K20D algorithms

qksilver · 06-25-2008, 03:14 PM

I am curious about the k20d algorithms for determining shutter speed in various conditions.

For example, I have noticed that in green mode, My k20 will go no lower than 1/50 or 1/60th at 50mm. when i zoom out to a wider angle, it will drop the shutter speed and lower the iso accordingly.

my question is this, i have noticed that switching shake reduction off has no effect on shutter speed. you would think that if it is really good for 2-4 stops, with SR on i could go down to around 1/25 at 50mm to preserve a lower ISO. so why does the k20 not act as though it knows SR is on or off and make shutter speed decisions based on this?

flyer · 06-25-2008, 04:49 PM

I can't tell you why it ignores the SR function (it might be inherited from a previous desing like the K110D, which didn't have SR), but, on automatic mode, it will always try to go for a shutter speed that makes the camera hand-holdable, taking into account the focal length. It is generally around 1/focal length.

Quicksand · 06-25-2008, 05:08 PM

If I had to guess, it's because "shake reduction" isn't called "shake elimination" for good reason.

Unless you're up around the usual safe shutter speeds, all it does is reduce the likelihood that you'll have visible motion blur, but it can never really eliminate it. By keeping the shutter speed up, the percentage of good shots is kept as high as possible.