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A customer need to furnish what quality?? in megapixels please.. It goes on the back of a motor home... Thanks, Jack
-------------------- "Don't change horses in midstream, unless you spot one with longer legs" bronzeo oti Jack Davis 1410 Main St Joplin, MO 64801 www.imagemakerart.com jack@imagemakerart.com Posts: 1549 | From: Joplin, MO | Registered: Mar 2000
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posted
at 100 dpi, the print will be 6000 x 8400 pixels or 151 megapixels, a factor of 30x over what's on the market.
at 50 dpi it'll be 3000 x 4200 pixels or nearly 38 megapixels.
Realistically, I'd settle for the best pic you can get, no less than 5~6meg digital, uncompressed, resample it up to about 40 meg and print it at 100 dpi from there, let the printer do the final interpolation.
-------------------- Mike O'Neill
It has yet to be proven that intelligence has any survival value. - Arthur C. Clarke
posted
DPI is irrelevant , it applies to ouput device resolution A 300 pixel by 300 pixel file will print best at 1" x 1" on a 300 dpi device , the same file will print best at 1/2" x 1/2" on a 600 dpi device etc. DPI embedded in a file means diddly squat - the actual pixel count is important.
Between 75 and 150 pixels per inch of printed output is whats required So at an average of 100 pixels per inch it's: (60 x 100) x (84 x 100) x 3(for rgb) or x4 (for cmyk) So for RGB file size will be 150 mb and for cmyk about 200 mb
It depends on viewing distance - from far away you might get by with 50 pixels per inch.
The theory is that CMYK can only print 7 colours (like a laser can only print one colour - black , however can print "shades of grey" these shades (or colours) are printed in cells to fool the eye as to colour gamut (1/2 toning) - and the amount of cells per inch the printer can deliver is called the LPI (lines per inch) and LPI is the determiniant of quality or "best print" According to Nyquists theorum , you need 2x the LPI value to deliver best (a 2880 x 2880 inkjet with variable droplet and 6 colour inks might do 300-500 lpi?) Nyquist can sometimes be ignored and you can get pretty good results with 1.25 x the LPI To better explain lpi , lets say we have a cell of 3x3 pixels , printing one black dot in the middle of the cell and printing another in a cell alongside will give the lightest shade of grey , printing the full 3x3 cell and the next one alongside will give black. If the edge prints at 300 dpi - and it uses a 3x3 cell for halftoning it will print 100 lpi. Obviously for vector graphics the file size is irrelevant. Resampling can sometimes give acceptable results , but if resolution is too low and you resample , you are guesstimating values. Rather too big a file resampled down then vice versa.
-------------------- Rodney Gold Toker Bros Posts: 57 | From: South Africa | Registered: Aug 2003
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If you are trying to get a print that large to look as good as possible from close up, I think your best solution would be to have a professional photographer take the picture with a 70mm camera, have the print blown up to 8 x 10, then have it scanned with a high quality scanner and burned on a cd for printing.
I had some signs shot by a pro once, and when I commented on the sharpness of the enlarged pictures, he told me he used a 70mm camera, twice the film size of a 35mm.
I'm not real versed in this stuff, but I've yet to get an edge print of an enlarged picture that didn't get very grainy or end up with 1/8th inch or larger pixels. I've been told these 4+ megapixel cameras are just starting to approach 35mm quality. I know digital prices have come way down and mega pixels have gone way up, but just 4 years ago, magazine quality digital cameras I saw in a catalog started at $20,000 and were as high as $40,000.
An understanding of LPI, PPI and DPI is necessary in order to get the most out of an Edge print. As they say, "Garbage in, garbage out."
Since the printhead on an Edge is only 300 dpi, then mathematically speaking, a 108 DPI image at full size is suficient for printing a full color image. The only time you would want anything higher is if the image contains "hard-edge" objects such as rasterized text.
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