Flat Images from 100-400L

I've had this lens for a couple of years and now that I have other L glass to compare to, the images from this lens on my 5D2 are always extremely flat and require a major curves adjustment and also seem to be lacking color. Is this common with this lens? Comparing this lens to images off of my 135L at the same focal length is just night and day. Wondering if I should take it up to Canon to have them look at it or if it's just normal? Also, I don't use any filters on this lens as I know it doesn't like them. I will be needing the 70-200 soon for my work, so I'm thinking about just bolting on a 2x on that guy and see if it's any better

Comparing the performance of a relatively ancient tele zoom with one of the sharpest primes available is a bit unfair. Primes tend to have better contrast overall. Newer zooms are bridging the gap.

aren't they coming out with a new 100-400L soon?

Canon_Shoe wrote in post #16638392
aren't they coming out with a new 100-400L soon?

Thar s the rumor. That was also the rumor 6 years ago. 3rd pastry makers are raising the bar in this class of lens so its likely to be true at some point.

My 100/400 is more than ten years old - shoots sharp as a tack. Plenty of contrast and no 'flatness' in the images - so, it's probably not a function of the 100/400 in general. I notice it needs a bit extra light under a lot of conditions tho ...

monkey44 wrote in post #16638424
My 100/400 is more than ten years old - shoots sharp as a tack. Plenty of contrast and no 'flatness' in the images - so, it's probably not a function of the 100/400 in general. I notice it needs a bit extra light under a lot of conditions tho ...

Mine does much the same. As long as I'm not comparing it to my135L.

Nice website Shoe, however judging by how you push the colors, I can perhaps see how you might find the 100-400L flat. I just checked through a bunch of 5D2 + 100-400 shots and don't find them flat at all, rather true to the reality of the subject when taking the shot. Since color rendition is optics and particularly lens coatings, I can't see how your copy would vary much, if at all, from mine. Exception maybe being a pre-2005 copy after which I suspect Canon enhanced the coatings on the sly, however having had both pre and apre 2005 copies I don't think that would account for your complaint. That said, a RAW image may appear a bit flat, but all the info is there and it doesn't take much to pull up whatever you want in color.

As for 2x TCIII + 70-200 2.8L IS II (on a 5D3) for 400mm, it's not bad at all, but I don't think it is quite up to a good 100-400L naked, though in some light it is close.

5D2 + 100-400L sample

John_T wrote in post #16638488
Nice website Shoe, however judging by how you push the colors, I can perhaps see how you might find the 100-400L flat. I just checked through a bunch of 5D2 + 100-400 shots and don't find them flat at all, rather true to the reality of the subject when taking the shot. Since color rendition is optics and particularly lens coatings, I can't see how your copy would vary much, if at all, from mine. Exception maybe being a pre-2005 copy after which I suspect Canon enhanced the coatings on the sly, however having had both pre and apre 2005 copies I don't think that would account for your complaint. That said, a RAW image may appear a bit flat, but all the info is there and it doesn't take much to pull up whatever you want in color.

As for 2x TCIII + 70-200 2.8L IS II (on a 5D3) for 400mm, it's not bad at all, but I don't think it is quite up to a good 100-400L naked, though in some light it is close.

5D2 + 100-400L sample

IMG NOTICE: [NOT AN IMAGE URL, NOT RENDERED INLINE]

It did take a short ride in the pacific ocean once in my backpack a couple of years ago, but seemed ok.......I can just take the same shot with the 100-400 and the 135 and one has real color and the other does not and looks really flat and lacks contrast

Short ride

It may be that you have a light residual film on some elements that would need cleaning by Canon. The film might not be visible in normal light, but an LED flashlight down the tube might show you something.

My concern is that you may not be making a fair comparison, in particular, by comparing images of different scene under different lighting.
Do a test comparing images of the same scene taken under the same lighting with your 135L and 100-400 at the same exposure settings. If there is a discernible difference, you may be on to something. You could even post the images here for us to ponder.