Mike Chaney's Tech Corner

I should know better but...

I like Qimage and have been able to print some very large banner images that look great at relatively low resolution.

I am using a Mac Pro and an epson 7800 printer.  recently I am also using Bonzai3d -3d modeling software where my work is authored.  Then I am using Qimage to print out to my 7800 through my windows xp in the studio.

The question is: Should I render and save my original image -out of Bonzai3d- as a 300 dpi image at actuall size -for instance 20x16 inches making a very large file but a file that contains a lot of information. Or should I make the image 16x20 inches at 72dpi? which makes a small file, quick to work with/print but shows some small pixel artifacts and may not contain all the colour depth and richness seen on screen. I know Qimage is amazing but am I asking it to do work that I should be doing ie setting up the optimum printable file.... I would really appreciate guidance on this issue.

Tom Piper
 

Hi Tom
Whatever, 300ppi is wrong for an Epson printer, 360 would be better because the native resolution is 720ppi (fine detail set) or 360ppi without that set.

EDIT: remember, an image does not really have pixels per inch, just pixels. It's only when the image is printed at a particular size that ppi become real.

1. You are better off to let Qimage do all the re-sizing and interpolation, just once. That's what it does best.
If you can cope with the large file - no need to bother about any tagged ppi and size - use that file in Qimage and set the size in the Qimage way with inches. You can then leave the output resolution to either the "native" value as reported by Qimage, just above the preview, or to reduce processing time, use a lower value, set at the bottom right of the main screen. The lower values offered are whole fraction of the native resolution and with very large prints, may well be adequate.
2. I'm not familiar the Bonzai software but if you are wanting to reduce your file size, 72 pp seems quite low. 180 would be better and it is a whole fraction of 720-360.
3. Another approach would be to make your image pixel size such that the file is as large as you want to go and let Qimage do it's magic.
Terry.

The colors in the design setup in RGB mode? For optimal quality and the artwork original a vector design, I would use the intended print size + 360 PPI resolution + anti-aliasing selected (if available) in Bonzai3D's export. Export as Tiff 8 bit. If you need a web page or smaller print make an extra rendering.
Could be that Qimage doesn't pick up the original (virtual) size + resolution when using Original Size for the print, check the job queue whether 360 PPI is quoted for that image. It will work without problems with Photoshop Tiffs.

That is what I do with vector designs from for example Xara Xtreme.


met vriendelijke groeten, Ernst Dinkla

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/