How to properly compare RX-100 and NEX-6 kit high ISO noise?

Started Apr 29, 2013 | Discussions thread
captura Forum Pro • Posts: 26,014
Re: How to properly compare RX-100 and NEX-6 kit high ISO noise?

Erik Magnuson wrote:

captura wrote:

Some irrefutable law of physics should allow that the smaller sensored camera, in this case the RX-100, will have more pixel density, therefore much smaller pixels and resulting higher noise.

Nope, that's not the laws of physics.  Pixel size has little relation to noise - total sensor size and pixel efficiency (q3, fill factor, color filter loss) matters more.  For example, the NEX7 has smaller pixels than the NEX5 and also has lower read noise.  (See

For the same reason, an APS-C sensor should outperform an m43, and a FF outperform an APS-C, all things being equal.

In the case of the RX-100, all else is not equal.  It has a very efficient sensor.

I disagree.

- borrowed from

Digital Cameras: Does Pixel Size Matter?
Part 2: Example Images using Different Pixel Sizes
(Does Sensor Size Matter?)


"Current good quality sensors in digital cameras are photon noise limited and that is the best one can do (improving electronics will not improve the noise). This means that the basic performance can be modeled and predicted. The number of photons a digital camera collects in each pixel is directly related to the size (area that converts photons into electrons) of the pixel and the lens feeding light to those pixels. The more photons collected, the better the signal-to-noise ratio in the image, thus the larger pixel sizes using larger lenses do better in this regard. Larger pixel cameras have better signal-to-noise ratios at all levels, but this becomes more obvious especially at low signal levels compared to cameras with smaller sensors which use correspondingly smaller lenses. In the extremes of current digital cameras with small cameras having pixel sizes near 2-microns, and large pixel cameras (currently found in DSLRs), there is a factor of about 12 to 16 in photons collected. That means the large pixel camera performs at ISO 1200 to 1600 with similar noise and dynamic range performance of a small pixel camera operating at ISO 100. If you are a DSLR owner, do you take all your pictures at ISO 1600? If you are a small pixel point and shoot camera user, do you use ISO 400 often? If so, that is like using ISO 6400 on a large pixel DSLR in terms of noise and dynamic range performance! (Such effective ISO's can be achieved with DSLRs by setting the ISO to 3200 and the meter compensation to -1 stop if the camera does not have an ISO 6400.) It is this fundamental difference of pixel size as to why large pixel DSLRs with their larger lenses have such great noise performance, which leads to superb low light and fast action performance. Whether the difference in noise performance is great enough for you to choose a larger sensor with larger lenses, and thus likely a larger and heavier camera, is a decision you must make for yourself."

"The large pixel camera still shows lower noise, because the lens delivers more light."

 captura's gear list:captura's gear list
Sony Alpha NEX-7 Canon EOS Rebel SL1 Sony a7 Olympus OM-D E-M10 Canon EF 85mm f/1.8 USM +3 more
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow