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Choosing a Smaller Camera for Outdoor Photos: How Small and How Light is Just Right?

Fussy about your photographs—and the size and weight of your outdoor gear? Me, too. So how small and how light can your camera be and still deliver high-quality images?

To find out, I talked with one of the main brains at—perhaps the internet’s premier photo gear website and a popular hangout for earnest camera junkies.

Richard Butler is the site’s News Editor, an outdoor fan himself and someone who has monitored the evolution of a new category of midsize cameras since the first models debuted in 2008—cameras that are smaller and lighter than full-size digital SLRs (think Canon and Nikon), but more sophisticated than pocketsize point-and-shoot cameras.


Can these ’tweener cameras, which categorizes as mirrorless cameras, offer the creative control and image detail that professional outdoor photographers attain with full-size DSLRs?

Butler, who earlier this year chatted with me at REI's downtown Seattle store (just blocks from’s new editorial offices), says yes. That's him in the photo below, using an Olympus OM-D E-M5.

OK, great. So how small and how light can an earnest but nonprofessional photographer ( calls people like me “enthusiasts”) go?


Butler—a native of Gloucester, England (“I very nearly wore my hometown rugby shirt just to sneak a reference to Gloucester into a photograph,” he said); a bright, affable fellow who studied to be a chemist (though his heart was in photography); an avid cyclist (both road and mountain) who owns more bikes than cameras; and an REI member—offered detailed input, which I’ll spread out over 2 posts:

  • Part 1 (today): Butler discusses the pros and cons of mirrorless cameras and explains why active outdoor types who are particular about their pictures ought to at least consider the mirrorless format.
  • Part 2 (tomorrow): He sizes up models available on the market today, though as with smartphones and televisions and even techy outdoor gear such as headlamps, cameras are constantly evolving. That means today’s cutting-edge model might be a has-been a year from now, maybe months from now.

Note: Butler and the rest of the editorial posse spent much time last month in Cologne, Germany, at Photokina, a major trade show where many interesting new models were unveiled (though not all are commercially available yet).

Before we head into the Q&A, we should define these basic terms:

  • Compact camera = point-and-shoot.
  • Mirrorless camera = middle ground between compact and DSLR cameras, offering interchangeable lenses but no optical viewfinder.
  • DSLR = Digital single-lens reflex camera such as full-size Canon or Nikon models.

    Note: The defining feature of an SLR is the reflex mirror that redirects light through an optical viewfinder. Some mirrorless cameras offer an electronic viewfinder (EVF), either built in or made available as an add-on option.

Check out the photo below to get an idea how mirrorless cameras size up. A standard DSLR, a Canon Rebel, is show at the far left. The other 7 cameras are all smaller mirrorless alternatives.


Canon Rebel XSi (one of the smallest full-size DSLRs on the market) on left; 7 mirrorless cameras on the right.

Most mirrorless cameras weigh less than 20 ounces with a standard “kit” lens attached. DSLRs start around 25 ounces and go higher. Mirrorless cameras are commonly 10% to 40% smaller than DSLRs.

Camera gearheads should be aware that I asked Butler to use layman’s language as much as possible when discussing camera technology. Content at is more advanced and aimed at tech-savvy pro and near-pro camera devotees. Even so, the site offers a splendid glossary that makes the nomenclature easier for casual readers to grasp. 

REI Blog: To produce high image quality, what factor matters most in a camera?

Butler: The No. 1 determinant of image quality is sensor size. Most people with compact cameras don’t realize just how tiny the sensor is, basically 4mm x 6mm. If you use a bigger sensor, you have a larger area over which to capture light. The more light you capture, the better your picture is going to be. It’s that simple.

The downside of having a large sensor is that you require a bigger lens to gain the same field of view.

REI Blog: How large are DSLR sensors?

Butler: Most DSLRs these days use a sensor size called APS-C, which comes from a rather obscure small-film format that existed at the very end of the film era called Advanced Photo System (APS). It’s about a third smaller than a traditional piece of 35mm film, but it’s still more than 10 times larger than a sensor in a compact camera.

Until a few years ago there was no real option. You either bought a DSLR, which as I say has a sensor 10 times bigger than a compact camera, but is a big, bulky piece of kit and quite hard to carry around. Even the smallest ones are quite sizable. Or you bought a compact camera and lived with the compromises.


Mirrorless cameras: Panasonic Lumix G3, left, and Olympus OM-D E-M5.

REI Blog: But is this new midsize category filling that gap?

Butler: Over the last few years a middle ground has started to emerge. Some of them have APS-C sensors, some of them have what are called Four Third sensors. They’re 8 to 10 times larger than a compact camera. We call them mirrorless cameras, though no sort of firm name has emerged for them yet.

But they really do offer a really nice compromise between image quality and size. In many respects the image quality is as good if not identical to DSLRs.

REI Blog: That’s impressive to hear. Yet people tend to equate bigger with better, so some may be skeptical of that claim.

Butler: For instance, the Sony NEX has exactly the same [APS-C] sensor in it as the most popular DSLRs on the market. The image quality is absolutely indistinguishable. Micro Four Thirds cameras have a sensor that’s a little bit smaller than that, about a third smaller. But as I say that’s still 8 times larger than a compact camera.

REI Blog: At the risk of getting technical, we better define some terms. What’s the difference between Four Thirds and Micro Four Thirds cameras?

Butler: Four Thirds was a DSLR system announced in 2002, but it was never the success they hoped it would be. It still included a mirror, and never really offered the size benefits over APS-C DSLRs that the system was supposed to give.

Whereas the Micro Four Thirds system, the newer system (introduced by Panasonic and Olympus in 2008), takes the mirror out and shortens the distance between the lens and the sensor. Because you don’t have to have a huge mirror flipping up and down if front of the sensor, you don’t need the clearance for it to do so. It suddenly makes the cameras a lot smaller without having any impact whatsoever on the image quality.

REI Blog: So what’s the difference between APS-C and Micro Four Thirds sensors?

Butler: It’s just about sensor size. To directly compare these systems, you need to think of equivalent focal length, which basically translates into the focal lengths we used in the 35mm film days.

So with an APS-C camera, you’ll multiply the actual focal length by 1.5 to work out the field of view it will give you.

For instance, to offer a 28mm wide-angle setting, an APS-C camera will need an 18mm lens, whereas a Micro Four Thirds camera will only need a 14mm lens. That just means that all Micro Four Thirds lenses can be that little bit smaller.

REI Blog: Is there a significant quality gap between APS-C and Micro Four Thirds sensors?

Butler: It’s not a huge gap. It just so happens that the 16MP (APS-C) sensor Sony has created is one of the best sensors that we’ve ever seen. It really is jaw-dropping if you’re not used to modern cameras. If you start editing the RAW files, and try and to pull detail out of the shadows, you can keep pulling more and more information out. The new information is there and it’s clean–there’s very little noise [the equivalent of graininess in film-based images]. The great thing is we’re starting to see a similarly good sensor in some Micro Four Thirds cameras.

If you fancy yourself as Ansel Adams, and you were going to spend your entire day sitting on top of a mountain to get one photograph, and you want that photograph to be as perfect as can be, you probably want an APS-C sensor. But then again if you’re willing to do that, you’re probably willing to hike up there with a full-size professional DSLR. Differences exist and can be argued about on the internet, but I think in real-world usage are not significant.


L to R: Canon Rebel XSi (among the smallest full-size DSLRs); Sony NEX-5N; Samsung NX-200; Canon Powershot G1X (all mirrorless cameras).

REI Blog: Can a full-size DSLR give a photographer any edge?

Butler: There are still some advantages. The choice of lenses and the auto-focus system’s ability to keep refocusing on moving objects are the main advantages that DSLRs still offer.

DSLR systems, for the most part, have been around for 15 years now and are roughly continuations of systems that go back 20 and 30 years. So they have very well-established lens ranges.

Also their auto-focus systems have been painstakingly developed over 30 years and are very, very good. So if you’re hiking and you think you might want to take pictures of birds in flight or other fast-moving objects, at the moment there’s not to match a DSLR in terms of its ability to continually refocus and keep tracking an object.

With the Sony NEX, for example, the image quality is fantastic in low light, but the focus speed drops off a cliff. If photographing fast-moving objects is your particular interest, then you’re probably still going to have to carry a DSLR.

REI Blog: Cameras remind me of backpacking gear. They include so many subtleties, and so many models exist, that a person can get dizzy trying to understand every nuance.

Butler: As soon as you start to talk about one thing, there’s so much variety that it’s easy to get carried away covering every possible product. “Ah, yes, then there’s this and this and this.” Instead of offering a clear picture, you just end up muddying the waters. There are always more choices than you can make sense of, which isn’t a very helpful thing to tell someone.

REI Blog: How do mirrorless cameras handle video?

Butler: Most if not all of them shoot full HD, 1080p video. The exact specifications and the exact format they shoot. If you’re really interested in doing video and you’re going to be doing some editing when you get home, it’s worth doing a bit more research about exactly what you want.

In general terms, if you just want to get high-quality snippets of video, any of these cameras will serve you well.



Left: Olympus OM-D E-M5 mirrorless camera; right: Olympus XZ-1 compact.

REI Blog: For people fanatical about weight and size, can any compact point-and-shoot satisfy a picky photographer?

Butler: If you want to go ultralight, there is a subset of cameras with what are called 1 over 1.7 or 1 over 1.8-inch sensors. That’s the [Samsung] NX-5, the [Samsung] XZ-1, the [Canon] S95 and S100. Those offer what was until recently the only alternative between buying a very small sensor compact and buying a DSLR. This breed of cameras is thriving, so if ultra-small is a priority for you, they may offer a good compromise.

Note: Since our initial conversation, Sony has introduced the Cyber-shot DSC-RX100, a much-touted compact camera with a sensor roughly halfway between the size of a high-end compact camera and most mirrorless models. Despite this larger sensor, it retains the size of a compact camera and will fit in most outdoor jacket pockets or even loose-fitting pant pockets. Says Richard: "You pay a premium for that bigger sensor (around $650), but it adds another interesting size/quality/price balance to the mix and is likely to be popular out on the trail." And for pro-level shooters, in December Sony will introduce the RX1, an elite compact camera featuring a full-frame sensor that will sell for (whoa) $2,800. Butler calls the RX1 “heroically niche.”

A discussion of specific models can be found in part 2 of this series.

REI Blog: It sounds fair to say you find mirrorless cameras to be a pretty attractive category.

Butler: I’ve worked for since 2007, so I’ve really seen these cameras emerge. The first one was the Panasonic G1 in late 2008. It’s amazing how much more mature they’ve gotten in such a short space of time.  They’ve gone from being a lovely concept to being genuinely competitive in terms of price, features and image quality.

REI Blog: What’s the category’s chief appeal to you?

Butler: It’s the much-needed middle ground between a full-size DSLR and a compact camera. There’s little, or in some cases no difference at all in image quality. They’re just that bit more portable.

Unless you have very specific needs, I think everyone should think hard about whether they really need a DSLR the next time they go to a camera shop. I really think these cameras are getting there.

Which is not to say there aren’t some people who will still benefit from the things a DSLR offers. Some people will never step away from an optical viewfinder. The continuous shooting and the ability to focus-track for various reasons that would are very technical. The phase detection autofocus in a DSLR is quite hard to match at the moment in any other system.

But, for an awful lot of people, for an awful lot of shooting times, they should at the very least have a go with one of these mirrorless cameras and see how they get on.


Photos courtesy of or by T.D. Wood. Above: Panasonic Lumix G3, left; Olympus OM-D E-M5 mirrorless cameras.

Posted on at 4:58 PM

Tagged: Photography

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