Hi all,
This airshow season I have been having trouble getting keepers with my Canon 300mm/2.8 I IS lens. I usually use it with the 1.4x extender (version III) on two bodies, the 7D mk2 or 5D mk3. Normally, this combo is sharp as a tack, but the keeper rate has been very low this year. In the meantime I have checked it a couple of times using the Reikan Focal program (as I have been doing for years) and it comes out fine. The MF correction value is fairly stable and in that respect it seems to be doing fine. During the last airshows I switched to my Canon 100-400mm mkII and then I have tack sharp images again.
Does anyone recognize this issue and if so, what would you recommend? I can have it serviced maybe, but that's not exactly around the corner for me, so that's something that has to be planned if it should be the best way to go. I have also experimented without using MF values in the camera, but that doesn't change it either. It really seems to have something to do with the lens itself. Last weekend I was at the Belgian airshow, and again a low keeper rate. The keepers I do have are razor sharp as they should be, but where I would normally get around 80-90% keepers, I'm now down to 50-60% or so.
One thing I did notice is that shooting static objects is giving me better results, as well as slow aircraft passes. Can it be that there is something wrong with the image stabilization?
Any help appreciated!