Let’s again start with the simple question of ‘how many of you print’? For those that do, inevitably, your development is going to look something like this:
- Make your first print – marvel at how different it looks to the screen version
- Make larger prints, start to note that the detail still holds and in fact you’ve got much more resolution than you actually need even for the largest prints you’re willing to pay for/ have space to hang
- Pause for a moment and then decide to try making your own prints because it’s cheaper and more convenient
- Buy a home photo inkjet, find that it takes half a dozen tries to get one good print, add up the costs and find that ink and paper will bankrupt you in short order; worse still, lab results are still better
- Stop printing for a while
- Go back to using the lab because your print heads have clogged and the ink has dried up, and it would be cheaper to buy a new printer than replace the cartridges and heads and you really don’t want to go down that route again…
- Find a better lab – assuming you’re not happy with what you’re getting
- Start to wonder what you’re going to do with all of these 24×36” prints; you have rolled up tubes and prints all over your house
- Abandon printing or start selling your prints so you can make more prints
- Start wondering what’s next?
I’ve found myself with two challenges of late: firstly, the postal services keep destroying my poster tubes and prints – they’re pretty rigid, which means that at least some of the damage appears to be malicious. It’s simply unsustainable to run a fine art print business where you have to replace 40% of the product. Beyond that, as much as I love to do 24” wide prints, I don’t think many people have the space to hang prints that large – you’re realistically going to be at 30” wide after framing – and with a print of that size, it’s permanent: you’ve really, really got to like the subject matter. At the same time, I’d like to be able to bring fine art, very high quality printing to a wider audience; I’d like more people to appreciate the beauty of the finished article and understand why we print. There is simply no way a screen can do justice to an image, and moreover, there’s no universal standard for calibration, so it’s very difficult to ensure that everybody is seeing the same thing.
Advance warning: I’m about to contradict myself twice, in two big ways, in this article alone. There is of course an explanation and qualification, but still. I thought you should be prepared.
Firstly, I think the current iPad Mini retina has the best screen of any output device I’ve seen. And that is perhaps the only screen that can do an image reasonable justice, but then only at small sizes. It’s partially to do with consistency of calibration across all devices, and partially to do with the assumptions behind the whole ‘retina’ moniker; beyond a certain output density, the unassisted human eye cannot resolve individual components of an image. Of course, viewing distance plays an important part in this: so long as your unassisted eyes cannot resolve individual components at the intended viewing distance, resolution is sufficient. The iPad Mini retina is interesting because our eyes simply do not focus close enough – i.e. we cannot reduce the viewing distance enough – for us to be able to resolve the individual component pixels.
Human vision is thought to resolve approximately 0.3 arc-minutes; this means that any single feature taking up less of the field of view than this will not be separately distinguishable from its neighbor. This is roughly equivalent to details that are 0.1mm across at a distance of a meter. To reach this level of acuity, a 10” wide print viewed at 10” distance therefore requires approximately 10,600 pixels on the long axis. This 1-to-1 scaling holds: a 36” print viewed at 36” still requires 10,600 pixels on the long axis. However, though this is a reasonable 294PPI for the 36” print, we’re now looking at an insane 1,060PPI for the 10” print.
Not all dots and pixels or points are created equal: all inkjets require dithering and/or halftones to make up a single ‘pixel’ e2quivalent; since each dot is a single color, multiple dots – up to 12 for some printers – are needed to achieve intermediate colors other than what the inks come in. This is where things get complicated: more dots (i.e. ink droplets) are not better overall: you may get more accurate color, and perhaps be able to resolve finer detail, but only if a) the printer can lay them precisely overlapping; b) the total ink volume is below the paper’s saturation limit; c) the drops are sufficiently small physically. In any other situation, you are likely to instead get the impression of smeared details.
Once again, printer resolving power isn’t quite that cut and dried; in some situations – usually where there is a lot of semi-fractal fine detail, such as forests – imperfectly overlapping dots can also sometimes help to create the impression of subpixel detail (akin to adding a little noise after upsizing an image digitally) – so it doesn’t always work against you. There is an optimal amount of ink and number of dots not just for each printer and paper combination, but also for each individual image type. A portrait, for instance, will require far fewer dots to create a visually pleasing image than a photograph of a field of different-colored flowers or a bowl of smarties.
But, this level of output resolution in the final medium is nothing new: anybody who’s looked at a slide on a light table with or without a magnifying glass will know what I’m getting at; a large format contact print – at least 4×5” and usually 8×10” and upwards – also has the same kind of impact. (Note that contact prints in small and medium formats make no sense other than for editing/ selection as the final print is both too small for us to view comfortably, and far outresolved by the initial capture medium.) In both cases, what’s happening is that irrespective of viewing distance, the image outresolves our eyes.
The reason images like this have impact is precisely because of this impression of oversampling. Large prints have impact both because of their physical size, and because the viewing distance is sufficiently far away that you cannot discern individual constituent elements in an image. Very few large prints will hold up to nose-distance inspection; I have no shame in admitting that even whilst my say 36×36” prints still look great at a 1-foot viewing distance, they’re not going to hold up to two inches.
And here lies the next frontier I’m planning to push in printing: going smaller. Going towards no limits on viewing distance; we – printmaster Wesley Wong and I – are going to create what I like to think of as digital contact prints. There is obviously no such thing – you cannot make a print off your sensor – but through some inkjet technology voodoo and careful manipulation of settings* you can make prints that require a magnifying glass to appreciate their full resolution. They look like large format contact prints.
*It’s a tradeoff between print DPI, precise scaling of the image to the actual output size with maximal output sharpening to enhance microcontrast; balancing ink density with paper oversaturation/ tonal clipping and resolution – multiple passes are better for resolving power, but may lay too much ink compromising tonal separation and thus microcontrast – drying time between head passes; edge smoothing; dithering and halftoning; paper choice; using a RIP to drive the printer, etc…let’s just say there’s a lot of experimentation behind it, and it’s highly likely that this paragraph will sound alien to most of you. Perhaps this is something to explore further in a future article.
I have made my fair share of large prints, and I can honestly say that these really do blow me away – they have impact for a very different reason. Perhaps the best analogy is an architectural one: though the tallest building in the world is impressive for its sheer scale and physical presence, a very intelligently designed and well-detailed small dwelling can also have a captivating beauty of its own that requires the viewer/ observer to interact with it in order to fully appreciate it.
We figure the printer is outputting an effective 720PPI or thereabouts; the DPI (actual ink dots laid down is far higher – 2880 or more). By way of comparison, a normal minilab print appears to be in the 100PPI effective range; an Apple Thunderbolt Display runs 109PPI (note how it looks great at typical viewing distances of ~2ft, but not so great at six inches); the iPad Mini retina runs 326PPI. In real terms, this means that on subjects with sufficient high frequency detail, you can tell the difference between 16 and 36MP at print sizes as small as 8×12”. Who’d have though you’d need the full 36MP for an 8×12”? A few months ago, certainly not I; the bar for sufficiency appears to have moved significantly upwards – but as always, it very much depends on your definition of ‘sufficiency’.
Whilst you can still make a very satisfying 16×24” at 150 or 200 effective PPI – for which 8-12MP is sufficient – unfortunately, once you’ve seen one of these prints…there really is no going back. What it does mean is that a 2400dpi scan from the 4×5” and Acros is only going to yield a native ~13×15” print – but oh, what a print that will be! Bottom line: this level of printing is very, very unforgiving of technique, resolving power and workflow.
At this point, I suspect some of you are probably wondering where film fits into this workflow. Frankly, other than large format, and medium format for certain subjects, it is not possible to extract sufficient information from the negatives to produce prints of this quality. The ‘certain subjects’ qualification is because the irregular nature of film grain at the macro level means that it resolves fine detail structures in a different, nonlinear way compared to digital; this works in concert with some subjects – again, nonlinear fractal subjects like people or trees or mountains – to give the impression of having more detail than there actually is. For other subjects, such as those with very straight lines and hard defined edges – architecture, watches – digital holds the advantage because the recording method matches the subject.
I briefly alluded to it before, but it’s worth noting that the paper choice makes a huge difference in the resolution of the final image; this is because certain substrates do not hold ink as well as others, resulting in smearing, blotching, spreading etc. of the individual ink dots – none of which is a good thing. Our tests so far have found that Canson Infinity Platine Fiber Rag 310 (a very high grade and very expensive baryta – about $2.50 in this part of the world for a single A4 sheet) is about the best there is in terms of both detail and tonal reproduction; it also has a very high D-max. Interestingly, the irregular microstructure of the fibers themselves appear to contribute somewhat to the impression of continuing detail under a very high magnification loupe (I’m using my 10x watchmaking loupes to examine the prints) – much in the same way that the film grain can help certain subjects, albeit at a much smaller level.
Further testing is of course required to determine the optimal envelope for each type of image – low contrast, low frequency images will of course be printable larger than high frequency, high detail ones. We’ve a huge number of test prints so far of various subjects – there are just so many combinations of settings to test – but I’m fairly confident we’re close to the point where I can produce something unique, and very, very special.
What makes the process particularly challenging is that the optimal settings vary based on the subject matter, pixel quality and tonal key of the image – there is no one-size-fits-all group of settings that works for everything; each image must be first prepped for optimal perceptual reproduction at that size, and then proofed several times to find the best group of settings. It’s a very labor intensive process; more so than for large prints because of the tolerances involved; small changes to ink density can make a huge difference in the shadow tones, for instance. I’m looking forward to offering a future print run in this format very soon – though now instead of getting just one print, it’ll be an edition of several. Perhaps I should include a magnifying glass. MT
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