Image resolution vs paper size

[cordy]

Im "evaluating" a large colour printer here at work, does all sorts of wonderfull paper sizes. So the questions I have are:

Whats a good image resolution for A3 prints?

Whats a good image resolution for A2 prints?

Whats a good image resolution for A1 prints?

Whats a good image resolution for A0 prints?

The reason why Im asking all those paper sizes is that pricing of the paper will determine what size i print off at.

Thanks,

Chris

[Sheetshooter]

Correct me if I have misinterpreted your query but I would think that the resolution for the printer would be a constant in the region of 300dpi. It would be the size of a file necessary for printing to the sizes that you list that would be the variable.

A client of mine publishes the following MINIMUM specifications for file sizes for acceptance by their publications. These relate to UNinterpolated files.

Camera = Screen = Printed Image = MegaByte= Paper Size (A)

2592x1944 = 91.44x68.58cm = 21.95x16.46cm = 14.4MB = A5
(5 megapixel)

3456x2304 = 121.2x81.28cm = 29.26x19.51cm = 22.8MB = A4
(8 megapixel)

4288x2848 = 151.27x100.47 = 36.31x24.11cm = 34.9MB = A4+
(12 megapixel)

4992x3328 = 176.11x117.4cm = 42.27x28.18cm = 47.5MB = A3
(17 megapixel)


From this you should get an idea of the elements relevant to you and with a bit of high-school maths you should be able to work out the rest. of the sizes.

Cheers,

PS: Does anybody know of a means of presenting data in TABLE format on these wretched forum boards?

[Luke Smith]

Albeit most human beings are happy with 100dpi in colour, particularly in larger prints because you don't generally get that close to them..

[Sheetshooter]

I've never been one to compromise on quality and I'm too bleedin' old to start now.

Especially if you are producing work for sale to others I feel it is incumbent upon you to avoid the near enough is good enough syndrome wherever possible.

Cheers,

[Nnnnsic]

In fact, when you're printing large format at A3 or A2, printing at 200 dpi is usually fine, and A1+ can usually accommodate 72dpi prints.

[bouyant_clown]

Given that you have this printer for 'evaluation' at work, run a few trials. Pick a 1 or 2 pictures and work your way up the sizes available until you reach a size that doesn't perform to your desired standard.
As they say, the proof is in the pudding. you can keep these as reference prints so you know what size you can go to in the future.
I have a 20" by 30" photo on my wall printed from a 5mp image and i would be happy to go larger.

[robboh]

I find this quite interesting. Its a matrix of recommended min pixel sizes for printing on a Fuji Frontier. They basically say there isnt a huge difference between 200 and 300dpi in most circumstances. One of the guys here at work does a bit of professional stuff on the side and uses them, reckons they do a really good job! Ive got a couple of pics I want to put through them to try them out and also maybe get a big one done to see what it looks like.

[Luke Smith]

Lots of places have Fuji Frontiers now- even the Harvey Norman at Oxley in Brisbane. I got 270 6x4s printed in about 30 minutes from a wedding I did and I’m quite happy with the results. Also quite cheap at 33c each. The price went up dramatically with the print size tho. From memory the biggest they could do on the frontier was 10x15, they could do A1 on an Epson they have.

[ozimax]

My local printer (digitalfotofx Coffs Hbr) prints my 30"x20" on an Epson 9600. His software colour profile is optimised at either 180 or 360 dpi, (he says it doesn't matter to him). After post processing I usually save an image in TIFF format at 180 dpi for printing and the results are very good. Even at 180, the file size is enormous.

Max

[informer]

Thanks sheetshooter for that.

Just wondering, if I wanted to print a poster size image (A3) would the D50/D70 do it?

I'm a little confused about the dpi of the camera and printer. I have the D50 and the Canon MP770 printer.

[Luke Smith]

Easily.

Your 6MP D50/D70's sensor is about 3000 pixels wide by 2000 pixels high.

It should be clarified that the dots in dpi (dots per inch) are the same as pixels... different term, same concept. From there its fairly simple math to figure out what DPI your print will be.

For example your sheet of A3 is 16.5 inches wide. The number of pixels from across the image from your camera (3000) divided by the width of the paper equals your DPI, in this case 181 DPI, which would generally be considered sufficient.

I hope this clarifies the situation

Luke

[gstark]

Thanks sheetshooter for that.

Just wondering, if I wanted to print a poster size image (A3) would the D50/D70 do it?.

In spades.

We regularly print A3 and A3+ from our D70 cameras.

[birddog114]

Thanks sheetshooter for that.

Just wondering, if I wanted to print a poster size image (A3) would the D50/D70 do it?

A good printer as Epson 2100/ 1960/ 2400 or R1800 will do A3 or A3+ for you and of course, photos taken from D50/70/70s can make good prints on A3.

[r2160]

Just to add a little fuel . . .

If you were suppling a photograph to be printed using an conventional offset press you would normally supply the file at 100% (the size you wish to reproduce and the resolution would be twice the screen you intend to use.

eg
If you wanted to print an A4 picture using a 175 lpi screen
210x297mm @ 350dpi

glenn