Extremely Large Rendering Question

[Smalerbi]

Hello All,

I have a client that would like a rendering for his corporate office lobby. The final image will need to be 29 feet long and 11.5' tall. According to his printer, they want me to render this at full scale at 100dpi. That will make the final image size 30,000 x 13,800 pixels. The first question is.....does anyone else find those specs a bit insane? Does anyone out there have any experience with something of this scale and if so.....how do you produce an image of this size. I know can render it in sections and layers and composite the hell out in Photoshop but is seems a bit odd I would half to create an image at full scale. I have seen very large billboards and I know the art is not at full scale. They want this image to poster quality so any insight to this dilemma would be very helpful.

Thanks,

Scott.

[joconnell]

Yep, we've had this discussion before.

DPI is all down to how close someone will stand to the final image. Printers only have 4 colours as standard so they have to use clever arrangement of dots in different percentages to give the illusion of other colours. If you're reading something that's printed high quality, and it's about a4 in size or small, you hold it about 18 inches from your face so they use 300 dpi for high quality print so you don't see any dots. For something a3, you have to stand back slightly further to take it all in with the standard field of view of peoples eyes. Likewise a2 or a1 might be printed at 150 / 200 dpi as if you're moving further back, those tiny dots are even further away and get tinier - you can get away with printing slightly larger dots and still have the same continuous tone effect. For bus shelter type images you're standing a few feet back so you could easily print this at 100dpi without any issues, and billboards where you're standing metres back can be printed at 50 dpi or less with no issues. If you're standing more than a few metres back then you're not going to be able to discern visible dots that are a fiftieth of an inch in radius, you can likely go smaller again.

I'd render the image maybe 6k along the width, and then use one of the photo resizing programs like photozoom pro to upscale to 30000px. Since it'll be coming from a cg render it'll be so clean and pure that it'll size up nicely. You could put a tiny sharpen and a bit of grain on the final image too.

[AJ Jefferies]

I've rendered a few images >30'000 pixels before but as John says it's rarely ever necessary. That said I'd definitely render larger than 6k as that's going to look pretty bad blown up across 29 feet. I'd go for 15k and let the printer handle the upscaling.

[Smalerbi]

Thank you so much for the response. I have another question. I'm not familiar with your referances to a1, a2 or a3. Are these print sizes?

Thanks,

Scott

[Smalerbi]

I've rendered a few images >30'000 pixels before but as John says it's rarely ever necessary. That said I'd definitely render larger than 6k as that's going to look pretty bad blown up across 29 feet. I'd go for 15k and let the printer handle the upscaling.

AJ......thanks. I was thinking the image should be larger as well. John mentioned up-scaling the image with a product called Photo zoom pro. You mentioned having the printer handle the up scaling. I thought the same but it was printer that specified the full scale rendering. I think the client should look for another printer. Do you know what software printers typically use to up-scale the image?

Thanks,

Scott.

[camilo.vargas]

If you are rendering such a high res image, make sure you have plenty of RAM and a speedy local drive, if you are rendering to 32 bit exr with render elements you are going to end up with a file of several GB and if you don't have a drive that can quickly save the image at render end, it might timeout and you will lose hours of render time.

[Laserschwert]

Thank you so much for the response. I have another question. I'm not familiar with your referances to a1, a2 or a3. Are these print sizes?

I've got to admit it's a bit scary that you don't know about international standard sizes, but here goes: http://www.papersizes.org/a-paper-sizes.htm

[joconnell]

The "international" sizes are european in origin thanks to the lovely people of the din / iso group (din might be my favourite font ever) but they're not common in the u.s. A4 = letter and so on!

Even mentions that in the last paragraph of the page you linked - "The A series paper sizes are now in common use throughout the world apart from in the US, Canada and parts of Mexico"

Yay for international relations

[AJ Jefferies]

Do you know what software printers typically use to up-scale the image?

I'm afraid I don't but I had a conversation with a very good printer a few years ago and he said that it's better for them to handle the upscaling as it's impossible for us to add anything to the image that they can't/don't do themselves.