Recommendation for a lenses for an EOS 70D - for hostile outdoor environment

NZ Paddler wrote:

Hi everyone,

(1) I am after a single lens that I can use with my EOS 70D for a remote kayak photography trip around an uninhabited island in the middle of Pacific. The lens will be used mainly for taking shots of flying and nesting birds from a moving kayak.

Because of the hostile environment (swell / big waves / salt water), it will not be possible to change lenses during the day - so one lens has to do. These are my criteria:

• The camera and the lens needs to be compact - so I can balance it with one hand and fit inside a big Dicapac waterproof camera bag
• Lens need to support continuous focus in video recording mode at the maximum zoom
• It need to get a sharp close up of birds from up from 100 meters.

Based on my research in here, I was thinking of getting the following combination:

• Canon EF 2x III Extender
• EF-S 18-135mm f/3.5-5.6 IS STM

(2) I am also after a second lens for underwater filming of marine life for the same EOS 70D camera. I was thinking of the Canon EF 8-15mm f/4 L USM Fisheye Lens.

I am pretty new to DSLR photography - and any help / suggestion will be appreciated

Thanks in advance

Tim

The Canon EF2x is only compatible with bigger white Canon L lenses, a limited selection.

The Kenko teleconverters work with pretty much all EF lenses, but NOT with EF-S lenses. EF-S lenses protrude at the mount, so no teleconverter will fit. Anyway, with a teleconverter on a lens that is f5.6 at the tele end, you will loose AF in standard viewfinder mode, because the aperture will become effectively f11, IQ will also suffer. While in movie/lifeview mode the AF might still work to some degree, since the 70D should be able to handle AF at f11, but I wouldn't bet on it working superwell. Even with big white L lenses, AF tends not to be the same as without the converter.

Anyway, what's the point of the teleconverter if you can't change it in and out as you say.

This leaves you with the 18-135 STM, which should work fine. You are limited in the tele range though. You might consider getting a bridge camera, which offer now zooms that are 24-1200mm (FF equivalent). While the IQ at the tele end certainly will suffer, in video mode you don't need such high resolution, so it might be ok. Good IS is more important at these long focal lengths, and some of these bridge cameras seems to do quite ok.

Regarding fish-eye, I presume you are aware that on a crop camera, you don't get the full benefit of the fish-eye, i.e. only at 8-10mm you will get the frame-covering 180 degree (diagonal) fish-eye on crop. When zooming in it's a wide-angle with curved straight lines. I think it still would work though. I just wanted to point out the issue, see also

http://www.the-digital-picture.com/Reviews/Canon-EF-8-15mm-f-4-L-USM-Fisheye-Lens-Review.aspx

Instead of the fish-eye, you could also get a standard rectilinear lens, like the Sigma 8-16mm.