In this post I will be talking about Large-sensor cameras (ie. Sony RX100) vs Mirrorless Interchangeable lens cameras (ie. Nikon 1 J2). Large-sensor compact cameras with fixed lenses are becoming more and more popular in the last couple of years. A few years ago, when we wanted to purchase a compact camera, the only option is to have a camera with a small sensor. This changed dramatically since the introduction of the Micro Four Thirds system in August 5, 2008. Both Olympus and Panasonic brought a new camera system with more compact camera bodies and with a relatively large sensor.
The thing is that in order to enjoy the compactness of MILC cameras, you need to also purchase a compact lens. Buying a Sony NEX-5N with a Sony E 55-210mm f/4.5-6.3 lens certainly looks pretty big. Some people opted buying smaller lenses with limited focal range and large focal lengths in order to keep the whole package portable for their usage. Indeed, when you want to check the camera size, as with mirrorless cameras, you should add the lens size into the equation.
Take a look at the following image:

This perfectly illustrated what I’ve meant. What camera plus lens combo do you prefer carrying around, the left (with 55-210mm lens) or the right (with 16mm lens)?
The answer for that is simple if size is concerned. But of course with interchangeable lenses it’s not only the size that matters, but their functionality. So that where the problem lies. Sony NEX MILC have relatively larger lenses because NEX utilize APS-C size sensors. The smaller the sensor, the more compact camera bodies and lenses can be made.
The following diagram (via camera image sensor) will give you a good overview of sensor sizes on various devices:

The sensors are arranged from the right to left: Apple iPhone 4S, Sony Cyber-shot RX100, Olympus OM-D E-M5 and Sony NEX-F3.
The iPhone 4S has a very small sensor, allowing it to be embedded in slim and compact devices, like mobile phones and tablet devices.
I mentioned that with a larger sensor, a larger lens need to be used for a given focal length in order for the projected image cone to cover the whole sensor. This is one of the “problems” with Mirrorless Interchangeable Lens cameras that use large sensors, you will have to buy bulky lenses if you want to shoot with telephoto-zoom lenses (ie 18-200mm, 55-210mm). So yes, you can but a MILC and purchase a Sony 16mm f/2.8 pancake lens because it’s small, but will it fit you shooting habits and help you get the results that you are after?
MILC have their own advantages. On of the best advantages is flexibility and versatility. You can attach many type of lenses, everyone was designed to perfectly fit specific needs.
That’s were large-sensor compact comes in. Large-sensor compact cameras have their own targeted market. First of all, people want to get high image quality, preferably image quality close to what you get with DSLR cameras. Second, people want to carry compact cameras rather than heavy and bulky cameras. Third, many people don’t want or need to mass up with interchangeable lenses nor they need that flexibility it brings with it.
Large Sensor Compacts with Prime or Zoom Lens?
So in general, Large-sensor compact cameras (LSC) are referred to compact cameras with fixed lens (not interchangeable) and relatively large sensor (Compare to compact point-and-shoot). Some large sensor compact cameras carry prime lenses (no zoom), like the Fujifilm with its APS-C size CMOS sensor. Others like the Sony Cyber-shot RX100 have a fixed 28-100 mm f/1.8-4.9 zoom lens with a 1-inch Exmor CMOS sensor.
So we can find two types of Large-sensor compacts:
- Large sensor compact cameras with prime lens (no zoom, fixed focal length)
- Large sensor compact cameras with zoom lens
The sensor size varies from one camera to the other. Many fixed-lens large sensor compacts have APS-C sensor, because they don’t intend to use zoom lens (lens will be larger on APS-C, depends on the focal length range of course) and they were designed for optimal image quality. In this category we can find cameras like the Fujifilm FinePix X100, Sigma DP1, DP1s, DP1x and Leica X2 (24mm f/2.8 prime lens with APS-C CMOS Sensor).
In the second category we can find consumer level digital cameras like the Sony RX100, and Canon PowerShot G1 X. This category is targeted to a much larger market. This is why those type of cameras are becoming so popular.
Disadvantage of Large Sensor Compacts
We’ve mentioned the advantages of large-sensor compacts (high image quality, compact size, on need to change lenses, etc.), but what about the disadvantages. Every type of camera has it cons and pros. The main disadvantage of Large sensor compacts is that you can’t change lenses and you can’t enjoy the same flexibility that you get with MILC.
The thing is that this disadvantage might not be a disadvantage at all. It really depends on what you need. If you just want to shoot great quality images of your family and friends, you probably be better with a large-sensor compact camera instead. If you are planning to shoot ultra wide-angle shots, 1:1 Macro or need long telephoto range, MILC is probably the best way to go. With MILC you can also enjoy a nice selection of fast prime lenses, that will help you get this beautiful Bokeh effects and shoot photos in low light.
If you intend to shoot stock photography or want to advance your photography skills, MILC will give you more tools to get the job done and you will not be limited in what you can achieved.
Not Superzooms, but Nice Range
The Sony RX100 and the Canon G1 X are the two large-sensor compact cameras that grab the most attention in 2012. The RX100 features 1-inch 20.2MP CMOS sensor and has a 28-100 mm F1.8 – F4.9 lens. The Canon PowerShot G1 X comes with a 1.5-inch 14.3MP CMOS sensor and has a 28-112mm F2.8 – F5.8 lens.
You can see that both utilize relatively large sensors, although not as large as APS-C.

Sony have decided to choose a much smaller sensor in order to keep the camera size much more compact.
The above image illustrates the difference in size between the Canon PowerShot G1 X and the Sony Cyber-shot DSC-RX100.
Sony has made a compromise, choosing a smaller sensor which may lead to decrease in image quality in general, but make a camera that is much more compact in size. You can visit camerasize.com to compare sizes of digital cameras yourself, even with interchangeable lenses!
Another thing to note here is that both cameras offer a modest zoom range (Canon: 28-112m 4x zoom, Sony: 28-100mm, 3.6x zoom). As I’ve mentioned, putting a larger zoom lens will actually kill the compactness, and it might not even fall into the large-sensor compact category by definition. It seems that the RX100 perfectly fits this category, because the camera is indeed very compact, one that you can even put in your pants or shirt’s pocket.
Another thing to talk about is the aperture of the lenses. The Sony features a f/1.8-4.9 lens and the Canon G1 X features f/2.8-5.8, very fast in the wide-angle, less when you zoom. This is also one aspect of large-sensor compact cameras that we see lately, faster lenses for low- light wide-angle shots. Pretty useful when shooting indoors, street photography at night, museums, etc. This is a feature that the targeted market will certainly take advantage of.
Which One Should I Buy, MILC or Large Sensor Compact Camera?
Making a decision is not as hard as you might think. There are quite a lot of differences between the two type of cameras. When you but a MILC you buy into a System. You will have the option to enjoy a wide selection of interchangeable lenses, everyone with its own unique strength. You will have the option to upgrade to more advanced model (ie. from PEN camera to OM-D E-M5). MILC cameras are also more advanced and offer more advanced features that you might not find in large-sensor compact. For example, let’s look at the OM-D E-M5, it is weather-sealed, have 5-axis image stabilization, offers a tilting display, etc.
Camera manufacturers invest more money in those type of cameras. You might prefer to buy a Sony RX100, but who knows if there will be a successor for this camera in the future (I guess it will be). The thing is that you might buy the RX100, but in two years from now it might be a Canon large sensor compact instead. With MILC you will probably show your loyalty to one company for quite a long time.
I thing that both type of cameras have their strength and weaknesses. I personally don’t like changing lenses, don’t need special lenses and find the compactness of the RX100 more appealing. After all, I will bring much more great photos if I can carry a camera everywhere I go. I already have a DSLR and it’s certainly not convenient to carry around, same as with MILC with several lenses. If you are buying a MILC with just one compact lens, it will probably won’t be a problem. The portability inconvenience starts when you carry more than on lens and a few accessories. Of course just stressed my own opinion, you might thing otherwise.
Make you own choice and don’t forget to take all the cons and pros into account, read the specs, look deep into your specific needs as a photographer and make a smart buying decision. Thanks for reading.