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Micro Four-Thirds Slashes Camera Size and Weight, Retains dSLR Benefits? (Outdoor Retailer Summer Market 2008)

New Micro Four-Thirds digital camera standard stirs hope for pro-grade, interchangeable-lens cameras that are lightweight, compact and can be tailored to your exact needs.

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by Rick Dreher | 2008-08-10 00:15:00-06

The premise, jointly announced earlier this week by Olympus and Panasonic, combines several elements in a way heretofore unknown to digital cameras: a very compact body, a sensor lifted directly from dSLRs, interchangeable lenses, autofocus, and real-time LCD/EVF viewing.

The Four-Thirds consortium evidently looked at their dSLR standard and asked, "What could we do if we dropped the SLR mirror box, pentaprism viewfinder, and 100% telecentric lens requirement, but kept the chip and the lens communications?"

What they could do is thin the camera body by about half and reduce lens-to-chip distance, lens mount diameter, and lens sizes, coining a new system name: Micro Four-Thirds.

Micro Four-Thirds Slashes Camera Size and Weight, Retains dSLR Benefits? (Outdoor Retailer Summer Market 2008) - 1
The smallest dSLR body is far thicker than the new Micro Four-Thirds standard. Source:

To place this proposal into context, the smallest Four-Thirds cameras are the smallest and lightest dSLRs ever made: the Olympus E-400, 410, and 420. Yet the Micro Four-Thirds bodies can be less than half the dSLR thickness and likely as not, half the weight. It's not unreasonable to anticipate perhaps six- to eight-ounce bodies and even two- or three-ounce lenses. Equally important, certain body-lens combinations will be pocketable or could at least slip into a small belt case, always at hand. What the photographer-backpacker can expect is dSLR results from a toy-sized camera.

Eliminating the SLR mirror ensures Micro Four-Thirds cameras will be quieter and simpler, and suffer less shutter vibration. Eliminating the optical viewfinder (OVF) means photographers will be relegated to an electronic view finder (EVF) or rear LCD screen, which to date haven't been as easy to use. (Note: zooming rangefinder OVFs exist, but accurate ones are complex and expensive.)

Via an adapter, existing Four-Thirds lenses will work on Micro Four-Thirds bodies, retaining most functions. However, most of the current lenses will dwarf the new cameras.

Micro Four-Thirds Slashes Camera Size and Weight, Retains dSLR Benefits? (Outdoor Retailer Summer Market 2008) - 2
Micro Four-Thirds bodies will accept existing Four-Thirds SLR lenses via an adapter. Source:

Changing Chips Alter Design Requirements

Of great importance, if not well understood, is the relaxation of Four-Thirds' rigid telecentric lens standard. CCD imaging chips used in early digicams need light to hit the chip surface at a perpendicular angle, as their photosites sit in depressions that off-angle light can't reach evenly. This creates havoc that the original Four-Thirds standard addressed by demanding system lenses be perpendicular (telecentric). However, newer NMOS chips new used by Olympus and Panasonic don't suffer fatally from angled light, and advanced in-camera processing can address intensity differences that still occur across the frame.

This allows the Micro Four-Thirds rear lens element to sit closer to the chip which, in turn, allows lenses to be smaller. Thus unleashed, camera and lens designers can now employ classic wide angle lens designs unusable in SLRs, create zooms with rear elements that protrude into the camera body, and shrink many lens parts.

Micro Four-Thirds Slashes Camera Size and Weight, Retains dSLR Benefits? (Outdoor Retailer Summer Market 2008) - 3
Comparison between a Four-Thirds 2x wide angle zoom and an equivalent wide angle full-frame rangefinder prime shows potential size reductions of new standard. Four-Thirds lens is 11-22/2.8 (22-44 equivalent); film lens is 21/2.8. Photo by Rick Dreher.

Unanswered Questions

Other than the system details unveiled this week, we know nothing about actual Micro Four-Thirds cameras-what they look like, how they'll be equipped, what lenses and accessories will be available, when they'll be available, what they'll cost, or how much they'll weigh. We do know they're likely to rely on contrast-detection autofocus rather than phase-detection (as used in dSLRs). Will EVFs be built in or only be a slip-on accessory? We don't know. The new system will allow video-impossible with current dSLRs-and autofocus will likely be contained inside the lens, not the body. We don't know whether image stability is possible and if so, if it will be in-body or lens-based. We also don't know whether Leica and Sigma, current Four-Thirds makers, will issue Micro cameras and lenses. One guarantee: due to "not invented here" syndrome, despite being an open standard, Micro Four-Thirds won't be adopted by big players Canon and Nikon.

Is It Really New?

Only two currently available digital cameras warrant comparison to the Micro Four-Thirds concept: the Leica M8 and the Sigma DP1. The Leica, a classic mechanical rangefinder converted to digital by replacing film with an APS-C chip, uses Leica M-mount lenses dating back to the 1950s and will drain your wallet of about ten thousand dollars once fitted with a couple of lenses. The M8 is significantly larger and heavier than a Micro Four-Thirds camera is likely to be, it also lacks autofocus or, for that matter, any automation other than exposure metering. Far closer in concept, the DP1 is the first compact digicam fitted with an APS-C chip (a rare Foveon chip at that). It has a fixed, prime (non-zoom) lens, and a viewfinder is an optional accessory. It's quite small and light, at about nine ounces, and Ryan Jordan has been putting one through its paces this summer with considerable success. A reasonably complete DP1 kit costs about a thousand dollars. To get an idea of how a Micro Four-Thirds camera might look, take a gander at the DP1 and imagine being able to swap the lens with another anytime you want.


Four-Thirds is an open set of standards that revolve around the Four-Thirds imaging chip that's roughly one-quarter the area of the standard 35mm film frame (18 x 13.5 mm vs. 36 x 24 mm). The vast majority of dSLRs use reduced format chips, and most of those are so-called APS-C chips. Compared to APS-C, Four-Thirds is less wide, slightly less tall, and a bit squarer. In practice, APS-C and Four-Thirds are essentially the same; image differences between cameras using the two arise from chip design and image processing differences, not chip size. By comparison, no compact digicam imaging chip is remotely close in size to Four-Thirds (for example, the 1/2.7" chip used in many compact digicams is 5.3 x 4 mm). So-called full-frame dSLRs do differ considerably, but are not relevant here.


"Micro Four-Thirds Slashes Camera Size and Weight, Retains dSLR Benefits? (Outdoor Retailer Summer Market 2008)," by Rick Dreher. (ISSN 1537-0364)., 2008-08-10 00:15:00-06.


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Micro Four-Thirds Slashes Camera Size and Weight, Retains dSLR Benefits? (Outdoor Retailer Summer Market 2008)
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Addie Bedford
(addiebedford) - MLife

Locale: Montana
Micro Four-Thirds Slashes Camera Size and Weight, Retains dSLR Benefits? (Outdoor Retailer Summer Market 2008) on 08/10/2008 14:36:56 MDT Print View

Companion forum thread to:

Micro Four-Thirds Slashes Camera Size and Weight, Retains dSLR Benefits? (Outdoor Retailer Summer Market 2008)

Franco Darioli
(Franco) - M

Locale: @Tarptent
Micro Four-Thirds Slashes Camera Size and Weight, Retains dSLR Benefits? (Outdoor Retailer Summer Market 2008 on 08/10/2008 18:00:50 MDT Print View

Not longer availiable but....
There was the very nice but expensive Epson RD1. APS-C sized sensor, 6MP by Sony (the one used by the Nikon D100) . Typical Cosina look, similar size to the M Leicas but a bit taller.

Jonathan Guilbault
(Gilbo) - F
The relaxation of the telecentricity requirement is huge. on 08/11/2008 16:11:07 MDT Print View

The relaxation of the telecentricity requirement is a very big deal.

One of the biggest complaints against the 4/3 format is that it failed to deliver on the smaller size it promised, at least with respect to wide angle and normal lenses (the telephotos are certainly much more compact than their 35mm equivalents).

The main reason for this is that designing & building telecentric wide angle lenses imposes additional lens elements and a larger size and weight. Non-telecentric wide angle lenses have the potential to be MUCH smaller than telecentric ones.

The comparison in the article is a good one. Here's another: compare the Olympus 7-14mm with the Nikon 14-24mm:

The Olympus is nearly the same size, just about 1 cm smaller in diameter and length, but the Nikon at f/2.8 has twice as large a maximum aperture, and covers a full-frame image circle (which is twice the diameter & 4x the area of the 4/3 sensor)! Why are these two lenses so close in size considering the substantially larger light gathering area of the Nikkor? Because the telecentric requirement makes wide angle zooms for the 4/3 mount bigger than they'd otherwise be.

Micro 4/3 lenses will be even smaller than the potential savings in size implied by the above comparison. Without a mirror box retrofocal designs will be unnecessary (the Nikkor is a retrofocal design), which should further reduce the size of wide angle lenses in particular. No telecentricity, and no need for retrofocal designs means MUCH smaller wide angles --as Rick suggests, the rangefinder-size designs are once again in reach.

But with a 4/3 sensor Olympus and Panasonic can go way past the rangefinder designs, which needed to project an image circle TWICE the diameter of the one needed for a 4/3 sensor. So... these have the potential to be seriously compact, seriously high quality cameras.

P.S. I passed this news on to Mike Johnston:

He felt it was a significant event, saying: "I think that potentially it could up-end the entire camera market—which could look very different a year from now as a result." He subsequently notes, of course, that until we see actual products, all we know is the potential of the format. There's a photographic grave yard full of great ideas which were pulled off ineptly.

Incidentally, the Online Photographer is the best photography blog I've found, focused as it is less on the gear head minutiae (which he knows very well, particularly lenses)and more on the art of photography.

greg degler
(gregdegler) - F

Locale: West
Light Weight Digital Camera on 08/13/2008 15:04:11 MDT Print View

I've owned and used extensively many film SLR's. After much research, purchased the Nikon Coolpix L5 as part of an overall gear-lightening effort about 2 years ago. Why?
1. Nikon's reputation
2. 7.2 megapixels
3. 6 oz weight
4. NON proprietary batteries (uses AA's)
5. 5 x optical zoom lense

I have come to love this camera. It cost me about $240, it can now be had for much less: has them at $125 refurbished.

thanks for visiting,

Rick Dreher
(halfturbo) - MLife

Locale: Northernish California
Some µ4/3 news on 09/12/2008 01:26:25 MDT Print View

The first hardware is from Panasonic--the DMC-G1
More here, with surely a lot to come before Photokina.

Body only: 385g (not as light as I suspect we'll eventually see). Interesting is a nearly 1.5MP EVF. I've never seen one with that much resolution.

I'd look for Oly to come out first with respectably small and light system lenses, probably when they launch their first body. However, Panny's lens roadmap has some interesting glass ahead as well, including a 20/1.7 prime and a 7-14/4.0 superwide zoom.

Edited by halfturbo on 09/12/2008 01:33:45 MDT.