High ISO Numbers and Compact Cameras
With advances in post production noise reduction technology it may be time to revisit the idea that high ISO settings and small sensors are completely incompatible.
I possess three point and shoot cameras, a newish Lumix ZS8, a Canon Powershot A3100 IS, and a much older Powershot, the A550. Up until yesterday I hadn’t used the A550 for several years. The main reason for this is that the camera doesn’t possess any form of image stabilization. Anyway, I got to wondering if there was any way to compensate for this fact now that certain things have changed.
1:1 crop from an Image taken with Canon A550 Powershot ISO 800 and post processed using Lightroom 3 to reduce the noise.
This exercise is more than just something dreamt up by a born tinkerer to while away a few hours. There are aspects of the A550 that make it a more comfortable camera than the two more recent point and shoots. It is a really easy camera to operate one handed, It has a normal viewfinder in addition to the LCD viewfinder and the gentle noise it produces at high ISOs is a lot more pleasant than the harsh jagged variety that seems to be a byproduct of image stabilization technology.
The easy one handed operation is due to it being chunkier than the later cameras and having a pronounced grip. Also the two AA batteries are housed in said grip causing the camera’s center of gravity to be in the hand and not at its opposite side. This stabilization alone is worth at least one and half stops over the other cameras by my estimation. A related factor is that the smaller viewscreen works in the cameras favor as non of it gets obscured by the hand when taking a photo.
The different quality of noise is very relevant here as the softer variant produced by the A550 is much more easily handled in post production than the harsher, jagged version. Lightroom 3.0 for example cannot really cope with the latter but does a really good job of taming the former. I don’t think Lightroom was even available when I was using the A550. The photograph at the top of this post is a roughly one to one crop, shot at ISO 800 with noise reduced in Lightroom 3. Now to my eyes, this is more than acceptable. With a bit more tweaking the noise could be completely removed but the resulting image would look plasticy. I’d rather leave a little noise in.
Another thing worth mentioning is that the A550 is respectably fast for a budget point and shoot. At an effective focal length of 35 mm it stops down to a respectable f2.6, almost a full stop better than my most recent purchase the Lumix ZS8 at the same efl.
Obviously the more recent cameras do have advantages over the now ancient A550 (in technology years at any rate). The two areas where the newer models are vastly superior are handling of contrast and close up/macro work. Even with this in mind though, by being prepared to go against the conventional wisdom that says high ISO settings on small cameras should never ever be used some very good results can be achieved. In the case that I’ve laid out two stops can be salvaged by taking advantage of post production software improvements and going from ISO 200 (considered the absolute outside usable for this vintage of point and shoots) to ISO 800. The better grip and balance is certainly worth at least a stop in one handed operation.
Here is something a little more advanced which won’t appeal to everyone but is worth a mention. The Canon Powershot A550 only takes JPG images but there is something that allows it it take RAW which, of course will work even better with any post processing noise reduction technology than JPEG. It is a piece of software that can be added to a memory card and gives the camera increased functionality. Saving images as RAW files in addition to the JPGS is just one extra function it adds. The software is available for many but not all Canon point and shoots. It is not available for other makes or for Canon DSLRs. Much more, including the download here: http://chdk.wikia.com/wiki/CHDK. Basically it is a matter of unzipping a file onto a camera memory card while the card is slotted into your computer and then starting the camera using the Play/Record button and scrolling down a menu to activate it. All settings are persistent which means that if you, say, select the option to create RAW files that will remain in place whenever you activate the software. If you understood this paragraph then it could well be worth having a play with this. Just in case you are worried about lasting damage this does nothing permanent to your camera. In otherwords if you were to put a different memory card in other than the one you unzipped the software on, the camera would behave exactly as it did prior to this little adventure. Furthermore you can use the memory card with the software on but without the software activated – In fact this is still the default.
One thing lesson that I got from all of this messing around is that, even if a camera has image stabilization, it is worth remembering that this can be turned off and that post production denoising is easier on an image with a higher unstabilized ISO than it is on a lower stabilized one. It is certainly different. I have only just discovered that I really like the grain produced by the Lumix ZS8′s 800 ISO setting, especially when the image is converted to black and white.
Finally a hat tip to Gary in Australia. It was his email, where he stated that his first camera was a Canon Powershot A550, that prompted me to revisit my old compact camera. Gary, if you read this I will respond to your email soon – honest!