400mm f5.6L vs 70-200 f2.8L+2x TC tests

[Lionheart]

Gave my new (slightly used found on e-bay deal) 400mm f5.6L a spin and tested against my not so handy-dandy 70-200 f2.8L IS +2xTC @400mm. Shot on a 1D Mk II, Large jpg mode, ISO 200, lenses mounted on a Manfrotto tripod.
First the large picture with the close up circled in red, then the closeups shot at f5.6. f8 and f16. Interesting that f8 seems to be sharper on both lenses than wide open and f16.
Wish I had the 100-400 f3.5-5.6L IS for comparison. Aw, shucks, I wish I had the 400 f2.8L IS and the 400 f4 DO IS for comparison, but I need a winning lottery ticket for that.

[another view]

A zoom with a teleconverter used to be a big no-no, but some combinations are designed to work together now. It's gotten much better, and the results you have with it would suit a lot of uses. Much better than not getting the shot!

A prime will still probably always beat a setup like this though. Far as aperture goes, I used to have a manual focus Nikon 300 f4.5 which was very sharp. It was best at 5.6 or 8, almost as good wide open - but horrible at f32, worse than these!

[walterick]

Leon,

These look really good. I love to see competent side-by-side testing done!

I must say I'm a little surprised to see the prime pull way ahead of the zoom w. TC. It makes sense, but I guess I expected more out of the stacked up combo. I had a Sigma 400 5.6 APO that I used for a while. It was a great, light lens but not that outstanding optically. It was hard to backpack with too because of its size. While at a gear show one day I found a guy selling a Nikon 2x teleconverter and he offered an even trade. The deal seemed slightly stacked in his favor but I was tired of carrying around a 400mm lens so I traded it. Now I can double my outstanding 180mm 2.8 and get results similar to the 400mm Sigma. I haven't regretted it.

I personally call f8 the "magic aperature." If you look at lens tests the sharpest aperature for almost all lenses is f8. With exceptions, but if f8 is not the sharpest aperature it's 5.6 or 11 (sometimes 16) so shooting at f8 is a great idea all around. I shoot f8, tripod, mirror lockup when shooting landscapes as I am certain to get great results doing so.

I like your tests! If you ever get your hands on some simiar gear, be sure to test it too!

Rick

[paulnj]

GUYS, the sweet spot on most lenses is OPEN 1 STOP hence the reason that F8 was the sharpest on both setups ;)

[walterick]

Open one stop? You mean closed?

I dunno Pauly, I think there's a lot of evidence out there suggesting otherwise!

By that same criteria, that would mean that my 50mm 1.8 is sharpest at f2.8? Or a 1.4 sharpest at f2?

[paulnj]

OPEN, CLOSED you know what I mean? I am tired when I post

you don't need to believe my MOST comment , only remember it in the back of your mind

the 50mm lenses break the norm. those things are a joke to perfect after 50 years of making them ;) My experience with a 50 is F4-F8 being the sweet spot.

[walterick]

I hear ya bro. I don't really discount anything that I hear. It gets filed away, under "waiting for more empirical evidence." I really do respect your experience just thought I'd give ya a little push there buddy ;)

Rick

[paulnj]

found this quote on the OTHER photo site through google

"The sharpness your lens is capable of achieving varies widely as the aperture size changes. If the aperture is too wide, the lens is most subject to loss of sharpness from lens aberrations. If the aperture is too narrow, sharpness will be lost due to light diffraction. Each lens has a “sweet spot”: a middle point in the aperture size range where it is least affected by aberrations on the wide end and diffraction on the small end. This range varies by lens model, but is generally somewhere around f/5.6 and f/8. By placing your aperture within the f/5.6-8 range, you will have the potential for achieving sharpeness far beyond what is possible at such apertures as f/1.4 or f/32. "

Ifind this to NOT apply to a F5.6 max aperture setup though Had the test been done with a 400F4 DO(dog optically for the price BTW) it would apply.

For instance my tokina 400 and 100-400IS are sharpest in the F7.1-F9 range to me. But also keep in mind I want JUST enough DOF to suit my purpose most of all ;)

MTF scores will tell all though ;)

[Photo-John]

I've always found that two stops down is where the sweet spot is. I learned this from printing with enlarging lenses. I'm talking about the aperture on the enlarging lens, not on the lens that tooks the picture. The problems at both ends of the aperture range are much more obvious when you're considering print quality. When you print with the lens wide open, you get falloff - vignetting and the edges of the print are soft. When you stop down all the way, the image is evenly and sharply focused, but the grain is soft because of diffraction. The sweet spot is where the lens gets a nice even, flat field of focus, but you minimize diffraction. Of course, there are other variables. You might need maximum depth-of-field. In which case you'd sacrifice some overall sharpness. Or you might need to use a large aperture to lighten up your exposure. In which case you'd sacrifice some edge sharpness to get a good exposure. Photography is a game of compromises. But it's good to be aware of these variables so that you can have more control and make informed decisions about how to stop down. The more you know, the better your pictures should be.

[Photo-John]

I just checked your profile page and only saw reviews for the EOS 10D and the 1D Mark II. You haven't posted any lens reviews yet. We need those reviews. And you know there's a contest this month. Since you've done that testing, your reviews will be even more valuable. You could even include links to this discussion in your reviews!

Post 'em, buddy!

[Lionheart]

I just checked your profile page and only saw reviews for the EOS 10D and the 1D Mark II. You haven't posted any lens reviews yet. We need those reviews. And you know there's a contest this month. Since you've done that testing, your reviews will be even more valuable. You could even include links to this discussion in your reviews!

Post 'em, buddy!

I should have a few more than that, but that was before the big makeover of the site, and I had to re-register myself as I was one of the few that got lost in the change. But I'll start posting on the lenses in my current arsenal.

[Photo-John]

I should have a few more than that, but that was before the big makeover of the site, and I had to re-register myself as I was one of the few that got lost in the change. But I'll start posting on the lenses in my current arsenal.

I wondered if that might be the case. I think we'll be keeping this current registration system for a long, long time. So in the future everything you post should stay attached to your profile. I think I can actually associate old reviews with your current profile. Tell me what you posted reviews for and I'll see what I can do.

Thanks!