I have now been shooting with the Sony NEX system for almost a year, and pretty much exclusively with it since March. I thought I should update my experiences with it not just because of my specific experience with the NEX system, but also because the mirrorless interchangeable lens camera will become an increasingly important part of photography. Even if you have no intention of working with such a camera, it is worth knowing a little about them. All of the photos here were shot with NEX cameras except for the photo of the cameras (shot with a Sony Hx9v). The shot above is handheld with image stabilization, White Mountains, New Hampshire, 18-55mm lens.
The Sony NEX system is an interchangeable lens camera system that has no mirror like a traditional SLR or DSLR. Olympus, Panasonic, Samsung, Canon and sort of Nikon make similar cameras. The reason I say sort of for Nikon is that Nikon went to a very odd format size for their sensor, creating a smaller sensor than anyone else's, which for me, makes the camera far less useful. The small sensor means less capability with higher ISO because of more noise, but more important, it requires extremely short focal length lenses which mean that depth of field control is very difficult. You cannot easily create a limited depth of field effect.
(Note on that: depth of field is affected by three main things, f-stop, focal length and distance to the subject, plus the appearance of depth of field is affected by the size of the image. As focal lengths get shorter, more "wide", depth of field increases. With very small formats like the Nikon 1, this can mean that f/5.6 with its lenses cannot do better than f/11 on more standard sizes. This is also true for Four Thirds and APS-C formats, though to much less a degree.)
No one really has a good name for these cameras. They are called mirrorless interchangeable lens cameras, advanced compact camera with interchangeable lenses, and more. The point is that none have an optical viewfinder and all have always on Live View or an electronic viewfinder. More on this in a moment.
I chose the NEX system because the cameras and lenses are extremely compact and small, yet use an APS-C size sensor (same size as a Nikon D7000 or a Canon 7D, for example). The size and weight gain (or loss!) is huge, yet I have lost nothing in image quality. I like having the slightly larger sensor compared to Four Thirds because it allows for more control over depth of field and noise characteristics are typically better. I also went to the NEX system because of Sony's well-deserved reputation for video (and the video from these cameras is very good indeed).
I have an NEX 5n and a F3K. I got these particular models because 16 MP is plenty for my needs and the tilting LCD is very important (it would be nice if it swiveled, but tilting is good). I have found that the images from these cameras is a little better than that from my Canon 60D and 7D cameras (they all have similar sized sensors).
I have a set of Sony e-mount lenses for the camera. These lenses are very compact and lightweight, a good thing. I have the Sony standard 18-55mm, which is a decent lens. I also have the 50-210mm, which is extremely compact for its size and very handy to carry, though the f-stops smaller than f/22 are worthless (this is pretty common on a lot of lenses -- manufacturers include smaller f-stops because people "want" them, but diffraction effects, an optical effect that has to do with physics and little to do with lens quality, catches up with them and images become soft and not very sharp).
The 50mm f/1.7 lens is a wonderful lens that I quite like for its speed and the ability to control depth of field so much with such a wide max aperture. The two shots below were done with it. I am still playing with its possibilities for shallow depth of field landscapes.
I also have the 16mm pancake lens that is very compact, but not quite as sharp as I would like it to be outside of the middle f-stops -- though I have found that I have to be very careful with focus to get the most out of it. Nik Software Sharpener Pro does help me get the sharpness needed, though. And I have the fisheye adapter for the 16mm which gives the equivalent of about 8mm (I had a chance to borrow a student's 8mm Rokinon lens for this camera and shot with it briefly -- it is quite a nice lens and better than the adapter). This next shot is with the fisheye adapter and 16mm.
The NEX is a relatively new system, so there are not a lot of lenses specifically made for it, BUT because of its size, you can get adapters to use a whole lot of lenses, including Nikon (though not the G series that must be set from the camera). Nikon has an advantage in that most of the standard Nikkor lenses allow you to stop the lens down from the lens rather than the camera, so adapters do not need to be fancy or expensive. They do not allow autofocus, though that is not so important for the lenses I have bought.
I wanted a small 300mm lens, so I bought a used Nikon 300mm F/4 manual focus lens that is a beautiful lens and very inexpensive ($199 from KEH plus $30 for the adapter -- the lens is practically brand new). The manual focus is amazing -- I had forgotten what a really good manual focus lens was like. Today's lenses, no matter how good they are, are optimized for autofocus and not for manual focus. The shot of the spider with its dinner is done with extension tubes and the Nikkor 300mm f/4.
I also have a Nikon 200mm f/4 lens that I use with extension tubes as a very compact, lightweight and very sharp "macro" lens. I have a Tamron 90mm macro with Sony Alpha mount that is a great little macro (and full functioned with the Sony adapter). And I have a Metabones Canon adapter that I can use with all of my old Canon lenses (Canon lenses must be set from the camera body, so this adapter connects the electronics to the body, and it is expensive -- it does not link the autofocus).
Another important point is that these cameras have no optical viewfinder. You can get an accessory electronic viewfinder (which I have), but when you first use this type of camera, it can be a bit unnerving because you are not looking at your subject with an optical viewfinder. The electronic viewfinder is quite good, but what you are seeing is what the sensor is seeing, not what you can see with your eyes.
That can be disturbing at first because it is not what one is used to with a DSLR. However, it is an advantage when you get used to it because this view always reminds you of the limitations of the camera and its sensor. You can only see what the camera is capable of recording. I do find I have to use the electronic finder for close-up and macro work or shooting in bright sun. I like the way it tilts so I can use the camera in more than just eye-level shooting. I do find that you have to be absolutely sure the internal diopter focus of the finder is set correctly, and unfortunately, there is no lock to this focus setting, so you need to stay vigilant.
That said, for most of my landscape work and any other work done early and late in the day, I use the LCD. It is a gorgeous LCD on both cameras and it works great in the conditions when most landscape photography is done, early and late. I have been asked about battery use, but Sony must be doing something right about power usage, because the batteries are small, yet I don't find these cameras use batteries anymore than my Canons under normal photography conditions. That said, I do have a tendency to turn the cameras off when I am not shooting, and video does use up batteries much faster.
One thing I do not like about focusing is the Sony lenses with manual focus. They use electronic focusing with an internal motor rather than direct gears on traditional lenses. I just find this really hard to use, so I rarely do. I do find that if I choose the focus points carefully with the AF setting that allows this, auto focus works very well.