Ben Altman
Allowing Ads
Hi All,
I've been refining my home-grown method for generating QTR digital-negative ink profiles. When I print one of those square 101-step density wedges and measure the steps with my X-Rite 361T UV densitometer, I have been finding odd jumps in the data when going from the end of one row of patches to the start of the next row. The input data looks pretty smooth, and I'm suspecting the way the printer dither works at the edge of the file.
I re-printed the sheet with a 3/4" 50% gray border, and that seems to have improved but maybe not entirely cured the problem. I also cut and pasted the rows of patches to get different ones at the edge. That seems to show that it's not the profile causing the problem. Part of the difficulty in figuring this out is that the sensitivity of the 361T is not much better than some of the differences.
It IS clear that densities fall off near the top edge of the OHP, so I recommend printing these charts (and your negs) with some free area on the edge of the sheet.
I'm using the Ordered dither on an Epson R1800.
Anyone else seen this? On QTR or other drivers? Thanks!
Ben
I've been refining my home-grown method for generating QTR digital-negative ink profiles. When I print one of those square 101-step density wedges and measure the steps with my X-Rite 361T UV densitometer, I have been finding odd jumps in the data when going from the end of one row of patches to the start of the next row. The input data looks pretty smooth, and I'm suspecting the way the printer dither works at the edge of the file.
I re-printed the sheet with a 3/4" 50% gray border, and that seems to have improved but maybe not entirely cured the problem. I also cut and pasted the rows of patches to get different ones at the edge. That seems to show that it's not the profile causing the problem. Part of the difficulty in figuring this out is that the sensitivity of the 361T is not much better than some of the differences.
It IS clear that densities fall off near the top edge of the OHP, so I recommend printing these charts (and your negs) with some free area on the edge of the sheet.
I'm using the Ordered dither on an Epson R1800.
Anyone else seen this? On QTR or other drivers? Thanks!
Ben
