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Rips resampling images?

D3D

New Member
Does onyx thrive resample source images? I have a particular application where I need as much 1:1 as possible between a pixel based image saved at 601.183 ppi and the printed output and it appears onyx is resampling based on the banding I am seeing. Seems strange that it would resample so perhaps there is something goofy I am overlooking.
 

D3D

New Member
In Onyx, look for; basic print mode setting > scale adjustment button.
Interesting. So it lists the resolution as 601 not 601.183 so I would need to find the difference between those two numbers and use that to adjust the scale? So I would be looking for a value of 100.0304 it seems. Is that what you were imagining?
 

D3D

New Member
I'd wager 601 is 601.183, just simplified. Sounds like this value is actually a PPC (pixel per centimeter or potentially mm) that has been converted into ppi for industry standards. I wonder if the hp behaves in any way different in this regard when set to imperial vs metric units?
You think Onyx is using the manufacturer value of 601.183 but only displaying 601. Could be. And I had the same feeling about the imperial vs metric thing. Regardless when I do a test by printing a ronchi ruling in two different places on the bed I get the same banding which I am being told indicates the RIP is resampling my file. I'll do some tests with the scaling and see if that gives me anything different. Also looking to see if I can get a demo of another RIP
 

balstestrat

Problem Solver
Yeah I wonder if you are trying to chase a problem that doesn't exist.

Tell your support to rip your image then send you the raster file. At least you can see if they can process it correctly.
 

Jessica S

New Member
I run both onyx and arizona's- running media in fine art mode can be tricky. Maybe double checking the 'steps' in color correction may help you. Banding in my experience tends to be a "step correction"- Good luck
 

D3D

New Member
This is the first time I've heard the excuse for banding being a resampled image, not saying you're wrong, just never heard of such an issue. Kinda like when you're training a new guy and send them off to find an air guage to check tire pressure before sticking vehicle lettering.
Fair assumption based on the information you have. You only see the banding when you put a piece of optical plastic over an interlaced print - its not visible otherwise. Its a difference between the actual DPI of the machine and the LPI (lenticules per inch) of the optical plastic.
 

ColorCrest

All around shop helper.
Interesting. So it lists the resolution as 601 not 601.183 so I would need to find the difference between those two numbers and use that to adjust the scale? So I would be looking for a value of 100.0304 it seems. Is that what you were imagining?
No. You might read the Onyx manual or the printer manual to understand the process of printing the certain measured file, say a 500mm version, on the particular media you require to learn the offset factor to enter into the Onyx scale adjustment field.

My experience is most large format printers will initially print short of what the file is and especially the longer the file and the heavier the media. Therefore, a RIP will provide an option for adjustment.

Some of this has to do with the difference between inches vs mm and the fact of manufacturing drums / rollers tolerances along with specifying number values rounded for convenience. Example; the old "300dpi" was oftentimes really 304dpi.

What exactly are you trying to reproduce? A high frequency set of ruled lines in the design?
 
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ColorCrest

All around shop helper.
Lenticular prints. I guess I need to see if Onyx is actually rounding the number they list mechanically or just in how they list it
perhaps there is something goofy I am overlooking.

It seems you're still overlooking the basic setup of the RIP.

Yes, RIPs resample files. First things first, be sure the print size you're asking for is actually being delivered.
 
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