Expressive Black and White Post-Processing: Part II

By 13/11/2017Uncategorised

Expressive Black and White Post-Processing for Fine Art Photography

Part II: Second Pass Approaches Explained

13 minute read | Walk-through, Advanced, Black and White, Fine-Art, Photoshop

In order to complete the black and white photograph I began in Part I, I need to adopt a more hyper-local, value based approach in my Second Pass if I wish to convey the refined, high-end fine-art finish I set out to achieve. Let’s go through these approaches in more detail.

Screenshot of work in progress comparison of First and Second Pass stages of black & white post-processing by M. Seth Jones, completed in Adobe Photoshop. Unretouched image: Johnston, Frances Benjamin, photographer. Carver's Old Mill, Gordonsville vic., Albemarle County, Virginia. 1935. Image. Retrieved from the Library of Congress.

The image on the left is the complete, finished file. The image on the right is the in-progress merged composite as it currently appears after applying the First Pass editing techniques I covered in Part I of this series. If you haven’t read the first pass overview yet, I’d encourage you to ‣ go here first, then come back when you’re ready to find out how I approached finishing this photograph.

In the First Pass of processing this black and white image, the approach I take is much more in line with traditional darkroom techniques; there are digital equivalents for basic proofing, test prints and basic darkroom based dodge and burn. This helps to establish Photoshop as a feature rich complement to fine-art printing methods. In the Second Pass stage of editing, we take the capabilities of Photoshop to a much more precise, hyper-localised tier, affording us editing methods, approaches and options we could only dream of with an optical enlarger.

Always use the values in your images to accurately finish your photographs

Let’s have a look at the before and after transition of the current in-progress file, and the complete finished file in motion first, to compare the difference between the two states. For the purpose of this video transition, the completed finished image appears on the left, and the in-progress merged composite containing the First Pass stage of edits is on the right.

All of the base composite adjustments were made with either first or second order curve response modifications. They were masked locally, but in a near binary manner, similar to how I would make test exposures in the darkroom; select a general area of the frame, cut or boost its luma values. There was a little gradation on the local masks, but only to minimise seams. It has been, until this point, rudimentary depictive masking.

Now I need to turn my attention to a more detective form of modification, in order to transparently finish the file. This is done in four discrete stages, into a final targeted mastering pass, before sending the image off for a spotting and output sharpening pass. These are progressive modifications, meaning that I will refine successive passes based on the adjustments I’ve applied in previous steps.

Balance the primary and secondary global elements of your file

The subject and it’s immediate surrounding environment is my initial focal point. The subject itself is too flat individually, and too muddy in relation to the overall finish, so I need to bring it out in the mix. It’s still essentially the brightest pictorial element in the file, and it’s compositional focus ensures that, even when lacking some amplified light quarter tones for additional luma planes and compositional impact, it’s not in danger of being lost entirely in the finish, but it needs some attention.

There is a little luma clash going on between the subject’s camera left arm and the barrels immediately behind, but there’s also a subtle, natural gradient from plus-right to minus-left on the barrel itself. The rigid structural horizontal and vertical right angle repeating lines on the barrel do establish enough of a marked difference to separate it from the softer, cascading fabric folds and creases of the subjects jacket, however I’ll add a few new planes of luma values to the arm in this step to further differentiate between the two elements, creating a stronger sense of perceived three-dimensional depth within the two-dimensional frame.

I’ll clip two channel modifiers together here for this adjustment: the modifier itself, a second order response curve targeting the upper transition between the mids and the light quarter tones, with a broad bandwidth rolling off into the lower mids and highlights. This response curve boosts everything below roughly 190 with a luma rolloff, into a narrow shelf cut around 210. This needs to be mixed into it’s detective surroundings, so transparency is cut to a little above 50%. This is being controlled by a manually added mask that allows 100% of the partially transparent modifier to show through from the crossed knee upwards – the jacket, the shirt, the subject’s face and hat – then rolls off gradually from that targeted focal point down the legs, along the two lightest grain sacks (top and bottom only) and spilling outside along the wooden steps. This helps to introduce a few new planes of luma values to the file. They’re closer to traditional mid tones than anything else, but because the foundation values of the file were established at such heavy, low densities, they have the aesthetic impact of behaving closer to light quarter tones and highlights in this particular boost.

Continuously review your previous adjustments as you progress

The difference the initial subject refinement made to the overall finish made me want to apply a similar modification to the front steps. The exterior of the cabin should be naturally brighter, but it’s looking a little dull against the previous modification. The contrast between the luma values of the front grain sack and the wooden step surfaces is jarring to me as well. Ideally, I’d like to create a gradual scanning roll off for the viewer from the subject/interior to the bottom edge/exterior of the frame, and it’s just too stepped for my liking at this point. The bottom shoe is a bit too dark as well, and gets quite lost in the transition from the dark quarter tones of the step edge to the dense blacks of the shadow under the chair and around the darker middle grain sack.

The process here is the same as the previous step, simply targeting different values. I clip two channel modifiers together: the modifier with a targeted luma mask, and the control mask which I’ll paint in manually. The luma modifier essentially boosts the mids and the lower range of light quarter tones, and has the same effect as the previous step. Even though it’s only a subtle boost to some fairly middle-histogram values, because the surrounding tones in the file are so dark, it impacts on the finish in much the same way as a generous boost to the light quarters and highlights would on a flat looking file. It adds just enough contrasting (relative to it’s initial baseline) luma values to the exterior steps, and because the steps have a natural tonal variance between horizontal and vertical edges, we get a much more pleasant, naturally stepped luma gradient to guide the viewer into the centre of the composition (or centre out), with accurate luma transitions.

It also brings the bottom edge of the composition into line, as far as mirrored luma values go, with the left and right exterior edges of the barn itself. This creates value harmony between the discrete elements of the barn exterior without losing anything in the overall finish; the surface and edge qualities of the wood in the steps is naturally different to the equivalent qualities of the left and right wooden planks. Structurally we already have clarity between the two elements, so we can safely have them share overlapping luma values without worrying about creating a muddy exterior and subject frame.

The control mask will target the front and top facing wooden floor and step planks, avoiding the grain sack and the subjects legs while partially including the bottom shoe. I’ll paint in a partial target on the camera right side darker horizontal plank that extends right beyond the door frame, and allow a gradual rolloff of the control mask to spill onto the ground at the bottom of the frame.

There are countless final truths, and none of them are correct

The process of gradually adjusting local values one element at a time often reveals the biggest caveat with post-production; modifying one value often reveals, or creates, the need to make subsequent modifications, throwing the balance of values out with even minor shifts. The initial base composite showed I veered off-tangent somewhat, in regards to the overall luminosity of the finished image; by setting a very dark initial baseline, and building up the environmental elements before the subject, I was perhaps too conservative with my mids and light quarter tones, having had the overall balance of the finish skewed towards the heavier shadows.

At this stage, I’m looking to push the subject, along with the pictorial elements within the frame of the doorway, out into the front of the mix a little more, for enhanced luma definition. It’s still a little too dark for my taste, but I need to be cautious of creating an obviously masked two-dimensional diorama by amplifying the subject too prominently.

Nested modifiers control one more local adjustment to the subject and grain sacks. Inner and outer control groups are active here; the outer targets the pictorial contents within the doorframe, as well as the first outer step down, while the inner stacks on this by applying a discrete modifier to the subject and grain sacks in a chain.

The outer modifier boosts the luma curve response just a little higher than 127. It’s a first order, single point lift that rolls off evenly at the upper and lower ends. The targeted luma mask applies that adjustment to the upper highlights only; it’s not an even luma rolloff here. The lower and upper shelf of the response ramp in a little to the left and right of the target value, which is roughly around 190 or so. This ensures that the fairly rudimentary global curve modifier deals most effectively with the values I’m after here, namely: boosting the light quarter tones relative to their current luma values. The base adjustment is exactly what I want, but it’s too loud in the overall finish and needs to be dialled back to around 30% opacity.

The inner modifier works on the same principle, but targets a slightly narrower band of highlights, with an overwhelmingly subtle control mask, reducing the intensity of the adjustment. I’m boosting the same range of tones as in the previous step, and halved the opacity reduction here, to stack two relatively minor adjustments on top of each other to achieve the overall finish. It’s a small shift, but plays a significant role in pushing the subject to the front of the finish, just enough to stand on it’s own in regards to it’s luma values. There’s enough luma definition between the inner compositional elements now to create pictorial clarity between them, as the inner centre of the frame is quite compositionally busy, which is at odds both with the overall pictorial qualities of the scene, and also the slowly transitioning diffuse environmental detective qualities.

Evaluate your finish after you’ve taken a long break from the screen

I have to admit, I actually thought I’d finished the image at that stage, ready for spotting and output sharpening. As is always the case, I let the file sit overnight, resting my eyes (and my sensibilities) before opening it up with a renewed perspective.

It was still too dark.

Tracing back through the process here, I can see I made a significant impact on the overall finishing process by establishing such a dense, heavy initial baseline.

The final finishing process is relatively straightforward: I want to brighten it up, basically. To do this, I drop in two modifiers targeting non-linear luma ranges, one focusing on the inner compositional elements – the subject, the doorway, etc – while the second focus on the compositional frame, so to speak – the exterior surfaces of the barn itself, as well as the exterior elements of the composition.

The inner adjustment rolls in around 140, targets around 160 and rolls off around 180, with a second order, narrow bandwidth minor boost around the 130 range. The base curve response is a standard single point, first order function that tapers off to 0 and 127 evenly. The outer adjustment is skewed more heavily to the right of the histogram, targeting the highlights, of which there aren’t many. In the purest sense, we don’t even really have true highlights. The brightest values in the file at this point probably aren’t even higher than around 200 or so. The lower shelf for the second target starts around 180 and rolls off around 220 or thereabouts. The brightest sections on the control mask probably don’t even push what we would consider to be lower mids, so it’s a very subtle modification.

What I get here is an optically accurate modification to the two main elements of the image; inner and outer pictorial elements, and an overall balancing of the final mix of luma values. While not quite as dramatic as it sounds, the overall finish does fall apart a little with only one of these modifiers applied. With just the inner adjustment, attention becomes focused on the unnatural compositional qualities of the subject, looking a little too poorly-collaged in it’s awkward balance in regards to it’s surrounding surfaces. Without the inner adjustment, the external frame of the file becomes the main luma focal point, pushing itself out to the front of the finish just enough to shift the overall compositional balance of the file. The weight of the composition skews towards the outside, away from the obvious pictorial focal point towards the centre of the frame. With both modifiers applied, each section gets luma accurate lifts relative to their current values, as well as each other, ensuring the overall balance doesn’t get thrown off.

Make your final surface and edge corrections and enhancements

Spotting is applied to a few distracting marks in the upper left of the heavy black background region. Some might prefer they were left as is, but the pure isolation of the central dust spot/scanner artifact against the heavy blacks just drew my eye too often. It’s a subjective thing, that’s the decision I made at the time. Any other day I might have chosen differently.

Output sharpening here is applied with a narrow band second order contrast increase to a finely tapered band of higher frequency edges, and dropped back to around 30% opacity to sit it right in the overall finish. In order to retain the sense of optical transparency that should be at the forefront of our post-production decisions, it’s being applied relative to the luma values of the merged composite. We want the sharpness to roll off relatively to the overall luminance of the image and it’s component pictorial elements and shelve back in as those values spike.

Trusting your expressive instincts against the lure of infinite aesthetic control

It’s output preparation time. Or is it? Honestly, the one thing that most of my students seem to stumble over the most is “how do I know when an image is finished?” It’s a bit easier to give a definitive answer for that when it’s client work; it’s the deadline, or when the client says its finished. That’s how you know. It won’t matter if you finish it a week in advance of the initial turnaround time, they’ll make sure you have enough revisions to see you through.

For personal work, however, it’s simply a matter of saying it’s done. Which is actually not simple at all. Everyones values are different. I could say a personal image I worked on is done when it reads correctly. However, as I’ve (hopefully) demonstrated in these two articles, what reads correctly means to me is, much like the 350 layers in your latest Photoshop masterpiece, a relatively convoluted mix of discrete interpretations of isolated imaging considerations. And every one of those considerations is entirely subjective, based on my own experiences and sensibilities. It’s not as clear cut as saying ‘my black point needs to be set to a value of 15 to avoid shadow clipping for outputting to that specific printer’. Not even technical imaging interpretations can lay claim to being a singular standard for truth, although they do have more rigid boundaries to keep their translators in place.

To paraphrase Ansel Adams once again, post-processing is a unique combination of technical execution and creative activity. When it comes to aesthetics, imaging interpretations are generational. They’re social. They’re cultural. They’re physical. They’re genetic. You can read other’s interpretations, but don’t take them as a definitive universal standard. It isn’t possible to tell another person what to see. The best I can do is give insight into my own unique interpretations of the process of first visualising a desired finish image, and the craft of achieving those results.

Image Attribution

Johnston, Frances Benjamin, photographer. Carver’s Old Mill, Gordonsville vic., Albemarle County, Virginia. 1935. Image. Retrieved from the Library of Congress, https://www.loc.gov/item/csas200904177/.

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