The Zeiss 21mm 2.8 Distagon is a beautiful lens. It’s the sharpest lens that I use wide open, and by 5.6, the sharpness becomes ludicrous. The build quality is what really sets it apart. Once you handle it, you realize that most other lenses feel like toys, and this one is going to last. But the most impressive thing you’ll notice is when you look through the viewfinder. What you see is a big bright, high contrast image that actually aids manually focusing the lens. That alone made me completely uninterested in the Canon 24mm 1.4, which was on the list of wide angle prime lens candidates. The difference is quite staggering, with the the Canon image feeling much more ‘muddy’.
There are two downsides to this lens:
1. Manual focus: This isn’t such a big deal considering the focal length. I wouldn’t want to be using a 50mm or 85mm with MF, but at 21mm there is a large enough DOF and that leaves a bit of room for error. Don’t get me wrong, I’ve lost my fair share of good shots because they are out of focus. But you eventually learn to make it work. I’ve also changed the focusing screen in the 5D mkII and that has helped with accuracy.
2. Smaller aperture: compared to the Canon 24mm 1.4 or even the Sigma 20mm 1.8, this lens is a little slow. But I like the fact that I know exactly what I’m going to get. And with the high ISO capabilities of camera bodies these days, I haven’t ever needed a wider aperture.
The one thing that needs to change on the Zeiss 21mm 2.8 Distagon is the big bright chrome ring around the front of the lens barrel (filter threads). It shows up a lot as a reflection in most situations when shooting through a window, and that is really tough to fix in post, so much that I’m considering painting it black. I searched for a design rationale, but could find anything on the issue. I wonder if it’s a marketing thing, similar to Canon’s red ring on their L glass. I sent an email to Zeiss asking them about it, and will let you know what they say.
Overall, I’m completely satisfied with it, and it seems to compliment the Canon 35mm 1.4 L quite nicely. These two lenses were acquired to replace the Canon 16-35mm 2.8 L zoom that I didn’t like. I use the 35mm when I absolutely need AF, and 21mm when I need something extremely wide. There has only been one time when I wanted something wider, and in that case, I stitched the shots together. The downside is that when I’m shooting with the 35mm 1.4, I’m wishing it was as good as the Zeiss.