8" x 12 " prints - acceptable dpi

[sn4il]

Hi.
I want to develop my shots for the first time. Most of the shots I will print at 5"x7" which should be pretty easy. I would love to try also something bigger like 8" x 10" or 8" x 12". To get 300 dpi on this huge print my shots should be 2400 x 3000 if i understand the whole dpi rule corectly.
Since i cropped couple of my shots I would have to drop dpi a bit.
How low i can go with dpi to get decent print at 8" x 10" or 8" x 12" ??
Thanks for all answers.
mAx

[mbze430]

240 is the max I would go down to.

[sn4il]

Wow, that was fast :)
Thank You.
mAx

[KevC]

180dpi seems acceptable if it were a wall hanger.... Try photoshop's bicubic sharpen when upsampling.

[Bodog]

You don't mention the camera you're using so I don't know what image size you're working with. A Drebel image will print a 12 X 8 at 256 ppi without re-sampling. I doubt that without a loupe you would be able to tell the difference between 256 and 300 ppi. (Pixel size 1/256" vs. 1/300"). 300 is the best, but not at the expense of re-sampling.

[PacAce]

180dpi seems acceptable if it were a wall hanger.... Try photoshop's bicubic sharpen when upsampling.
Say, Kev. Somebody already set me straight on this bicubic sharpen thing so I thought I'd do you the same favor. :mrgreen: What you want is bicubic smoother for upsampling, not sharpen. Yeah, I know. I get this mixed up all the time myself. :D

http://www.photography-on-the.net/forum/showthread.php?t=71211&highlight=bicubic

BTW, 180dpi is my lower limit, too, although I may even go as far as 150dpi for certain shots that aren't too detail oriented. :)

[sn4il]

You don't mention the camera you're using

Oh.. I'm sorry. Its 20D.

mAx

[rdenney]

Most folks believe that 300 is optimal on the printer, and it is. But the difference between 240 and 300 would take a mighty close inspection to detect, and a first-class printer to reveal.

Just go into Photoshop's "Image Size", unclick the "Resample Image" box, and set your size parameters. It will calculate the pixels/inch. If that number is 240 or over, don't think a second thought about it--hit print. If it's between 180 and 240, it will probably still be fine.

If you resample your image, do it to a copy and not the original, ever. Resizing and resampling are things you do to target an image to a particular output device. I keep my targeting workflow separate from my correction workflow, where I do all the contrast adjustment, color correction, dodging, burning, and cloning out dust. During targeting, I resize, resample if necessary (either you do it in Photoshop or the printer does it--about the same results either way), and sharpen at the final resolution.

Rick "who can't tell the difference on his old Epson 1270 between 240 and 300" Denney

[NGrinerPhoto]

millers says that they will not print any higher than 250 dpi

[Bodog]

millers says that they will not print any higher than 250 dpi
I think you're confusing printer output (dpi) with image resolution (ppi).

[NGrinerPhoto]

I think you're confusing printer output (dpi) with image resolution (ppi).

no ... not really - he's talking about printing - printing is dpi - ppi is the display of an image on a monitor

[tim]

I've an A1 image taken with my old 300D hanging on my wall that was printed at about 98dpi. At that size you need to stand at least a meter or two away to take it all in, at 2 meters it looks almost perfect.

[Jesper]

no ... not really - he's talking about printing - printing is dpi - ppi is the display of an image on a monitor

No. PPI is not "the display of an image on a monitor".

Most of the time when people are talking about DPI, they really mean Pixels Per Inch (PPI). When you make a print, the printer will use multiple drops of ink (dots) to print one pixel. Remember, the printer only has between 4 and 7 different colours of ink. When you're talking about Dots Per Inch with regard to a printer, the dots are not pixels, but ink dots.

So that's why printers are marketed with terms like "1440 DPI" or "2880 DPI". They're talking about ink dots here, not pixels.

You can make a print with 240 PPI, and have the printer set at 1440 DPI. If you do that, the printer can use 1440 / 240 = 6 ink dots per pixel.

[UncleDoug]

I've been guilty of tossing around terms like DPI, PPI etc. in the past.
So have Adobe and many other companies.

But here is how I see it.

SPI - Samples Per Inch
Unit used to express or measure the resolution of a scan or other digitized image. (Scanner)

PPI- Pixels Per Inch
Unit used to express or measure the number of pixels displayed in an digital image file. (Monitor)

DPI-Dots Per Inch
Unit used to express or measure the number of dots per inch or density of dots in a printed image. (Printer)

To me this makes the most sense.

[NGrinerPhoto]

PPI- Pixels Per Inch
Unit used to express or measure the number of pixels displayed in an digital image file. (Monitor)

thank you ...

[NGrinerPhoto]

the number of pixels on a monitor directly effects the number of dots on a page outputted from a printer

[Hellashot]

Do what you want to do and print it and see if you the quality is acceptable. There really isn't any rule of DPI for printing and enlargement because the quality of the image itself will dictate how well it prints at larger sizes. Grainier images cannot be enlarged as nicely as low noise images.

When I print out of PSE 3 it'll give me a warning when printing at less than 220 DPI. Remember that on larger prints, your eye will not be as close to the print as with a 4x6 print.

[UncleDoug]

Do what you want to do and print it and see if you the quality is acceptable. There really isn't any rule of DPI for printing and enlargement because the quality of the image itself will dictate how well it prints at larger sizes.

Your suggestion to try printing it is great! The only way to see how it will actually look.
However, if we use an arbitrary "quality" level to describe an image, the image "quality" will dictate how well it will print at any size, period. If you print it at 4''x6'' and it looks great, look at it under a loupe. Now print it at 4feet x 6feet and look at it from about a foot away. Same difference.
"Quality" is such a subjective concept.....

Grainier images cannot be enlarged as nicely as low noise images.
I'm assuming you are comparing film to digital here, if so you are right.
But a noisy image will not reproduce as well as a low grain image..... ;)

[Hellashot]

I'm assuming you are comparing film to digital here, if so you are right.
But a noisy image will not reproduce as well as a low grain image..... ;)

No I was not comparing film to digital. Grainy (noisy) digital image won't print big as well as a clean digital image.