Well it seems the rumor mill was right on this one. Canon’s first announcement for the fall season was the EOS 7D as expected. With an 18 megapixel sensor stuffed into Canon’s 22.3mm x 14.9mm APS-C format, the 7D promises to be a bit noisy, if only from the 8 frame per second motor drive.
However, as un-compelling as I thought the 7D would turn out, mostly due to cramming more pixels in an already small sensor, it carries some interesting improvements over the EOS 50D. Even more so, in terms of the user interface and customization options, the 7D looks like an improvement over all of Canon’s camera’s to date.
Key Features
100% viewfinder
19 point autofocus system
±3 stop metering range for exposure and flash exposure compensation
8 FPS
ISO 100-6400 native, ISO 50-25600 expanded
Transparent LCD in viewfinder to display AF points and grid lines
E-TTL II commander mode
The EOS 7D supports the same ISO expansion options as the EOS 5D mark 2, specifically 2 stops over and 1 stop under the native range. That is a native ISO range is between ISO 100 and ISO 6400 in 1/3rd, 1/2 and full stop increments. In addition, ISO 50, ISO 12800 and ISO 25600 expanded settings are provided.
The 7D’s exposure meter now supports the same ±3 stop range of exposure compensation as seen in the EOS 1 bodies, something that’s not found even in the 5D Mark 2.
I’m in the process of writing a rather long essay on the evolution of focusing and focusing aids from ground glass to contrast detection, and everything in between. It’s probably going to be a while before I get that finished and this was interesting enough that I thought it warranted an aside.
Nikon has filed for a patent on a mechanism to embed what amounts to auto focus pixels in the imaging sensor itself. This would in affect solve the performance issues contrast detection autofocus poses.
A bit of background, contrast detection AF systems suffer from a number of limitations that prevent them from matching the speed of the simpler phase detection systems. There are three main problems that contrast detection systems need to overcome. First is pixel sensitivity, because the camera is using information from the imaging pixels, it’s not possible to tune the the autofocus pixels to be more sensitive to light. This means that the camera makes more of a trade off in autofocus speed as light levels drop.
The second issue is it’s nearly impossible to tell which direction the image should be shifted without performing very complicated image analysis on other parts of the image, and even then there’s no guarantee that will be right. This is because to the imaging pixels a front or back focused lens simply produces a diffuse blob.
The contrast detection problem, which way do you shift the focus? Both examples are out of focus, but to the sensor they simply appear as diffuse blobs.
The final problem is the required processing power. In a contrast detection AF system the camera’s processor is actually trying to quantitatively find the point where to pixels have the highest different in brightness. A phase detection system simply compares the brightnesses of each pixel in two different rows of pixels. In an in-focus image they two rows of pixels will be the same, in an out of focus image they won’t line up.
What it appears Nikon is doing is miniaturizing the optical path of prisms and lenses that feed our current phase detection sensors and embedding them in the actual imaging sensor in place of imaging pixels where they want the auto focus point to be. This givens a camera using this system all the speed and efficiency benefits of phase detection without requiring a mirror or other beam splitter to direct some light away from the sensor.
None of these problems apply to a phase detection system. Because of the way the prisms bend light the direction that the lens needs to be focused is already known (except in the case of a severe defocus situation). In addition the specialize pixels used in the AF array can be tuned to be sensitive at much lower light levels while maintaining a good signal to noise ratio so they can be read quickly. Finally, processing is almost a non-issue thanks to the limited number of pixels the actual operation being performed on them.
The only possible problem is that the camera has to interpolate image data to cover up the holes the autofocus pixels leave. But truthfully that’s probably not much of a problem at all. Cameras current map out defective pixels and replace their measured values with interpolated values from the surrounding pixels. Even the basic Bayer layout of the sensor requires interpolation to turn the RAW data coming out of the sensor into something we can understand as a picture.
What it ultimately boils down to is this could give a point and shoot the same AF performance SLRs have. Of course if you pair this with another Nikon patent for what looks like an interchangeable lens camera in the Olympus E-P1 style, you might be able to start putting together an image of what Nikon has in store for us in the future. One thing that’s clear this patent has the potential to close the performance gap between Point and Shoots and SLRs, and pave the way for a mirror free/prism free SLR that can maintain current autofocus performance levels.
Photokina wrapped up last week, and I have been trying to following along on the news as best I can. The big news to me was that there wasn’t an awful lot of news, outside of the cameras and lenses I’ve posted about previously. There were a lot of rumors about a new 70-200 VR from Nikon and a new 100-400 IS from Canon, neither materialized. Sigma announced a new revision of their SLR, the DP15; and a new point and shoot, the DP2. The DP2 is similar to their DP1 but complementary with a faster (f/2.8) more normal (41mm equivalent) lens.
Probably the biggest news on the camera front was the announcement of a couple of Micro 4/3rds cameras. If you’ve not seen Olympus’s announcement on what it is, Micro 4/3rds is an adaptation of their 4/3rds system to a thinner mirror-less design. The new system is compatible with 4/3rds lenses—through an adapter—but supports a new smaller lighter series of lenses designed specifically to be as compact and portable as possible.
The most interesting new camera, at least form an SLR user’s perspective, is probably the Panasonic Lumix G1. Not much bigger than more traditional super zoom point and shoots, it supports interchangeable lenses and a SLR sized (2x crop factor) sensor, giving it more flexible lens choices and potentially better low light capabilities. That coupled with the forth coming 20mm f/1.7 (40mm equivalent) micro-4/3rds lens would make quite a powerful yet unobtrusive camera for street photography.
Some things that did catch my eye include the announcement of Adobe Photoshop CS4, which brings 64-bit support to windows machines and support for using your video card to accelerate calculations among other things. I could write about it, but most of the cool features are demonstrated in this podcast (creativesuitepodcast.com), and it’s far more fun to watch than it is to read about.
On the storage front, SanDisk announced Extreme III and Extreme IV flash cards, including 32 GB Extreme III cards. Speaking of which, while it’s been trumpeted all over the web as of late, but SanDisk has been running a rebate on their compact flash media for the last few weeks (ends the 11th of October), on their flash media. 16GB Extreme three cards are going for as little as $7 to $25 a card in some places, if you can find them in stock. Most of the online camera stores are participating, so if you’re in the media market right now that may be a place to look.
The other announcement in storage was by a company I’ve never heard of, Pretec (pretec.com), of two new compact flash flashcards, a 64GB and 100GB 233x (35MB/s transfer) flashcards. Something that’s sure to come in handy with the today’s high resolution and video producing cameras. I’ve never used them, and I can’t seem to find them listed any ecommerce sites I’ve used for ordering media, so I have no idea if they work well or even at all.
On the lens front, Tokina has added motors to their Nikon mount lenses. I’m not sure if this is good or bad yet though. On the up side, they will focus on the D40, D40x and D60 bodies; on the down side, Tokina doesn’t have an Ultrasonic lens motor design, so they will likely be louder than they otherwise would be when driven by the in body motor. One thing that is for sure, this gives entry level Nikon users access to fast f/2.8 zooms of decent optical quality in focal lengths of 11-16mm, 16-50mm and 50-125mm. All told, it’s not a bad for set of pretty close to pro grade lenses and can be had for less than $1900 for the three.
Also completely unrelated to Photokina, there is currently an update for Adobe Lightroom 2 in the final stages of testing. According to the Adobe Labs page, it fixes several stability issues and makes some performance improvements. As a Lightroom user, I’m keeping on top of this, and I can only hope it fixes a couple of the issues that I’ve experienced with Lightroom on Windows XP.
Well it seems the rumor mill was right on this one. Canon’s first announcement for the fall season was the EOS 7D as expected. With an 18 megapixel sensor stuffed into Canon’s 22.3mm x 14.9mm APS-C format, the 7D promises to be a bit noisy, if only from the 8 frame per second motor drive.