Canon 17 40Mm F4

This little piece of gear took my Canon lenses and made them amazing. I have a 17-40mm L USM F4 and it reads in my camera as F2.5, before I only used this lens as an outdoor lens, now I can use it indoors. I also have a Rokinon 35mm Cine Prime T1.5 That works perfectly with this I cant tell you what the F stop is opened all the way up but all I can say is wow its bright! Great product, since the GH4's strengths aren't low light this is a must have.

Protects me Canon 17-40mm.

Updated from a Canon 17-40mm, this is sharper and the IS is a great bonus.

Works excellent on my canon 17-40mm f/4L... I though i might need a thin filter but this one is not visible at all in my wide angle shots. I can see no difference in image quality with or without the filter.

I have replaced my Canon EF 17-40mm with the Canon EF 16-35mm and what a difference it made. This lens is sharp and with the IS, I am able to shoot in much lower light and get quality images. So far, this lens has not let me down.

It works well with my Canon 85mm f1.8, 17-40mm f4L and I especially like it with my 40mm f2.8.  With the 40mm pancake its still nice and compact.  My only complaint is that the data port competes for space with my fingers next to the grip.  If they could just move that to the bottom it would be glorious.

I mostly shoot landscapes and used the Canon 17-40mm f/4L USM lens till now. Just switched to the Canon EF 16-35mm f/4L IS USM Lens and have been amazed by how sharp the images are especially the corners at either end of the zoom spectrum. Its a lightweight wide angle zoom with superb construction quality. I am sure it will provide me many years of service similar to the 17-40mm lens which I am now inclined to sell.

I used this bag on vacation and it was the perfect size with the perfect look. I had a Canon 5D, two lenses (17-40mm, 50mm), a spare battery, a compact card carrying pouch, a 430ex flash, a wallet and an ipod, all of which fit comfortably in the bag. Visually it looks like a messenger bag.

I use this with my 17-40mm L and 24-105mm L lenses from Canon and my Lee Filter holder. This really helps get your filter as close to the lens as possible to eliminate vignetting. Well made and easy to screw on and off. A must have...

I used this to hold my Canon Rebel DSLR with a 17-40mm lens and it was sturdy and so convenient. I was carrying my camera all day all over the place on hikes and around the city and it was comfortable, definitely glad I bought it for this trip. Way more comfortable and convenient than a neck or cross-body strap, I'm not going back to those.