I was having an interesting discussion with one of the local camera club members recently. Now, I'm not normally too heavily involved in the "gear head" side of the camera thing, but the subject of high ISO shooting and camera noise came up. My camera club friend was exposing the virtues of being able to get high quality images at high ISO using his Canon EOS 5Dmk II.
Well, I'm not about to say the 5DMK II won't make a good image at high ISO, but I was totally willing to argue the point that high ISO shooting for day-to-day photography isn't all that important. Not so say that some photographers do not truly need the capability though. Concert venues and other poorly lit subjects, if a staple of ones profession, will require a very capable low light/high ISO camera. Still, my experience with weddings, events and landscape photography doesn't really present a challenge and I've found that I can shoot up to ISO 1600 and just about take care of everything I need.
But all this got me to thinking even more. As part of my discussion with the camera club buddy, I expressed the sentiment that 93% of all my photographs were taken at ISO 800 or less. Now, I was making an educated guess when I said this, as I hadn't really done the math. Then it occurred to me that the math is simple using lightroom. I'll just call up my master RAW arcchive going back to 2005 and I'll simply let Adobe Lightroom give me a count.
So, here are the results. With my photography, both private and in my business, here is the breakdown of ISO and my low light shooting needs. I'd venture that I'm doing about the same as most folks in this regards, but I have no way of calculating that.
For the sake of argument, I've put any shots above a base ISO in the next highest ISO category. IE, a shot taken at ISO 360 would be considered a shot taken at ISO 400 for this calculation. These calculations only include shots I've kept, not every shot I've taken. I can say though, the only shots I normally don't keep are unusable compositions, out of focus images, tests and duplicate scenes that are simply not needed. I'm using approximately 50,000 keeper images here. I've probably taken 3 times that many over the years.
ISO 100 = 9.56% I'm shooting at this iso roughly 10% of the time.
ISO 200 = 21.03% This probably wouldn't be this high if it weren't for the fact that my Nikon D300 had a base ISO of 200 instead of 100, which doesn't make a bit of difference in reality.
ISO 400 = 43.18% Almost half of my photographs are at this ISO. Reason is, that's where my cameras are set when I turn them on and turn them off. Best place to keep it imo.
ISO 800 = 14.1% Sometimes, I'm working in lower light. Just about any digital SLR on the market since 2005 will take a great image at ISO 800 unless you seriously underexpose your images. You can leave your camera at this ISO and it will cover about 85-90% of what you'll ever encounter.
ISO 1600 = 11.05% I shoot at this ISO mainly when I'm indoors doing a wedding in low light or a poorly lit venue. I'm typically using some fill flash and I'll normally be at ISO 400 when I'm using fill flash. There's no reason to go above this ISO in 99% of the photography you'll be doing. The only situations I have encountered are low lit scenes where a flash is prohibited. Seldom if ever does that occur. Any modern Digital SLR can handle it.
ISO 3200 = 1.08% I've probably shot fewer than 1000 photographs over the past 7 years at this ISO. Most of those probably weren't needed either and were just me playing around.
So, the bottom line for me is 88% of my photography occurs at or below ISO 800 and ISO 1600 will cover 99% of what I'm doing. I'm shooting weddings, events, sports, advertising, products, restorations, landscapes and just about anything else I can point a camera at. Because of my professional needs, I estimate that is possible my High ISO shooting requirements may be higher than a normal amateur will need. So, when you hear people talking about high ISO and the need to shoot in darker conditions, take it with a grain of salt. The need isn't that great and if you're making hardware decisions based in large part on what you think the higher ISO capability is of a camera, you're on the wrong page.