48 inch (120cm) Printing Test Experiment

I started up my new Epson P800 about a week ago, and have already printed about thirty 13x19 beautiful prints with it. It's faster than the one that died.

But this machine can also print long panoramics, and my favorite 1:3 ratio would result in a 16x48 inch (ca. 40x120cm) print on 17x5 inch roll paper.

Could this be done from a cropped DP-Merrill or SD1M camera picture?

TEST A:

The original tiff image is 24x16 at 180 ppi.

I changed that to 48 inches wide, which resulted in 98 ppi.

I then cut a ca. 8x10 section from it, started a new file/pasted it, flattened it, then sharpened it slightly at around 35%, radius 2, and printed it at best quality on matte paper.

Not bad, especially considering the eventual viewing distance. But I felt the image was just a tad soft.

TEST B:

Started with the same original image and also set it to 48 inches wide, but this time bumped the ppi to 130ppi, and resampled, which is only about a 30% increase in resolution.

This time sharpened it to 90%, radius 2, and printed a small section. Closed the original without saving it.

CONCLUSION:
Hard to see any difference in resolution with naked eye, BUT; the extra sharpening helped a lot, but I think a bit less than 90% would have been OK too. The sharpening upped the contrast also just a tiny bit. At least no sharpening halos, but there are of course jaggies at this low resolution, but only visible under a loupe, and not to the naked eye.

THUS: You can print 32x48 (ca. 80x120cm) from a Merrill camera, given the original is pinsharp, with a slight bump up in resolution and sharpening at around 50-60% radius 2.0.

Such a print is not for pixel peepers and loupe-on-print inspectors, but will be very pleasing to the eye with a proper viewing distance of at least 3 feet or more.

The ladies in the house spotted the better test print right away, even from a ca. 2 feet viewing distance.

I might just go for it, when I get my rollpaper holder from my older printer set up properly behind my P800.

CONSIDERATIONS:

Possibly I can upres the image more, in increments to let's say the original 180ppi. How much sharpening it will need then, remains to be seen.

Possibly, someone already figured out the best method for doing this. Would love to hear it!

That's it for now.

Thanks for reading!

P.S. I also ran snippet tests from two other cameras so far: Sony A7iii, and Fuji GFX50S. Needless to say, the latter is quite something! Quelle resolution. Mama mia! I am really not convinced that the Quattro H can beat that! The A7iii, on the other hand, does look a little smeary. It was from a raw.

A7iii: at 48 inches wide, dpi is reduced to 125dpi.

The GFX at 48 inches wide has 172 dpi (the same for the Hasselblad X1D).

The Sigma SD Q H at 48 inches has 129 dpi.

The Canon 5DSR at 48 inches: 181 dpi

The Sony A7Riii: 166dpi at 48 inches.

Phase One 100MB back: at 48 inches you have 242 ppi.

Picture below:

This is just 1 cm wide, and has 49 pixels in it (you can't fit 50 pixels in a cm, apparently! Lol). That means, basically 5 pixels of picture data per millimeter. Naturally, when blown up and viewed from a proper distance, it won't mater too much. Some billboards have photos from iPhones printed on them. I remember seeing a backlit Nikon 4 or 8MP camera image display in the early days of digital at Grand Central Station in New York, and it must have been the size of a billboard as well. And it looked really great! From a proper distance, of course!

49 dpi, 1 cm wide; ca. 5 pixels per millimeter, actual resolution 125 dpi (per inch)