Hi
I am getting interested in the A550 as an upgrade to my A100. As I'm reading a lot of post commenting about the lack of MLU and if it is important or not, I have done some tests on my A100 to check the effect of using MLU or not. I know that the conclusions won't be valid for other cameras different from A100, but is the only camera I have for test. I suppose that the behavior of A550 no-MLU will be similar or better, but not worse.
I have tried the conditions that I consider a realistic bad scenario with the gear I have and the type of photography I usually do: Beercan at 210 (the longest lens I own). An old, not specially robust Velbon tripod. I have been photographing a portion of an underground map (9 x 6 cm) at a distance of 1.15 m. The shutter speeds range from 1 sec. to 1/125. For maintaining a constant f8 aperture I had to change the lamp position between shots. I needed also to change from IS0100 to ISO400 when passing from 1/4 to 1/8 shutter speed. I used a remote cable and waited > 6 sec. from shot to shot. I repeated each shot twice, but the results were always almost identical. SteadyShot off. JPEGs from camera (Fine).
The next picture shows a 1:1 crop of the central part (approx. 1/6 of the full width an height of each frame).
This experiment was only intented for me to get an approximate idea of the magnitude of the lack of sharpness due to not using MLU, which I previously ignored. I must say that I believed that the effect of camera vibration would be more evident without MLU, so I am a little less worried now. It seems to me that the worst results for no-MLU are obtained between 1/2 and 1/30 sec. I suppose that more difficult conditions (longer lens, macro) could make the effect of vibrations more evident. I also tested the effect of activating SteadyShot with no-MLU. Sadly, it didn´t provide any enhancement (it didn´t get worse, neither).
Vincent
I am getting interested in the A550 as an upgrade to my A100. As I'm reading a lot of post commenting about the lack of MLU and if it is important or not, I have done some tests on my A100 to check the effect of using MLU or not. I know that the conclusions won't be valid for other cameras different from A100, but is the only camera I have for test. I suppose that the behavior of A550 no-MLU will be similar or better, but not worse.
I have tried the conditions that I consider a realistic bad scenario with the gear I have and the type of photography I usually do: Beercan at 210 (the longest lens I own). An old, not specially robust Velbon tripod. I have been photographing a portion of an underground map (9 x 6 cm) at a distance of 1.15 m. The shutter speeds range from 1 sec. to 1/125. For maintaining a constant f8 aperture I had to change the lamp position between shots. I needed also to change from IS0100 to ISO400 when passing from 1/4 to 1/8 shutter speed. I used a remote cable and waited > 6 sec. from shot to shot. I repeated each shot twice, but the results were always almost identical. SteadyShot off. JPEGs from camera (Fine).
The next picture shows a 1:1 crop of the central part (approx. 1/6 of the full width an height of each frame).
This experiment was only intented for me to get an approximate idea of the magnitude of the lack of sharpness due to not using MLU, which I previously ignored. I must say that I believed that the effect of camera vibration would be more evident without MLU, so I am a little less worried now. It seems to me that the worst results for no-MLU are obtained between 1/2 and 1/30 sec. I suppose that more difficult conditions (longer lens, macro) could make the effect of vibrations more evident. I also tested the effect of activating SteadyShot with no-MLU. Sadly, it didn´t provide any enhancement (it didn´t get worse, neither).
Vincent
I see you had a nice trip in Northern Spain. The picture "Grilled sardines - After" certifies that 
Very nice pictures, and great legs! Congrats for your challenge-winner picture.