I don't know whether this is the right place to ask this question, but does anyone here know how to calculate the number of pixels required, at 300 ppi, to obtain the various sizes of high res. prints, i.e. A1, A2, A3, A4, A5?

Until recently I was working in 200 ppi, not 300 ppi, but that's not enough for our professional printers!  Also my sizes overall have been too small to go higher than A4.

One printing firm is asking for 2480x1650 pixels x 300 ppi in order to print A4, and to be able to still get a good print at A3.

This is a really odd size!  It doesn't correlate with any fractal program's pre-supposed output sizes for renders, for example.  UF renders at 300 ppi - hoorraayy!  But not at that precise ratio!  You have to lose some of your image when you resize it!

FE only comes out at 200 ppi, and squeals at the size I want to create an image to compensate for this when resizing.

Apophysis again, I think is 200 ppi - or is it less - and in any case, with all of these, it takes several hours to get a good render, unless in the case of UF, it's a fairly simple fractal that's being rendered.

Any advice would be very gratefully received...  Thanks.

ppi stands for pixels per inch, so what you really need to figure out is what size an A4 print is in pixels at 300 ppi. When I go to Photoshop and create a new image, I am given the option of selecting a default size. There it says that A4 is 2480 x 3508 pixels. If we play like it is a fraction, like 2480/3508 and reduce it to lowest terms, we come up with a ratio. Well, I don't kow about lowest terms but it does look like both numbers can be divided by 4, which gives 620 x 877. In UF, don't use the pull down menu in the image size tab. Deselect the "maintain aspect ratio" button and key in the values of 620 x 877. From there on select the "maintain aspect ratio" button and let UF figure it out.

Hi Anna,

Keith is right...when they speak of 300 ppi, that means 300 pixels per inch. To calculate your render size, multiply the inches of the width and the inches of the height of your print size by 300.

For example, an A1 is 594mm x 841mm (23.4 x 33.1 inches) - so:

23.4 x 300 = 7020
33.1 x 300 = 9930

So to render an A1 at 300ppi, you would need to render the image at 7020 x 9930.

The following is a link showing international paper sizes in mm and inches:

http://www.hintsandthings.co.uk/office/paper.htm

Thanks so much for this info - which shows me I've basically wasted an awful lot of time!!!!

I will print this out and use it for future reference - I don't think I have the heart to re-do yet again all that I've already done!  Arrrgh!  I asked this question in the 2D forum too, and of course all the info given correlates exactly, so now I know!  What a horrendous learning curb!  (And huuuge files to work to as well!)

I'm very grateful to you all for your help.