A Mirrorless Future?

The Panasonic G1 leads a potential trend to digital cameras with larger sensors, interchangeable lenses, and no mirror

By Uwe & Bettina Steinmueller Back to


In late 2008, Panasonic launched the Lumix G1, the first of a new breed: cameras with larger- sized sensors (compared to compact cameras), interchangeable lenses—and no mirror. You may say that the classic rangefinder is such a camera. True, but the usefulness of rangefinder cameras stops in the low telephoto range because the viewfinder crop gets too small; also, because you’re not looking through the lens, parallax can be a problem. Even at wider angles you often need extra viewfinders to cover the angle of view. (Single lens reflex cameras [SLRs] don’t share this problem because they offer a view directly through the lens.) Unfortunately, the mirror is not only a solution—it’s also a major problem.

• Mirror-slap produces noise
• Mirror-slap introduces shake (I consider this one of the major drawbacks of using a mirror)
• Manual focus is not the strength of this system
• Because of the mirror, wide-angle lenses have to be designed differently (as retrofocus lenses) to allow the space for the mirror. This makes them bigger, but it also seems as if it is more difficult to produce top-quality wide-angle lenses.
• The lenses and cameras get more bulky because of the inclusion of the mirror box and retrofocus lenses.

Rangefinders and SLRs were the two main systems to allow viewfinders on cameras (I am not talking about view cameras here). The digital world changed this a lot. Most consumer fixed-lens cameras use the LCD as the only framing device. There is an entire generation of new photographers that may never use a classic optical viewfinder (be it rangefinder or DSLR). Focusing is very often left to the camera’s auto- focus system. The beauty of this system is that the LCD can show exactly what the camera sensor sees. Why was this first implemented in point-and-shoot cameras? Because using the sensor for focusing and preview introduces heat that degrades the image quality with older sensors. Most DSLRs now feature live preview/video, which means they have to deal with the heat issue, but it is less of a problem today.

In the end, many photographers (myself very much included) want to use an eye-level viewfinder. So how can a viewfinder be implemented differently in the digital era? The solution is the electronic viewf inder (EVF). Unfortunately, most EVFs today are no real match for a good optical viewf inder, but to me, it seems just a matter of future engineering advances. I recently looked through an EVF on an RED f ilm camera and it displayed a great image, though it was also very bulky.

Manual focus can be excellent with EVFs because the EVF can show a magnified portion of the scene and focusing is very easy (even on today’s best DSLRs you cannot beat manual focus using live preview).

Digital SLRs also use a mirror box, but for a different purpose—auto focus. Consumer cameras use so- called contrast focus, which works from the sensor’s data. Today nearly all contrast-focus systems are slower than their DSLR equivalents.

Here are some of the promises of the new Micro Four Thirds standard:

• Smaller-sized cameras and lenses
• Less weight
• Improved EVFs (or none)
• Improved contrast focus
• Larger sensors than compact cameras
• Fast handling like DSLRs
• Video capability

Micro Four Thirds system

In mid 2008, Olympus and Panasonic, the main companies behind the Four Thirds standard, announced a new Micro Four Thirds standard. It has the same-size sensor as Four Thirds, but the design is without any mirror box. At Photokina 2008, Panasonic launched the f irst camera following the Micro Four Thirds standard: the Lumix G1. (Olympus recently launched the second Micro Four Thirds, the E-P1.) Actually, I think the G1 is even more interesting as a camera that shows what we should be expecting in the future from Panasonic and Olympus, as well as their competition.

While the G1 is smaller than all digital SLRs (though some Olympus cameras get close) it is not a compact camera by any means. When you look at a set that includes the G1 with two lenses (14–45mm and 45–200mm, which cover a range of 28–400mm in 35mm terms), the size and weight benef its show very well. The Panasonic-kit lenses are even image- stabilized (more later).

I now carry the Lumix G1 with these two lenses nearly all the time as my light travel kit.

The G1’s EVF is clearly a major step forward from all the other camera EVFs I have seen so far. A large DSLR’s optical viewf inder provides a still clearer picture but it doesn’t provide that great support for manual focusing. The G1 has the first camera EVF that I can live with. At the Photo Marketing Association (PMA) 2009 conference, I looked through a competitor’s EVF and it seemed poor in comparison. Clearly Panasonic raised the bar for camera EVFs. As always there is some engineering left to improve.

Focus and sensor

The autofocus on the G1 works very well, though not as fast as the best digital SLRs. This is only true with the two kit lenses so far. Some Olympus lenses work in AF but are much slower than the Panasonic lenses. The contrast AF relies on some lens features and the new Panasonic lenses are designed for it. Because Four Thirds lenses have firmware in the lens, some features can be improved later. In fact, Olympus offered firmware updates for some of its lenses so they could work better with the G1 (via a Four Thirds to Micro Four Thirds adapter).

The sensors for the Micro Four Thirds system are much larger than common point-and-shoot sensors, which translates into less noise. Conversely, the usual APS-C sensors and full-frame 35mm sensors are still bigger and create less noise.

The handling of the G1 is excellent and matches good DSLRs. It has good startup time and fast reaction on the shutter due to good AF performance. The G1 features a large swivel LCD that is one of the best in its class (matching the very good Olympus swivel LCDs).

Lens selection

Why would you want interchangeable lenses in the f irst place? Either you limit the focal range for a zoom or you create so-called “super” zooms (range 10× or higher). The higher the zoom range the lower the image quality. There is no way that, for quality photography, one lens can do it all for everybody. Making zooms with wider apertures also would lead to very bulky designs.

Right now only two dedicated lenses for the Micro Four Thirds system are available. These are both consumer-grade lenses and don’t allow the G1 to show what is possible with its sensor. Two more lenses were announced at PMA 2009. One is a 7–14mm ƒ/4 lens, which is small and has an great range of 14–28mm in 35mm terms. This is an amazing wide-angle range. I have used the much bigger Olympus 7–14mm ƒ/4 lens and just love it. I have to see the quality and also the price to make a proper judgment. But this an interesting lens indeed.

The other lens is a 14–140mm ƒ/4– 5.8 lens—an attractive range, but the quality remains to be seen. Normally 10× zooms are a major compromise. Still, this lens is very unique because it is built to support video on the new GH1. Panasonic says that this lens features continuous f-stops, which provide finer exposure adjustments if moving the video camera. It also should be silent, a benefit given that video also records sound. On the other hand, the G1 is the only camera that allows nearly all other lenses from other camera systems to be mounted via adapters. Even classic or new Leica M-mount lenses can be attached and work just fine in manual focus.

Note: some of the wide-angle M- mount lenses may produce blurred corners, likely due to a flat angle of light toward the sensor.

Image stabilization

Unfortunately, Olympus and Panasonic use different strategies for image stabilization. Panasonic has it built into its lenses (the Mega Optical Image Stabilizer), while Olympus uses anti- shake sensors. This means that the Panasonic image-stabilization lenses won’t stabilize on the Olympus cameras, though a photographer could still use them with image stabilization if Olympus implements sensor anti-shake in their f irst Micro Four Thirds camera. Alternatively, the excellent Olympus zooms can be attached to the G1(via a Four Thirds-to-Micro Four Thirds adapter), but don’t have IS support.

On another note, clearly the new trend is making hybrid cameras that function as still and video cameras at the same time. The G1 does not support any video, but Panasonic will soon ship the Lumix GH1, which has all the features of the G1 and supports 1080/24p and 720/60p video. Panasonic even designed the new 14–140mm ƒ/4–5.8 lens to feature continuous aperture and silent operation to allow a better video performance.


I find the development of the Micro Four Thirds system and especially the G1/GH1 quite exciting. We need to see more good lenses though. If this were so exciting wouldn’t the competition have some answers? At PMA 2009, Samsung showed an early concept camera called Samsung NX that follows the same path. Unfortunately, Samsung hasn’t joined the Four Thirds standard and instead has created its own APS-C–based camera. I predict that Nikon and Canon will follow this year or next with their own proprietary solutions. In the long run, the days of cameras with mirrors may be numbered.

About the Author

Uwe & Bettina Steinmueller
All images are copyright Uwe & Bettina Steinmueller. German photographer Uwe Steinmueller and his wife and partner Bettina came to live and work in the United States over a decade ago. They concentrate on taking photos for fine art prints, mainly nature and urban landscapes. Uwe has authored numerous books and articles about digital workflow. He is also the owner and editor of Digital Outback Photo www.outbackphoto.com.