difference between resolutions 1200dpi\8bit and 2400dpi\1bit

[vitek.david]

How is difference between resolutions 1200dpi\8bit and 2400dpi\1bit?
Example KM has 1200dpi\8bit and Xerox has 2400dpi\1bit

 

[Stephen Marsh]

Dots per inch (DPI) and or Pixels per inch (PPI) is one variable.

Bit depth per channel is another separate, independent variable.

8 bit equates to 256 unique intensity values = 0-255, or shades of gray (grayscale mode in Photoshop)
1 bit equates to 2 unique intensity values = 0-1, on or off, black or white, lineart with no shades of gray. (bitmap mode in photoshop)


Stephen Marsh

 

[vitek.david]

i see, but more people ask me, what resolution is better.

 

[Stephen Marsh]

It is all about job content.

Text, vectors, lineart etc is in theory better at a higher resolution - however you may not be able to see that much of a noticeable difference between 1200 and 2400, depending on your input files.

If you are looking at two different machines, then the reps from both manufacturers should be more than willing to give you a sample print from your test file on each printer.

There are many things that go into a decision on a machine, this (resolution) is just one small factor in the decision making process.


Stephen Marsh

 

[Stephen Marsh]

Some links to test forms that may help you decide:

Digital Press Certification: Press Test Forms v2.1 | IDEAlliance

FograCert Testforms - www.fogra.org

Downloads [ECI.ORG] (various Altona Test Suite forms)


Stephen Marsh

 

[SWTilden]

Typically, a one-bit (black and white) file will be best for reproducing a black-and-white line drawing or similar -- such as a scan of provided page of type you need to reproduce.

The 8-bit file, with input grays, allows the RIP to apply a bit more of its "smarts" in reproducing the input file the best way possible on the output device you've selected.

 

[gordo]

How is difference between resolutions 1200dpi\8bit and 2400dpi\1bit?
Example KM has 1200dpi\8bit and Xerox has 2400dpi\1bit

A one bit device needs to cluster the marks it makes into halftone dots in order to simulate grey levels/tones in the final printing.
An 8 bit device simply makes marks that have different tones. The result looks continuous tone (no halftone dots).
Potentially an 8 bit device will give you smoother less grainy appearing pastels.

Neither 1200 or 2400 are specifications of resolution even though that is how they are being used. They are specifications of addressability. I.e. they are saying that they can image 1200 or 2400 marks per inch - but that does not tell you how big the marks are.

You need to examine and compare test printouts to decide which unit has the appearance that you prefer.

Best, gordo

 

[rsands]

We went from a Xerox to KM...all be it not direct competitors to each other in terms of capabilities but the KM C8000 has excellent output - gradients are alot smoother, print in general is great from it

 

[onwsk8r]

Let's skip over the mumbo jumbo and get to the point. He was approached by KM and Xerox offering 1200dpi and 2400dpi respectively, but he found out that Xerox is 2400dpi at "1 bit" and everyone else on earth is 1200dpi at "8 bit".

Thanks to Gordo for actually providing some useful information.

As far as image quality is concerned, I've never heard a SINGLE person say that Xrx image quality is noticeably better at 2400dpi than anyone else at 1200dpi. Another thing - a Xrx toner particle is actually larger than 1/2400th of an inch, so take it with a grain of salt.

In my and everyone I've ever met's experience, the difference is essentially a mute point; I would imagine it's first and foremost a marketing thing for Xerox. Maybe take a look at this video:
hizbub PRESS C8000 vs. Smearox 800 - YouTube

You'll notice a greater difference between different types of paper than you will between different equipment of the same class.

May we ask why you want to know? Are you considering purchasing a machine? If so, this is a wonderful place to get facts and opinions.

 

[gordo]

ROTFL!

gordo