My 800/6.3S PF lens is about to ship and I wanted to make sure I need it. (LOL) Since I photograph birds a lot, focal length, handholdability, and close focus are all especially important. As usual, I take testing too seriously and am providing way too much detail, but here are the results from my comparison of three lenses that can reach 800mm.

I had hoped to do the test outdoors so I could have a lot of distance to the target, but the recent addition of a pool in the backyard has created a thermally unstable atmosphere back there. The shimmering of the test target on the screen even with no magnification made it clear that was a non-starter. So I brought everything back inside down in the basement but, while the air is much more stable, I was limited to about 50′ as my maximum target distance. As you can imagine, with these focal lengths, there is no printed test target fine enough that they can’t resolve at such a short distance. So, I just used a generic little target I picked up at NAB and judged the lenses based on their ability to resolve the dots from the printer. Even though my tests did not produce any quantitative resolution numbers, the relative results are very obvious, and meet my need at the present. (My 3600dpi typesetter-printed test chart would have to be at least 280′ away for the finest lines to be unresolvable with these long lenses!)

The lenses I’m comparing are the 800/5.6E, 400/2.8S, and 100-400S at 50’ and 20’. The lenses were mounted on my biggest tripod, with my Gitzo stabilizing the lens where possible. I used a wired release and watched the image on the screen at the highest magnification so I could tell when the vibrations had settled. (VR off, of course.) Since I was indoors using studio lights, I used a fixed set of exposures to also detect any differences in transmission. And with the Z9, there’s no shutter vibration to worry about. I took anywhere from 3-5 frames at each setting to mitigate any lack of sharpness and intended to choose the sharpest in FastRawViewer, but there were no bad frames (!) among any of the sets.

The screen shots I include throughout my commentary were taken from Capture One. Of course, the images were straight out of the camera.

Here’s my setup:

Results:

This post is divided into two sections, first the tests at 50′, and then 20′. My comments are listed in order as I viewed the test images from each lens, and then summarized for 400mm, 560mm, 800mm, and 1120mm as a comparison among the different options at that focal length.

Here we go at 50′:

400mm – 400/2.8S vs 100-400S

At 400mm, the 400/2.8 wide open absolutely smokes the 100-400 at any aperture.  Contrast, sharpness are on a whole different level.

100-400S @ f/8 (best aperture)

400/2.8S wide open

400/2.8S @ f/4

I only tested at one stop intervals.  400/2.8 is better at f/4 than wide open or f/5.6. It would be worthwhile to retest the 400 at 1/3 stop to identify the exact best aperture.

560mm – 400/2.8S w/built-in TC:

400 w/TC is sharp and good contrast, but I don’t have anything to compare it to.  Seems best stopped down 1 stop (f/5.6), but barely.  Looks really good wide open.

400@2.8S @ 560 f/4

800mm – 800/5.6E vs 100-400S w/2x TC vs 400/2.8S w/2x TC:

800/5.6E looks good.  Definitely better at f/8.  Better contrast and sharpness.

100-400S w/2x TC looks OK wide open, but improves dramatically at f/16 (one stop) despite diffraction.

Wow the 400/2.8S w/2x TC is awesome!  Best stopped down to f/8 (one stop).  Really nice image.

Top left, 800/5.6E wide open, middle stopped down one stop.  Top right, 100-400S w/2x TC, stopped down one stop (best aperture). Bottom 400/2.8S w/2x, left wide open, middle stopped down one stop (best aperture).

Comparing all three @ 800.  Oh my!  The 400/2.8S w/2x TC totally destroyed the 800/5.6E!  And then there’s the 100-400S w/2x TC left in the dust by them both.

1120mm – 400/2.8S w/TC w/2x TC: (Yes, I forgot to put a TC on the 800/5.6E. Would’ve been interesting to try the TC800-1.25E matched TC, a TC-14E III, and a TC-20E III. Maybe next time?)

Wide open on top, stopped down two on bottom.

The 400/2.8S with both the built-in and 2x TCs was OK wide open, better @ f/11, and best @ f/16 despite diffraction.

There are my results at 50’. Very very impressive showing by the 400/2.8S at all focal lengths.

Now I’ll review the 20’ images:

The 400/2.8S is great.  Maybe a third of a stop dimmer wide open.  Excellent at f/4-f/8. Probably best at f/4, but very nice wide open. Same story with the built-in TC, but sharpest two stops down (f/8). Same story w/2x TC, and a tough call between f/8 and f/11 as the best aperture.  Probably have to go with f/11. 400/2.8S with both TCs, looks great @ f/11 (one stop) and f/16 (two stops) is another tough call.

400/2.8S w/2x TC wide open through f/16

The 100-400S is really good wide open, a little better at f/8, and then a little better still at f/11. The 100-400S takes the 2x nicely and stopped down one stop to f/16 it looks very good.  But it’s not bad wide open with the 2x TC.

The 800/5.6 is at its best stopped down one stop to f/8.

And a surprise entry:  70-200/2.8S w/2x TC. It seems fine wide open but better stopped down one stop.  And maybe better again at f/11, but only a little.

OK for the comparisons at 20’:

400mm – 400/2.8S vs 100-400S vs 70-200S + 2x TC

Here are the 400mm contenders:

Top row is 400/2.8S, wide open on left, f/4 (best aperture) on right.  Bottom left is 100-400S @ f/8, best aperture, and then the 70-200/2.8S w/2x TC on right at f/8, best aperture.

Clearly the 400/2.8S at f/4 is the best, but they’re all surprisingly close.

560mm – 400/2.8S with TC

No comparisons to share @ 560, but here is the 400/2.8S with the built-in TC engaged.

400/2.8S w/built-in TC stopped down one stop (best aperture)

800mm – 400/2.8S w/2x TC vs 100-400S w/2x TC vs 800/5.6E

And a surprise outcome, in my opinion:

Top left and center, 400/2.8S w/2x wide open and one stop down.  Top right, 100-400S w/2x stopped down one stop (best aperture).  Bottom 800/5.6E, left wide open and right stopped down one stop (best aperture).

My assessment:  The 100-400S w/2x at f/16 is as good as the 800/5.6 wide open. The 400/2.8S w/2X is the best of the three when they’re wide open. But, best sharpness and contrast came from the 800/5.6E @ f/8. Looks like some significant focus breathing on the 400/2.8S and 100-400S. The 800/5.6 really came into its own at the closer distance.

Final Words:

None of these lenses are slouches. The 100-400S made a great showing, considering its size and lower cost. The 800/5.6E performed very well, especially at the closer distance. And the 400/2.8S was great at every distance and at every focal length, or at least very good (1120mm).

So, which is the best lens? As always, it depends. But the 400/2.8S has dethroned the 800/5.6E from its place in my kit. Drastically lighter, and much more flexible, it can match everything the 800/5.6E can do, and do plenty that the 800 can’t, like for instance focus to less than 10′, versus nearly 20′. And all that without killing your arm or requiring a support.

Only two things remain to be seen now: How is the 400/2.8S for astrophotography, and how will the 800/6.3S compare?