Tamron wins on weight at 2/3 that of the Sigma
Sigma wins on lens speed at f-4 to 6.3 vice Tamron f-5 to 6.3
It really comes down to useage. Is one stop gaining you anything?
The weight difference may be a factor, depending on how long and what
type of shooting you will be doing.

Thanks for that John, appreciate the feedback especially as I hadn't
even begun to consider the weight angle - great point! Aviation use for
me would be for flying shots and I would be using a monopod. This would
be my first foray into DSLR with a longer lens having been using a
Panasonic digital with quite appauling shutter lag... but that's another
story altogether!

Cheers...


Peter D Evans - Administrator
LEMB - Luftwaffe Experten Message Board
http://www.luftwaffe-experten.org