Hi everybody,

as a follow-up of a conversation about

Ole's field-of-view table (which I have misunderstood in the first place) I would like to ask all of you a simple question and I hope many of you can contribute to give a solid answer:

**What is the real horizontal width of your imaging sensor ?**
I did a quick test shoot with my K100D and came up with the answer:

22,8mm (common wisdom is 24,0mm)
Obviously it all depends on the real focal length of the lens used. I took the fl number from a Zeiss data sheet, who are known to be exact. Here are my measurements:

Camera: K100D

Lens: Contax Planar 50/1.4

fl: 51,8mm

distance: 3860mm

width: 1700mm

I attach an excel sheet à la Ole's table and a quick calculation method on the right side where you only have to put in distance and width to see the FOV. You might have to change the term WURZEL to SQRT for your excel to run properly. Width and distance can be of any unit as long as they are the same and use decimal commas.

Column B and row 5 can be changed to your liking and the whole table will change as a consequence. I really hope I've done the math right this time !

If we have enough data we might also proclaim reference lenses in order to have verified focal length measurements for them. Once your sensor width is verified, it would be easy to determine any lenses' focal length too.

I would say for the test shots to be valid one would have to take shots with a subject as far away as possible in mid-frame. Measuring the distances is of course the flipside of the coin .-)

Looking forwards to your measurements,

Georg

PS:

Another very nice table from Venturi