Am I expecting too much from the 100-400?

Am I asking too much from the lens?

you sure are!

I'll echo what Nighthound said. I find that my 100-400 us sharpest just under the 400 mark.

I've found it's much easier to get sharp shots of birds if I put them in the freezer for a couple of hours first.

The 100-400 is the bomb lens. Here are some samples the first is with the 17-40 just to see where I am shooting from then the next two are out of the camera un-cropped, 100 then 400

IMAGE LINK: http://www.flickr.com/​photos/jwtphoto/119119​88495/

IMAGE LINK: http://www.flickr.com/​photos/jwtphoto/119128​71456/

IMAGE LINK: http://www.flickr.com/​photos/jwtphoto/119124​31664/

With a 5dm3 and a 100/400, you can get another 160 out of it for $450 and add a Canon 1.4x ... that lens works very well with it, especially on the 5dm3 ... and x2 on no filter, not even sky or haze filter ... lens truly does not like filters for a reason I don't have a clue.

I think you're asking too much from the Laws of Physics.

You might want to consider one of the new Tamron 150-600 units. A Canon 100-400 and a 1.4TC will cost around $2000. The Tamron is $1069.

http://www.lensrentals​.com …150-600-telezoom-shootout

MCAsan wrote in post #16620641
You might want to consider one of the new Tamron 150-600 units. A Canon 100-400 and a 1.4TC will cost around $2000. The Tamron is $1069.

http://www.lensrentals​.com …150-600-telezoom-shootout

But he already has the 100-400, so for another $450 it adds the 1.4x ... if starting over, other lenses may make sense. And, then of course, you have a Tamron and not a Canon. And depends on what you shoot and what you want too ... at the pro level, it might make a difference - for the family or hobby shooter, it might not.

Some may think that makes no difference - I'd disagree. I've always found if you buy Canon with Canon, and Nikon with Nikon for example, you get equipment designed by the manufacturer for that equipment. That's just my opinion - over the years using equipment made by one manufacturer for itself.

If you are shooting from that distance you need one of these Cameras
I reckon this bird was around 500 feet away.

Taken at 17mm on the 7D

MCAsan wrote in post #16620641
You might want to consider one of the new Tamron 150-600 units. A Canon 100-400 and a 1.4TC will cost around $2000. The Tamron is $1069.

http://www.lensrentals​.com …150-600-telezoom-shootout

Your insane, The New Tamron 150-600 is proven to be very soft, its better to just get a 1.4x Extender

EricTober wrote in post #16618012
So I have had the 100-400 4.5 - 5.6 for about a month now and have had some success. But, some shots I feel should be more sharp. Here is a Kingfisher shot about 40 yards uncropped and then cropped. The cropped version is not as sharp as I think it should be held with a monopod. Am I asking too much from the lens?

YES.

monkey44 wrote in post #16619889
With a 5dm3 and a 100/400, you can get another 160 out of it for $450 and add a Canon 1.4x ... that lens works very well with it, especially on the 5dm3 ...

I recently tried the 1.4x III with my 100-400 and 5DIII. I actually found the non-TC shots cropped down to match the TC's FOV to be sharper.

DJHaze596 wrote in post #16621351
Your insane, The New Tamron 150-600 is proven to be very soft, its better to just get a 1.4x Extender

Was that meant to be a joke?

DJHaze596 wrote in post #16621351
Your insane, The New Tamron 150-600 is proven to be very soft, its better to just get a 1.4x Extender

Given the reviews done at Lens Rentals and what those of us that actually have one have seen, the lens has HARDLY proven itself "very soft".

http://www.flickr.com …s/snydremark/12​039369323/

It's not going to compete with, say, a multi-thousand dollar 600mm f/4 MkII, but I'd use *it* well before bothering to throw a TC on a 100-400. That's just silly.

also:
http://www.dustinabbot​t.net …-f5-6-3-di-vc-usd-review/