Originally posted by Kguru Yes that is correct.

Easier to think in terms of percentage change. 21 over 15 is 1.4 ie. 40% change; whereas 81 over 75 is only 8% change.

Back to the poll, if I leave out the DA40 (due to its exceptionally low price) the 77 and 70 are currently joint 1st. That's quite remarkable.

oooh...that's a useful piece of information there.

I put it into a spreadsheet laying out all the limiteds (including the DA15, but excluding the DA35-Macro)

So in terms of percentage-chage, this is what it looks like:

so I dunno... putting it this way, it sure changes my POV about the 15mm and 21mm being redundant... Having both the 31mm & 43mm is even more redundant in terms of %-change compared to the 15mm & 21mm.

Originally posted by creampuff I'd choose the FA43 & FA77 Limiteds.

FOV increases tangentially. In short, this means that as focal length progressively gets shorter, the field of view increases dramatically. So comparing say a DA 16-45mm versus the Sigma 17-70mm wide angle zooms for example, that 1 mm difference works out to about 10 degrees at the wide end.

Specifically the formula is:

2 x tan-1( l / (2 x f) )

where ' l ' is the length of the frame in the direction that you want the reading and ' f ' is the focal length of the lens.

wow. that looks interesting, but is there any way to simplify it a bit? Do you have an example where you can put values to 'l' and 'f'?

Thanks a lot! This is very informative.