I have been plagued with blurred images while using my 55-250 mm lens at the longer focal lengths.
Examples:
and
I suspected camera shake, but with exposure at 1/400" I discounted that.
I was somewhat frustrated because I had taken many shots that morning and had to dump many which were otherwise nice images. I did not think that I could be out of focus so many times so I looked for some other cause.
I noticed that shots I took at 55mm were quite clear.
So I suspected something with the lens' ability to focus at long focus lengths close to 250mm; although this did not sound too convincing to me.
I had mounted a CPL on this lens, as I had been shooting in bright sunlight, so today I tried a test of about 12 shots with the CPL and 12 without all at 250mm. The results were very clear sharp exposures:
So clear pics without the CPL at 250mm. Is the CPL affecting the ability of the lens to focus sharply?