They are too slow for martial arts indoors. A constant 2.8 would be preferred, but I'll take a 2.8-4 for compactness (and price). 5.6 indoors when you want 1/500th of a second shutter speed or faster? Crazy ISO/noise. Maybe the 28-135 on the 6D would work, but then it would be too short.Hmm, I saw this lens on ebay: http://www.canon.com/camera-museum/camera/lens/ef/data/standard_zoom/ef_35~135_4~56_usm.html28-135?
I think this range would be awesome for indoor sports/martial arts (like taekwondo) on a APS-C camera.
Can one hope for an EF-S 35-135 f2.8-4 USM?
I would buy it in an instant.