[alt-photo] Re: Sky banding - 3800 Printer

[ender100]

Hi Amy,

No, it isn't the exposure unit or the settings you use in the driver, or the Pictorico, or whether you use colorized negatives of one ink, black ink, all inks, etc etc.  The cursed "Venetian Blind Effect", is a banding in the direction of the printhead movement with a frequency about the width of the print head.  It can be measured with a UV densitometer as a slight fluctuation in ink density.  It can occur on any printer model.  Some models are far less prone to it thought than others and some individual printers of given models are more prone to it—some don't do it at all.  I had it with the Epson 1280, 2200, 10000, and to a lesser extent the 2400.  I finally resolved the problem by printing problematic negatives on an R1800.  When the 3800 came out, it was a Godsend because I have rarely seen it happen with that printer and I have prints that would definitely show it if there were any hint of it and they don't.  There are a couple possible causes—either paper feed being inconsistent or ink delivery system being inconsistent.  I am not aware that anyone has truly diagnosed the problem.  It tends to show up in images with smooth tonal transitions in the upper midtones and highlights.  I first saw it in a portfolio of Pt/Pd prints that Dick Arentz printed with negatives from an Epson 4000.  If anyone has experienced it and has a suggested cause rather than speculation, I would love to hear it.
--
Best Wishes,

Mark Nelson
Precision Digital Negatives
PDNPrint Forum @ Yahoo Groups

Mark Nelson Photography


On Feb 23, 2010, at 2:07:02 PM, "Amy Holmes George" <amyhgeorge at hotmail.com> wrote:


Hi David,
I only have 1 bulb (it's a Nuarc). And actually, I just made a print of the same image output as a negative on someone else's 3800 without the banding . . . so it's not the exposure unit.
Amy