The general rule of thumb to prevent shake is to never shoot at a shutter speed lower than the reciprocal of the lens focal length. With the 300mm f/2.8, this would mean hand-holding the lens below 1/300 sec would not be advised. In this case, I wanted to see if I could get reasonably sharp images below a 1/30 of a second. Mind you, I'm not sure I'd want to shoot any assignment where the images had to count with this lens at such a slow shutter speed. However, I wanted to see what was possible.
My tests only took about 30 minutes total and therefore are only a casual observation about how shake reduction worked with this 300mm lens. However, I am pleasantly surprised that I was even able to hold the lens at shutter speeds of 1/8, 1/20 and 1/45 of a second and produce reasonably sharp images.
Another observation (that will require more experimenting on my part as well as other K100D users) is that it appears that SR works better if you hold a big lens somewhat loosely, versus trying very hard to grip the lens with your hands to eliminate any movement at all before you compose and shoot. This is pretty hard to describe, but so far I find that SR seems to work better when I refrain from using a "death grip" but simply steady the lens as best as I can and then let SR do the rest of the work.
Below are three sets of examples. In the case of my Bizen plate photos, I'm showing two samples each of results with SR "ON" and "OFF" just to show the likely reliability I might achieve by using SR with long lens at extremely slow shutter speeds. By clicking on the small images posted in this blog, you should be able to view a larger image where the blur or degree of sharpness is easier to see.
In summary, I considered testing SR with this 300mm f/2.8 lens somewhat of a "worst case" stress test, in that I'll likely never use the lens hand-held at an 1/8 of a second. However, it's nice to know that in a pinch, I could probably get away with shooting this lens at a shutter speed well below the old reciprocal rule!
Japanese Bizen Plate.
SR "ON f/8.0 @ 1/8 sec; ISO 400
SR "On": f/8.0 @ 1/8 sec; ISO 400
SR "OFF": f/8.0 @ 1/8 sec; ISO 400
SR "Off": f/8.0 @ 1/8 sec; ISO 400
Bottle Chateau Lafite: First image had SR "ON": f/2.8 @ 1/45 sec; ISO 800. Second image had SR "OFF": f/2.8 @ 1/45 sec; ISO 800. Hand Cream and Swiss Doll: First image had SR "ON": f/2.8 @ 1/20 sec; ISO 800. Second image had SR "OFF": f/2.8 @ 1/20 sec; ISO 800
