Workflow for Printing Large

[JB Rasor]

Greetings everyone,

My apologies if this is a topic that belongs in the printing forum. I can move it there if need be.

I'm going to be doing some very large prints (36" and above) for the first time, and when it comes to rezing up the files I'm not sure what the ideal approach should be. I'm not new to printing by any means but I'm not a master printer either. So...

For prints in the 12x18" neighborhood, shot on 35mm format, I'd generally just let Lightroom do the up-rez to 360ppi and call it a day. Printing on Epson printers by the way. 290 to 360ppi isn't a huge leap and the prints turn out fine. But getting into larger print sizes, especially very large, would it be best to interpolate 5-10% at a time in Photoshop? Or is this the old way of thinking?

I know in the past doing a small interpolation through Photoshop was the best approach to maintain image and print quality, but obviously the software has come a long way. But, I have a hard time believing Lightroom can rez-up that much and still print ok. I could totally be wrong...I just don't know.

One other quick inquiry. I've always aimed for 360ppi to match Epson's native resolution, however, quite a few colleagues print at 300ppi for standard prints and say they see zero difference. What gives? I know on paper 360 is better than 300, and yes I should do a personal test, but is there really a discernible difference that anyone has noticed? I'm assuming I'll need to go down to 300ppi for extremely large prints as well.

Anyways, thanks everyone! If you guys have some experience with printing in these kind of sizes I'd love some advice!

Best regards,
JB Rasor   

[JRSmit]

Greetings everyone,

My apologies if this is a topic that belongs in the printing forum. I can move it there if need be.

I'm going to be doing some very large prints (36" and above) for the first time, and when it comes to rezing up the files I'm not sure what the ideal approach should be. I'm not new to printing by any means but I'm not a master printer either. So...

For prints in the 12x18" neighborhood, shot on 35mm format, I'd generally just let Lightroom do the up-rez to 360ppi and call it a day. Printing on Epson printers by the way. 290 to 360ppi isn't a huge leap and the prints turn out fine. But getting into larger print sizes, especially very large, would it be best to interpolate 5-10% at a time in Photoshop? Or is this the old way of thinking?

I know in the past doing a small interpolation through Photoshop was the best approach to maintain image and print quality, but obviously the software has come a long way. But, I have a hard time believing Lightroom can rez-up that much and still print ok. I could totally be wrong...I just don't know.

One other quick inquiry. I've always aimed for 360ppi to match Epson's native resolution, however, quite a few colleagues print at 300ppi for standard prints and say they see zero difference. What gives? I know on paper 360 is better than 300, and yes I should do a personal test, but is there really a discernible difference that anyone has noticed? I'm assuming I'll need to go down to 300ppi for extremely large prints as well.

Anyways, thanks everyone! If you guys have some experience with printing in these kind of sizes I'd love some advice!

Best regards,
JB Rasor    

why not do a test print on a smaller piere of paper of a crop of the image but at the ppi of the large image?
LR uprezzing at print is close to perfect. 360 is what epson uses . Sending the print at a different ppi can result in a sort of moire pattern at places in the image.

[PeterAit]

You are right in thinking that the "uprez in multiple 10% steps" approach is outdated by improvements in the software. LR does a great job, as does QImage. But remember, there is always a limit to what even the best algorithms can do. You cannot uprez a 12MP image to 36MP and expect it to look like it was taken with a 36MP sensor! You have to determine the cutoff because it's subjective in terms of what's OK with you.

Recall also that large prints are typically viewed at a greater distance, so super-fine detail and sharpness are not as important. Yes, there will always be those poor souls who persist in pressing their noses against even the largest print, but there's not much you can do about that.

[Stefan Ohlsson]

I've done several tests on interpolation programs and my favorite is PhotoZoom Pro. The difference between PhotoZoom Pro and interpolating in Lightroom isn't that big, but when you interpolate more than 200% you can see a difference.

You really have to start out with a good, clean file. And all the little mistakes in focus, bad lenses or noice is enlarged at the same time.

[JB Rasor]

Thanks for the feedback guys. I will look into the programs mentioned and run a couple of tests.

Obviously doing a smaller sample test would be ideal for cost.
JR, I think you're suggesting cropping the image to the complimentary size...a little math involved but as it would appear in the final large print...and printing at 360ppi on smaller paper? I hadn't thought of that approach. Good suggestion!
I'm a little confused about the methodology but I think I know what you mean. I'll give it a try.

Thanks again!!

JB