Canon 70-200 f4L IS unusable at f4

Marc dbr wrote:

Hi all,

I went out and shot some foto's of planes at the airport of Amsterdam this afternoon. First I shot wide open with my 70-200 f4L IS on a 5D mark III, but after looking at the images on the back of the screen I noticed they weren't really sharp. So I decided I'd bump the aperture up to f8, and was happy with the results there. Once back home, I reviewed the images in Lightroom and ended up trowing away all of the images take at f4... Below are a few of them, straight out of camera, with standard Lightroom profile and 25 sharpening.

I did apply AFMA to this lens so that is not the issue... I have been noticing the lack of sharpness at f4 earlier already, and it makes me want to sell it to buy the 70-200 f2.8L IS II. I also thought this f4 lens was considered to be tack sharp even wide open! BTW I also have a 16-35 f4L IS and that lens is stunning at f4 across the whole frame. I would like to hear your thoughts about this.

Marc

The last one is one shot at f8

Marc.

I carried  my 70-200 f/4 L IS along with my 16-35 f/4 L IS and 24-70 f/4 L IS last month to Amsterdam. Looking back at images I see consistency through out all three lenses.

Having never MFA any of my lenses, mostly because I would be so anal about it, I can't really comment on that. You may want to consider sending it in to Canon to at least have it looked at.

Funny you mentioned the 70-200 f/2.8 L IS Mark II. I have been leaving it at home as I have been traveling quite a bit to Europe lately and more so in the future. Since my 16-35 f/4 L IS and 24-70 f/4 L IS were f/4, do I really need f/2.8 in the 70-200 range? Will I see dramatic loss of image quality? I now only bring the f/2.8 L IS Mark II on location when I absolutely need it, like weddings for example.

And the weight difference is drastic.

I let  the job determine which 70-200 to bring. Sometimes my back and shoulder tell me also.