I’ve been looking for a good fast fixed-focus lens for a while. It was quite tough because I have a Nikon D40 and very few lenses autofocus on this camera because it doesn’t have it’s own built-in focusing motor. This means that only lenses that contain their own motor will auto-focus on the D40. After a lot of searching I finally settled on the Sigma 30 mm F1.4 DC lens. It arrived earlier this week so I’ve been doing a little playing around with it since.

[tags]30mm, Sigma, DSLR, Nikon D40[/tags]

I had three reasons for wanting a lens like this. Firstly, this is equivalent to a 50mm lens on a 35mm film camera. Such lenses give the most natural-looking perspective. Secondly, I like the paper-thin depth of field you get from fast lenses which lets you take great portraits. And finally, I wanted a fast lens so I could take pictures indoors without a flash. When you’re at a family gathering and you want to get some nice pictures the last thing you want is a flash. As soon as camera flashes start going people stop acting naturally. So, even if it wasn’t for red eye and all the other problems associated with flash photography, the pictures would still not be as good because people don’t look natural once flashes start blazing. For a more detailed discussion of the merits of 50mm lenses (or their DSLR equivalents) checkout Gary Voth’s The Forgotten Lens.

Now that I’ve explained my reasons for buying a lens like this it’s time to have a look at the actual lens I got. The very first thing you’ll notice is how heavy this thing is. There’s some good glass in here! The sheer weight of this thing really hits you when you compare it to the weight of the 18-70mm zoom that comes bundled with the D40. The 30mm Sigma is easily twice the weight if not more. In some ways the lens looks small but it really isn’t. It’s very wide and barely fits onto the D40. If it was any wider it wouldn’t fit in under the built-in flash! The glare-guard that comes with the lens is also very big so when it’s all attached to the camera it looks as big as the bundled zoom.

As for the quality of the pictures it takes, so far I’m very happy. Its certainly living up to my expectations. Below is an un-processed shot of my cat Houdini taken indoors at night without a flash.

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