Daily Archives: Saturday, 24th Feb 2007

Pictures, 23 February

And here, in record time, are the pictures from yesterday’s little walk. I went past the Westgate House site, then past the station and into the Centre for Life before returning past the station. There are some moderately interesting pictures, including a few that demonstrate what I was talking about earlier in relation to that depth of field thinginess. More soon. Or soon-ish, at least.

Canon EF 50mm f/1.8 ll Lens

Well, I’ve had the Canon 30D for seven months now, and in that time I’ve taken a few pictures. Well, a couple of thousand, some of which I’ve shared with the Losing it[1] audience[1]. And I’ve been very happy with it, too.

Of the two lenses I bought, I mostly walk around with the actually rather nice Canon EF-S 17-85mm f4-5.6 IS USM[2] rather than the Sigma zoom, which only comes out of the bag occasionally. It’s a very nice general purpose lens, whose only significant limitation is that its maximum aperture of f/4 isn’t quite as wide as one might like. But good wide aperture lenses don’t come cheap…

However, Canon do make this little beastie. It’s the cheapest lens they make for their SLRs, and the cost is reflected in the build quality. Compared to the big and really quite heavy 17-85mm, it’s very small and light, and has a very plastic feel to it. Even the lens mount is made of plastic rather than metal as on the more expensive lens. And the focus ring is a very small thing indeed.

But, and it’s a big but, what we have here is a 50mm prime lens with a maximum aperture of f/1.8 for around £65. I read a lot of reviews before buying it, and the consensus seemed to be that it’s optically pretty damn good, and that so long as you’re not rough with your toys, the build quality isn’t really an issue. Canon do make more substantial wide aperture lenses at significantly higher prices, so if you need something more robust, you can ignore this lens.

Now I can see I’ve lost some of my readers already, so I’ll explain a few things in distinctly non-technical terms[3].


What’s that then? A prime lens is quite simply one with a fixed focal length, in this case 50mm. Unlike a zoom lens, if you want to get closer to something, you’re going to have to move yourself and your camera rather than turning the zoom ring. This might sound like it’s not a Good Thing, but optics are funny. To get a lens to perform well throughout its zoom range turns out to be tricky, and in general, a lens made for a fixed focal length will produce a better image.

f what?

OK, I’ll keep this simple[5]. Those f numbers are a measure of how wide the hole is that lets light onto the camera’s sensor. The lower the number, the wider the hole. The wider the hole, the more light gets in, which means that you need to open the shutter for less time in the same lighting conditions. Also, a wider aperture, as the hole is more usually known, means you get a shallower depth of field.

Depth? What’s this about fields?

Depth of field is the proper name for describing how much of the image is in focus. A deep depth of field means that pretty much everything from very close to as far as you can see is sharp. A shallow depth of field means that the actual subject should be sharp, but closer and more distant objects will be blurry. This is often just what you want – it’s a common style for portraits, and can produce some really interesting images.

Anyway, understanding all that, I decided that my camera had been very good, and it was time I bought it a present. I shopped around a bit, and at the time, Amazon had the best price I could find, especially with the free delivery option. So I ordered it on Tuesday, and it was delivered to the office on Thursday while I was in London. I took it out for a walk on Friday, and had some fun, the results of which will appear once I’ve sorted through them.

So far, though, I’m quite impressed. It’ll never replace the 17-85mm as my main walking around lens, but I do plan to make more use of it. It was interesting to have to take a different approach to my photography – having to move closer to something (or further away) to frame the image I wanted was quite different from my usual approach. OK, I usually move around, but not that much. Not a bad thing at all, and it definitely encourages me to think more about what I’m trying to do, which might just improve my photography. Which would be a Good Thing. It was also fun playing with that wide aperture, stopping it down a bit from time to time, but mostly leaving it wide open.

[1] Hint: click on Gallery in the heading
[2] Prehistoric link removed
[3] More photographical readers[4] may wish to look away, or laugh…
[4] Hi Sam :wave:
[5] Only way I’ll understand it :lol:

Old Gateshead Pictures

iSee Gateshead is cool, or rather will be cool once they’ve fixed a wee problem. It’s a huge collection of old pictures of Gateshead running from some time in the 19th century up to the 1990s. You can search by various categories, and where it’s known, there are details of when each picture was taken.

The site is run by Gateshead Libraries with National Lottery funding. Nice to see my money going into something that’s useful to me. :grin:

However, there’s a bit of a problem with the site. Some of the pages I looked at were fine, but clicking through to the “Structures” category proved to be a bad move. Neither Firefox nor Internet Explorer wanted to know, really. Now my PC isn’t all that powerful by current standards, but it’s never had trouble with a page of thumbnail images before. And it’s certainly never had to use 2 gigabytes of virtual memory to render a page before. From the part of the page I managed to look at, I could see two problems:

  1. There were well over 200 pictures on the page. I’ve no idea how many, as I couldn’t get to the bottom of the page. Oddly, some other categories were nicely paged, with only about 20 pictures
  2. The “thumbnail” images weren’t. They were the originals, resized by the browser. So instead of being around 10k or so each, a typical thumbnail was over 300k. Some might have been bigger.

The site has been generated by a specialist application called TriO. I can only assume that someone at Gateshead didn’t tell it what to do correctly. I’m going to contact the relevant department and ask them to fix it.

In the meantime, it’s worth a look. But if you’re looking under S, don’t click on “Structures”….