Photographers who are old enough can probably remember the – by now discontinued – low-sensitivity slide film- and black-and-white films, like Kodachrome 25, Kodachrome 64 and Technical Pan. Those were produced for decades and had many fans because of their fine grain and the vivid colours, that is, the breath-taking reproduction of detail.
Even though photographers had been happy with these low-sensitivity films for decades, the sensitivity range below ISO100 disappeared rather quickly after the change in technology from analogue to digital photography. For some reason, most sensors today have a sensitivity of ISO200 as their basic setting, even though it is still possible to have acceptably short exposure times with ISO25 to 64 during the day.
I don’t know if the demand for sensors with an extraordinary High-ISO performance is really this high or if it is just the photographers who actually need this feature shouting the loudest. In any case, sensor manufacturers feel pressured to optimize their sensors towards low light photography – in most cases at the expense of the picture quality at lower ISOs.
For some – either because they do not have high expectations or because they already own a high-end camera – the picture quality that current sensors offer at ISO100 to 200 is sufficient. I belong to the so-called Gear-Heads, who are never satisfied. 🙂
Also, one should not forget that the the moment all segments of the camera market are shrinking. The pressure to miniaturise, headed by the smartphones, will lead to a lot of the mechanical parts of a camera being rationalised away – whether we photographers like that or not.
One example for this trend is the booming segment of high-end compact cameras, many of which are featuring a hybrid shutter mechanism. A mechanical shutter that allows exposure times of 1/4000 of a second and shorter is comparatively big and expensive to make. For a manufacturer it is therefore much more profitable to build a shutter that might only be able to do 1/1000, and then make shorter exposure times work electronically. However, the problem is that, at the moment, the sensor-data cannot yet be transmitted fast enough to actually achieve the promised shutter times of up to 1/32,000. This becomes obvious with fast movements, which lead to the rolling-shutter-effect.
Since an electronic shutter is obviously not suitable for action and sports photography, it is predominantly used to solve a problem – photographing in bright light without having to over-expose or stop down the aperture – which only exists because of the too-high base sensitivity to begin with.
Personally, I think this problem can be solved more elegantly with lower base ISO sensitivities. In addition, this solution would also have the following advantages:
- Less noise, higher dynamic range and larger headroom in the RAWs. This would be an advantage especially for the 1”, m4/3 and DP cameras.
- Longer exposure times would also be possible without using a ND filter. It would be possible to achieve an exposure time of 1/25s at ISO25 and f/16 even on a bright summer day (“Sunny 16” rule). Under the same light conditions, current cameras absolutely need a ND1000 filter.
- There would be less or even no rattling of the diaphragm if the camera is one of those that are programmed to stop down the aperture if they cannot further reduce the sensitivity in very bright light (this only applies to Liveview). This is the case with practically all m4/3 cameras by Olympus.
What is your view on High-ISO performance being prioritised in the development of sensors? Do you think that the path that sensor manufacturers have set out on is the right one, or would you, like I, rather have some more sensitivity settings at the lower end?