Having owned a pocketable point and shoot, Julia has discovered the convenience of the size but at the same time the poor quality of the photographs and the unreliability of the outcome from these inferior quality cameras. Like many people who had previously owned 35mm cameras, she knows the point and shoots simply do not measure up to the quality of the old film cameras. The predicament then is when she buys her next camera how does she keep the camera small and convenient but get that original quality back?
Not being an expert she has to rely on reviews, which can be very misleading, even on more professional sites like dpreview.com. One such review compared a Canon camera with a 1.5 inch sensor with another camera with a 1/2.3 inch sensor, suggesting that they might be of similar quality. Anybody who can figure out how to look up the effects of sensor size would know the quality coming out of a sensor almost seven times the sensor size of the lesser quality camera could not possibly have the same results. So her predicament is even more problematic unless she finds a camera sales person he can trust to give her the straight goods.
The sensor is the part of the camera that replaces film; in the old film days the larger the film the better the picture quality. The same is true of the digital sensors that replaced film. To give you an idea of how small a point and shoot sensor really is look at the difference in size between the 1/2.3 inch sensor is in comparison to the 1.5 in the following chart.
You can see immediately that Julia is not going to really improve her camera results if she simply replaces her camera with another point and shot with a 1/1.7 or 1/2.3 sensor, they are barely larger than the sensor you find in your cellular phones. The only way to improve her camera will be to get one with a larger sensor. So how does she do this while keeping the size manageable? The answer is in that in the last few years mirrorless interchangeable cameras have come into their own, these cameras have sensors than range from 1″ to sensors the size of the old 35 mm film. The sweet spot are those that have APS-C sensors which are 1.8″, sensors that are 14 times larger than point and shoot sensors. Keep in mind these new mirrorless cameras are as small as some point and shoots.
So what does she have to watch for when she is looking for a new mirror less camera? The key things in order of importance are lens quality, camera age, sensor size and processor age. Keep in mind all four of these elements are needed to ensure good quality. Remember lenses are something that do not age quickly so they will outlast your digital camera. Cameras these days have a life of three years before the technology leapfrogs. So it is quite likely you may be replacing the camera in a few years, but fortunately with mirrorless cameras usually the lens do not have to be replaced, and a good lens can sometimes be more expensive than the camera.
So lets take these issues one at a time. Lens quality is a tricky thing but generally speaking one looks for “fast lenses,” lenses with an f-stop of f2.8 or less when the lens is at its widest angle and hopefully not more than f4 when the lens is in maximum telephoto mode. If you look for a fast lens you will find that with zoom lens ranges such as 24-300mm, are never within this range; whereas lens with shorter ranges such as 24-70mm or 70-200mm can be f2.8 at wide angle and at maximum telephoto. So zoom lenses with shorter ranges are usually higher quality lenses. So the first issue is how low are the f-stops but the second issue is how the sensor size impacts how a lens magnifies. This is important so you are able to compare apples to apples. To compare lenses on different sensors you need to know the multiplier for the sensor. The multiplier enables you to will convert the camera’s lens specifications to a 35mm standard so you can compare the lenses of various cameras. The following table shows you how this works and includes the multipliers for each standard sensor sizes, to facilitate comparisons of various lenses.
So if you had a 4/3’s camera with a 24-105mm lens it would really be a 48-210mm lens, after you applied the multiplier of “2.”
The next thing to keep in mind is camera age and the age of the processor. It seems every three years there is a significant increase in the quality of cameras. A good example of why this is important would be the new Fujifilm E-X1 camera with a 1.8 inch sensor. If you compare its performance with a three year old Canon 5DMark II with a 35mm sensor almost twice its size, the Fujifilm camera outperforms the Canon! So camera age is very significant when it comes to quality. The following chart compares the best in class of the current mirrorless cameras, keep in mind I have not included full frame mirrorless cameras. It shows you the age of the sensor and camera as well as other important information.
If you take the time to research these cameras you will find that the Fujifilm is currently the top camera in this class, and has won the top prize at the worlds most prestigious camera show. This is likely because it is the only camera that does not use a bayer filter, nor an anti aliasing filter. The result is unparalleled sharpness and colour. For a good comparison between the Sony NEX and the Fuji X-E1 check out the following video (http://youtu.be/jmwEQB0KM8U). It is also interesting to note that Fujinon lens made by Fujifilm are found in Hasselblad lenses.
The following chart compares the noise and resolution of a 5DMarkII (full frame 35mm digital camera) with the Fujifilm X-Pro1( this camera has the same sensor and processor as the X-E1) and the Fuji comes out ahead!