lenses/

I assume these lens were for "full frame", i.e. 35mm. 

However, I always thought the sensor size was 36mm x 24mm.

I am guessing I was wrong....or these lens are not for FF.

Any guidance?

John

Title: Re: Sensor size v. Lens image height
Post by: BJL on January 27, 2014, 09:17:03 am

Quote from: jrsforums on January 26, 2014, 05:23:28 pm

Canon patents for 85mm, 100mm, & 135mm lens show a height of 21.635mm
http://www.canonwatch.com/canon-patent-image-stabilized-85mm-100mm-135mm-lenses/

I assume these lens were for "full frame", i.e. 35mm.  

However, I always thought the sensor size was 36mm x 24mm.

I am guessing I was wrong....or these lens are not for FF.

Any guidance?

John

Here, "height" is strange optics jargon for "distance from the center of the image", as used in the labelling of lens MTF graphs. That 21.625mm is exactly half the diagonal length of a 36x24mm sensor, so is the distance from image center to the corner of the 36x24mm frame, and the maximum relevant "height" for an MTF graph.

TL;DR: these are lenses for the traditional 36x24mm format, aka "35mm".