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Forums > Digital Art and Retouching > Best DPI for printed images ? Search   Reply
Photographer
Smedley Whiplash
Posts: 17,257
Billings, Montana, US


I thought this might be the right place for this post, since the retoucher is most likely the last one to work on the file... (not always, I know)

But, I've always heard that 300DPI at print size was the right resolution, but...

My large format inkjet guy says he wants print size at 100dpi

and I've heard other guys say it's a multiple of 320 (so 320, 640, 1280, etc) at print size...

And I have no idea what the printers at Costco or H&H would suggest for sharpest, let alone magazine print, or offset printing...

I've noticed that every time one of my images goes to print, the sharpness is all over the place, and never consistent, even when they they look sharp on the monitor.
Feb 02 13 02:40 pm  Link  Quote 
Retoucher
Peano
Posts: 4,106
Lynchburg, Virginia, US


Smedley Whiplash wrote:
My large format inkjet guy says he wants print size at 100dpi

Give your print guy what he asks for. If it's large format, 100 ppi (not dpi) sounds about right.

Feb 02 13 02:43 pm  Link  Quote 
Photographer
Bill Sylvester
Posts: 1,463
Cincinnati, Ohio, US


Depends on the printer. Both the technology and the brand. For HP inkjets   300 dpi, for epson 360. Other printers may need other resolutions.

If I didn't know what my printer needed, I would go for 300.
Feb 02 13 02:53 pm  Link  Quote 
Photographer
P-Studios
Posts: 1,359
Hayward, California, US


300 DPI IS NORM FOR ME
Feb 02 13 03:01 pm  Link  Quote 
Photographer
Kev Lawson
Posts: 6,796
Las Vegas, Nevada, US


Smedley Whiplash wrote:
And I have no idea what the printers at Costco or H&H would suggest for sharpest, let alone magazine print, or offset printing...

We want 300ppi which when plated gives 4800 line inch on our full color offset printing.

Feb 02 13 03:09 pm  Link  Quote 
Photographer
Blue Cube Imaging
Posts: 11,139
Ashland, Oregon, US


Aughhhhhh................

Sorry, had to get that out. Seeing this makes me crazy:

Smedley Whiplash wrote:
I've noticed that every time one of my images goes to print, the sharpness is all over the place, and never consistent, even when they they look sharp on the monitor.

What are you trying to print? What size, what media, where will it be viewed, etc?

There is no single right answer across the board, but there is a right answer for your immediate needs.

Whether your inkjet guy is in the know or not will depend on those factors.

Feb 02 13 03:10 pm  Link  Quote 
Photographer
Smedley Whiplash
Posts: 17,257
Billings, Montana, US


lol...  Just what I figured. No standard answer.

What bugs me though, is that I could give the same file to 3 different printers, for example H&H, Costco, and JoeBlow's Drugstore, and none of them would match in terms of sharpness (or color, for that matter).

When I do magazines I just send them at full dpi from the camera, cuz when I've asked them what they prefer, they don't appear to know the answer either.

It feels like we're all flying by the seat of our pants, allowing the machines to interpolate the dpi, which is why I believe the resulting prints look randomly different each time.
Feb 02 13 03:26 pm  Link  Quote 
Photographer
salvatori.
Posts: 3,720
State College, Pennsylvania, US


Smedley Whiplash wrote:
lol...  Just what I figured. No standard answer.

What bugs me though, is that I could give the same file to 3 different printers, for example H&H, Costco, and JoeBlow's Drugstore, and none of them would match in terms of sharpness (or color, for that matter).

When I do magazines I just send them at full dpi from the camera, cuz when I've asked them what they prefer, they don't appear to know the answer either.

It feels like we're all flying by the seat of our pants, allowing the machines to interpolate the dpi, which is why I believe the resulting prints look randomly different each time.

I would imagine that if you go to a professional printer, they can tell you exactly what they require (BlueCube is a case-in-point - excellent work).

No, JoeBlow's won't know shit - that's why they are called JoeBlow's... Do you really expect professional quality work from the same place that develops somebody's MySpace pics?

smile

Feb 02 13 03:40 pm  Link  Quote 
Photographer
Blue Cube Imaging
Posts: 11,139
Ashland, Oregon, US


First you'll want to know whether your printer(s) are working in a calibrated environment and set yours up to emulate theirs as close as possible.

Here is what I tell my clients and ask them for:

Our workflow is calibrated as follows:

Monitors should be set between 5500 - 6000 degrees kelvin
Luminance of between 100 - 140
Gamma 2.0 ~ 2.2
(while those settings are not exact they will get our prints in the ballpark of what you are seeing if you are calibrated similarly.)

Ideally files should be set up as follows:

Adobe RGB (preferred) or sRGB
8 bit color for printing
Native camera resolution (for full frame prints) or cropped to size at 300 ppi
(example: 11x14 = 3300 x 4200 pixels)
Saved as a jpg file for upload to our ordering site

You should be able to give your printer a native camera resolution file. They should have one or more RIP's at their disposal to properly rasterize the files for output.

Feb 02 13 03:41 pm  Link  Quote 
Photographer
Blue Cube Imaging
Posts: 11,139
Ashland, Oregon, US


DP
Feb 02 13 03:41 pm  Link  Quote 
Photographer
BCADULTART
Posts: 1,986
Acton, Massachusetts, US


All the files I send out, publication, are at 300dpi, when I print on my Epson I use 300, 450 and on occasion 550 dpi depending on the output size.  I only work in aRGB.  I do not print at Costco, but I've heard they are not bad?  They have, or at least use to have their own color space that you use to be able to get off the web.

Chuck
Feb 02 13 03:52 pm  Link  Quote 
Photographer
Fashion and Flesh
Posts: 36
CARDIFF BY THE SEA, California, US


I print my own limited edition releases using Epson high end photo printers.  I simply test print until I am happy with the settings.  I use 300 dpi as the base.  No coordination or special calibration required beyond what looks right.  Course this isn't very commercial, but my projects aren't.  Then I save the file and use it again to get the same results...providing the paper is the same, the inks aren't dried out a bit, the humidity is the same, etc.  You waste a lot of ink and paper as well.
Feb 02 13 04:01 pm  Link  Quote 
Photographer
Ren Murray
Posts: 542
Salem, Oregon, US


BCADULTART wrote:
All the files I send out, publication, are at 300dpi, when I print on my Epson I use 300, 450 and on occasion 550 dpi depending on the output size.  I only work in aRGB.  I do not print at Costco, but I've heard they are not bad?  They have, or at least use to have their own color space that you use to be able to get off the web.

Chuck

I print a lot of non-critical stuff at Costco, and have always been impressed. I just have my account set so that there are no color corrections made by them. There have been a few times when the larger, poster sized prints are off, but when I point it out they calibrate their printer and make me another one that always looks perfect.

Feb 02 13 05:13 pm  Link  Quote 
Photographer
Ren Murray
Posts: 542
Salem, Oregon, US


I have shot for several calendars and the printers have always asked me for 300dpi PDF files in CMYK for those. I use Nik Sharpener and set it for offset printing for the calendars and all of them have looked fantastic.

I'm not really all that technically knowledgeable about printing, but just doing what they ask from me and following those steps has always gotten good results.

I have also picked up the phone and talked with Blue Cube Imaging and gotten excellent advice.
Feb 02 13 05:16 pm  Link  Quote 
Retoucher
Pictus
Posts: 961
Teresópolis, Rio de Janeiro, Brazil


Feb 02 13 06:35 pm  Link  Quote 
Photographer
Ruben Vasquez
Posts: 3,090
Puyallup, Washington, US


You just want to find out what the resolution of the printer you will be printing on and go from there.

For four color process, offset press, ISO 12646 specifies 300 ppi file.

Canon wide gamut printers have a maximum resolution of 2400 x 1200 dpi.
http://www.usa.canon.com/cusa/professio … ifications
So recommended image resolutions would be 300ppi, 240 ppi, and 120 ppi (though your viewing distance should be pretty great if you print at that low of a resolution).

For wide gamut Epson printers, their maximum resolution is 2880 x 1440 dpi.
http://www.epson.com/cgi-bin/Store/jsp/ … Cookie=yes
So recommended image resolutions would be 360 ppi (2880/360=8; 1440/360=4), 240 ppi (2880/240=12; 1440/240=6), or a minimum resolution of 180 ppi (2880/180=16; 1440/180=8).

See the math? If you were to send a resolution of 300 ppi file to be printed on an Epson printer, the math wouldn't quite work out (2880/300=9.6; 1440/300=4.8), so the print driver or the RIP software would have to interpolate the data.
Feb 03 13 12:07 am  Link  Quote 
Photographer
Neil Snape
Posts: 9,444
Paris, Île-de-France, France


DPI and PPI are often mixed up for what they are.

DPI is indeed a printing specification.

Printers from digital need a certain integer number to pass through the printer driver or RIP. That process writes the pixel (PPI) information into a plotter or grid of  1bit printer files ( for ink jet other than variable drop)  in some cases it does this later inside the printer ASIC).
The plotted  file is what is sent to the print head, which has it's own resolution of the number of micro dots that make up the notion of continuous tone. With ink jets that can be 360, 720, 1440, 2880 etc.
Color LED and Laser  can of course have variable levels.

So to answer your question, it is entirely dependent on the driver.

Most photographic printers use drivers or rips that run optimized on 300 PPI document files which gives the right amount of information for the highest quality print file.

Yet all printer drives will, if the file is not in native optimized PPI interpolate. Say you send a file at 228 pip, it will upsized in resolution which may cause some degradation in purity of continuous tone.

Files in wholly divisible increments byt the native size are always best.

Say 75, 150, 600 are also good for drivers wanting 300 pip.

Canon and HP in almost every driver I know run on 300 PPI, Epson on 360 PPI.

Commercial photographic printers a little more variance, 240, 300, 400 I've seen. Yet by far 300 PPI is the, most common.

Safe practice is 300 ppi for all but Epson. Don't be afraid of other numbers though, they will still print. Just don't expect a 72 pip file to have enough pixel info for the driver to make a wonderful print.

It's early, hope I haven't mixed up my words.

Recap: the print file if optimized is set to dimensions and ppi grid resolution.   The driver or rip separate this into a plot grid for the printer device at whatever print media resolution is set by the media and print head plot. The file is best optimised as if native resolution as an whole number integer runs faster and more efficiently rasterizes the file without rounding errors, which avoids banding.
Feb 03 13 12:42 am  Link  Quote 
Photographer
Shoreline Pictures
Posts: 91
Toronto, Ontario, Canada


My printing workflow:
After I've done all my work on the uncropped file at camera resolution on a calibrated monitor  I save the file as my master.
Then I duplicate the file, crop, and resize to the size I want to print and sharpen. Because I use an Epson 4880 this will be 360dpi.
I've made a shadow and highlight test wedge that I print on the papers I use which tells me exactly how my printer, paper and ink combination handles those tones.
I then add a curves layer set to luminousity to the duplicated file and adjust the shadow
and highlight outputs to match what I learned from my test wedge. I have found that soft proofing is not accurate enough even on a calibrated monitor. After all Photoshop had a built in densitometer, the eye dropper tool!
Lastly, I rename and save the duplicated file eg: Cindy-1234-14x21in-4880-CansonBarytPhoto.
Feb 03 13 09:52 am  Link  Quote 
Photographer
Smedley Whiplash
Posts: 17,257
Billings, Montana, US


Wow... there is some good info on here. I'll have to play with it a little more.
Feb 04 13 10:47 am  Link  Quote 
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