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26th January 2006
Olympus E-330 DSLR has live LCD and new sensor technology
by Ian Burley


Olympus' new E-330 DSLR is first to offer dual sensor system for live viewing plus new Live MOS sensor technology


UpdateE-330 Live MOS sensor confirmed as being designed and made by Panasonic
Official press release and full specifications

UPDATED: Friday, 27th January

Someone had to do it sooner or later – make a digital SLR camera that provided a live preview via a built in LCD screen and Olympus gets the prize for being the first to deliver this important new stage in camera evolution with today's announcement of the E-330 (EVolt in some markets) DSLR. The E-330 also has another interesting new feature; a new type of 'Live MOS' image sensor.


Why has it taken so long?
I personally find it striking that the camera industry took so long to make a DSLR with live preview. It seems faintly ridiculous that there are dozens of inexpensive compact digital cameras that have external tilting screens to display exactly what the lens is 'seeing' while even the most expensive DSLR can't yet do this.

Who needs live preview anyway?
Some have questioned the need for a live preview on a DSLR, but I believe it will become a natural feature in future DSLR cameras, across the board.


There are no other DSLRs, just yet, that can do this party trick.


Live viewing on a tilting LCD display built into thew camera means you can frame scenes comfortably and conveniently even when the camera is mounted or held at extreme angles or positions. It's ideal for tripod work, low angle shots, over-the-heads-in-front shots and for candid photography. It's particularly useful for marine photography while the camera is encased in an underwater housing. So it's no surprise that the E-330 gets its own underwater housing, the PT-E02, in May.

Live preview TTL viewing nothing new for Olympus, but...
Indeed, it was Olympus that demonstrated the value of live preview in an SLR-style camera some five years ago with its E-10 camera. This was a fixed lens camera employing a beam-splitting prism to permanently share light from the lens between an optical through the lens (TTL) viewfinder and the CCD image sensor. It was SLR-like, but unlike a conventional SLR you could not swap lenses, the viewfinder was relatively dim, plus there was no focusing screen for critical focus adjustment. It also suffered from slow and insensitive autofocusing. The live view was also low resolution, rather coarse in quality and difficult to use in bright sunlight. The E-330 fixes most of these issues.


With the E-330, Olympus has worked to retain the advantages of a conventional SLR mirror-type TTL viewfinder while introducing a live TTL view displayed via a large 2.5 inch external LCD. Contrary to rumour, the E-330 does not employ an electronic eye level viewfinder. A pure optical TTL reflex viewfinder is retained, although some light is shared to feed one of two sensors that provide live LCD viewing in two viewing modes. Apparently 20% goes to the Mode A live view sensor. This would be equivalent to viewing with a the aperture of a lens closed up by a fraction of a stop, so it shouldn't be dramatically darkened. I'd probably be happier with this than an electronic viewfinder only arrangement.

Dual mode live viewing
Mode A is uses a secondary image sensor in the viewfinder and the second.Mode B, uses a live view streamed from the main image sensor itself. Mode A, is a full-time system, preserving the conventional DSLR optical TTL view and sees 92% of the recordable image area, a little less than the 95% view you would see through the viewfinder eyepiece yourself. We understand that the Mode A sensor is a high resolution (8 megapixel) part specified to provide a high quality live view display.

The tilting 2.5 inch LCD screen has 212,000 dots, on a par with the highest resolution screens available in that size, equating to over 200ppi. With Olympus' Hyper Crystal Sunshine LCD branding, the screen has a wide 160 degree viewing angle and remains usable in bright sunlight. However, the screen only tilts up or down and cannot be reversed.

Conventional phase detection autofocus is retained in Mode A operation. Autofocus SLRs generally use this system, which employs a small CCD sensor in the optical viewfinder system, because it's fast and works well in low light. This is one reason why SLR cameras are more satisfying to use than compact cameras.


Olympus says its Porro-style sideways mirror path TTL viewfinder is ideal for implementing the E-330's unique dual-sensor live view system.

Manual focus only in Mode B
Mode B, using the main image sensor sees 100% of the recordable area and has a 10x zoom critical focus mode. However, Mode B can only be used in manual focus mode. This is because for the main sensor to 'see' the view transmitted by the lens the mirror must be locked up and blanks the TTL finder.

Theoretically, Olympus could have employed a contrast detection autofocus system in this mode, but this would probably have added cost and perhaps extended the development time of the camera. But I would expect main sensor live view mode to feature autofocus in the future, even though it would be slower and less reliable in low light than an SLR-style phase-detection system.

Porro viewfinder
If you think the E-330 looks familiar, that's because it's a direct descendant of the E-300 and, like the E-300, employs a Porro-style sideways all-mirror TTL reflex viewfinder system. Olympus suggests this arrangement enabled the straightforward location of the secondary Mode A permanent live-view sensor, something that would be much more difficult and expensive to do with a conventional pentaprism arrangement. It may also throw light onto Olympus' original decision to go with the unconventional Porro system with the original E-300.

That new Live MOS sensor
And what of the new primary image sensor? When I first heard that the E-330 would sport a 'MOS' sensor, I naturally thought this meant CMOS, as used by Nikon and Canon on some of their DSLR models. But MOS-type sensor technology is a new type of sensor that retains the low cost advantage of CMOS and solves some of the scalability limitations of CMOS. It also promises improved sensitivity for like-for-like size/resolution compared with CMOS.

Put simply, compared to CMOS, the space needed for the microscopic electrical connections that are routed around the photo-sensitive pits on the surface of the sensor chip, or photosite photodiodes, is significantly less on a MOS sensor than a CMOS sensor. This is because less transistors are required in a MOS sensor.


On the left a conventional CMOS sensor has thick inter-photosite tracks, while on the right these tracks are narrower, enabling larger, more sensitive, photosites.


With more space to play with, you can either scale the sensor down further than is possible with CMOS to make physically smaller sensors without reducing the number of photosites, or you can make the photosites larger on the same size sensor, so making them more sensitive, offer greater dynamic range and less susceptibility to noise.

Panasonic, which is partnering Olympus in the Four Thirds DSLR system platform, announced almost a year ago that it had developed small MOS sensor with double the resolution of a comparable sized CMOS chip, without sacrificing sensitivity. Being reminded of this old news prompted me to think that Panasonic was providing Olympus with the E-330's new sensor.

(Update Contrary to our original speculation below, we are now certain that the E-330's sensor is not a Cypress design, but indeed a Panasonic one. A Panasonic representative put this one to rest for us.)

However, there is a school of thought that Cypress Semiconductor is the supplier. Cypress acquired the Belgian company, FillFactory, last year. FillFactory designed the CMOS sensors used in Kodak's ill-fated Pro DSLRs and since FillFactory's acquisition, Cypress has released details of a low cost, high performance APS-sized sensor that has all the hallmarks of a MOS-style architecture, including streaming video capability for live view mode.

More to come during PMA
Whatever, next month's big PMA photo trade expo in Orlando, Florida, will see Olympus and Panasonic jointly hosting a press conference to update us on the progress of their Four Thirds collaboration. DPNow will be reporting live from the show as usual.

The E-330's new sensor is a 7.5 megapixel device, has marginally less resolution than the conventional eight megapixel Kodak CCD sensor used in the E-300 and the new E-500. It's not yet clear how the new Live MOS sensor will compare, performance-wise, with the conventional CCD equivalent, though it's probably cheaper to make. If one speculates, the sensitivity of the new sensor ought to be comparable, at least, with the slightly larger eight megapixel CMOS sensor used by Canon in the (Digital Rebel XT ) EOS-350D, for example. That camera performs better than the E-300 and E-500, noise-wise, at mid-to-high ISO levels, though the maximum ISO setting available on the E-330 is 1600 rather than 3200, which rather suggests Olympus isn't happy with the sensor's ISO 3200 performance.


Style over Substance
On a more basic level, it was generally agreed, if not unanimously, that the old E-300 suffered from an image problem because of its unconventional styling.

The E-330 has been subtly revised, but it's probably not going to win over the most ardent critics of the E-300's design, so much hangs on the E-330's live view capabilities and new image sensor performance.

Pricing and availability
We are told to expect a US body only price of $999, $1099 with the 14-45 (28-90 equiv) kit lens and $1499 with the new super-compact 10x 18-180 (36-360) zoom. The UK street price has been officially pitched at £900 with the 14-45 kit lens, which once again shows a very large premium over US pricing, even if you factor out VAT. First shipments are expected some time in March.

What do you think?
Tell us what you think of the new Olympus E-330 DSLR or go to the DPNow Discussion Forum and share your views there. You'll be very welcome.


 
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