Sony NEX (Zeiss) 24mm ƒ/1.8 Sonnar Initial Experience
For a full picture of my views on the Sony NEX-7, and many high-res examples, see my in-depth review of the Sony NEX-7.
I have the Sony SEL24F18Z 24mm f/1.8 E-Mount Carl Zeiss Sonnar in for testing.
It was a frustrating experience today, and it will get a fair shot, but I have to vent a bit here.
First, I had difficulty with focus accuracy on the Sony NEX-7 with the Sony 24/1.8 Sonnar: the focus-by-wire electronic focus is frustrating as heck compared to a focusing helicoid; it has hysteresis going back and forth. Which means if you go a little too far in focusing and then back up just a little, it does not back up in focus by the expected amount, but by some variable amount. Drove me nucking futs trying to focus it manually. This is not technology in search of a problem, this is technology creating a problem.
Focus by wire might be OK for casual work shooting at ƒ/8, but for zoomed-in precision work, forget it unless you’re stopping down to cover the slop factor. (Focus by wire means that it’s all electronic, no mechanical linkage between turning the ring and the focus change).
So my test series was not focused accurately even though I shot it twice, once with manual focus and autofocus. When I relied on autofocus, it mis-focused just as badly, about 40 feet too far forward at a distance of 120 feet. Flush that 30 minutes of careful work down the toilet, except that I might show it anyway to demonstrate the problem. And that was on a tripod trying as hard as I could to get focus right. Another different series using autofocus did focus accurately, but it was at a much closer distance.
UPDATE: I wrote the above after a quick look. What I see now is that the Sony/Zeiss ZA 24mm ƒ/1.4 Sonnar apparently has a prounounced focus shift. It is sharp at ƒ/2.8 (the aperture at which I focused), and blurred at ƒ/1.8 and ƒ/2. It also appears to have quite pronounced field curvature. Unusual with the Sony NEX-7 is that it autofocuses at the aperture to be shot at (DSLRS always autofocus wide open). But it also means that if one focuses at ƒ/2.8, then sets focus to manual (no change in focus), then shoots at ƒ/1.4, the focus shift will be there.
The Sony/Zeiss 24/1.8 has unusually strong lateral chromatic aberration. As in stronger than many a lens I’ve used in quite some time, as if it were corrected for moderate LCA for a full-frame sensor, but someone forgot that the photosites on Sony NEX-7 are absolutely tiny, about 2/3 the size (linearly) of the Nikon D3x. While LCA is correctable, I find it troublesome to have to fix lens problems in my workflow. I make my images in the camera, not in the computer.
Add in the Sony NEX-7 ruination of images by accidental ISO changes, which forced me to redo work again today, twice, and I am becoming disillusioned with the NEX-7 as anything but a happy-go-lucky camera. The Dial / Wheel Lock = Control Wheel is a solution but I did not have the right setting. And then there is the diopter adjustment, which changes itself, is not marked, and is extremely difficult for me to adjust (I shoot with my left eye, very hard for me to get my finger on the tiny dial at the same time), I doubt that I will buy the NEX-7. It is plain that its usability in terms of “don’t ruin a shot” is not a priority. Yes, it is great fun with great results at times, as I show in my ad-hoc beach shots in my in-depth review, but too many booby traps for me to be able to rely on it. Oh, and it took some videos on its own today, as usual— another booby-trap button I tend to press without noticing.
In short, I am not feeling gruntled with my afternoon’s work. It will have to be redone, maybe more than once, given the issues.
I look forward to the Fuji X-Pro1 and it sure was a pleasure shooting my reliable and predictable Leica M9, getting perfect focus and seeing the world’s sharpest 24mm lens deliver the goods on full-frame (the 24/3.8 Elmar-M ASPH). Worth the money, for sure, because the M9 and M lenses deliver the goods with no nonsense, no camera-caused modes or accidents, which is the most important camera feature, as any pro knows.