The 1200mm Sharpness Test

[scyrene]

Alrighty. I've done some more testing. I am beginning to distrust FoCal...it does not seem to be calibrating my equipment as ideally as it could be. I decided to do a quick and dirty AFMA check and tweak. I just set it at 0, -10, -20, +10 and +20. Took a few shots of the same target (lens and camera were on a tripod.) The differences were fairly obvious, +10 looked best. I tried +5, that looked slightly better.


The differences with the 600 + 2x TC OOC look MUCH better now. The birds are quite sharp strait out of camera, and they get very sharp with just a little sharpening. Below is a single photo from a more challenging burst of frames, as I was at 1/100th shutter...with a Chickadee. Anyone who's photographed Chickadees knows how ludicrously insane it is to try and get a sharp result at 1/100th second.


Anyway, managed to (with the limited 6fps of the 5D III even) get one frame that was sharp, at 1200mm f/10, ISO 800. I'm attaching three full size 1:1 scale crops, of the original image, sharpened only, then with a little bit of toning to bring down those highlights...just to reveal all the detail that is there. Personally...I'm pretty impressed at how sharp the 600/4 L II+2x TC III can be strait out of camera. My earlier softness was apparently just due to an improper AFMA selection by FoCal (that my extremely rudimentary and hackish approach handily bested.)

Glad to see you're a convert! I found the 2x III needed a big AFMA setting, but not the mark II fwiw.

 

[scyrene]

Alan, a couple of things. First, did you click on my images for full size?


Second, regarding the feet. I was at 1200mm f/10...working with a ridiculously thin DOF. My chickadees feet aren't sharp because they are not in focus. My goal wasn't to get sharp feet, though...it was to get the head and eye sharp. To that end, I believe, despite 1/100s, I succeeded. (I just wish he hadn't hopped from the beautiful pine branch to the tripod before I did! )


As for the sharpness of your shots overall...honestly, I'm a little disappointed. Maybe it's just the disheveled nature of the birds, not sure...but, I guess I kind of expected more out of that lens. The Canon 100-400 could get MUCH sharper than that...and I mean the OLD 100-400...

I have to say, jrista's shot shows quite a bit more detail, especially on the feathers. The second of AlanF's shows a hint of motion blur imho.

 

[scyrene]

Alright. Here is a set of shots taken with the 7D and 100-400 L (original). I grabbed a few, with birds of varying sizes in frame, to bring some diversity of pixels-on-target to demonstrate that isn't necessarily the issue with the 150-600. These are all original shots, original crop, no scaling, no processing, no sharpening or NR of any kind. Strait out of camera RAW exported to 75% quality JPEG from Lightroom. (Blame CR forums for links to images instead of just images...I don't know what it was doing, but it wouldn't let me post with them embedded as images.)


http://i.imgur.com/TiKthrU.jpg


http://i.imgur.com/Z2vWEQF.jpg


http://i.imgur.com/TSoCerX.jpg


http://i.imgur.com/ZBAK66E.jpg


Every image here appears to be sharper than the 150-600mm shots. To be fair, one of your shots seems to have some motion blur. For the other, I cannot say, not really sure if there is any motion blur or not, but it still seems a little soft. Not as sharp as either my 100-400 shots or my 1200mm f/10 chickadee. Now, don't get me wrong. I'm a fan of the idea of an affordable lens that reaches 600mm. For the novice or budget birder, I think having such a lens is a HUGE benefit. That said, if the sharpness from your example shots is around the best the lens can do at 600mm, then I'm rather disappointed. I'm happy to accept if the issue is technique, or too slow a shutter speed, or lack of IS use (or IS kicking in and screwing up the shot), etc. If you can demonstrate as much, then more power too you, prove me wrong! But, as it stands, I don't think the sharpness of those shots is what I would call "ideal"...I think my 100-400 does better, and my 600 with a 2x TC at 1200mm f/10 (!!) does better.

Those are good, especially number 4

 

[scyrene]

The Canon 100-400 could get MUCH sharper than that...and I mean the OLD 100-400...

First of all, the two shots of the chickadees are not necessarily the best I have or even representative of the lens but they are the only two I have of that North American bird (I am in the UK), but they are similar to your shot of the chickadee.

Secondly, the quality is comparable to those of yours from the 100-400, when comparing them side-by-side and certainly not MUCH less sharp.


I was never able to get very sharp shots with the old 100-400 on a 7D. Top is a dunnock at 400 on the 7D, typical of my efforts, below is a dunnock taken on the 300/2.8 + 2xTC III on the 5D3. They are chalk and cheese.

Second dunnock shows excellent sharpness as you say

 

[jrista]

I have some more examples to share. I'll try to get them up today. I think the 5D III is experiencing a little bit of diffraction softening at f/10+, and it seems aberration limited at f/8. Tough call there, but with sharpening, it cleans up pretty nicely.