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sigma-19mm-f28ex-dnJust published new review of Sigma 19/2.8 EX DN on Sony NEX-5n and Sony NEX-7


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Tagged in: nex-5n nex-7 sigma sony
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A new day and a new quick test. This time around we're gonna take a look at the UWA lenses for the NEX system. Sony E 16/2.8 was one of the first lenses introduced along the NEX cameras and so far is the widest lens available for the E mount. SLR Magic announced that it will start manufacturing its HyperPrime 12mm f/1.8 lens for the NEX camera, but so far it has been just waporware and the lens is not available anywhere in the world. Sigma's 19/2.8 EX DN is the only other wide angle lens for the NEX cameras and marks Sigma's official entrance into the race. We recently saw how well Sigma's other NEX lens, the 30/2.8 EX DN performed against its Sony competitor, the E 30/3.5 Macro, so obviously there is a tremendous interest in the 19mm lens as well. Can Sigma deliver better performance at a better cost again?

Before we begin, and before you flood us with thousands of messages, let's be clear that this is not really an apples to apples comparison - you can't compare a 16mm lens to a 19mm lens. Well, you can - that's what we're doing here obviously, but the comparison is biased in a couple of ways. Firstly, a 16mm lens is wider and hence at the same focusing distance will have different EFOV and different DOF. To solve the EFOV problem, we used a larger target with the 16mm lens, which placed the measurement areas roughly into the same place as with the 19mm lens. But only roughly - we can say that we measured MTF50 in the corners for both lenses, but the points of measurement were different between the two lenses - the variance of 10% in true distance from the image center to the corner points of measurement between the two lenses is quite probable. We can't obviously do anything about the DOF difference, so we just ignored this issue. Secondly, we can't really do anything about the variance in optical characteristics of lenses that can arise due to the difference in the true FL - for example we can't compensate for distortion to measure true resolution, so again, we simply ignore this. But not everything in this test has as much variance - vignetting and lateral CA measurements are, for example, more comparable than say raw MTF50.

So why are we doing this comparison, knowing all in advance that this is an apples to oranges comparison? Curiosity, which as they say, 'killed the cat' (please note that no cats or other animals were actually used or hurt in this test). More importantly, this test can give the foundation for intuitive guesses that many practitioners have been expressing in online forums - after all, if it looks like a duck and quacks like a duck, it's most likely going to be a duck. And so with that...

Tagged in: nex-7 sigma sony
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Today we're gonna do a quick comparison of Sony'e E 30/3.5 Macro lens against the new kid on the NEX block, Sigma's 30/2.8 EX DN lens. Sigma has just released two dedicated primes for the NEX systems (also available for the m43 platform) and based on the initial feedback from the user community, the new 30/2.8 EX DN is quite a performer. But really, how good of a performer? Let's check it out...

But first thing first. The two lenses are really targeting different segments of users - Sony's lens is a 1:1 macro while Sigma's lens, well, it's just a general purpose lens. If you're even remotely interested in macro photography, this comparison is useless to you - just go get Sony's lens. On the other hand, if you were considering getting Sony as a general purpose prime (given it's EFOV of 45mm, you get a normal-ish lens), than read on - you're the primary target for this review.

Even before we compare the actual resolution, vignetting etc. numbers, Sigma already holds an advantage over Sony - it's cheaper, lighter, smaller and faster. Sony sports slightly better build quality with aluminium barrel, but Sigma's barrel is just  fine as well - I managed to bump the lens a couple of times and it does not show any damage. It's not clear how well either of the lenses would survive a fall from say 3 feet, but whatever - few lenses would survive such a fall anyway.

Tagged in: nex-7 sigma sony
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