05-14-2012, 03:51 AM
[quote name='wim' timestamp='1336838712' post='18149']
What do you mean to ask by this? By using a (coloured) filter like we used to do with film, in theory one increases resolution slightly, because we filter out unwanted parts of the spectrum, which overall make images less sharp, due to the reciprocal effects of recording a spectrum band on a medium. By limiting the light to a single wavelength, one can get theoretically the highest resolution (which is exactly why this concept is used in, e.g., imaging devices for creating processors on silicon wafers etc.).
[/quote]
I thought about it too naively. I thought that, placing a glass (or even plastic) in front of a lens always causes some dropping in the lens resolution, and the amount of resolution dropping depends on the quality of the added glass. (I know that for high-quality modern UV filters the affect on lens resolution is tiny, but I don't know about other filters like GND filters <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='
' /> ) After reading your response now I think that this influence is much smaller than the resolution increase caused by 1) limiting the waveband of photons that reach the sensor; and 2) removing the colour filters from the sensor.
Good to learn about this. It is intersting to know that for films, usually BW films have a much larger DR capacity than colour films; while for digital sensors, coloure sensors tend to have a larger DR capacity than BW sensors <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />
Thanks again,
Frank
What do you mean to ask by this? By using a (coloured) filter like we used to do with film, in theory one increases resolution slightly, because we filter out unwanted parts of the spectrum, which overall make images less sharp, due to the reciprocal effects of recording a spectrum band on a medium. By limiting the light to a single wavelength, one can get theoretically the highest resolution (which is exactly why this concept is used in, e.g., imaging devices for creating processors on silicon wafers etc.).
[/quote]
I thought about it too naively. I thought that, placing a glass (or even plastic) in front of a lens always causes some dropping in the lens resolution, and the amount of resolution dropping depends on the quality of the added glass. (I know that for high-quality modern UV filters the affect on lens resolution is tiny, but I don't know about other filters like GND filters <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='
' /> ) After reading your response now I think that this influence is much smaller than the resolution increase caused by 1) limiting the waveband of photons that reach the sensor; and 2) removing the colour filters from the sensor.Quote:Monochrome cameras, or rather sensors, have one disadvantage: they are much less forgiving when it comes to recording the DR of the subject than an RGB sensor (or film even). Essentially it means that we are back to very carefully applying Zone System parameters for optimal results, much more so than with RGB sensors, where when highlights are blown out, we may still have the situation where that only happened for a single channel. With Monochrome, it is just about luminosity, so if one channel blows out, that's it, as there is only "one channel".
Good to learn about this. It is intersting to know that for films, usually BW films have a much larger DR capacity than colour films; while for digital sensors, coloure sensors tend to have a larger DR capacity than BW sensors <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' /> Thanks again,
Frank