gvarner wrote:
What determines the dynamic range in a sensor? Is it just the number of pixels and the sensor dimensions? I don’t recall seeing dynamic range info featured in camera specs, e.g. +- 5 stops. Thank you for you thoughts.
Soooo many factors.
> Sensel size (the size of each photosensitive site on the sensor)
> Sensel technology (lenses, tri-color filters, anti-aliasing technology, IR/UV filtration, etc.
> Physical properties not related to sensel size (distance from next point in circuit, heat dissipation, shielding, etc.)
> Amplifier design (sensel output is voltage, and is usually amplified at certain ISOs)
> Analog-to-Digital converter configuration (pre- or post-amplification, shielding, etc.)
> Processing scheme (Bayer algorithms that merge adjacent digitized sensel voltage values into pixel values)
That's just a small sampling.
Most cameras can record raw files that contain the digitized values from each sensel, so you can process the data on a computer. However, each raw file ALSO contains a JPEG processed in the camera for use as a preview image by your computer operating system. That JPEG also contains an EXIF table of metadata that records exposure data, hardware configuration, time, date, and camera menu settings.
The processing algorithms used to develop raw data into images CHANGE OVER TIME. They get better! So a modern algorithm in 2021 software might provide cleaner, more accurate images than software used in 2005.
Dynamic range is typically measured by dxomark.com, for most popular camera bodies. It is an IMPORTANT measure of sensor performance, but hardly the most important in all situations. If you head over there and check out some of the graphs, you can see a trend:
> Full frame cameras tend to record 14 to 15 stops of dynamic range.
> APS-C cameras tend to record 13-14 stops of dynamic range.
> Micro 4/3 cameras tend to record 12-13 stops of dynamic range.
There are exceptions, of course, but this is close to state of the art.
THAT SAID, to get the full potential of that range, post-processing raw files into images generally is required.
In-camera JPEG processors produce images with only around 5.5 to 6 stops of dynamic range. Silver Halide photo paper can reflect about 5 to 5.5 stops of that dynamic range. Monitors (typical 8-bit monitors) can display maybe six stops of dynamic range properly.
And while you CAN manipulate camera menu features on most models to extend highlight and shadow range conversion to JPEG, most people don't do that. It's easier to record raw data and post-process it to recover some of the remaining details the sensor recorded.
In post, you can COMPRESS the tonal range to fit the output medium of choice, giving viewers the illusion that they are seeing a better approximation of reality.