Large Print - Quality Maximization

[maddogmurph]

Main Question:
The dimensions of the image I'm working with are 7279x4807 which allows me to print at 200 ppi when printing 24" x 36" - Would I achieve better image quality if I interpolated the image to the dimensons of 10918x7200 and printed on canvas at 300ppi?  I cannot print test strips because I'm ordering in bulk from a printer who uses an Epson Eco Solvent Printer and heard something in these threads about setting the resolution to 360, but I didn't fully understand and am having trouble digging up the referenced article.

Sub Questions:
Does anyone have a workflow chart that shows how to maximize the print quality on a 36MP camera or smaller when printing 30" x 60" or larger?  I'm looking for the end product to show Peter Lik type quality (forgive my reference).

I'm interested in things like, at which point in the process do you sharpen?  Should I let my camera do any in camera adjustments? What stitching software are you using? Etc.

[disneytoy]

I've been working in this area. In the end your workflow will increase the look maybe 5-10%.

Example.

I have an Epson 9890. Its native print resolution is 360dpi. If you send anything other than 360 dpi to the printer it does an inferior scaling up or down. again this is only a 5-10% quality difference. I find scaling to the final size at 360dpi in PS the best option. Decide if you want to re-sample either "Smoother" or "preserve detail.'

I do different things based on the image. I don't want to Preserve Detail with a sea scape or clouds. Smoother re-sampling is better.

I have tried Perfect Resize. It uses a fractal scaling that is interesting. More painterly.

The best workflow for printing large is good file processing. Get the cleanest image you can, proper noise reduction (not too much). Some people forget about chromatic aeration removal. Just a click in LR. You can really see it on a large print, where you might not mind it on screen or an 11x17."

And at the very end, after you resize, you can add any sharpening or noise/grain.

I have had amazing results up to 36x60" from a 16mpx Panasonic GH-2 RAW. That is with a very low ISO, and the steps I mention.

For canvas i would not worry. I doubt canvas resolves 200-300 dpi.

[Bart_van_der_Wolf]

Main Question:
The dimensions of the image I'm working with are 7279x4807 which allows me to print at 200 ppi when printing 24" x 36" - Would I achieve better image quality if I interpolated the image to the dimensons of 10918x7200 and printed on canvas at 300ppi?

Yes it would, if you resize to 360 PPI for Epsons or 300 PPI for Canon/HP printers. How much of a difference, depends on image content and resampling algorithm used, and if you take benefit from subsequent output sharpening after resizing (at the native printer resolution). Sharpening the final resampled image gives much better control over the amount of sharpening and its other settings, and you can tune it for the media you use (some papers require more sharpening than others, due to ink diffusion characteristics). Some canvases do produce high resolution, despite their reputation, so do not think it's less important for that type of medium.

I cannot print test strips because I'm ordering in bulk from a printer who uses an Epson Eco Solvent Printer and heard something in these threads about setting the resolution to 360, but I didn't fully understand and am having trouble digging up the referenced article.

Epson printer drivers require 360 PPI (or 720 PPI with proper driver settings) input, or else they will resize to that themselves, and they use a poor algorithm for that, and do not add (optimal) output sharpening after that. So you're leaving quality potential on the table, without taking benefit of the possibilities to create better output quality for the different output media, if you don not upsample to 360 PPI and sharpen that for specific content/output.

Cheers,
Bart

[Bart_van_der_Wolf]

Sub Questions:
Does anyone have a workflow chart that shows how to maximize the print quality on a 36MP camera or smaller when printing 30" x 60" or larger?  I'm looking for the end product to show Peter Lik type quality (forgive my reference).

I'm interested in things like, at which point in the process do you sharpen?  Should I let my camera do any in camera adjustments? What stitching software are you using? Etc.

The basic workflow of; Capture sharpening, Creative 'sharpening', and Output sharpening, still makes a lot of sense.

As for Capture sharpening, it's unfortunate that most software doesn't help us as much as it could. What's needed here is a means to reverse the inevitable blur that is caused by the capture process itself. The blur is almost entirely hardware induced, and thus has virtually nothing to do with the subject matter (although some subject matter is more forgiving than other). Lens issues such as residual aberrations, focus issues, diffraction, all play a role, although the weight of diffraction in the combined equation becomes more and more important as we use ever narrower apertures. That's why the aperture that was used will determine the radius size parameter we usually can adjust in sharpening tool dialogs. So that optimal radius setting can differ with each image we take, and the software doesn't tell us that. Even worse, the dialog usually presents an Amount slider as the first thing to change, which is an ass backwards approach. With a tool/PS plugin like FocusMagic it's not too difficult to find the optimal setting by trial and error, and it produces great quality.

As for Creative 'sharpening', it's not really sharpening but more local contrast enhancement and/or detail modification. Local contrast can be improved a lot with a tool like 'Topaz Labs Clarity', which goes several steps beyond likewise named controls in some other software. It's halo free, and has several types of detail/contrast it allows to tune, and is not limited to mid-tones only. It also keeps the visual integrity of colors intact (they coined it IntelliColor Technology), and offers Edge and Color aware masking for those host programs that do not offer such masking capability. Another invaluable tool for me is 'Topaz Labs Detail', which really make a huge visual difference to how detail is increased and/or reduced. 'Detail' is also very useful for the final step, after first resizing the image to the printer's native PPI.

Output sharpening is the last stage of a sharpening workflow, and needs to compensate for the deficiencies of the upsampling algoritms, and those that come from e.g. dithering and ink diffusion in the media we use. That may require different settings for different media and sizes, and maybe for specific viewing distances. While Topaz Detail can also work miracles here, it does become very slow on large upsampled output. You can also use FocusMagic for this step, although it also requires a lot of processing power, it can make a significant difference (although it addresses different things than Detail does).

Cheers,
Bart

[maddogmurph]

Bart - thank you for this explanation, huge help.  I was looking at Topaz Clarity a few days ago so your suggestion will result in me purchasing and working with this software.  You should get a commission  Or is the full disclosure that you work for them ;P

I sent them a very large TIFF file and they showed me a JPG for the mock up.  So I'm already a little worried.  I ordered a sample after all before placing a large order.

[Edited to remove Spam link. CS]

[enduser]

If you can work with "Windows" the Qimage program answers your questions without touching the original image.  It does all resizing on-the-fly and uses industry leading rouitines to achieve very high quality enlargements.

[Mike Sellers]

I think Perfectly Clear from Athentech does a nice job of making your image look its best.
Mike

[maddogmurph]

I think Perfectly Clear from Athentech does a nice job...

Thanks Mike, I actually have Perfectly Clear, and for some things it does the job perfectly.  Especially if I want to bulk edit photographs of people or events.  It often fails at landscapes for me, which is what I do mostly.  Sometimes it nails it, most of the time it over sharpens, over saturates, or over lightens my images.

I've been experimenting with using it, Clarity, Detail, and having some interesting results.

Back on topic: Who are you people using for large prints, high quality, low cost?

[hugowolf]

You have to remember, most people on this forum are printing not outsourcing.

Both Lightroom and Qimage (Win only) have automatic resizing and sharpening at the print stage, and both do remarkably well at this. In Lr you have to set the resolution to 360 ppi, or whatever is optimal for your printer, Qimage automatically detects what resolution to use.

There is an option in Lr to 'print' to a jpeg file instead of directly to a printer. In doing this the image is resized and output sharpening is applied. There may be a similar option in Qimage, but I haven't done that with Qimage.

I have heard that there is a new resizing algorithm in Photoshop CC and it is very good, but I don't have Ps CC.

Brian A

[Mike Sellers]

I put it on a layer and fade it until I get the effect I like...

[Ernst Dinkla]

There is an option in Lr to 'print' to a jpeg file instead of directly to a printer. In doing this the image is resized and output sharpening is applied. There may be a similar option in Qimage, but I haven't done that with Qimage.

Brian A

There is the Print to File feature in Qimage. Tiff or Jpeg output and all the resampling routines, smart print sharpening, ICC printer profile (RGB-Device) or sRGB, AdobeRGB color space choices are usable. And way more QU features like nesting, etc. People use Print to File to prepare their images for outsourcing. For an Epson printer the output resolution should be 360 PPI or 720 PPI depending on the available image resolution and what the print shop allows in print quality. 8 bit limitation though. Windows only.

Met vriendelijke groet, Ernst

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