Dumb Printing Question-16 bit?

I agree, Darrell: it is an interesting thought. One question if I may: where did you come to understand that printers only work with 8 bit data? Can you point me to a reference (for my own understanding)? In an Adobe manual I have that's devoted strictly to printing, for instance, much to my surprise there's barely even a mention of bit depth.

Moshe, sorry I missed your point earlier. Perhaps you'd best make the S3 RAW file request in a separate thread. The skeptic in me has difficulty believing Fuji would create a smorgasbord of true bit depths in the output TIFFs. If HS-V2 output files' highlight pixels do contain 16 bits, perhaps Fuji had a momentary lapse of common sense and made the decision to not market the concept as it would just cause confusion. I hope you'll keep us posted on your findings (I write optimistically). Good luck!

earthbound_ca said:

I agree, Darrell: it is an interesting thought. One question if I
may: where did you come to understand that printers only work with
8 bit data? Can you point me to a reference (for my own
understanding)? In an Adobe manual I have that's devoted strictly
to printing, for instance, much to my surprise there's barely even
a mention of bit depth.

Click to expand...

You are very sharp to question this. Here is an excerpt from Real World Adobe Photoshop 7, p.739

"Tip: Don't downsample High-Bit Files for Printing. If you're printing a high-bit file directly from Photoshop, it's both unneccessary and unwise to downsample it to 8 bits per channel prior to printing. It's unnecessary because Photoshop is smart enough to downsample the data before handing it off to the printer. It's unwise because if you request color space conversions, you'll get better results allowing Photoshop to do the conversion on the high-bit data before it does its automatic downsampling than you will forcing Photoshop to make the conversion on an image that's already been downsampled to 8 bits per channel."

On the surface, that might seem to say that Photoshop "downsamples" the file to 8 bits. While the file is downsampled, it is not quite accurate to say it becomes an 8 bit file as in describing a digitally captured file.

The downsampling referred to here is the conversion of the files color bits to fit into the printers color capabilities (gamut). This is done according to the color profile for the printer. Even when not using color management printer profiles, the printer driver itself has a characteristic profile that it uses to tell it "when the computer sends me light-red-X, I need to spit out these inks in this pattern to make light-red-X." Different printers use different methods to acheive the creation of color on paper, from more dpi to varied dot spacing and patterns to varying the dot size.

So, you are correct that there is no specific reference to printers only using 8 bits because as defined for captured pixels it would not apply. Todays photographic inkjet printers, using their own ingenious methods, can create colors more infinately variable (within their gamut limits), than a simple one-color-per-pixel file.

A good current source of information is Real World Color Management. Very detailed and easy enough for even me to understand. For the down and dirty on printers, Mastering Digital Printing is one of a kind. There is information in there you would search long and hard to find anywhere else. Online sources and of course forums here sometimes help refine my understanding.
Darrell

snip*
"Tip: Don't downsample High-Bit Files for Printing. If you're

Darrell Wilks said:

printing a high-bit file directly from Photoshop, it's both
unneccessary and unwise to downsample it to 8 bits per channel
prior to printing. It's unnecessary because Photoshop is smart
enough to downsample the data before handing it off to the printer.
It's unwise because if you request color space conversions, you'll
get better results allowing Photoshop to do the conversion on the
high-bit data before it does its automatic downsampling than you
will forcing Photoshop to make the conversion on an image that's
already been downsampled to 8 bits per channel."

Click to expand...

Hi Darrell

So back to my very first post on this thread. It DOES seem to be better to leave a 16 bit file at 16 rather than print with an 8 bit file. Correct??

Craig

Darrell Wilks said:

earthbound_ca said:

I agree, Darrell: it is an interesting thought. One question if I
may: where did you come to understand that printers only work with
8 bit data? Can you point me to a reference (for my own
understanding)? In an Adobe manual I have that's devoted strictly
to printing, for instance, much to my surprise there's barely even
a mention of bit depth.

Click to expand...

You are very sharp to question this. Here is an excerpt from Real
World Adobe Photoshop 7, p.739

On the surface, that might seem to say that Photoshop "downsamples"
the file to 8 bits. While the file is downsampled, it is not quite
accurate to say it becomes an 8 bit file as in describing a
digitally captured file.
The downsampling referred to here is the conversion of the files
color bits to fit into the printers color capabilities (gamut).
This is done according to the color profile for the printer. Even
when not using color management printer profiles, the printer
driver itself has a characteristic profile that it uses to tell it
"when the computer sends me light-red-X, I need to spit out these
inks in this pattern to make light-red-X." Different printers use
different methods to acheive the creation of color on paper, from
more dpi to varied dot spacing and patterns to varying the dot size.
So, you are correct that there is no specific reference to printers
only using 8 bits because as defined for captured pixels it would
not apply. Todays photographic inkjet printers, using their own
ingenious methods, can create colors more infinately variable
(within their gamut limits), than a simple one-color-per-pixel file.

A good current source of information is Real World Color
Management. Very detailed and easy enough for even me to
understand. For the down and dirty on printers, Mastering Digital
Printing is one of a kind. There is information in there you would
search long and hard to find anywhere else. Online sources and of
course forums here sometimes help refine my understanding.
Darrell

Click to expand...

--
http://www.pbase.com/crs

craig said:

craig57355 said:

printing a high-bit file directly from Photoshop, it's both
unneccessary and unwise to downsample it to 8 bits per channel
prior to printing. It's unnecessary because Photoshop is smart
enough to downsample the data before handing it off to the printer.
It's unwise because if you request color space conversions, you'll
get better results allowing Photoshop to do the conversion on the
high-bit data before it does its automatic downsampling than you
will forcing Photoshop to make the conversion on an image that's
already been downsampled to 8 bits per channel."

Click to expand...

Hi Darrell

So back to my very first post on this thread. It DOES seem to be
better to leave a 16 bit file at 16 rather than print with an 8 bit
file. Correct??

Craig

Click to expand...

Yes, that would make sense from the point of view that converting color spaces or bit depth ALWAYS loses or rearranges color data. This would be true even if converting to a LARGER color space and then back.

Working with 16 bit files is generally done to preserve original color fidelity as much as possible. Converting to 8 bit tosses out most of the original data, never to be seen again. This does not make sense when you are sending the file to a device that can print colors "in between" the 256 steps offered by 8 bit. When you think of how a printer produces the colors on paper for us to see, you will realize that it doesn't have an 16.8 million colors like a box of crayons. It can spit out the colors it does have in combinations that will create millions of colors to our perception. Within the limits of the inks used, this is what happens. Incidentally 8 bit is capable of roughly 16,777,216 colors, 16 bit of roughly 281,474,976,710,656 colors.

That is not to say that 8 bit color is bad. Many fine photographs have been printed using 8 bit digital color.
Darrell

This turned out to be an interesting thread. thanks for taking the time for clarify a few things.

cheers
Craig

craig said:

This turned out to be an interesting thread. thanks for taking the
time for clarify a few things.

cheers
Craig

Click to expand...

--went to a sign show and they had a bunch of printers printing on vynl. some were very large, i asked what software they used and they all said RIP.

i recently bought a hp dj130 and the rip software but have not used the rip because i am learning how to use the thing without it first and that is challenging enough.

hy

My point was that printer drivers or RIP's cannot be categorized as 8 or 16 bit. You can send them data from a file (your picture) that is in 8 bit or 16 bit mode, but the printer driver or Raster Image Processor is just a converter. It does the conversion of your file into numbers the printer understands.
Darrell

hy said:

craig said:

This turned out to be an interesting thread. thanks for taking the
time for clarify a few things.

cheers
Craig

Click to expand...

--went to a sign show and they had a bunch of printers printing on
vynl. some were very large, i asked what software they used and
they all said RIP.
i recently bought a hp dj130 and the rip software but have not used
the rip because i am learning how to use the thing without it first
and that is challenging enough.

hy

Click to expand...