Billboard, how ?

[poliokov]

Hello

Im studying Fashion Photography and i have been asked to do a research folder including a 24 sheets poster.
However I don't really know where to search informations about how to do it.

I need to know how to present this file digitally. Resolution, dpi... all this stuff. I will shoot it in studio with a camera that will do the trick, i just need to know how to present it as a digital file.

As it needs to be 24 sheets of A4 my logical was to do so :
A4 = 210x297 cm
210x3 = 630
297x8 = 2376
SO the billboard size is 630x2376 cm

And then i was thinking about :
630/10 = 63
2376/10 = 237,6

63x237,6 at 300 dpi ?

i am terrible at maths and i don't understand anything about resolution for big prints.

If anyone could help on this I'd be grateful.

 

[tsaraleksi]

The bigger you get, the lower your resolution needs to be because you increase your viewing distance. A billboard in no way needs to be 300 dpi, probably under 50 will work.

 

[adamwilliamking]

This might help you out.

 

[Alleh Lindquist]

I think most billboards are about 25 dpi

 

[Garbz]

300ppi means you can't seen the pixels with 20/20 vision at arms length. Inverse laws apply. From 2m 150ppi will do, for 4m 75ppi will do, for 8m 30ppi etc etc.

These are all for a "photo quality" appearance. You divide by 10 is wrong. Pixels Per Inch. So distance in inches at bottom, pixels at top. A 10.2mpx image is 3872pixels wide. Your 2376mm (I imagine you didn't mean 23meters wide) billboard is 93" wide.

3872/93 = 40 PPI. Which would appear to be of photographic quality from within 7m for someone with perfect vision. But you don't need photographic quality production for this type of work anyway so you'll be just fine.