how many mm do you use?

[E-R-I-C]

28-80mm
70-300mm

+ the crop

[Erik_7Xi]

I use my 70-200mm f/2.8L about 90% of the time.

[tonno1970]

It's difficoult to say which is main used. For this hobby you need all the focal lenghts you can. Infact when you enter bases/airshows you need a wide zoom and medio tele zoom for static and taxyshots.
Here you are covered with the 17-85 but you need some more reach like a 70-xxx zoom.
For display / landing and take off shots youu'd better buy a fast prime.

Like many here I have covered quite all from 20 mm up to >400mm.

My most used lens is 300+1,4x as where I live here in Italy you can't stay so close to bases fences and I am obliged to do landing shots from far spots.

As many suggest a nice lens could be the 100-400/L and if you can't afford it you could go to 70-300 IS or 70-200/4L.
Another very good option is the sigma 100-300/4 EX. It seems to be a very good performer, on pair with canon L lenses.

ciao Giampaolo

[Redskin301]

I'm working with the canon 100-400mm and the sigma 170-500mm

[topgun1984]

on my fuji i have about 380 mm zoom capability and a teleconverter of 2.2 times... so do the math ...

it's quite handy for some distance shot