Review: Canon 17-40mm F4 L

Originally posted: June 2012; Updated October 2025

Well look what arrived in the post today:

The Canon 17-40 mm F4 L. Shiny!

Up to now, I've always used the Tamron 17-50mm F2.8 zoom lens to cover this range, and I've been almost completely happy with it. The Tamron produces excellent images (especially on 1.6 crop sensors), and have an extra f-stop and 10mm at the zoom end over the Canon 17-40mm which I must admit I think I'll miss.

So why did I buy the Canon? Essentially it's because I'm completely sold on Canon's weather-sealing and I'm about to lose the second Tamron in 2 years to salt and/or water and/or mud and/or slime damage so I figured it was time to make a switch. As you will know if you've already read about my photography gear, I give my stuff a pretty hard time. Aside from dragging it around on boats wherever I go, I tend to just shove it all into a rucksack I'm heading out anywhere, which is great for hiding the fact that you're carrying expensive gear, but not always so great at protecting the stuff inside. I'll use my cameras in rain, seaspray, snow or whatever and I've alarmed more than a few people with the amount of mud and fish scales that have occasionally coated it! The lenses and camera are covered in scrapes and bumps, but not a single bit of it has ever stopped working or failed to produce images as sharp and clear as the day I bought the kit. Except the Tamron. Which is a real shame because like I said, it's a great lens and I'll miss it.

Anyway, my first impressions of the Canon 17-40mm so far are pretty much that it works. I wandered through the main campus at Glasgow University on my way home today and took loads of pictures of wildflowers, architectural shots, a view of Glasgow from the top of the hill, and even a load of shots from a graduation celebration in the main quadrangle, which was great until I got home and the thunder and lightning started and I got too excited... In my haste to try and shoot the storm, I deleted everything off my memory card to make room for the video files and I lost everything I'd shot today.

2025 Update: I've used this lens a lot more since that first day, and it's pretty great. It's probably the lens I use least often because I shoot wildlife so much, but when I want a lens for scenic shots or wider views it's my go-to lens, and, after 13 years of use, you'd never guess it spent much of that time rattling around a backpack! Here's a few examples:

Back to the original post: What I can really say about the lens so far though are that the autofocus is absolutely silent (to the point that I thought I'd switched it off completely) and incredibly fast and the build is nice and light, but feels sturdy. The zoom ring feels a little heavier than I'm used to from my other lenses, but it's not a big deal at all. The one thing I can't quite figure out is the ridiculous lens hood that is supplied with the lens. It's absolutely enormous and converts an otherwise perfectly normal-looking lens into  something that looks more like a giant cartoon flower. Maybe it's just there to make it look more impressive, but I can't imagine it offers that much protection or shading? I'll use it anyway since it can't hurt (except to make it slightly more awkward to squish everything into that rucksack), and since I regularly whack lenses off things it makes more sense to have the lens hood take the impact than the glass. Still, I'm pretty glad I bought a polariser to fit it as well since there doesn't seem to be a lot of front-end protection there.

2025 update: To this day, I get way more value out of it for front-end protection so it's never off the lens. I have no idea if it helps with shading, but it definitely helps when my camera is over my shoulder and swings into something on a rough day at sea. If you're more careful with your gear and/or don't regularly risk banging it into metal ships, let me know what you think of the hood for shade!

Canon 17-40 mm lens with and without the hood

Anyway, if the weather stops terrifying the dog long enough that we can actually go outside again for more than 30 seconds I'll hopefully have some replacement photos to share with you from this lens over the weekend. If not, the hound will have to be my test subject!

UPDATE!

Ok, so the weather improved over the weekend and although we couldn't head out of the city because we had some friends staying over, I took a wee trip out to the Glasgow Botanic Gardens and the Kibble Palace to test the lens out. I'm quite pleased with it! Here are a few test shots, all taken wide open at F4 across the zoom range. None of these have been sharpened, so they're shown here as they were shot:

Koi carp in the Kibble Palace pond. The glass roof is reflected in the water.

A close-up of one of the statues ('Stepping Stones')

As a portrait lens, it's pretty nice at the 40mm end. Kev was grumpy about being dragged around to look at plants.

Close up of a banana leaf.

Triffids! ... I mean Venus fly traps and pitcher plants. A close up of a red flower. The bokeh is pretty nice too, though it doesn't give quite the same separation of subject and background that you can get with wider or longer lenses.

I'm impressed with this. The sharpness and overall image quality already seem better than I was getting with the Tamron 17-50mm so I'm looking forward to seeing how it performs in more 'real-life' shooting scenarios on my next research cruise.