bit depth Archives - John Paul Caponigro

The Big Overview – The Key Reasons Why Your Tools Matter When Printing

Technique - Printing Comment

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Prints are produced by not one but many things – a system. You can make better prints if you understand how each of the tools you use to make them influences quality. In addition, you’ll be able to identify and come up with solutions for problems you run into, now or in the future.

I’ve written whole articles on each one of these components (Follow this article with the individual ones you’d like more clarity on.), nevertheless, rather than having to piece all of that information together, I find it’s also useful to have a broad overview of how the whole system works.

Here’s a quick survey of why each element of a printing system matters.

Camera resolution – dynamic range – bit depth

Lens sharpness – low distortion – few artifacts

Editing Space saturation

Bit Depth gradation

Software color – detail – composition

Monitor accurate preview – saturation – brightness of white

Printer ink – size

Ink black – saturation – longevity

Paper whites – materials

Printer Profile accurate color – graybalance

Light how well you can see

I’m currently testing the Fuji GFX 100

100 mp / 14 bit / ISO 12,800 expandable to 102,400

Camera

resolution – dynamic range – bit depth

A camera’s chip determines how much detail it can render with three primary characteristics – resolution (sharpness), dynamic range (shadows and highlights), and bit depth (gradation). More is better. It’s easier to throw away what you don’t need than create it.

Among several lenses, I favor the Fuji 32-64mm

Lens

sharpness – low distortion – few artifacts

Good lenses are sharper, better lenses maintain that sharpness edge to edge, while the best lenses also produce beautiful bokeh (depth of field blur). Good lenses are also free of distortion and artifacts like chromatic aberration. Fixing these things in post-production can sometimes be arduous and at a certain point impossible.

Prophoto is bigger than Adobe RGB and sRGB

I edit in ProPhoto RGB

Editing Space

saturation

Pro-Photo RGB can hold all of the saturation your camera can capture while other standard editing spaces cannot. If you use one of the smaller spaces (like Adobe RGB or sRGB) you may lose and not be able to produce that saturation.

Read more here.

I edit in 16-bit

Bit Depth

gradation

16 bit’s thousands of shades of gray don’t give you more separation in prints. Printers can take 16-bit data but they can only print 256 shades of gray. Editing in16-bit eliminates the possibility of producing posterization (which can produce harsh graphic transitions and/or noise).

Read more here.

I use Adobe Lightroom Classic and Photoshop together.

Software

color – detail – composition

You can pretty much change anything about the way your images look … for better or worse.

Good software lets you be more precise and go further. Better software does it more easily without cutting corners.

For traditionalists, it’s shadow and highlight detail, midtone contrast, color clarity, sharpness and reduced noise.

For non-traditionalists, it’s the ability to produce unique color palettes, special effects, and composites.

Read more here.

I use Epson’s P900 and 9000

Printer

ink – size

A printers manufacturer determines which ink set you’ll use.

A printer’s series determines which of the manufacturer’s inkset you’ll use.

A printer’s model determines how big you can print.

Additionally, a printer’s head also impacts speed.

I use Epson’s Ultrachrome HDX ink

Ink

black – saturation – longevity

The ink you use has a huge impact on print quality and longevity … but to see what it can do you need paper.

Read more here.

Ink & Paper

black – saturation – longevity

Together, ink and paper determine …

Black

The black of the ink and the white of the paper set the limits of a print’s contrast ratio.

No matter how much ink you put down on some substrates you won’t get a blacker black and each substrate has an ink limit, which is the maximum amount of ink that can be put down before detail starts being lost.

Saturation

Good inks and paper coatings produce more saturation in all colors.

Longevity & Durability

Some are more archival than others. (Visit Wilhelm Research for reliable data.)

I use Epson’s Legacy Fibre and Legacy Platine papers

Paper or Substrate

whites – materials

Substrates determine an image’s white (where the ink doesn’t go) and so contrast ratio. A brighter, bluer white is more versatile, but may or may not be as archival.

Only paper (or substrate if it’s canvas, plastic, metal, wood, etc) can give your images a look and feel. It’s first and foremost about the physical characteristics of materials including things like reflectivity and texture.

Read more here.

Photo papers have greater gamuts than matte because of their blacker blacks.

I use Epson’s profiles

Printer Profile

accurate color – graybalance – gradation – shadow and highlight detail

A good profile can be more than getting a good match with your screen. But it can be more. Poor profiles can cause color shifts, reduce saturation, produce posterization, and even lose shadow and highlight detail.

If you’re using Epson profiles for Epson papers, you’re in good shape. Epson makes great profiles for their papers. But if you’re using a third-party or hand-made substrate you need a good profile. Don’t assume that the profiles you download from websites are good. Test them. If they’re not great, get a professional to build one for you. Or, build your own.

Read more here.

I use Solux 3500K lights

Light

how well you can see good results

Event the best print can’t be seen in the dark. To be seen well, good prints need good light.

Think about three things …

1 Use a generous amount of light. Not so much light that it creates eye strain but use a lot. Good prints glow when they reflect light but they need enough light to create that glow.

2 Use the right color temperature. If you can’t control the light people view your prints in, assume it’s warmer than 5000K (most people prefer warmer light, like 3500K) and make your prints look good in a similar light.

3 If you really want to dial in the color for your exhibits (or your clients) recommend a full spectrum light source (like Solux) that doesn’t make one color look more saturated than another and so preserves the color relationships you produced in your prints.

Read more here.

It takes some initial research and testing to find the tools that are best for you but once you settle on a system of your own you only occasionally have to repeat this and only for specific components. It gets easier because you have a baseline. All you have to do is ask how much better can the new gear do and is it worth the cost and effort?

Meanwhile, if you run into issues (like my blacks aren’t black enough or my colors aren’t saturated enough or I’m losing detail) you’ll know which pieces of your system to tweak to get better results.

Read more on Color Management here.

Read more on digital Printing here.

Learn more in my digital photography and digital printing workshops.

Benefits of Editing Images In 16 Bit Mode

Software - Photoshop Comment

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More bits of data make more shades of gray.

What’s the difference between 8-bit and 16 bit? The number of shades of gray. 256 versus 65,536 to be exact. With more shades of gray, gradation becomes smoother.

How do you get at these numbers? Digital files are binary. 2 to the 8th power is 256. 2 to the 16th power is 65,536.

2¹ = 2
2² = 4
2³ = 8
2 ⁴ = 16
2 ⁵ = 32
2 ⁶ = 64
2 ⁷ = 128
2 ⁸ = 256
2 ⁹ = 512
2 ¹⁰ = 1024
2¹¹ = 2048
2 ¹² = 4096
2 ¹³ = 8192
2 ¹⁴ = 16,384
2 ¹⁵ = 32,768
2 ¹⁶ = 65,536

16-bit files take twice as much memory to store all those shades of gray. It’s worth it. For an arithmetic increase in file size you get a logarithmic increase in the number of shades of gray.

256 shades of gray are just enough shades of gray to do reasonably well for most imaging applications. The human eye can see approximately 1,000 shades of gray. With 65,536 shades of gray, 16-bit files contain tens of thousands of shades of gray more than you can see.

So what are all those extra shades of gray good for? Editing your files to get the best results possible. When a digital file is edited, it loses some shades of gray. If a digital file contains too few shades of gray, it begins to posterize. You may see signs of posterization if an image’s histogram displays combing or gaps and spikes. Before you panic, examine smooth areas of an image to make sure there’s visible posterization. Do this at 100% screen magnification; many times the posterization you see on a monitor is a result of a monitor not being able to display the data as smooth as it is at other screen magnifications. 16-bit files contain so many shades of gray, it’s very difficult for posterization to occur with normal editing – unless you deliberately posterize it with digital filtration.

16-bit doesn’t extend color gamut; 16-bit files can be either small or wide gamut. 16-bit is recommended for files created in wide-gamut color spaces, like Pro Photo RGB, because the steps between tonal values are spread out over a larger distance to achieve greater saturation and so tend to posterize more quickly.
16-bit doesn’t extend dynamic range; it doesn’t generate a blacker black or a whiter white. 16-bit source files are recommended for high dynamic range because HDR images are heavily processed when tone-mapped and would posterize without higher bit depths. In HDR processing, multiple bracketed 16-bit files are combined into a single file with a 32-bit mode used to hold the varied data they contain over a dynamic range that is wider than the device that created them. A 32-bit file is subsequently tone-mapped and rendered down to a 16-bit file with an improved dynamic range.

With the exception of 32-bit files used for HDR tone-mapping, files in Adobe Photoshop can either be either 8-bit or 16-bit.

To get true 16-bit data, you need to generate it when you create a digital file – and preserve it during image editing. JPEG files can’t contain 16-bit data; they’re cooked down to 8-bit. Raw files can. (So can scanned images.)
Not all Raw files contain a true 16-bits of data. While many DSLRs can only generate 10-bits, 12-bits, or 14-bits data, all DSLR Raw files contain more than 8-bits of data, which can only be preserved in Photoshop if edited in 16-bit mode.

You can change a digital file’s mode from 8-bit to 16-bit, but doing this won’t magically add shades of gray to the old 8-bit data; all this does is create the possibility of adding new 16-bit data information on top of the old 8-bit data; and it doubles a file’s size.

Editing files in 16-bit mode limits some of Photoshop’s functionality; many filters don’t work in 16-bit mode.
You can apply a filter to an 8-bit copy of a 16-bit file and drop and drag the filtered file into the original 16-bit file as a layer. Again, the layer won’t have 16-bits of data and may be adversely affected by subsequent edits if they are aggressive. If edited minimally, the results can be quite acceptable.

Editing your images in 16-bit mode is worth the time and effort. You’ll generate fewer imaging artifacts during editing and so create better-finished files.

Right now, creating 16-bit files is largely about generating the best 8-bit data. (Most monitors can only display 8-bits of data. Improved results in print can only be discerned by the very discriminating eye in select files.) In the future, when monitors and printers make better use of more than 8-bit data, you’ll begin to see visible improvements in gradation when your images are viewed in both display and print.

A smooth histogram.

A posterized histogram.

Gaps happen when contrast is increased; tones that were close together are spread apart. Spikes happen when contrast is reduced; tones that were close together become the same.

Avoid this by editing in 16-bit.