Mike Chaney's Tech Corner

Mike's Software => Qimage => Topic started by: nbagno on April 08, 2022, 02:51:44 PM



Title: Mac 16bit setting
Post by: nbagno on April 08, 2022, 02:51:44 PM
I noticed that my new Mac printer driver for the Epson 3880 has a 16bit output checkbox, I don't recall that setting on the Windows side. Should I select 16bit? What will it do for me?  Also, I do recall a comment by Mike someplace that said something to the effect that we should always select the highest print resolution. In my case, that's Max 720 vs. 360/220/180. That's a correct statement?

Ned


Title: Re: Mac 16bit setting
Post by: awilford on April 08, 2022, 05:53:55 PM
Hi Ned,

I looked this up online, and you can read about this setting in the 3880 manual if you have it on hand (Page 52):

https://files.support.epson.com/pdf/pro3880/pro3880ug.pdf

"AccuPhoto HD2 for any type of photographic printing. If you are
printing 16-bit color images, select 16 Bit Output for the most
accurate transitions and gradations."

So you would check that box if the image you are printing is 16-bit. In this case, the Qimage One pipe line is 8-bit, even for 16-bit source images. So that box should NOT be checked for use with Qimage One.

As far as resolution, use the highest resolution for printing smaller prints, where they will be viewed closer. For very large prints which will only be viewed at a distance, you can use the lower resolution settings, which will reduce processing time to print.

Andrew


Title: Re: Mac 16bit setting
Post by: nbagno on April 08, 2022, 06:27:08 PM
Hi Ned,

I looked this up online, and you can read about this setting in the 3880 manual if you have it on hand (Page 52):

https://files.support.epson.com/pdf/pro3880/pro3880ug.pdf

"AccuPhoto HD2 for any type of photographic printing. If you are
printing 16-bit color images, select 16 Bit Output for the most
accurate transitions and gradations."

So you would check that box if the image you are printing is 16-bit. In this case, the Qimage One pipe line is 8-bit, even for 16-bit source images. So that box should NOT be checked for use with Qimage One.

As far as resolution, use the highest resolution for printing smaller prints, where they will be viewed closer. For very large prints which will only be viewed at a distance, you can use the lower resolution settings, which will reduce processing time to print.

Andrew

Hi Andrew, thanks for your reply. Without any further context, this implies that with Qimage One I wouldn't have "accurate transitions and gradations." In my color images due to its eight-bit pipeline? Can you expand on that a bit?

Thanks,

Ned


Title: Re: Mac 16bit setting
Post by: admin on April 08, 2022, 07:44:02 PM
For 16 bit images, both Qimage One and Qimage Ultimate produce visually identical output whether the driver is 8 or 16 bits.  It does this by intelligently dithering the 8 bit values using the 16 bit data in images so you get much higher than 8 bits/channel even with 8 bit drivers.  You can test it if you like: create any type of 16 bit gradient you want and print it in both Q1 or QU and then also print it in any application that supports "true" 16 bit printing (in Windows, you'd need a dedicated 16 bit print plugin to try this as Windows itself has an 8 bit/channel pipeline).  There will be no visible difference in the output.

Regards,
Mike


Title: Re: Mac 16bit setting
Post by: nbagno on April 08, 2022, 08:29:05 PM
For 16 bit images, both Qimage One and Qimage Ultimate produce visually identical output whether the driver is 8 or 16 bits.  It does this by intelligently dithering the 8 bit values using the 16 bit data in images so you get much higher than 8 bits/channel even with 8 bit drivers.  You can test it if you like: create any type of 16 bit gradient you want and print it in both Q1 or QU and then also print it in any application that supports "true" 16 bit printing (in Windows, you'd need a dedicated 16 bit print plugin to try this as Windows itself has an 8 bit/channel pipeline).  There will be no visible difference in the output.

Regards,
Mike

Ok thank's Mike. I also think that I accidentally clicked on the report to moderator button instead of the quote button. :-O

I'm not a pixel peeper per se, I have a drum scanner that outputs 8 bit and another 16. My pudding is always the print, and I normally don't hold them up side by side. If I like the print and it moves me, I don't care how it was printed.

Cheers,

Ned



Title: Re: Mac 16bit setting
Post by: admin on April 08, 2022, 09:24:19 PM
That's OK.  I'm a pixel peeper: kinda have to be.  :)  I ran a lot of stress tests using slowly changing 16 bit gradients to make sure the 8 bit output looked the same as the specialized 16 bit driver.  The beauty of the 8+8 output vs true 16 is that Q1/QU can print smooth gradients on any driver, even with printers that don't support 16: drivers that only support 8 bits/channel.  Q1/QU is reading and making use of the 16 bits/channel, just in a little different way.

Mike