U of S | Mailing List Archive | alt-photo-process-l | Re: dpi for digital negatives

Re: dpi for digital negatives



Warning:
the below may be far too much info . . so, don't read if it seems to blather on

Thank you for the sweet answer Ms. V. Acronyms, as we well know (RADAR, WYSIWYG, HAL) shorten longish terms.
The RPM by Epson, being one, uses one to inform the user to employ that attribute. The explanation of the amateur
is waaaay to long. It not only means such a print resolution but the management of it via an algorithm of quite complex
mathematics.
If you divide the 5760 by 4 (CMYK) you'll get 1440, which was once the max DPI in the Epson printers. What that meant
is that each of the four printer heads, using piezo-electric technology (such as used in a BBQ fire starter and based upon
the squeezing tightly of quartz crystals) would 'squirt' out 360 tiny drops of ink in a one inch space/length. 4 times 360
equals the 1440 DPI.
Now each head is (apparently) able to squirt out 1440 tiny drops of ink, which really is rather fantastic. To control this, as
said prior, complex math is required. The computation made from a Photoshop (or other) file made in RGB to the printer's
CMYK printing is huge. RPM, or the Resolution Performance Management, takes care of this.

And, finally, I'm not really sure about this, but Mark's use of Rottweilers Per Minute, I think, originally, was Rabbits Per
Minute so as to reflect that mammal's capacity for swift reproduction, whereas that of the Rottweiler is not nearly as quick.

Jack


On November2007, at 9:06 AM, SusanV wrote:

Thanks, Jack, not as entertaining as Mark's reply, but a tiny little bit more informative.  I just googled that and found out that it simply means print resolution of 5760 x 1440. 

Why couldn't they just say that? 

(Hope your travels were happy, and welcome back.)

susan

On 11/5/07, jfulton < jfulton@sfai.edu> wrote:
Having been gone on travels since early June it is refreshing to return to Paradise, here where I live
and experience the ongoing providing of alt. photo info and Mark's consistent humor. About the only
thing I can add is that RPM means Resolution Performance Management and is proprietary acronym 
used by Epson.
Jack



On November2007, at 6:23 AM, Ender100@aol.com wrote:

I think it stands for "Rotweilers Per Minute"


In a message dated 11/5/07 7:21:27 AM, susanvoss3@gmail.com writes:


Hey Mark,

I was glad to hear you mention the "photo RPM" setting because I've been curious about it for a long time.  Does anyone know what that stands for?  With my 1280, that setting gives me the best results with my digital negs made for gravures.

I've had banding problems in the past, but solved them by using some and all the methods you described.

Susan






Best Wishes,
Mark Nelson

Precision Digital Negatives - The System
PDNPrint Forum at Yahoo Groups
www.MarkINelsonPhoto.com






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susan
gravure blog at www.susanvossgravures.blogspot.com
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