Sony a7R II announced
-42 MP-4K Video
-5-Axis Steady Shot INSIDE Stabilization
-399 Phase-Detect AF Points & 5 fps Burst
-0.5" 2.36M-Dot XGA OLED Tru-Finder EVF
-3.0" 1,228.8k-Dot Tilting LCD Monitor
-ISO 102,400 and Silent Shutter Mode
http://www.dpreview.com/articles/8917769536/sony-alpha-a7r-ii-has-42-4mp-on-full-frame-bsi-cmos-sensor features look nice at 42 Mp I don't think I can hand held using RF lenses anymore..... 有無手動對焦ASSIST 呢下? From now on, photographic lenses belongsto world of Optus and Sigma ARTs :$ Too many MPs.Only viable if used with medium or large format lenses with adaptors. 呢部正呀！！！！ 希望快d有sample 睇 hands on report
http://www.stevehuffphoto.com/2015/06/10/sony-creates-a-monster-the-new-a7ii-r-see-my-hands-on-report/ 又要洗錢，希望快門聲改進，閃光同步有加速 Wish it comes with built-in flash in the next release. The shutter sound of M240 is too loud for me, maybe A7R II is good choice, but I care more about the image edge when using a wide angle lens. it's still using compressed raw if it matters to anyone..the thing with Sony is, it will be quickly outdated by the same time 6 months from now.. 希望像素戰到此為止，專注改良影像質素。 Did Sony just do the impossible?
Published Jun 22, 2015 | Rishi Sanyal
http://www.dpreview.com/articles/7945517371/opinion-did-sony-just-do-the-impossible
June 10, 2015 was a fun day. It saw the announcement of the Sony a7R II, along with a the new 1"-type stacked sensors in the company's updated releases of the popular RX100 and RX10 camera lines. Our Editor Barnaby Britton was lucky enough to be at the launch event to witness the announcements in person, and with every text message he sent me about a new feature Sony was introducing in the a7R II, I couldn't help but feel like a kid in a candy shop being given far more candy than I'd expected. But like a greedy child, I was quite happy to take whatever was given me.
As a photographer intent on always optimizing my systems, I'm constantly on the search for the best tools for the job. As someone who also doesn't like to own too many things, spend needlessly, or have to choose which camera to take on which job (I hate making decisions), I'm also always searching for that 'one size fits all' option. Of course, as technologies evolve, our expectations increase, and so searching for 'perfect' is a bit of a fool's errand, as 'perfect' is a moving target.
So what we typically 'settle' for is 'as close to perfect' as we can get for our needs. But for the first time in a long while, I feel like we're getting much closer to this moving target. And for the type of photography I like to do* - landscapes, weddings, engagements, portraiture (especially candid and environmental), newborn, to name a few - here's why I'm almost unreasonably excited about the new Sony Alpha a7R II.
Getting the most out of all those megapixels...
42.4MP... ignoring medium format, who would've thought that we'd have to call that not class-leading? You can thank the Canon 5DS and 5DS R for that, which the a7R II falls short of with respect to resolution. And yet, in almost every other respect, the sensor in the a7R II is bound to outclass the 50.6MP sensors in Canon's latest high-resolution beasts. Why? Read on...
No AA filter
For one, there's no anti-aliasing filter at all, rather than the two birefringent filters in the 'anti-aliasing canceling' setup we saw in the D800E and, now, the 5DS R. Although the improvement may only be subtle, we saw slight improvements in micro-contrast when shooting our studio scene with a D810 vs. a D800E with the same exact lens (samples to be published shortly).
Backside illuminated
A bigger deal is that this is the world's largest backside-illuminated (BSI) sensor ever put in to a consumer-grade camera. BSI sensors flip the position of the photodiodes and the wiring of the sensor to allow more light to hit the photodiode without being obstructed by some of the other wiring and electronic components of the sensor. It's commonly understood that BSI has greater benefit for smaller sensors, as the smaller pixels have a larger percentage of their overall light-sensitive area taken up by electronic features, which don't necessarily get smaller as pixels get smaller.
However, this understanding is predicated upon a correlation of BSI benefit and pixel size, with the effect on sensor size only being an indirect correlation (since smaller sensors tend to have smaller pixels). But as we go to higher and higher resolution sensors, we may still have small pixels in a relatively large sensor. And such large, high resolution sensors may very well still benefit from BSI design. And that's exactly what Sony's thinking was - to not trade off resolution and sensitivity. We recently saw BSI help the APS-C Samsung NX1 achieve rather impressive low-light performance, and we expect to be similarly impressed when we test the a7R II, especially considering that the original a7R was no low-light slouch.
Shutter shock, or lack thereof
An issue we're becoming acutely more and more aware of as sensor resolutions increase is sources of mirror and shutter-induced shake. It was an issue with the first 36MP full-frame camera, the Nikon D800/E, and particularly so with the Sony a7R. All of these cameras initiate the exposure with a mechanical shutter, with DSLRs like the D800/E and 5DS/R having the additional issue of flipping a mirror out of the way first. When it comes to the mirror, camera manufacturers will typically dial in a bit of delay to allow for vibrations to die out, but even if this delay is 100% effective (our tests would suggest it isn't), a mechanical shutter often still causes some vibration, the effect of which will depend upon your focal length, as well as the duration of the exposure.
Very long or very short exposures typically won't affected, but we've found a whole chunk of shutter speeds, for example from 1/15s all the way to 1/500s, affected deleteriously by shutter shock, and optical image stabilization systems' reactions to such shock, at longer focal lengths on a Sony a7R, Nikon D810, and Canon 5DS.
Nikon's electronic front curtain on the D810, and Canon's use of an electronic first curtain in Live View, aim to mitigate these problems, but are cumbersome. Canon requires you to shoot in live view mode, and in the D810 you have to engage two shutter button presses with a delay in order to take a shot.
What likely made matters particularly worse for the Sony a7R was that the mechanical shutter had to be closed and opened to initiate an exposure, since the sensor is always exposed to light in a mirrorless camera. That's a lot of movement, with the shutter landing with a resounding thud! (literally sounding like it hits the bottom of the body frame) before opening again to initiate the exposure. At least with DSLRs, once the mirror is out of the way, the shutter only has to open (its 'default' position is closed). This shutter actuation was enough to cause significant motion blur in long telephoto shots, and even enough to cause a parasitic interaction with lenses' optical image stabilization systems to yield results such as the one below in our studio scene:
Shutter shock plagued the original Sony a7R, and in the example above, which was taken at 1/100s with a Canon 70-200 F2.8L II IS attached via a Metabones Smart Adapter III, is not only obvious, but also reduces the resolution of the camera well below its lower-resolution peers, since cameras like the 24MP a7 at least offer a way to avoid this issue altogether (electronic first curtain).
Thankfully, with the a7R II, Sony has doubled down on removing all sources of softness-inducing shocks. The shutter itself has been redesigned to minimize its impact, but the biggest story here is an electronic first curtain. The sensor readout speed has been increased sufficiently such that all the 42 million plus pixels can be reset fast enough electronically to not require the mechanical shutter to initiate the exposure at all. Like the a7, a7S, a6000, etc., when you press the shutter button, the entire sensor is reset electronically, and after the chosen shutter duration time, the mechanical shutter drops to end the exposure.
Furthermore, like the a7S, a totally silent shutter mode is available as well, with the exposure concluded, in addition to initiated, electronically. This likely comes at a cost though: we've seen additional noise in shadows with this mode on the a7S (it lowers dynamic range), as well as increased rolling shutter effect, to be expected as we haven't reached the holy grail of global electronic shutters yet with these sensors.
In summary...
42.4MP is a lot. Enough for those large landscape prints I like to make every now and then, and enough to afford me enough cropping freedom to find photos within photos, or to strengthen compositions. But getting the most out of these pixels is increasingly difficult. Full-frame mirrors and shutters are rather massive, potentially creating lots of vibration that can blur images - at no fault of the photographer him/her-self. It almost behooves mirrorless cameras to have electronic first curtains, as there's no mirror to flip out of the way, making it that much easier to initiate exposures without any physical motion inside of the camera. The a7R II finally realizes this, offering an option to begin the exposure electronically, while ending the exposure mechanically (which typically doesn't affect the exposure deleteriously, since any induced vibrations occur at the end of, or after, the actual exposure).
This literally makes the a7R II the first high resolution full-frame camera with no potential source of mirror/shutter-induced shake during normal operation.
The Sony a7R II will almost undoubtedly offer the Raw dynamic range we've come to expect and love of Sony sensors. And for a high resolution camera undoubtedly to be picked up by landscape photographers, dynamic range is bound to matter. With the latest generation of high performance, full-frame image sensors, we're starting to approach the point where many high contrast scenes can be recorded in one exposure, as long as you expose for the highlights and tonemap in post-processing. And for scenes still demanding techniques to work around dynamic range limitations, such as the very high dynamic range scene above, the higher the dynamic range of your sensor, the better.
For example, for this particular shot, taken with a Sony a7R and a Canon 16-35mm F4L IS lens, I've gotten away with just the use of a 3-stop GND filter, obviating the need to merge bracketed exposures - something I was in the habit of doing with my Canon EOS 5D Mark II. This allowed me to focus on other aspects of the shot, such as shooting f/22 for the sunstar, and f/8 for everything else (to avoid diffraction-induced softening for most of the shot), as well as focus bracket. Had I had to worry about exposure bracketing as well on top of all this, I might've missed nailing the perfect moment.
And even if it's not landscape photography you do, dynamic range helps - it offers you exposure latitude (the ability to 'rescue' exposures) and the ability to underexpose your images to retain highlight information by selectively brightening tones in post-processing, as I've done in this action shot of a horse galloping on the beach against a bright, setting-sun sky (above).
In fact, if I may engage in some speculation here: with the expanded photo-sensitive area of each pixel, and the off-loading of electronics to a separate area, one might wonder if the BSI sensor in the a7R II might offer even more dynamic range than its predecessor, as there may be room or capability for larger photodiodes and potential wells. I must stress that I'm purely speculating here, but we'll be excited to test if dynamic range has increased over the already high capability of the original a7R, and particularly if it catches up with the class-leading dynamic range of the Nikon D810 at ISO 64, where Nikon appears to have increased the full-well capacity of the pixels on the already excellent 36MP sensor from Sony (the more light you collect, typically the higher the dynamic range, unless read noise is the limiting factor).
Here's where things get disruptive. We've seen on-sensor phase-detect AF (PDAF) for some time now, and every iteration appears to make these implementations better. We saw a huge jump in performance with the introduction of Sony's alpha 6000 (a6000) camera, as well as Samsung's NX1. And even though one could adapt third party glass, such as Canon EF lenses, to the Sony a6000 and a7 cameras, full with electronic communication for aperture control and rudimentary AF, for some reason PDAF was never available. I'd always wondered if there were some technical difficulty, if there were some protocols that had to be reverse engineered, or if there were some other explanation unbeknownst to me as to why this hadn't been done yet.
Having never received a satisfactory answer as to why on-sensor phase detection measurements couldn't be used when driving attached DSLR lenses, I'd kind of given up hope that we'd see this, thinking it impossible.
And then the a7R II announcement. And a text from Barney: 'it focuses Canon lenses. Using PDAF. Pretty fast'.
Whatever the hurdles, it appears that Sony has overcome them. The a7R II may even be a solid replacement for the a99. Sony claims that the camera can utilize focal plane phase-detection with A-mount lenses, when using a LA-E3 lens mount adapter. One of the biggest complaints of the a7 system was the lack of available glass, but this development renders this point moot - with the a7R II you'll have access to one of the largest, and most desirable, libraries of glass available. And not only that, the AF system of the a7R II might actually provide some benefits to using that glass natively... so let's talk about that.
Subject tracking
Subject tracking is about the camera understanding what you wish to focus on. And while this piece is too small in scope to get into the merits of subject tracking, suffice it to say we firmly believe that proper, usable subject tracking will usher in a new, and better way of autofocusing in the future. And mirrorless cameras will likely lead the way.
Subject tracking is implemented and used, to varying degrees of success, in a number of different ways by different manufacturers. At its very best, subject tracking can mean the camera automatically finds (for example) the largest face in the scene, and always keeps it in focus no matter where in the frame, and how far away, it is. When you press the shutter, that face is in focus at the time of capture. Even during continuous shooting. If it's not simply the largest face in the scene you're going for, good subject tracking implementations will understand what it is you're trying to focus on by 'remembering' whatever was initially under your selected AF point when you initiated focus, and will continue to track it as long as you have the shutter button depressed halfway or fully.
A sophisticated tracking implementation, like Nikon's '3D tracking' will even be specific enough to track the eye of a face (even the correct one), while a less sophisticated one such as Canon's iTR, or intelligent tracking and recognition, will, well, wander and lag, as our test with the new EOS 5DS shows*. That can mean the difference between an in-focus vs. totally out-of-focus shot when you're shooting with fast primes, where it's critical to nail focus on precisely the right feature on a face.
But why do I say 'mirrorless cameras will likely lead the way'?
Unlike DSLRs, which rely on relatively low-resolution RGB metering sensors to identify subjects in your scene, mirrorless cameras are always scanning their main image sensors. These sensors can provide higher resolution data at high speeds as well, with the increases in readout speeds we're seeing, and they can do so with all of the available light going to the image sensor. Hence, mirrorless cameras have the potential, with enough computing power and clever algorithms, to possibly surpass what we see even from Nikon's full-frame cameras, which represent the current state of the art when it comes to AF tracking.
And initial marketing videos indicate that the a7R II might not disappoint here. Take a look at tracking of a speed racer in this video from Sony below:...................
OK then, what are the downsides?
If the Sony a7R II can focus DSLR lenses just as well as DSLRs can, is it game over for DSLRs? Well, not so fast. It's not all double rainbows and ponies in Sony and mirrorless AF land, so let's talk a bit about the downsides.
First of all, subject tracking, or 'Lock-on AF' as Sony calls it, isn't always perfect. It'll start on your subject, but in trying to understand your subject, that green box highlighting what the camera thinks is your subject will sometimes grow, shrink, or wander off your subject. Frankly, we found its implementation on previous cameras to be a bit over-engineered: in trying to understand and adapt to your subject, sometimes it misunderstood what it was you were trying to maintain focus on. It often didn't offer the pinpoint precision of Nikon's 3D tracking in the D810 (again, here). We expect this to improve with every generation, though, and the fact that the a7R II offers something as precise as eye-tracking in continuous AF has our hopes up.
What about low-light AF? One large remaining problem with on-sensor phase-detect is that it gives up in low light, with the camera reverting to the slower contrast-detect AF. And that means the dreaded focus-hunting. Despite the sensor getting all the light (rather than having to share it with a dedicated PDAF module, and an optical viewfinder), the phase-detect pixels are small (they're masked, only receiving half the light of any full imaging pixel). For this and other reasons, on-sensor PDAF shuts off on most mirrorless systems in dim light, whereas the latest DSLRs can focus using phase-detection at every AF point down to -3 EV (Nikon D750, D7200).
We don't know the low-light limit of the a7R II's on-sensor phase-detection, but reversion to CDAF in low-light may continue to be a problem compared to DSLRs for now.
Finally, DSLRs have a honed ability to initially acquire AF very fast. They can do this because of their ability to make phase measurements even when the lens is extremely defocused. This is quite important for certain applications, particularly anything involving long telephotos where, quite often, the image through the viewfinder is a blurry mess because your focus is initially far off your subject. Even more so because any amount of hunting can make or break your shot.
What we're a bit less happy about
Not much, for now. Actual testing and performance evaluation may of course kill off some of the initial enthusiasm, as it often does, but we remain thoroughly impressed with what the camera promises. Ergonomics and menu systems aside, there is one thing though: lossy 14-bit Raw.
As far as we can tell, Sony is still only offering a lossy 14-bit Raw. We spoke to a highly technical representative at Sony about this, and he mentioned that he was aware of the issue, and the desire for at least an option for uncompressed Raw - even if it came at the cost of shooting speed. We were told that Sony is aware of the issue and are working on it, and that it's possible we might see the issue addressed in firmware in the future, but we were not able to get any guarantees or specifics beyond this. The reality is, while this won't affect all of you, nor will it affect every photo, it's a bit of a sticking point for some considering these cameras: it's odd to spend north of three grand on a pro-level camera, and then find posterization artifacts like the ones around the arches in our a7S image below.
Concluding remarks
One could remark that in challenging the giants, Sony must innovate to offer a competitive advantage. And one would be absolutely right.
But the level of innovation and effort that we're seeing here is formidable. I haven't even touched the surface in this opinion piece - I've completely left out all talk of 4K video, usable phase-detect AF in video, and 5-axis image stabilization with most lenses (remember when some thought that was impossible with a full-frame sensor?). These sorts of features, along with everything I've talked about in this piece, along with everything I've forgotten to mention, spell out real benefits for photographers and videographers. Too many, in fact, to spell out fully here, and too many to, of course, test before definitively stating them as benefits! So I'm going to leave you with a short anecdote:
Just the other night I was at a candle-lit dinner with my fiancée, a Nikon D810 and Sigma 35mm F1.4 lens, trying to shoot at f/2 to let in as much light as possible while allowing for some wiggle room with respect to AF accuracy. I was, in fact, struggling with AF accuracy, wondering if the optimal AF microadjustment value changes not only with temperature, but also as the color of the primary light source changes. I hiked up the shutter speed to 1/80s since I had no image stabilization, and to ensure absolutely no mirror/shutter-induced shake as well. I can't help but wonder what an a7R II might have done here. Image stabilization would easily allow a shutter speed of 1/20s, while lack of AF accuracy issues would've allowed F1.4. That's a potential 3 EV noise advantage right there (the difference between, say, ISO 800 and 6400), with no mirror and no shutter vibration issues to worry about when optimizing my shutter speed to boot.
The point is that worrying less about focus, worrying less about how to get the most out of all those pixels, worrying less about running into the noise floor of my camera because I want to expose to keep those highlights from blowing - these all have one thing in common: they're all about 'technology getting out of the way'.
More candy, please.
Interview: Kimio Maki of Sony - 'the customer’s voice is the most important data for me'
Published Jun 22, 2015 |dpreview staff
http://www.dpreview.com/articles/0717419525/interview-kimio-maki-of-sony-the-customer-s-voice-is-the-most-important-data-for-me
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What is the biggest technical challenge to making a camera like this?
KM: To create a balance between resolution and ISO sensitivity. Usually, if you increase resolution, you have to sacrifice sensitivity. To achieve both we created a full-frame back-side illuminated sensor. We needed resolution of 40MP+ and we also needed ISO sensitivity greater than 6400, and in order to achieve that balance, this technology is necessary. Once you’ve gathered the light, improving processing speed is an important issue, so we changed the wiring inside the sensor from aluminum to copper, and reversed the structure. So we’ve improved the resolution and the ISO sensitivity over the original a7R.
MW: We wanted to overcome the idea that has been prevalent since as long as there have been digital cameras, that you can have one virtue or the other but you can never have both. Look at the Canon EOS 5DS. A maximum ISO sensitivity of 6400, and crippled movie capability. Canon says that it intentionally created the camera to fit the requirements of certain photographers, and that the material science of their device technology accomplish both objectives.
One of our main criticisms of the a7-series has been raw compression. Is the raw processing of the a7R II the same as previous cameras?
KM: Right now it is the same, yes. We’re still working on it. In the future we may change the software but that’s not completed yet. We have consumers who require 14-bit etc., and we’re considering .
Is the dynamic range of the sensor equivalent to the older 36MP sensor?
KM: The dynamic range is the same or maybe a little better. I don’t have quantitative data at hand.
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Thank you MYM8 Ching. The articles are very interested to those owing A7 like me:)
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