Sony a 9

[arthurking83]

.... You assume the Sigma lens will be better just because it is heavier. I doubt that, but I'm sure there'll be plenty of reviews over the next weeks and months.

Not really better because it is heavier!

Sony have the advantage in that they're designing a lens for their own system, and it's well known that they use the camera's internal software to enhance the optical performance of their lenses .. ie. things like distortion and vignetting tweaks that can't be unedited out of the image if you use mainstream software. Olympus and Panasonic do the same thing.

Sigma don't have this luxury! The need to make their lenses vignette less so by actually designing that ability into the lens, no favours from Nikon and Canon on that front for them ... so invariably the lens will have to be much larger. Larger = heavier!
Same with distortion. Sony have the luxury to compromise on raw distortion performance, use the in camera software to process that distortion out and concentrate on designing the lens smaller and maintain a high level of IQ at the corners.


The 16-35/2.8 comparison is a more pertinent indicator on the topic of lens backfocus distance .. as we do have direct like for like comparisons to work with.
And looking at the equivalent Canon lens's physical specifications, there's nothing in it .. even weight is not worthy of a mention as a difference.
That 80 gram difference is almost certainly due to the Sony's unique focusing mechanism(they have an interesting linear electronic contraption that does away with large heavy ultrasonic ring motors).

What is surprising about the 12-24(more so than the 16-35) Sony lenses is the price. That's a very good price on a new lens design with those optical specs. It's very close to the Sigma, and Sigma have three brands of cameras to market it towards(ie. higher potential volumes!)

[Steve Axford]

If you could correct any optical imperfection of a lens with software, we would all be using mobile phones. The optical performance of a Sony lens may have small imperfections corrected with software, but nothing major can be "corrected: without introducing other problems. Good luck to them if they can do it, but I suspect that mount features and chip design have far more to do with it than software. It would be interesting to see how these lenses perform across the range of A7 models.

I find the 12-24mm a little tempting because of it's weight. The whole idea of a zoom (for me) is convenience and heavy lenses are not convenient. If the 12-24mm looks like being a sufficiently high quality lens, I may be tempted to get one. The 16-35 will be a great lens, I have little doubt of that, but it is expensive and I have the Zeiss Loxia 21mm and it won't be as good as that.

As for the dynamic range of the A9. Interesting, and I would guess that DPR are right in assuming that it is a trade off for speed. Can't say it would worry me much as the ISO invariance kicks in at ISO 640. The A9 strikes me as a specialist camera that is released for bragging rights and to catch a few sports photographers so Sony appear on those Olympic games pics of lined up photographers. The chip design is very interesting though and it points towards future advancements where speed isn't so important. As has been pointed out, few of us would ever want to use 20 fps. I suspect that it won't be all that long before Sony releases a high res camera using an A9 type chip together with a good telephoto prime. Maybe I'll get one then, but probably not. Good telephoto primes cost as much as a small car. However, I could use a camera that can track a moving subject in very dim light, say a platypus at dawn in a forest. Impossible at present, but in a few years?