Scarlet Killers - Attack of the HD DSLRs!

HD capability in new crop of DSLRs deserves a look
Steve Hullfish
By Steve Hullfish 10.31.08

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Nikon is claiming its recent release of the D-90 is the first HD DSLR camera. Plus there's the news of Canon's entry into the HD DSLR race, the EOS 5D Mark II as well as the Sony DSLR-A900. The combined pressure of these seemed to sink the much anticipated release of the Scarlet.
 
So why are these SLR form-factor camera's making a scene? Well, lately it's been about the release of Vincent Laforet's HD film "Reverie" on the Canon website. The images are stunning and the entire project was shot on a 72 hour deadline with a budget of $5,000. So many people downloaded the movie that it shut down Canon's video webserver.

Out of the three cameras, Canon does seem to be the one to beat. It starts with a CMOS imaging sensor that is exactly 24 x 36mm and 21 Megapixels (5616x3744 pixels). That entire image (with the exception of the aspect ratio difference) is used as the basis for the HD video that the camera produces. Oddly the camera shoots at an HD frame rate of exactly 30fps. The frame size is also the most impressive of the competition at a full 1920x1080p. The cool thing is that the footage is created in native QuickTime using an MPEG-4, H-264 codec. The audio is a little skimpy, with a built in mono mic that must not be good for anything other than slating shots or maybe as an assist in syncing some dual system sound. There's an optional stereo mic than can provide stereo sound through a 3.5mm stereo mini-plug, so I would think that dual system sound is the way to go. Audio is recorded uncompressed at 16bits, 44.1K, PCM.
 
I think that what makes the images in Laforet's film amazing is that he shot with almost no additional lighting. Virtually everything was shot with available light, or available with a single, small additional source, like and LED light. The only way that that modus operandi is possible (have I been watching too many cop shows?) is that the still camera can be rated at an astonishing ISO of 25,600! That is an "extended" ISO, but the basic ISO is from 100 to 6,400! And most of the footage in Laforet's movie was shot at about 1600 ISO with virtually no noise. This incredible low-light sensitivity is due in part to the size of the individual pixels on the chip. In HD mode, the sensitivity of the camera can go up to 12,800 ISO, but normally operates in the same standard range that the camera uses for stills.
 
Canon is mum about stating the dynamic range of this camera (which is expected to street by the end of November), but estimates based on other Canon cameras with similar sensors put it over 8 stops.
 
The images also benefit from the depth of field provided by the wide range of prime and zoom lenses available for the camera (using Canon's EF lens mount) and the large, full-frame sensor size. The bigger the sensor, the shallower the depth of field when all other factors are considered.  Compare the 36mm chip of the Canon to most prosumer video cameras at 1/3 or 1/2 inch. For those without a metric calculater 36mm is more than 1.4 inches. I'm not sure how the HD manufacturers measure their tiny sensors, but if it's diagonal then you have to have to compare that to a sensor size of 1.7 inches for this Canon!
 
The camera records to off-the-shelf, inexpensive UDMA CF cards. The QT files can be played directly off the cards. And HD video out is available via an HDMI-mini port or a standard def RCA jack, switchable between PAL and NTSC. CF cards have a maximum single file size of 4gigs. This has translated - depending on subject matter - to about a maximum shot length of 12 minutes at full 1920x1080p. Multiple 4gig files can of course be held on a single 8gig or 16gig CF card.
 
Some of the excitement about this HD capability is tempered by the fact that this is not SUPPOSED to be an HD camera, but rather a still camera with the ability to shoot HD, so certain features are definitely missing, like timecode. Also, the camera can only operate in essentially full auto exposure mode when shooting HD. (In still mode, the camera is capable of being fully automatic or fully manual.) The cool thing is that you can make adjustments using an exposure compensation control. You can also lock the exposure so that changes don't occur in mid-shot. The camera's "flowchart" for doing the auto-exposure is to first control the sensitivity or ISO of the camera, then adjust shutter speed, then f stop.  The shutter speed range in HD mode goes from 1/30th to 125th.
 
The camera can use auto-focus in HD mode, but Canon suggests sticking with manual focus for video. Remember, that the SLR viewfinder is inoperable in movie mode, so you have to monitor your image using the LCD on the back of the camera, or with an external monitor fed by the HDMI jack.
 
Photojournalists are pumped about the camera because many outlets want them to shoot video as well, and this allows them to shoot with the same lenses without having to carry a video camera. The Canon is capable of switching between HD and stills almost instantaneously.
 
All of that is pretty impressive for a camera retailing for about $2,300.
 
The Nikon D-90 is also in the hunt in this competition. I have always been a Nikon shooter, since high school, but the specs on the D-90 are just not as impressive as the Canon and there are some seemingly fatal flaws. The D-90 has a 12.3 Megapixel image sensor (60% of the Canon). It has three different size modes when recording video, however, which is a feature not offered by the Canon. The sizes seem aimed at capturing video for the web however: 320x216, 640x424. and 1280x720. And for most people the fact that the native capture is in AVI with motion-JPEG compression could be a killer. Though for others, that could be a selling point.  The Nikon records to SD memory cards, and it approves models up to 32gigs. The small type on the Nikon site states that the auto-focus does not work while in video mode.
 
Sony's entry - the DSLR-A900 - has a 24.6 Megapixel, full 35mm frame CMOS sensor, rated at ISO 200-3200.  HD was unveiled with an earlier version of the camera - the A700 - last year at this time, but the camera seems to only output HD via the HDMI-mini port, not actually record it.
 
As someone who shoots with SLRs, DSLRs and video cameras, I think the form factor of the HD DSLRs will be a problem for adoption as serious HD workhorses. The way the cameras can be held and moved will not be acceptable to many cinematographers and videographers looking for an HD option, But formany, the form factor will be a benefit. The lightness and compact size of the body will allow it to be mounted and held in ways that are impossible with even the smallest of camcorders.
 
The real benefit in image quality seems to be the size of the sensor which allows a beautiful depth of field and the impressive ISO ratings of the cameras which allow minimal lighting to deliver exceptional results.
 
(If you are interested in reading the full interview with Chuck Westfall, the Technical Advisor for Canon, about the Canon EOS 5D Mark II, check out the next page.


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