在有名的Canon传言网页大本营
http://www.northlight-images.co.uk/cameras/Canon_5d2_3d_7d.html我再度注意到一些有趣的消息，关于5D后继机(Ok..可能是5D II或其他的新命名原则)，关于新技术.. ..
大致简单翻译一下:
下周再来一台新相机如何?可录影的2000万像素相机听起来很有趣
我们一致的认同是Canon在Photokina展只会有一台新相机。如果你的好奇心够，你应该会想知道我们的消息指出，Canon future developments在去年40D发表之前，5D后继机就已经准备好了，你可以把40D想像是1D MK3轻量版，5D后继机将会像是1Ds MK3轻量版一样。但是由于缺乏真正的竞争者(而且5D卖的很好)、更希望能在性能表现上有更大的跃进，因此当时后继机计画就暂停了
D90的可录影功能吸引了不少目光，因此录影功能也再度出现在5D后继机可能的规格表"(from Canonrumors.com)中，但我们其他的消息来源并不认为这项功能会比明年初可能发表的500D还早出现在5D后继机里
8/25日全球举办了好几场记者会，会中很明显的暗示今年还有另一款新相机会发表(某场官方记者会中有个Canon职员提到:我们刚发表了40D的后继机- 50D。今年我们还有另一台新相机会发表，它将会是令人高度期待的机型，但不是EOS-1系列，敬请期待更进一步的发表讯息。)，不过在挪威的记者会中我被某位Canon内部的人清楚告知今年将还会有两台新相机要发表。
下面是Canonrumors.com网站中提到的5D后继机可能规格:
* 21.1MP FF
* DIGIC IV
* ISO 100-6400 L:50 & H:12800
* 5 FPS
* 3.2" High Resolution Screen (LCD)
* 19 point AF
* HDMI Out
* Liveview
* HD Movie Mode
* Viewfinder: 100% Coverage
* Full weather sealing
* EF Lenses only
Canon利用缩小Microlens Gap、降低每个像素的杂讯等技术，让更多像素塞入同样面积的感光元件，杂讯却比以往更低，这项技术在40D、1D MK3、1Ds MK3上已经被强调过，这次发表的50D更是进步到"Gapless Microlens"。
这得归功于DIGIC IV的强大影像处理技术与能力，同时这也被认为是近年来Canon最大的进步之一。
这个技术允许21~25MP全幅感光元件的杂讯抑制，比3年前5D的12MP全幅感光元件的杂讯抑制表现还要好1~1.5级
对这些技术有兴趣的朋友可以好好看一下这一大段原文
●Reducing the micro lens gap to capture all the light hitting the sensor. This has been highlighted in the 40D, 1D III and 1Ds III sensors and the new 50D sensor now achieves effective 100% coverage. Only very minor improvements are expected from this point on (eg shaping the lenses towards the corners of the frame to capture angled light.
●Reducing the noise level of each pixel. Canon have made changes over several generations of sensors to achieve this, bringing the amplifiers closer to each pixel, changing micro-circuit configuration and lowering voltages so the sensor runs colder. Again the design of the 50D is a big step forward here from the 40D and 1D III etc. Canon have one more big jump lined up, with low voltage cold running CMOS designs to gain at least an additional stop in lower noise at higher ISOs or long exposures.
●Better digital noise reduction. These are the changes in DIGIC noise processing. First with the Chroma Noise reduction in DIGIC III and now with more advanced multi-level noise reduction options in DIGIC IV. Canon believe they have made most of the gains possible via processing algorithms but do still have some areas to develop. The next focus will be faster noise reduction processing so that it does not come at an impact on frame burst rates (look to the 1D3 replacement for example)
●Pixel binning for high ISOs. A new technology enabled by the complexity and processing power of DIGIC IV where they can bin 2, 4 or 8 pixels together at the raw level and average out the noise between them. This is seen by Canon as a key technology in balancing very high resolution sensors (in the 50mp range) with low noise at very high ISOs. Right now they are not pushing this too much with the 50D so as to not create confusion in the market (they see more potential for the technology as sensors get larger and in the pro-market).
●Increased image resolution – This is a newer strategy (most evident on the 450D where they have changed the anti-aliasing filter (thinner and closer etc) so as to achieve a crisper image per pixel without loosing the benefits of anti-aliasing filter on diagonal edges etc.. The 50D has the same technology. One further option for the future is for Canon to drop the anti aliasing physical filter and do it in a future DIGIC generation where there can be smarter allocation of colour values than the blurring achieved by a light based filter.
●Increased raw bit depth for improved dynamic range. Here Canon have made the jump to 14 bit and will move to 16 bit in their future sensor technology generations. Canon see the main usage of extra bit depth as providing the dynamic range to translate the sensor image into a printable or viewable image with a higher dynamic range. In other words mapping the 14 or 16 bits into an 8 bit viewable or printable image that mimics the dynamic range in the scene.
●Dynamic range preservation options – Canon are putting a lot of focus into how to provide the photographer with the best options for preserving the dynamic range of the original image in both a RAW file and the 8 bit JPEG. The highlight tone preservation option on the 40D, 1D III etc was the first step. The new 'automatic brightness' options in the 50D are another, where they try and optimise the brightness of various parts of the image to reduce the dullness from shadows. Canon are planning much more in this area, down to the equivalent of varying the ISO level across the different parts of the sensor when the image is taken (easier in live view mode of course).
尤其是第三点 Pixel binning for high ISOs，这可能也是5D后继机有能力把像素规格开到很高(比如谣言指出的21.1MP)的原因，或许可能让最大像素拍摄时，高ISO略输D3/D700，但缩到约12MP拍摄时，杂讯跟D3/D700一样，解像力却更高
当像素越高时，是否可把这些像素拿来做其他应用?把数个"(ex: 2、4、8个pixels)pixel资料合并当成一个pixel资料，借此分散杂讯到每个pixel里，因次当需要使用高ISO时，可能是降低拍摄像素来达到，让高像素感光元件同时能保有可用高ISO的能力
50D让我赞赏的继1Ds3的sRAW之后，在15.1MP RAW之外还提供了7.1MP(sRAW 1)与3.8MP(sRAW 2)两种RAW格式，就是这种解决方案，让高像素与杂讯能取得更佳平衡点；相较于S家采用近乎非破坏性的破坏性压缩来做较小体积RAW档，Canon的非破坏性sRAW几乎可说是目前业界最佳作法
假设5D 2用改良式1Ds 2感光元件(gapless micorlens) --我认为是能维持跟1Ds 3差距的一点可能性，但也不排除使用改良式1Ds 3感光元件，毕竟像素只是一项影响等级认定的要素，并非主要或全部--但不管可能用哪种感光元件加上这些技术与DIGIC IV晶片，可能都可以让杂讯表现更好
1Ds 3去年8/20发表，台湾定价约24万6左右，假定5D后继机规格接近上述，消费者怎能抱着虚幻不实际的想法，希望5D后继机又要如此高规格又要比当初5D上市价还低?在商言商还是不变的基本观念
有可能利用9点双十字对焦、观景窗视野率放大率、结构材质、、耐用性、防滴防尘等级这几个地方来跟1Ds 3区隔，毕竟我认为即便在这种氛围下( Nikon D3/D300/D700/D90、Sony α200、α350及可能的α900等市场竞争者纷纷出笼)，Canon也不会让5D后继机规格太过以下犯上
我不会也不愿去猜测5D后继机可能定价，因为5D后继机不管怎么开规格，性能跟价格都有可能稍微打到1Ds 3
两机可能的区隔，每个人有自己的著眼点，在我看来光是观景窗视野率放大率、结构材质、耐用性这三点，差别就很大了，更别说是对焦系统等级差异啦~
译文by mskeith.pixnet.net
