Just for fun, I rattled off 10 images from the X10 at full zoom at a target that was about 5 feet away from me. I stabilized the camera by bracing my elbow, just as I would always do when attempting extreme low shutter speeds hand held.
I used as slight pressure as possible to release the shutter, but I did not use the classic stabilization trick of releasing using self timer. This would prevent the slight extra shake as your finger jabs, no matter how slightly, the shutter.
Both cameras shot at f/5.6 … obviously the X10 could shoot faster shutter speeds by opening the shutter, but this is an IS test, not a lens test. The X10 created brighter images than the F550 for some reason. It took .3s for 8 of the images and .4s for the first two, while the F550 consistently took .25s for all 10.
This, of course, was a limitation of the auto mode. The F550 would presumably have reached a tad higher for more shutter had it been able. I wonder why the X10 allows auto modes to reach for so much more shutter?
Bottom Line
The X10 gives you a 50/50 shot at a crisp image at 5 stops down. Not bad …
The F550 manages to raise that to a 60% chance. If you include usable images with only slight blur, then the X10 is 60% and the F550 is 70%. This is pretty impressive and outlines how important technique can be. If you learn to breathe slowly and to brace your elbow, you can get pretty crisp images at very low speeds.
One further thing … even the crisp images don’t look very crisp on the X10. Edges never quite settle down with this camera in jpeg …