I have been asked to make a poster size print (40 inches in the long side) from a small original digital file of only 2000 px in the long side. I have tried enlarging the file on PS to 6000px and made a 20" print which was acceptable in quality (viewed at 18"). However, I have not tried to enlarge this to 12000px and make that 40" print. The question really is whether this is possible without significant drop in quality? The alternate suggestion I received from a friend who worked in graphic design is to enlarge the file to 4000px and make a 35mm slide and then make that 40" print directly from the slide. Comments on the above or alternate solutions appreciated.
"The question really is whether this is possible without significant drop in quality?
No.
Now it's another question entirely whether that significant drop in quality is acceptable to you. Depends on several factors...was the image taken under the very best circumstances (tripod, best lens quality, RAW, optimum processing, etc.)?
Also, many commercial printers upsize images themselves using sophisticated RIP technology that can do a far better job than Photoshop.
You might find this article titled 'Advanced Photo Enlargement Processing for Digital Photos' helpful.
I agree with John... Are you printing yourself or having a lab do it? If a lab, I would definitely ask them what their recommendation is. You can almost always get better results in big enlargements with a RIP or sometimes even just letting a printer driver handle the increase in size. I wouldn't bother trying to keep the file at 300ppi by increasing it much in Photoshop.
The article John posted talks about using a RIP. It also mentions Genuine Fractals (which is now called Perfect Resize). I've not found much advantage to Genuine Fractals, and I've seen some more rigorous tests on line that show benefits only in some rare circumstances. I'd think the RIP would make the bigger difference, since it will size the file based on the way the printer works.
Either way, you are blowing up the file a LOT, and you can't avoid a big loss in quality. (And taking a 35mm slide makes no sense to me. You would be throwing even more information away. Maybe your friend just likes the look of the film printing.)
It depends. I did a series of 75 photos, some as large as 54 x 72 inches, most of them originally from antique postcards. Fine detail is lost in any big blowup. Faces, for example, are hopeless. But larger objects with uniform colors and shapes do pretty well. My subjects were all autos in Alaska in 1900 - 1925, all in black and white (some converted from sepia). Some of the originals were pretty sketchy. But the purchaser, an antique auto museum, was happy with all of them.
Like David, I didn't find much difference between the interpolation features in PS5 and Genuine Fractals/Perfect Resize. But I disagree with David on the RIP of various printers. They just aren't as good as PS5. I don't recall the printers we tried, but whatever the benefits of customization for the printer were lost is the bad algorithms they had. And the attempts were pretty expensive, too.
I think the key step is to get the source image as clean as possible before you blow them us. A dust speck becomes a quarter sized blob, for example. Those old emulsions weren't very uniform, and whites are really, really blotchy. Oh, and do the expansion all at once, not in steps. Steps seem to magnify error. And work from RAW or at least TIFF, not JPEG.
Discussion
3 repliesNow it's another question entirely whether that significant drop in quality is acceptable to you. Depends on several factors...was the image taken under the very best circumstances (tripod, best lens quality, RAW, optimum processing, etc.)?
Also, many commercial printers upsize images themselves using sophisticated RIP technology that can do a far better job than Photoshop.
You might find this article titled 'Advanced Photo Enlargement Processing for Digital Photos' helpful.
The article John posted talks about using a RIP. It also mentions Genuine Fractals (which is now called Perfect Resize). I've not found much advantage to Genuine Fractals, and I've seen some more rigorous tests on line that show benefits only in some rare circumstances. I'd think the RIP would make the bigger difference, since it will size the file based on the way the printer works.
Either way, you are blowing up the file a LOT, and you can't avoid a big loss in quality. (And taking a 35mm slide makes no sense to me. You would be throwing even more information away. Maybe your friend just likes the look of the film printing.)
Like David, I didn't find much difference between the interpolation features in PS5 and Genuine Fractals/Perfect Resize. But I disagree with David on the RIP of various printers. They just aren't as good as PS5. I don't recall the printers we tried, but whatever the benefits of customization for the printer were lost is the bad algorithms they had. And the attempts were pretty expensive, too.
I think the key step is to get the source image as clean as possible before you blow them us. A dust speck becomes a quarter sized blob, for example. Those old emulsions weren't very uniform, and whites are really, really blotchy. Oh, and do the expansion all at once, not in steps. Steps seem to magnify error. And work from RAW or at least TIFF, not JPEG.
Good luck.