Just for fun I decided to compare the focussing speed of a number of my lenses on my K3.I mounted the camera on a tripod and set up a target approx 20 feet away. I mounted my video camera to the tripod using a Manfrottosuperclamp so I could record how long it took from my pressing the 'AF' button until I got the audible focus acknowledgement.I took six readings for each lens. Three with the lens at infinity, and three from the minimum focusing distance.I went through each video clip frame by frame to find the time, as best I could.I make no claim as to this being a definitive, or accurate, test so be gentle with me :)What did I find ? The time from infinity to 20 feet were much quicker than from the minimum focus distance. Sometimes there was a pause, and a little 'jump',just before focus was achieved which greatly increased the time in some cases.Here are the results in 1/100s seconds:DA 300mm 14 18 20 101 101 113DA 200mm 13 14 10 101 28 28DA 50_135mm @135mm 21 16 11 100 22 22DA 50_135mm @70mm 17 15 10 27 23 24DA 70mm 9 10 15 16 15 15F 35_70mm @ 70mm 8 10 11 10 11 10FA 50mm 6 8 10 12 16 14I converted the DA 200mm to screw drive when the SDM motor failed for the 2nd time last year. The first failure was fixed under warranty several years ago.

タグ: focus, speed, pentax