2.28.2010

Canon S90 goes cross country skiing at Windblown in New Hampshire



I spent two more days of skiing with the S90 in my parka pocket. Both days were at Windblown XC Ski Center in New Ipswich, NH and within eyeshot of snowcovered Mt. Monadnock. So far I have been shooting the highest quality and largest resolution JPEG files.  I'll check out RAW files sometime in the future.

Like most cameras, I find the S90 has a tendency to underexpose snow scenes.  Metering systems tend to underexpose snow because they are trying to convert a bright scene into mid-tones.  Unfortunately, when you underexpose white, the mid-tone you get is gray.

The easiest way to get whiter snow is to increase the exposure, using EV compensation.  I typically shoot scenery in the P mode, and I have programmed the S90's unique front ring (around the lens barrel) so I can adjust EV (exposure compensation) with it.

When on snow, I set the front ring at +1 EV. This adds one stop of exposure to the metered amount.  It makes the snow whiter, and dark objects against the snow, such as trees and people, become brighter.

The following are some examples.

Normal evaluative metering (If you don't notice the grey color of the snow,
put a piece of white paper up against it):

+1 EV makes snow whiter (Still a bit grey, but much better):

Having said all this, in the bright light that accompanies skiing and with polarizing goggles, it is often impossible for me to use the LCD and the histogram to verify that the exposure is reasonable, even when I have set the EV compensation at +1 EV.  For this reason, I have come up with an additional procedure.

I have customized the custom mode (which is then accessed by turning the command dial on the top of the camera to "C") to provide me with instant three-shot exposure bracketing.  I set up my custom mode to shoot in P-mode, auto ISO, auto WB, no flash, center focus, evaluative metering, and exposure bracketing. I have the three-shot bracketing set up to shoot at 0 EV, +1EV and +2EV. I download everything onto my computer at the end of the day. I then pick the image I like best of each set of three, and delete the rest.

For what it's worth, the small free-spinning wheel on the back of the camera adjusts ISO in the P mode.  I usually keep this set at AUTO ISO. In low light situations, the camera will bump up the ISO as far as 1600 if necessary, though when outdoors on snow the ISO will generally remain at its lowest level of 80.

All these settings work nicely for me, as long as I don't inadvertently nudge the spinning wheel on the back of the camera.  I find it interesting that on the larger G-series cameras like my G-9 (and I presume also on the newer G models) the spinning wheel has clicks on it.  This is preferable in my opinion and in the opinion of everyone I've read on various photography forums such as at dpreview.  My hope is that they will change this on the next version of the S-series.

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