4K is all the rage these days, and it will be a bit before the pricepoint for it comes down to typical consumer levels. This is what i find somewhat peculiar about the ax100, it seems distinctly geared towards the consumer market, yet it boasts a $2000 price tag, not very consumer-like for a camcorder. It seems to make up for this though, by including some more pro-oriented features such as full manual control, 3 ND filters, and extras such as exposure zebras and focus peaking. So who is this camera really for? If you're a high end consumer, it certainly fits the bill, but what about filmmakers, music video makers, and others who might want to use this camera in production level situations?
4K, it's a lot of detail
Had to put this item front and center, because without this feature, this would be mostly just another camcorder(albeit a good one). So, it's got the big 4K badge, but does it actually resolve all that detail? The answer is a yes, that same 20mp sensor from the RX10 has plenty of pixels to get a solid, fully resolved 4k final image. I do believe it has at least a bit of sharpening added, but it doesn't seem to be an objectionable amount
I usually save this for later on, but it's one of those questions many people ask when talking about a camera with 4k resolution: with such tiny pixels, is it limited for low light use? The blackmagic cameras have this limitation, but debatable because they don't employ in camera noise reduction like most do to give us de-noised high iso. The ax100 expresses it in db instead of iso, which is another usually consumer thing to do. (with some notable exceptions) It goes up to 33db, and i have to say, even at 33 it doesn't look utterly horrible if it gets you proper exposure, and i'd personally consider up to 18db very good. I think it may have some improvement over the RX10, though i could be wrong. As always, do your own testing to see what level of noise is acceptable to your tastes.
It's a step back, and one of my reasons for returning the camera. To be fair, there are more situations than not that it won't be noticeable for, but i like to do a lot of wildlife shooting of things like birds. Many don't sit still, and there are plenty of situations where rolling shutter can be apparent. I took it out to the skate park to see how it would fair, and as expected, it wasn't apparent for a good number of shots, but fairly significant in several others.
Using the optical and digital stabilizers can help reduce the effect, but not by huge amounts and not in every situation. It's one of those things that many folks won't notice in anything but extreme cases, and others will see it far more often. Each rolling shutter'd camera will have more or less of this negative effect, In cameras like the C100 and even the RX10, it's so low that i see it as a non-issue. With the ax100 it's notably worse, and hovers around that line of acceptability, and thus will ultimately be up to you, your needs, and your opinion on the matter. It might sound incorrect that it's worse than the RX10, being the same sensor, but remember: 1080 to 4k is twice as many horizontal lines.
Most cameras are built plenty well these days, i don't actually recall ever handling a camera of anywhere near this price range that wasn't at least acceptably constructed. It may not be solid metal, but the fit and finish feels quality as i've always expected of sony cameras. It isn't a brick of a beast like some high end DSLRs, but this isn't a DSLR, it's a consumerish oriented camera, and for that, and it's price tag, it feels solid. Let's move on to more important things.
The lens & stabilization
While i love the RX10 for its constant aperture, parfocal power zoom lens,(with of course the larger than EX1 size sensor) it has a few issues which keep it from being my perfect small camera unicorn: the optical stabilizer is OK at best, the active stabilizer introduces artifacts, and the zoom extension adds a wobble at certain angles which the stabilizer can't fix.That being said, with some warp stabilizer in adobe i can get what i've been missing in the larger sensor market: a usable power zoom that isn't astronomical in price.(A few sony E lenses are interesting, but don't hit the mark for me) So, when the ax100 was announced, i had high hopes for vast improvement in these areas over the RX10.
The ax100 has a Zeiss 12x optical zoom with an optional extension to 18x with the Clear Image Zoom, sony's 'high end' digital zoom. So we gain 4x optical over the rx10, but lose the constant aperture to a f2.8 at the wide, to f4 at the long end. It's not as wide as the RX10's 24mm Full Frame equivalanet, but it's still satisfyingly wide for most situations, and you can always get a fairly nice quality wide angle adapter for the 62mm front threads.
Something odd/surprising about that aperture range, i did a bunch of zoom in-zoom out testing to try and see the gain/loss in light, but for the life of me could not decsern much at all different from full wide to full tele. And yes, i double checked that all settings were in manual. This makes me wonder if either the rating of f4 is under-estimated, or the f2.8 over-estimated. Either way, if there is a light transition, it's very small and very smooth, which is a good thing for getting usable power zoom shots.
The fact that the lens does not extend solves the wobble issue over the RX10, but the optical stabilizer isn't a great improvement, its marginal at best. But what is a nice improvement is the active/digital stabilizer. It was confusing at first because the CIZ, which refers to digital zoom, is connected to the AIS. When enabled there isn't any indicator on the zoom bar that you're getting anything extra. This confused the heck out of me for quite a while, There's zero information in any of the sony documents about this, and only after digging around some forums, found mention of how it's differently implemented. See, with traditional CIZ/digital zooms, you get a zoom bar which starts with the optical, then when you reach the end of that, there's a line which represents the beginning of the digital zoom. Not with the ax100: instead, the CIZ is integrated with the optical zoom: as you optical zoom, it's very slowly digitally zooming along with it, giving you a very smooth constant 18x zoom, instead of the usual smooth 12x, then a bump, then digital. Pretty smart! It is a downside however that if you want CIZ or AIS, you have to have the other, they cannot be enabled separately. Thankfully though, the AIS seems to be a good improvement over the RX10, as i haven't seen any significant increase in artifacts, nor a significant loss in resolution in combination with the CIZ. The AIS does give a decent bit of extra stabilization over the standard optical, but it still doesn't feel on par with competitors. Also keep in mind that you'll lose a bit of wide angle with AIS/CIZ, as it needs to use some edge pixels for stabilization.
60mbit/s was a concern, but if prior 24mbit/s 1080 cameras were any indication, there was a good chance 60 would be pretty good. That seems to be the case, as i don't see any big issues with that bitrate, it handles motion pretty well. The main concern over low bitrates is high motion macroblocking. Long GOP codecs take a single frame called a keyframe, and base the encoding of several following frames off the changes from that frame, making it very efficient since it only needs to manage the changes. But if you're recording rippling water, branches blowing in the wind, etc...then it needs more data because there's a ton of motion changes. What happens if there's not enough data is you get chunks of pixels appear as blocks, which muddy up the image. It's not glaringly obvious, you see it all the time on videos compressed for the web, but if you care about your image capture, you should prefer to not have any of it. On the ax100 the effect is pretty well controlled in high motion, likely because by having 4x the pixels of 1080, the effect is effectively shrunk, becoming less apparent. It's one of those things mostly only technical people will spot and could only be demonstrated to a layman with a side by side.
Both are plenty satisfying, with enough resolution to make like reasonably easy for focusing. Being that my two other cameras are an RX10 and a C100, it was quite pleasant to finally get my hands on a fully articulating lcd screen! Sony has also been one of the best in terms of LCD usability in sunlight. I don't know what magical technology it is that they have that i haven't seen in Canon, Panasonic, etc.. But Sony's LCDs are very usable in even direct sunlight, and the Ax100's is no exception. The EVF is also very decent, not remarkable, but very usable, they could have included an eye cup, but there are plenty of aftermarket ones you can slap on there. Thankfully the EVF pops out, and can tilt up enough to make it comfortable for numerous camera/human positions.
Pretty much none. No kidding: The only control you have is a cinematone preset, which has no settings of its own. No sharpness/contrast/saturation controls. I'll say that the standard profile looks neutral enough to do some adjustments in grading, and the cinematone has a nice baked in look, but it's just bizarre to me that a $2000 camera lacks the basic controls that countless vastly cheaper cameras possess.
Face recognition: Say you're following someone around, and they're for the most part facing the camera, the camera can do a pretty good job of recognizing the face, and keeping it in focus.
Touch focus: Also pretty interesting, when enabled, it will focus on whatever you touch on the LCD.
Remote shooting: Connects to a tablet/smartphone and gives you a fairly low lag live preview. The downside? Zoom and record are your only options, all auto otherwise.
Sum it up
Let's see, we have a smallish camcorder with a larger than usual sensor, 3 ND filters, Zebras, Peaking, and shoots 4K. Those are the hilights, and all of them i personally consider to be rather prosumer. One of my issues is that despite its price tag and those features, it's a bit dumbed down in areas like image control. That coupled with the worse than i would prefer rolling shutter, equals a camera that's not right for my needs & preferences.
To be clear though: Despite a high price tag, it's one of the lowest price, very usable 4K cameras, and has features that the other 4k cameras in that price range don't have. So regardless of some downsides, it's one of the only games in town depending on your needs and preferences. Hence, you should get to your camera store and give it a feel.