Canon 17-40mm UW

Has anyone been using th Canon 17-40mm underwater, I am thinking it may be good for video and stills.

I am going to the reds soon and think it may be a good solution to shooting WA and still having the opportunity to capture a shark should one be a little further away

Camera is a 5d

??

I use this lens for my 5D3 - and previously with the original 5D and also 5D2. I have an Aquatica set up and also add a +2 dioptre. It is a very sharp lens with great contrast. However, it is a little less sharp at the corners than the 16-35mm which many people prefer but which is much more expensive. This can be minimised by keeping your aperture at f8 or tighter, upping the ISO if necessary which is no great penalty on this camera. I use the long end for the more distant, larger subject and find it works well. I consider the 17-40 a first class cheaper solution and can recommend. No idea about video - don't even know where the switch is on the housing!

Let me know if I can help more

I have been using it primarily for my WA lens UW. It is a good lens.

We have shot both the 17-40mm and the 16-35mm F4L. The 16-35mm is hands down better. If you can swing it, that is the lens I would recommend. The F4 lens is very affordable.

It's my wide zoom as well. I've used it for sharks, dolphins, and other big animals. The 16-35mm seems to be more popular, but I can't see much difference between them except being a stop faster and over double the price. The only downside is that when I zoom all the way out, I need to be around f18 to have sharp corners. I'm not sure if the 16-35mm has the same limitation in the water, or if it's just my rig (Ikelite/5D2.)