No, I'm not one of those guys who does the scientific testing with test charts or brick walls - I'm more of your 'real world' applications kind of tester for my own gear. So I set my tripod up in my lounge, pointed it towards the corner of the room, set the aperture to a middle-of-the-road f8 (should be pretty sharp around there), set my lens to a middle-of-the-road 50mm(ish), and fired away on all full ISO settings.
|Just a boring ISO shot - but hopefully a revealing one? Canon 1D MkIII with Canon 28-135mm IS USM|
Once I had taken all the shots (using the 2 second timer delay on the camera so camera shake shouldn't be a factor), I enlarged a portion of the shadow area by 200% and had a good look-see....
|The results at 200%|
These were all shot in RAW and then converted unaltered the high res jpegs using Adobe Lightroom. NO noise reduction was used in the process.
Probably not great at this resolution, but what do 'I' see? I see fantastic, almost noise-free results up to ISO 400, with just a hint creeping in at ISO 800. At ISO 1600 there is definite noise in the shadow areas, but it's quite a 'granular', film-like noise, and not the horrible banding type I was getting with the 50D. ISO 3200 is pretty grainy - but this is without any noise reduction, and I reckon it might clean up enough for a reasonable 8x10" print - plenty for a wedding album.
|Canon 1D MkIII @ ISO 3200 - 200% enlargement|
To put this theory to the test, I ran the 200% enlargement from the shadow area through my noise reduction software of choice - Noise Ninja. Above is the un-filtered enlargement, while below is the same section run through Noise Ninja.
|Canon 1D MkIII @ ISO 3200, filtered through Noise Ninja (default settings)|
Don't know why it's slightly darker (?), but anyway - it is definitely less noisy (albeit with a little less detail). These were the default Noise Ninja settings - I could probably get it looking even better with a little more effort :-)
So where am I comfortable shooting the 1D Mark III at in terms of high ISO?
|Canon 1D MkIII @ ISO 1600 - 100% crop|
Above is a 100% crop at ISO 1600, and this is probably where I would be happy 'pushing' the 1D MkIII to if I had to. Especially with noise reduction software added into the mix....
|Canon 1D MkIII @ ISO 1600 - 100% crop and put through Noise Ninja (default settings)|
So yes, ISO 1600 looks pretty good to me once it's all been 'cleaned up'. I wouldn't go there unless I 'had' to, but sometimes, especially during a wedding service, in a church, without flash, I do 'have' to. So it's nice to know that I can.
If the Canon 1D MkIII had an auto ISO feature (it doesn't), I'd probably let it roam between ISO 100 and 800 without a second thought. But I prefer to choose my ISO's anyway, so I will go up to 800 in a church no bother - and 1600 if my shutter speeds need the extra boost. Without comparing the two cameras side by side (which I may do later), I feel that the 1D MkIII is giving me better ISO performance than the Canon 50D. What noise there is, is much 'cleaner' in the 1D MkIII - probably not surprising given its larger sensor and smaller pixel count. Sometimes 'more' in terms of pixels, isn't always better - especially when they are crammed into a smaller surface area.
Overall, I'm very happy with the ISO performance of the 1D MkIII. It reminds me of the high ISO's on my full frame 5D - again not surprising since they are contemporaries of each other (both released around 2007/2008). Sure, it ain't no Nikon D3, and the APS-C Canon 70D would probably eat it for breakfast. But I'd rather have a 1D than a 70D anyday, and even when I've got the performance, I always try to shoot at the lowest ISO I can get away with - period.
So it's a thumbs up for ISO performance with the 1D MkIII for what I will use it for. I'm sure some more 'real world' examples will follow and the proof will be in the next pudding (oops, I mean wedding).