本文發表於正妹顏攝美學院 ( http://mskeith.pixnet.net/blog/ )
在有名的Canon謠言網頁大本營 Northlight-Images 裡面，我再度注意到一些有趣的消息(謠言?)，關於5D後繼機(Ok..可能是5D II或其他的新命名原則)，關於新技術....
我大致簡單翻譯一下:
下週再來一台新相機如何? 可錄影的2000萬像素相機聽起來很有趣
我們一致的認同是Canon在Photokina展只會有一台新相機。如果你的好奇心夠，你應該會想知道我們的消息指出，Canon future developments在去年40D發表之前，5D後繼機就已經準備好了，你可以把40D想像是1D MK3 輕量版，5D後繼機將會像是1Ds MK3 輕量版一樣。
但是由於缺乏真正的競爭者(而且5D賣的很好)、更希望能在性能表現上有更大的躍進，因此當時後繼機計畫就暫停了
D90的可錄影功能吸引了不少目光，因此錄影功能也再度出現在5D後繼機可能的規格表\"(from Canonrumors.com)中，但我們其他的消息來源並不認為這項功能會比明年初可能發表的500D還早出現在5D後繼機裡
8/25日全球舉辦了好幾場記者會，會中很明顯的暗示今年還有另一款新相機會發表(某場官方記者會中有個Canon職員提到: 我們剛發表了40D的後繼機 - 50D。今年我們還有另一台新相機會發表，它將會是令人高度期待的機型，但不是EOS-1系列，敬請期待更進一步的發表訊息。)，不過在挪威的記者會中我被某位Canon內部的人清楚告知今年將還會有兩台新相機要發表
底下是Canonrumors.com網站中提到的5D後繼機可能規格:
* 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利用縮小Microlens Gap、降低每個像素的雜訊等技術，讓更多像素塞入同樣面積的感光元件，雜訊卻比以往更低，這項技術在40D、1D MK3、1Ds MK3上已經被強調過，這次發表的50D更是進步到\"Gapless Microlens\"。
這得歸功於DIGIC IV的強大影像處理技術與能力，同時這也被認為是近年來Canon最大的進步之一。
這個技術允許21~25MP全幅感光元件的雜訊抑制，比3年前5D的12MP全幅感光元件的雜訊抑制表現還要好1~1.5級
請參考以下兩張參考圖:
縮小微型聚光鏡片間隔
縮小低通濾鏡與感光層的距離
對這些技術有興趣的朋友可以好好看一下這一大段原文
●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 (e.g. 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).
尤其是第四點"Pixel binning for high ISOs，這可能也是5D後繼機有能力把像素規格開到很高(比如謠言指出的21.1MP)的原因，或許可能讓最大像素拍攝時，高ISO略輸D3/D700，但縮到約12MP拍攝時，雜訊跟D3/D700一樣，解像力卻更高
假如是這樣，我對於這個謠傳的規格可能不滿的地方就是對焦模組、錄影功能這兩點了，50D讓我讚賞的繼1Ds3的sRAW之後，在15.1MP RAW之外還提供了7.1MP(sRAW 1)與3.8MP(sRAW 2)兩種RAW格式
[ 本帖最後由 KEITH 於 2008-8-29 07:16 編輯 ] |
發表於 2008-8-29 07:12
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