Proposing a simple shorthand for writing "35mm equivalent field of view"

Started Feb 6, 2013 | Discussions thread
dosdan Contributing Member • Posts: 522
Re: Use Radians Completly Junk '35 mm equivalent'.

relate2 wrote:

50mm 1.8 on the NEX camera that it reminded them of the "Nifty Fifty" of old days even though the actual focal length on the NEX was 75mm...

This is not correct. The FL never changes regardless of the crop factor. 50mm FL on APS-C is still 50mm FL on FF. What changes is the AOV. The AOV on APS-C is equivalent to that of a 75mm FL lens on FF.

There is no actual magnification due to CF either. Assuming the same pixel pitch, e.g. D800 & D7000, with the same 50mm FL lens, the image of the subject falls on the same number of sensels (assuming it fully fits within the narrower AOV of the APS-C sensor) in both formats. But since the APS-C sensor is smaller, the relative proportion of say subject height to sensor height is greater for the APS-C version compared to the FF one. So the APS-C version appears larger within its output frame.

Dan.

 dosdan's gear list:dosdan's gear list
Pentax K100D Super Pentax K20D Pentax K-5 Pentax K-01 Pentax K-3 +1 more
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow