Need Advice – Extreme Upsizing of Image

Hey there everyone, I'm looking for a little advice. Okay, I have an image that is 5421 px wide by 1843 px high in it's native resolution which a client wants printed 100 inches by 34 inches. The print is being made on this printer http://www.ablimaging.ca/product/lightjet.html I realize that is a lot of interpolation and am wondering if anyone has any advice on doing this and achieving decent results. I have included an example of the image to give you an idea of the amount of detail in the photo. Thanks for any advice.

Wayne

Wayne,

I'd drop the resolution to 125 ppi then double the file size. That should get you almost where you want to be. It's an extreme uprezing so I would make sure your client is aware of that and that they know some detail will be lost. You don't want them to expect digital back quality from an upresed 6x18" at 300ppi original.

No suggestions, but very cool image!
Sandy

Wayne, did you ask your printer if they can help? They might be used to uprezing to extreme large sizes and even have special software to do this. If not, Alain's approach sounds like a good one.

Hello Wayne,

Very nice image! I would recommend asking the printer what their minimum resolution requirement is to avoid to overdoing the re-sampling. If we were to print this image, I would suggest targeting a resolution of 125 to 150 ppi at full size. Our RIPs do not require pushing the resolution to 300 ppi at full size. The more you push the re-sampling, the more fine detail will be lost. Make sure you do your sharpening after re-sampling. The other factor is knowing the distance from which the final print will be viewed. If your client is going to display the print in an area where it will not be viewed closely, you can get away with the negative results caused by re-sampling. Hope this helps.

I find the trick to significant upsizing is adding grain and texture as you upsize. That way when the viewer gets up close it looks like a 'grain painting', which IMO is much more pleasant than a smooth artifacty digital mess that you get without the grain. In print form, most people don't think twice about grain, it just lets them know that they got too close to the print, and that they should take a step back. Getting the grain right, though, is tricky, especially when dealing with someone else's printing process. Personally, I would make some test crops with different grains and textures applied, with different ppi's, and see what they look like.

Thanks everyone, some great suggestions here! I will have a chat with the printer, and if that fails I may experiment with the method Floris mentioned. Apparently the print will be about 9 feet up, so people will not be able to get too close to it, but I want it to look the best it can since this is a very good client. Have already sold a 24x36 and 60x20 to him and he was very pleased with the results... but this is going to be much larger than I have ever printed in the past! Thanks for your help guys!

Wayne

What about programs like Fractal?

They are supposed to increase the resolution before processing and printing.

the fisch

Larry - Genuine Fractals, and any other program like it, are very minorly better than other techniques and only on certain images. Most people find the usual Bicubic or Lanzcos methods found in PS and other programs to be just as good. I have heard that certain RIP software and print drivers do a better job because they are working on the actual ink dots below the pixel level so they are also changing the way the pixels themselves are reproduced.

The basic problem is that you can't really create detail. Adding grain helps because it sort of fakes your eye into seeing detail and sharpness, but there's not really a way to actually add detail no matter what you do.

Here's some very in depth reviews of Genuine Fractals (versus Blow-Up versus Bicubic) if you're interested :

It's Bigger, But Is It Better? Part I
It's Bigger, But Is It Better? Part II
It's Bigger, But Is It Better? Part III

About how much grain would one use in photoshop? Would you make it barely detectable or noticeable but moderate? It's really hard to tell what might trick the eye best when looking at the screen. Floris, if you have used this technique with an image with a similar level of detail, would you care to share your approximate settings in the Add Noise filter in PS. Thanks!

Wayne, it totally depends on the image, and even on different parts of the image. For example, you add TONS of grain to a rich forest scene, sandstone, or sand and it'll look like real detail (up to a point), but you can't add much to the sky before it looks real crappy. So I do a lot of masking along with my grain addition.

Most of my prints that I use grain on are 21MP 5D2 files printed at 20x30, which is not a huge enlargement. For those I upsize to 360 ppi with bicubic smoother, and then add 400% monochromatic gaussian noise on a separate layer, with ~0.8 radius gaussian blur. Then I set the opacity to around 10% for most scenes, just at the point where it starts to show through... and lots of masking. For bigger enlargements, like a 5D file I printed at 30x40 with lots of detail I added grain several times between enlargement steps.

Go to your nearest bus stop with a movie add with people (not CG). Or and Abercrombie & Fitch store, and look at the giant poster prints they have -- often there's a lot of grain in those images, my guess is that it is added in PS, IMO it looks organic, natural, and a whole lot better than the smooth digital CG look you'd get from just enlarging (or Genuine Fractals, which IMO looks terrible in most cases).

Wayne if you upsize roughly 3X at 150ppi output with Genuine Fractals you should be fine. Bear in mind that images that size are not going to be viewed from a few inches or even 2-3 feet away. They are generally viewed at a distance which allows you to get away with lower resolution than you need for a print that you look at while holding it in your hand. As David observes Genuine Fractals is only modestly better than Photoshop but modestly better is still better in my book so if you have it use it.

Thanks for those tips, Floris. I haven't made many 20x30 prints from my new 5D2, but this is something I'd like to experiment with. Do you add your final output sharpening after you've applied the grain, or before?

Jason - definitely before. I actually apply my sharpening filters on a separate layer before upsizing. I find upsizing sharpening artifacts looks better than sharpening upsizing artifacts. I adjust the opacity after upsizing to fine tune the amount of sharpening applied.

Thanks!