Fools rush in where angels fear to tread. Only mad dogs and Englishmen go out in the noon-day sun. I’m going to ask a question in the spirit of these two quotations.
The April 30 IJM newsletter discusses the higher resolving power of piezography. There’s the statement: “[I]Piezography K7 curves can resolve over 1000 pixels per inch[/I]”. For followers of Piezography, this statement is familiar. It’s been made before and is included in the new Piezography Manual on p68.
The discussion surrounding this statement is usually about using 7 inks and QTR’s different dithering patterns which mean that there’s no white space between the dots, unlike the Epson K3 driver. I’m no expert, but I don’t have any trouble understanding and believing the resolving benefits of K7 over K3 and QTR dithering over OEM. There was that small font test image which was used as proof once upon a time. What I don’t understand is the benefit of sending more than 720dpi to QTR.
Anyone who reads Lula will know that there has been a debate raging for years about whether or not to resample when printing using the Epson driver. I think there’s now a consensus that you’re better to send a file to the driver in the driver’s native resolution (for an Epson - 360dpi or 720dpi depending on printer and settings) than to let the combination of the OS and driver do some low-grade resampling for you.
But what about QTR? Roy made a post on Yahoo QTR a while back:
Now at first blush this seems to agree with Jon - he seems to say to set the print size to whatever you need without any resampling, so that the dpi adjusts to suit, and let QTR do the rest. But he also says “[I]QTR works on 720ppi input data so on Mac OSX that is provided by the system, on PC there is an extra step to resample to 720ppi for QTR[/I]”.
Given this, what’s the point of sending more that 720dpi to QTR? As I read this, QTR is going to resample down to 720dpi. We understand that K7 and better dithering is going to provide more detail, but in what sense is Piezography resolving 1000dpi? Are you really saying that you can see a difference between a 1000dpi image sent to QTR and one resampled to 720dpi and then sent to QTR? Or have I misunderstood what Roy seems to be saying?
Roy holds the view that it’s hard to spot the difference in real world images if you resample before sending to QTR, but if it’s true that QTR does want 720dpi as the input resolution then surely it is open to the user to use high quality resampling tools, .e.g. Qimage on Windows, to deliver a 720dpi image to QTR if they feel that they can see the difference.