Archive for January, 2008

New Photoblog

Posted on January 13, 2008, under photography.

Although I’ve been updating this blog less frequently than I used to, I have been taking a lot of photographs over the last few months. Gradually I’m getting slightly more and more confident in the results, and I have enough of a buffer of publishable photographs that I’m finally ready to start blogging some properly.

So, to that end, I’ve kicked off a Photoblog over at all costs, and you can subscribe to the feed too.

The blog itself is a mix of a custom theme and plugin I’ve hacked away on, for WordPress, and some styling from the Juicy theme too. There’s also some python hackery behind the scenes to fetch the photos from flickr, tinker with the colour-spaces, overlay the signature and then output two named renderings.

The photos will continue to go up to flickr, and each entry includes a link to the flickr page, along with tags explaining what equipment was used to take the picture. Hopefully I’ll be blogging photos at the rate of about 3 a week, and getting better as I go!

Mini-review: Sigma 10-20mm f/4 DC

Posted on January 3, 2008, under general, photography.

So, now that I’m back writing these things, there are two reviews to be done, and where better to start than with the Sigma 10-20mm f/4 DC I got way back in August.

Orly from heaven

The 10-20mm is an ultra-wide-angle for small-frame Digital cameras, giving about the same field of view as a 16-32mm would conventionally. Typical uses of this range are for architectural and landscape photography along with gritty street photography and photojournalism. Over at InPhotos this lens seems to be Donncha’s favourite, and there’s a ton of examples you can oogle at.

My experience with the 10-20 has been more of a mixed bag. I’m glad I bought the lens, and it lived in my camera bag until I upgraded to a larger format camera, but I didn’t use it as frequently as I had hoped (mainly due to travel).

Hoogslandse Kerk Leiden Everyone at the Tapas bar
Orly, choosing Irish Hunger memorial

First off, the lens does an excellent job of architectural photography. If you need to take a picture of a tall or wide building, and there’s not much going on, it can do a great job. If you take the time to learn how to get a decent exposure, it can do an amazing job of capturing rich tones and textures. I was pleasantly surprised by just how much detail came out in the photo of Hoogslandse church above, including details inside the building.

But when it comes to street photography, or people, the lens isn’t quite as versatile as I’d hoped. It’s not so much the lense’s fault as a problem with the format in general. The lens is so wide, and the sensor so small that this leads to two problems.

Firstly there is quite noticeable distortion and barrelling. Objects and people can take on a very wooden and 2 dimensional look. Very little of the depth comes across from the stones behind Orla, in the lead photo of this article, for example. And if you look at the plate of crackers on the table at the restaurant it’s positively oval (in reality, it was round, the distortion is particularly harsh at the edges).

Although a wide-angle lens is certainly not a portrait lens, the distortion means that when you want to shoot a subject, they are going to have to be at or near the centre of frame, which is pretty restricting in terms of composition. This is pure physics, and there’s nothing Sigma can do about it, it takes that short a focal length to get a wide viewing area on a small-frame camera. But it’s worth keeping in mind if the main purpose is for indoor use.

Grande Arche

The second problem is that because the viewing area is so wide, the camera’s metering system (and you!) has to do a lot of work. There can be huge degrees of variation in the exposure levels across the shot. Notice the over-exposed sky in the lead shot, or Simon’s white shirt in the group shot at the tables. Again, this is physics, there’s nothing Sigma can do about it, but it is worth keeping in mind that learning how to expose properly, having a 9-point (or more) in-camera metering system or getting a hand-held meter will be what makes the real difference with this lens.

Off the cuff and photo-journalistic shots will tend to have some of the scene blown out and overexposed. That’s not always a bad thing, it’s a valid and distinctive look (most of Donncha’s photos are shot like this), but if you prefer a more naturalistic capture it might be worth thinking about it.

Since I upgraded to a full-frame camera, I’ve sold this lens to Colin, who’ll make good use of it, but it definitely made a useful part of my collection while it lasted. It wasn’t anything like the lens I used most frequently, and it wouldn’t be at the top of my shopping list if I was building a new set. As a wide-angle for a digital SLR, it is very good – and presently has no competition, and if you know how to use a metering system it will reward you with excellent photographs.