Tuesday, January 18, 2011

A Tale of Two Lenses

When I bought my Canon T1i, it came with the "kit" lens, the Canon EF-S 18-55mm lens. As kit lenses go, it's not bad but I always figured I could do better.

That's the thing about SLRs - there is always a better lens out there, if you are willing to spend the money. The thing I always wondered was whether the difference would be noticeable.

I did some research recently and decided that I would like to purchase the Canon EF 50mm f/1.8 II lens. It has good reviews and is known to be a fast lens with good optics.

I went on Kijiji and found one for sale here in Winnipeg for about $30 off retail, and less than 6 months old. Lenses don't depreciate much so this was a pretty good deal. The seller was also selling a battery so I figured I'd get that too... always good to have a spare.

We met at the Forks and I had a look at the lens. It's tiny! I was satisfied with it so we exchanged cash and I went on my way. On the way out, I noticed that VIA 693 was backing into the station at 16:30, "only" about 6 hours late!

I headed over to CN Subway, and on the way shot CN 111 rolling past Canwest Park with CN 8932 and CN 2307 on the head end. This was a grab shot.
CN 8932 in Winnipeg at Canwest Park
As I went down toward Osborne I saw CN 8948 was the DPU unit in CN 111. I also saw an eastbound with CN 2663 and CN 2651 on the north track going by CN 111.

At Subway, there was an eastbound train waiting to head out. I think it was either 302 or 306. As an experiment, I decided to shoot it with both the 18-55mm lens and the 50mm lens. At first glance, the pictures look pretty much the same.
CN 8826 with 18-55mm lens
CN 8826 with 50mm lens
The top one was taken with the 18-55mm zoom lens, and the bottom with the 50mm lens. No editing was done on the images other than to crop the 18-55mm shot a bit and resize the images.

However, the devil is in the details. I shot both in shutter priority mode (1/200s) and the EXIF details show a little difference. For the 18-55mm lens, the camera used an exposure of f/5.6 and ISO 200. The 50mm lens earned an exposure of f/4.5 with ISO 100, showing the greater light sensitivity of the 50mm lens.

If you look closely at the images, the difference in detail is quite apparent.
CN 8826 with 18-55mm lens
CN 8826 with 50mm lens
Again, the top one was taken with the 18-55mm zoom lens, and the bottom with the 50mm lens, with no editing. You can see that the 50mm lens was quite a bit sharper when the image is magnified.

This is definitely a better lens than the 18-55mm lens. I don't think I will be using the 50mm exclusively, of course, since it doesn't have any zoom and is therefore less versatile than the zoom lens. However, I think for "whole train" shots the 50mm lens may become my preferred lens. Stay tuned.

1 comment:

Adam said...

I love the 50mm f/1.8. On a bright day, I can shoot ISO 100, 1/3200, f/1.8 and fast moving objects (trains, cars) look great, even on my humble Canon Xs.

The Walker Express