100-400 Sharper than 300 f4 !!

Has the 300 got a filter on? If so can you try with it off?

The 100-400 is a quality lens if you have a sharp copy, which most new ones are.

I'll pipe in and agree with the person who says the shots are overexposed. You're clipping those highlights pretty severely and that ruins the test. Try it again and dial down the EC -1/3 and see if the exposure is right, if not go down to -2/3. Then back up the tripod another three feet just to make sure you're not inside the MFD of those lenses. Also try one comparison using manual focusing just to rule out the 300 f/4 perhaps back or front focusing. If it is this test will tell you and you'll have to have it calibrated.

No filter on either lens

I do believe that I have a sharp 1-4 copy so I'm not surprised that it would be hard to beat, but the 300 should.

I'll have to try again with a better exposure and a few with manual focus.

Thank's for the input.

Well I took some more test shots tonight and I uncovered a focusing issue with the 300 even though the battery and ruler test I did look fine, much closer though, but the 100-400 still looks a slight bit sharper. I ended up taking about 50 shots trying to get good examples and narrow down the focusing issue. I tried manual focus on a bunch of shots but they all came out OOF ?? I wear eye glasses, maybe that was throwing things off ? The boxes are staggered at 6" intervals. The (F) is the focus point, center only, followed by 6" back, 12" back and 18" back. The camera was set up aprox 50' away and the boxes measure 3 1/2 inches square. For the 100% crops below I threw the focus off between shots and re-focused then picked the best of 3 for each lens. I realize that the 1-4 will have a greater DOF. The 300 focus looks to be off by 6-12" but those boxes are still not quite as good as the 100-400, or am I being too picky ??

300mm f4
wide open @ f4

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Def looks like a focus issue. Also, look at the horrible bokeh of the 100-400 image. Yikes!

Get the 300/4 fixed and try again.

My 300/4 is one of the sharpest lenses I own (alongside the 135L and 85L).

Also, 3 1/2 inches at 50 feet is a bit much. Not too many lenses will do well with that. The 100-400 looks good besides the bokeh and color. The 300 has it's number there. I'm shocked at how good the color is when using my 300, even with the Canon TC. Any focus isse will usually make the entire image softer.

Here's one from my 300 F4 IS + 40D, wide open and hand held in AI Servo mode(all focus points) on a motorcycle, no post processing except exposure adjustment:

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That's sharp for a motion shot for sure. I guess I'll see what Canon can do with it. The 100-400 is capable of some nice bokeh though..............

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Very nice!

Diver-Down wrote in post #6067426
That's sharp for a motion shot for sure. I guess I'll see what Canon can do with it. The 100-400 is capable of some nice bokeh though..............

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Nice shot

Diver-Down wrote in post #6067059
Well I took some more test shots tonight and I uncovered a focusing issue with the 300 even though the battery and ruler test I did look fine, much closer though, but the 100-400 still looks a slight bit sharper. I ended up taking about 50 shots trying to get good examples and narrow down the focusing issue. I tried manual focus on a bunch of shots but they all came out OOF ?? I wear eye glasses, maybe that was throwing things off ? The boxes are staggered at 6" intervals. The (F) is the focus point, center only, followed by 6" back, 12" back and 18" back. The camera was set up aprox 50' away and the boxes measure 3 1/2 inches square. For the 100% crops below I threw the focus off between shots and re-focused then picked the best of 3 for each lens. I realize that the 1-4 will have a greater DOF. The 300 focus looks to be off by 6-12" but those boxes are still not quite as good as the 100-400, or am I being too picky ??

Diver,

if your trying to do a fair comparison of the two lenses it doesn't matter that both are wide open, you need to have them at the very same F-stop not F4 on the 300 and F5.6 on the 400.

I can get my 85L and take a shot at F1.2 vs a 100mm F2.8 lens wide open
and the 100mm wide open @ F2.8 will look sharper in most cases but if I stop my 85L down to F2.8 and take another shot vs the 100mm wide open at F2.8 then the 85L will be the winner.

The 100-400 is no doubt an awesome lens but it's one whole stop slower wide open at 400mm so it's not really an even comparison.

Stop your 300 f4 to f5.6, that is the best your 100-400 would give you at 300mm then take some shots and see which one is sharpest. If your 100-400 is still sharper then you may want to send the 300 to be checked. Otherwise all should be fine.

In your test with the shell boxes the 300 f/4 appears to be front focusing. The grain in the wood on the edge of the table appears sharper than the writing on the closest box. Of course it's tough to be sure, but that's what it looks like. If it were my lens I would have it calibrated.