Monday, November 12, 2007

High ISO Noise Comparison

I have already talked a little about the effects of high ISO noise in a previous post. And one of the reasons I wanted to upgrade from my Canon EOS 300D to my new 30D was it's alleged better performance at high ISO settings, plus the ability to choose ISO 3200 in really dark situations, whereas the old camera would only go up to ISO 1600.

So I thought it might be useful to take a closer look at some photos taken with each camera, and see if things really are any better in dim conditions.

EOS 300D - Sigma 135-400mm EF f/4.5-f/5.6 - ISO 1600

Back in December 2005, I went to see Saracens play Wasps away in High Wycombe. It was a fairly late kickoff, and being December, it wasn't long before the floodlights were on and things were getting pretty dingy on the pitch. Here's a picture of ref Ashley Rowden supervising the scrum:

[The ref's head is highlighted above]

The picture doesn't look too bad resized for viewing on the web. But looking at it at full resolution, you'll see what happens:

[The highlighted section shown at Actual Pixels (100%) size]

You can see that the skin tones show noticeable coloured noise, and the black areas are also very mottled. The whole image is fairly soft and not very saturated.

EOS 30D - Canon 100-400mm EF L f/4.5-f/5.6 - ISO 1600 / ISO 3200 (HI)

Yesterday, I was back to see Saracens play Glasgow at home in Watford. Admittedly with a different lens, but it's the camera body itself which is the biggest factor in image quality in low light. By the second half, the floodlights were on again, and this is the first shot we'll look at taken at ISO 1600:

[The Scrum Half's head is the piece to be enlarged]

Again, the photo above is good quality at web resolution, but I think there's a definite improvement at full size:

[The second highlighted section shown at Actual Pixels (100%) size]

This time, the blacks are cleaner and there is less obtrusive coloured noise in the skin tones. It looks noticeably sharper, and the colours are more vivid.

Here's another one, as it was getting even darker. In order to keep the shutter speed up, the only option was to increase the ISO setting, since I was working at the lens' maximum aperture, f/5.6. So I used the ISO setting on HI - which basically means 3200:

[The Prop's head is the bit we're interested in]

I'm impressed with the web resolution image - certainly crisp, clean and good colours. And closeup?

[The third highlighted section shown at Actual Pixels (100%) size]

Pretty impressive! I'd say 3200 with the 30D looks better than 1600 with the 300D. So I reckon it's been a worthwhile upgrade for that alone. Plus the fact the 30D is much quicker a writing images to the Compact Flash card - vital when taking a sequence of high-speed action photos. With the old camera, I would often be left frustrated after following the action up the pitch - I'd miss a try because the camera was still unloading it's buffer to the card!

Needless to say, rugby in the dark days of winter push the capabilities of a camera quite hard. The speed of action and low light are both factors which probably won't bother you too much if you just take a few holiday snaps or family pictures with your SLR.