surf video with 1.150 mm
 

Hi, I tested some things in this video.
I used the 400 mm 5.6 with 2 extenders. 2.0X and 1.4X from canon. So I got 1.150mm
I used twixtor for slow effect.
YouTube - Campeonato de España de SURF. Caravia Surf Festival 09 Video
Best in HD
Manual shooting, Lowest apperture is 11f and speed is 60.
Enjoy it.

other video
 

other video with same configuration. In the park, some ducks.
YouTube - Canon EOS 5D Mark II HD Video. IN THE PARK 2
Watch here the camera with the extenders and some still direct from video:
Blog del realizador Jim-Box: Video Test de Canon Eos 5D Mark 2 y Teleobjetivo canon 400 mm 5.6 con 2 duplicadores= 1.150mm

Very interesting.
I loved the shot of the duck's feet and the lighting on the feathers look great too.
There were not too many artifacts in all that surf. The playback was a bit jerky though ;-) Seriously, the slo-mo worked well and had a nice photographic quality about it.
A monster of a rig but it certainly does the job.

What tripod are you shooting on? That footage looks rock steady...at that focal lenght I would expect even the tiniest puff of wind to shake the image all over the place!

I really like the look of the twixtor'd slow motion - it's doesn't look 100% natural but has a very unique style to it. I'm going to have to give that a try...

The tripod is an old Manfrotto. With a video head, but I need one stronger. I suffer a lot about trepidation.
Of course you must click Record button 2 seconds before to have the camera stabilized. Wind must be low.

Jaime:

Beaitiful shooting.

I double doubled a 400mm for 1600mm once, and actually it didn't do so bad. Problem I have seen with the long lenses is that dust and lint on imagers become highly pronounced. Have you noticed that in your testing?

Yes, is true. Sensor must be very clean to play this game.
I had a lot of dirt in the image.