32 bit exr's

[Dariusz Makowski (Dadal)]

In prints too ? I was working on a project and photographer did ask specifically for 300 dpi. They use it to print at billboard sizes but since image is not big enough they scale it down in dpi to 100 or soo which kinda make it work somehow dunno...

[WobiNich]

Yeah, I know. 90% of the people that I am working with will never understand the relation between pixels and dpi. A pixel is a single image point (so to say...). If you have 10 pixels in a row, this does not have to do ANYTHING to do with dpi. The dpi value just comes into play when you want to lay down your pixels on a sheet of paper for example (I am speaking of a single row of pixels, just to keep it simple). Lets say you want your 10 pixels to be printed in full size on a DIN-A 4 sheet of paper (Assuming you take the longer side of DIN-A 4 which is 29.7 cm). This means that you have to put 10 pixels - meaning 10 points of ink - on a distance of 29.7 cm. So THEN - and ONLY then - you have to assign a value that says HOW you want your virtual pixels layout out on a real world medium. So if you have 10 pixels on 29.7cm you will have a resolution of - TADAA - 10 pixel PER 29.7cm... (29.7cm are 11.69 inches) . So you have 10 pixels PER 11.69 inches - and that is 0.855 pixels PER inch (0.855 DPI!!!)

So, I hope you see that when talking about DIGITAL images (that only live in a virtual space in the computer) there is really no need to talk about anything like DPI. Because in the computer, these images have no real world size... this only gets important when you want the image to be printed or projected on a wall or whatever...

For example, if you save a GIF image... the DPI, which you can set in photoshops image size dialog is totally ignored. You can set the dpi to whatever you want and the save the GIF... when you open it again it has a standard value of 72 (or was it 96?) dpi. And that is because the GIF format was invented for displaying pixels on a monitor NOT for printing... so there is no need to save any information about a real world size inside the image.

Hope this helps, as I trying to tell people this for years now, but they just dont seem to understand... this is somewhat frustrating...

Greets Ben

[stevesideas]

Alternatively, if you have 2 pieces of A4 paper and one is printed at 72dpi and one is printed at 300 dpi, the 300 dpi image has just over 4 times more information per cm and creates a much better print.

[Dariusz Makowski (Dadal)]

Heya

Ok got it.. I think, basically anything I render I can print at any DPI I want and it will not affect print quality...(as long as I threw high DPI...) Cool thanx !

[themaxxer]

do you mean the vray vfb ?
As for the vrayVFB you can set this via maxscrtipt:


.output_rawExrUseHalf : boolean

defaults to on saving half-float. Setting it to false will write 32bit full float.

Regards,
Thorsten

when to run the script? before saving or rendering? thanks.

best regards
themaxxer