F Stops & mm's
 

Please tell me (a)how the final set of pictures on your FOV Comparison might have been different if you had chosen different f/stops to those you chose and (b)what is meant by f/4 full wide and f/5.6 medium and (c) what the mm measurements for 16:9 & 4:3 refer to?


Sigma EF 70mm - 300mm with Canon EF Adapter and 1.6x Extender
320mm f/4 full wide
16:9 = 2,496mm / 4:3 = 3,072mm

480mm f/5.6 medium
16:9 = 3,744mm / 4:3 = 4,608mm



Top row: Sigma 70mm-300mm at 200mm w/ 1.6x Extender in 16:9 and 4:3
Bottom: Sigma 70mm-300mm at full tele w/ 1.6x Extender in 16:9 and 4:3

I'm not sure what FOV Comparison you are referring to, but I believe to answer b):

f/4 is your f stop when the zoom is all of the way wide and f/5.6 is the f stop at halfway zoomed.

That would be my guess, anyway, but I've been wrong before.

The reference is to my XL2 FOV page at http://www.dvinfo.net/canonxl2/articles/article10.php

I simply used the maximum aperture available at each f/stop (that is, each end of the zoom range at full wide or full tele). That was the method. The mm measurements for 16:9 & 4:3 refer to their 35mm still photo lens equivalents for those particular fields of view.

Thank you for the info which I'll be absorbing slowly as usual.

I'm sitting in front of my Sigma DL Zoom 75-300mm 1:4-5.6, made in Japan bought 10 years ago which I've only used for long-shot stills (on Digital Rebel now). Is this a similar lens to what you were able to use on your XL2 (simply because XL2 accommodates interchangeable lens)? Or does the XL2, being a camcorder, require a different sort of lens? Could the XL-H1 use my Sigma 75-300?

I'm beginning to think that there should be a separate thread entitled: Implications of XL2 FOV Comparison. It would have deep significance for me at any rate if (a) the comparative detail revealed would also apply if, say, the tractor was a moving object, and (b) the results obtained with your XL2 could be equalled by the XL-H1.

Could the XL H1 use your Sigma 75-300? If that lens has an EOS mount, then yes you can, providing you also obtain the Canon XL to EF adapter (about $450). The lens may provide a suitable image for SD but I don't think it's up to scratch for HD. Also I noticed a significant amount of chromatic abberation with that Sigma lens at the long end.

Thank you kindly, Chris