DancingFlame

Sigma 15 is a fish-eye lens. Canon 14 mm is rectilinear. That's why price differs. On some cameras (Rebel, RebelXT, 20D) edges are cropped and Sigma 15mm looks more like a wide-angle with lots of distortion (no fish-eye effect).

Try this lins: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?do=search_results&search_forum=forum_7&search_type=AND&search_string=Zenitar Definitely worth reading :)

Soft-box and umbrellas will do the trick better. However one wouldn't call them 'mobile solution'

Manual says 'Error 99 - unidentified (unexpected, unknown) error'. Thus it could be anything from improperly inserted lens to the bent CF card pins. If camera still making any shots, shutter is OK, body does not require any repairs. Check your lens (in particular, aperture settings). I had that error with older Sigma lens that did not understand any aperture setting except 'wide open'. There is a simple way to check this out. Set Av mode with F/8 and press the small button near lens release lock (aperture repeater button IIRC). Through the lens glass you should see aperture blades. If that works, check electrics.

It's common feature of most AF lenses (excluding macrolenses withount infinity). It is required for AF system to focus on infinity. Setting focus ring behind infinity mark will cause lens to focus 'beyondTheVoid' - behind infinity.

Not all AF lenses have motor inside. Nikon and Pentax bodies have built-in motors and lens uses special servo "screwdriver" for AF. Canon bodies do not have built-in motor. Lenses with USM/HSM/SSM (ultrasonic/hypersonic motor) cannot use motor that resides in body thus they have their own motor.

This lens is quite heavy. I wouldn't like it to be strapped to my head on one of those incidentally hard openings. On the ground Sigma is pretty good but my choice is Canon 17-40/4L for far superior colours, contrast and AF speed. As for the fisheye lens, I use Zenitar 16mm.

Try this one: http://www.dofmaster.com/dofjs.html Simple DOF calculator.

Bigma (Big Sigma 50-500, about 7 lbs!) is equipped with HSM (hypersonic mechanism). Auto focusing is fast enough to catch such a big bird. However that long lens is never needed for landing shots, 200 mm is more than enough. But with 500 mm one will be able to shoot people in freefall from the ground! I saw shots made at 500 mm and was quite amazed with the quality. VR is not required for landing shots as tripod might be used. Personally, I use Sigma 70-300 APO that costs something around $200 and get perfect shots.

My vote too. But the weather sucks... Average temperature today is already about 3 degrees (Celsius) over zero. That's how one could survive cold winter ;)

There are two sources of that sound: rails of built-in flash and orientation sensor (sensor that tells camera whether you shoot vertical or horizontal frame). Generally, first source is a louder one.

What about this one? http://skyphoto.ru/phpgallery/displayimage.php?album=topn&cat=0&pos=1

Yes, it is very agressive at 100-150 jumps, be prepared to be grounded at some DZs. I would also recommend demoing Safire2 and Fusion. At ~1.3 they all fly the same. From my experience Pilot had more oversteer than Sabre2. But it also had better openings.

Yeah, that's the right way :)

Disagree. It is the BEST scenario. What could be better than a good swoop...