How to create a massive Photoshop image?

May 8, 2010 7:37 PM

Photoshop help? Making an extremely large image. What size/dpi should I work with?

I need to make a 24 x 40 foot image for a stage backdrop. I'm going to create the image digitally in Photoshop. How can I do this without working at actual size? Does it sound feasible to do it at a large but much smaller size like 2x4 ft at a very high dpi and then blow it up? Thanks for any advice.

posted by Liquidwolf to media & arts (12 answers total)

depends on how you're outputting it. If you are having it somehow printed, whoever is printing it for you should be able to give you the details on resolution, dpi, size.
posted by phogirl at 7:40 PM on May 8, 2010

300 dpi is my usual go-to size.
posted by ThaBombShelterSmith at 7:55 PM on May 8, 2010

As phogirl says, your answer depends on how it's going to be output. I assume this is something your will be sending out to a service bureau to output? Or, perhaps, an outdoor sign company? You need to contact whomever is going to print the backdrop and get their requirements. You'd be surprised at how small and low-rez the art can be for large-scale output.

For instance, I'm currently putting together an outdoor display for a client. The final size will be, roughly, 10.5 ft. x 22.75 ft. The final art will measure a mere 10.5" x 22.75"at around 219dpi. Generally speaking, the larger the art, the lower of dpi you can get away with, since people will be viewing it at a large distance.

So, again, contact whomever is outputting the thing for you and get the specs.
posted by Thorzdad at 8:03 PM on May 8, 2010

The Broadway show "9 to 5" recently did a video LCD wall with ~1 inch wide LCD "pixels" on the display (scrimmed over to help blend). When you figure for the 20-foot rule, instead of looking like giant one-inch dots, they looked like actual images by the time they got to the audience.

While you might not want to be working at that low a DPI and might want a bit more detail (especially in a smaller house - the Marriot Marquis is one of the deeper Broadway theatres), you can probably get away with anywhere from 10-30 DPI and still be totally fine, and thus be able to work at the actual 24x40ft size in Photoshop.

But again, as people before said, talk to who's doing the printing. If it's someone like Rosebrand or another specialized theatrical company they'll be absolutely sure of how the graphics should be prepared.
posted by cvp at 8:19 PM on May 8, 2010 [1 favorite]

If you're going to be printing it out 24x40', you don't need 300 DPI, by any means, unless you need it to look flawless at about 12 inches viewing distance.

Ask the printers.
posted by signal at 8:20 PM on May 8, 2010

Do ask the printers, but in my experience most large scale output (like vinyl banners, cloth printers, etc) are about 110 dpi. Since it is a backdrop you could probably get away with less DPI....I just opened photoshop to see what a 40 foot x 20 foot document at 110 dpi would be file size wise and it was 2.2 Gig(!)
posted by Wink Ricketts at 9:09 PM on May 8, 2010

Are you sure Photoshop is the right tool for the job? If the image you're creating lends itself to a vector format (such as Illustrator), that will probably give much better results (since it can be scaled infinitely and still remain razor-sharp).
posted by ixohoxi at 9:20 PM on May 8, 2010

The only real question is how many pixels you use. A 2x4 image at 1000 DPI is the same as a 20x40 image at 100 DPI.
posted by delmoi at 9:34 PM on May 8, 2010

The last two full sheet billboards I shot were imaged by the service bureau that produced them at 9 ppi, and looked great from the street. They even looked good from 15 feet away.

The original images were shot on a Nikon D2x and the original files were 4288x2848 pixels.
posted by imjustsaying at 1:37 AM on May 9, 2010

Yes, this question is very poorly formed. As delmoi said, size and DPI are completely interchangeable; to photoshop they are meaningless numbers, the only thing that actually matters is the number of pixels. You need to first figure out how the backdrop is going to be physically printed, which will tell you how many pixels the representative image should contain.
posted by Rhomboid at 3:04 AM on May 9, 2010

Ok, thanks for the tips everyone. It does need to be created in Photoshop so it can't be a vector image. I'm doing this for a client so I"ll have to talk to their printer to get some answers it sounds.
posted by Liquidwolf at 8:54 AM on May 9, 2010

@Liquidwolf - Photoshop does support vector objects in .PSD files, and I'm pretty sure Illustrator can save in .PSD. If the only requisite is that the client needs a .PSD file I wouldn't rule out vector images just yet.

If you have to do this raster, then you're going to need to work with the same pixel size that you want to output. Trying to scale a low-pixel image to a higher number of pixels never works out well. 24' by 40' is 20,736x34,560 pixels at 72 DPI... which is 716,636,160 pixels. A lot of pixels, to be sure! Still, Photoshop might be able to handle this, depending on your computer. And you might be able to go with an even lower resolution. Use 36 DPI and you're down to 179,159,040 pixels.

You might be able to make do with a much lower DPI than you think. For example, suppose you have a 42" LCD TV showing a 1080p DVD picture. You probably think that's pretty crisp, right? A 1080p image is 1920x1280. A 42" (diagonal) widescreen display is about 36.6" by 20.6". That's a resolution of only 52 DPI, and it still looks great to someone 6-10 feet away.

If the image you're creating is a stage backdrop, and observers are going to be more than 10 feet away from it, you can probably get away with a fairly low resolution.
posted by Vorteks at 11:42 AM on May 11, 2010