Scanners 36 Bit Vs 42 Bit?

[Tom the Tenor]

Hi, Can anyone set me right in relation to what 36 Bit Versus 42 Bit means with Scanners as I am thinking of buying one. Not quite ready yet for the plunge with digital cameras. Thank you, TTT.

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What we want is a bit of Pop Music, none of this Beethoven!!

[Century]

I have a cannon 1220U scanner, 42 bit, coupled with a notebook, I can tell you that when scanning complex horizontal and vertical lines etc in a schematic, it would appear that the 42 bit makes a big difference. I might add that I don't know what I'm talking about here, it's purely an observation. Good luck!

[fobotcso]

Although I don't doubt that what Century says is correct I can't see why it should be the case. The crispness of a scanned image is more to do with the resolution; that is the dots per inch (dpi). Typically this is 600 dpi and better that anything that your monitor or printer can show you. However, when you enlarge a scanned image, that's when high-res scanning is useful.

The "bit" count is more to do with how each of those dots is "seen" by the scanner. Simply, if you scan an image in greyscale and all you want is 256 shades of grey (a lot!) then 8 bit scanning is enough as 2 raised to the power of 8 is 256. So colour scanning at 36 bits coding for each pixel will give lots and lots of colours. My scanner (top range Umax but three years old) does 36 bit sampling but then says that the output is 36 bit hardware and 24 bit system. I have no idea what that means! I imagine that 42 bit sampling will detect delicate textures and subtle colour differences better than 36 bit. Hope some of this may help. Mr F.

[Tom the Tenor]

Thanks, Century and fobotcso for your replies. I have now been up since 6 pm yesterday evening and feel that I will need to re-read your replies later tonight after some sleep to get my head around the information given, I am just too tired at the moment! Thank you, TTT.

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What we want is a bit of Pop Music, none of this Beethoven!!