Introduction.
While the "point and shoot" market is rapidly being over-taken by smart phone cameras, there is an emerging category of small cameras that have excellent image quality, interchangeable lenses, high resolution image sensors and other qualitites which make them more like DSLR's than point and shoots. And they're not cheap.
My personal favorites are the SONY NEX-7 (Updated to the A6000) and the Nikon 1 V2 (updated to the V3). The NEX-7/A6000 is an APS-C class camera with a 1.5X image magnification factor over a full-frame camera. The Nikon V2/V3 is a "CX" or 1" class camera with a 2.7X image magnification factor.
The image quality from these cameras, under the right circumstances, is so good that it prompts the question of what are those circumstances where images from these cameras are indistinguishable from the larger DSLR's such as the D800E and the 5DMKIII?
Clearly not all circumstances. High end DSLR's have superior image sensors, generally lower noise and higher dynamic range. They support features such a exposure bracketing, off-camera flash, etc. They have longer battery life, fast auto-focus and focus tracking. And, of course, they support a vast collection of lenses which have grown over the years allowing for every possible picture-taking opportunity. But they are big and bulky.
On the other hand, these small cameras suport features which are not yet available on their larger counter parts. The A6000 has an articulated LCD display and does 10fps. It also supports "focus-peaking" for high precision manual focus. The V3 can do 60fps, focusses as fast as a DSLR and supports nikon lenses through an adapter (see link to V1, V2).
So, the purpose of this section is to explore the areas where small cameras are at least as good as DSLR's and to develop a set of "best practices" in using small cameras to ensure the highest picture quality.
My benchmark of quality is modest and simple. It is that when images are printed, sized 8" X 10" @360dpi, you cannot tell the difference, one camera to the next. The images should have the same sharpness, dynamic range, color saturation and contrast, and there should be no significant noise. The images should have the same color balance and, overall, have excellent quality. The benchmark is modest since it requires a resoultion of 3600 X 2880 which, for all cameras considered, is down-sampled from their native resolution. For the DSLR cameras, the lenses used should be the "walk around" lenses - 24-104mm f/4 (Canon), 24-120mm f/4 (Nikon).
I acknowledge that, even if the pictures are equivalent, there is still an argument for the larger DSLR, simply to generate a higher quality "negative" for archival purposes. Also, the impact of cropping has not been explored here (yet) and clearly the higher resolution cameras have a greater capacity for cropping and retaining overall quality.
Here are my recommendations:
1. Shoot RAW, calibrate cameras and white balance. Most cameras interpret color balance slightly differently and have slightly different color profiles. Hence, with all things being equal, the same image taken from multiple cameras will all look slightly different. As a minimum, images should be white balanced to a gray card. Ideally, a custom profile should be created using the Colorcheckr Passport or equivalent. In some circumstances, this may present a challenge (golden hour light, for example), so judgement may be necessary. In general, I have found that by creating a profile, the image quality of the smaller cameras is enhanced due to higher contrast and color saturation. See link to calibrating cameras.
2. Use fast lenses on the small cameras. This solves a multitude of problems. First, while generally more expensive, fast lenses, especially the primes, have superior imaging quality. Second, using fast lenses is particularly advantageous for medium to wide angle work, especially in low light. More on this later. Here is a list (as of May, 2013) of available fast lenses for the NEX-7 and the V2:
SONY E-Mount (A6000, NEX-7, etc.)
A comprehensive list of native E-mount lenses available/announced as of now (November 2014).
Most Samyang/Rokinon lenses also have Cine version:
Premium Zooms
Sony E 10-18/4 OSS
Sony E 16-70/4 OSS ZA - GOT
Sony E 18-105/4 OSS G PZ
Sony FE 24-70/4 OSS ZA
Sony FE 28-135/4 OSS G PZ (announced, not yet available)
Sony E 70-200/4 OSS G
Consumer Zooms
Sony E 16-50/3.5-5.6 OSS PZ
Sony E 18-55/3.5-5.6 OSS
Sony E 18-200/3.5-6.3 OSS
Sony E 18-200/3.5-6.3 OSS LE (Lighter, smaller version)
Sony E 18-200/3.5-6.3 OSS PZ (Power Zoom version for video)
Tamron Di III 18-200/3.5-6.3 OSS
Sony FE 28-70/3.5-5.6 OSS
Sony E 55-210/4.5-6.3 OSS - GOT
Primes
Rokinon E 8mm f/2.8 Fisheye
Rokinon CS 10mm f/2.8
Rokinon CS 12mm f/2
Zeiss Touit (E) 12mm f/2.8 - GOT
Rokinon FE 14mm f/2.8
Rokinon CS 16mm f/2
Sony E 16mm f/2.8
Sigma DN (E) 19mm f/2.8 - GOT
Sony E 20mm f/2.8
SLR Magic E 23mm f/1.7
Rokinon FE 24mm f/1.4
Sony E 24mm f/1.8 ZA - GOT
Rokinon FE 24mm f/3.5 Tilt-Shift
Sigma DN (E) 30mm f/2.8
Sony E 30mm f/3.5 Macro
Zeiss Touit (E) 32mm f/1.8 - GOT
SLR Magic E 35mm f/0.95
Rokinon FE 35mm f/1.4
SLR Magic E 35mm f/1.4
Sony E 35mm f/1.8 OSS
Sony FE 35mm f/2.8 ZA
Handyvision IBELUX 40mm f/0.85 (supposedly the fastest lens on any mount in production today)
Mitakon FE 50mm f/0.95 (new "Pro" version just announced)
Nikon 1 V2
10mm f/2.8✓
18.5mm f/1.8✓
32mm f/1.2 ✓
✓ - I have these