Questions About Sensor Size and Pixel Pitch

Started 2 months ago | Discussions thread
Mark Scott Abeln
Mark Scott Abeln Forum Pro • Posts: 13,941
Don’t forget quantum efficiency and read noise

Pixel pitch = mm per pixel = square root ( area of sensor in square millimeters / number of total pixels )

Quantum efficiency is also important as it is equal to the light falling on the sensor divided by the amount of light actually detected, and this QE was often very low for old sensors. But this is tricky, because presumably most people want color images and you’ll get the most efficiency from a sensor that captures only monochrome light. Arguably, the optimal efficiency is one where the color filters exactly match the spectral efficiency of the typical human eye, but we aren’t there. That being said, some sensors are more efficient than others and still give good colors. But please understand that this is still hard to characterize simply. If you so desire, I can give you some more information that can help.

Back in the old days, the area of the sensor that was actually covered by actively light sensitive pixels was rather low, with the bulk made up of insensitive circuits. Microlenses have helped counteract this and so QE increases.

Finally, read noise has decreased significantly over the years, and along with this, high ISO performance is much better.

 Mark Scott Abeln's gear list:Mark Scott Abeln's gear list
Nikon D200 Nikon D7000 Nikon D750 Nikon AF-S DX Nikkor 35mm F1.8G Nikon AF Nikkor 50mm f/1.8D +2 more
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow