Unsharp Masks - When Not Worth the Effort

[Jerry Bodine]

I've been researching this technique and have come to some conclusions regarding which mask film to use and which developer. It's also clearly a time-consuming effort, but I've not found any information about whether there are certain characteristics of the original negative that prevent any benefit from the technique. In other words, when is it not worth the effort? Is it even possible to verbalize these characteristics, or is it just a matter of experience?

[Tin Can]

Incoming...

[Drew Wiley]

It has its own learning curve and requires its own specialized equipment. Of course, you can learn the basics without needing to hunt down the relevant punches and registration frames,etc. But it's difficult to do this kind of thing accurately or in volume without specialized gear, so you might get prematurely frustrated without it. Or you might get frustrated just trying to find proper gear in good condition. The punches and pin glasses have to be matched, made at the same time, or else be precisely adjustable. And let me add that masking is not a single technique, but a whole tool box with all kinds of image enhancement opportunities to explore. Now the hard part: which drives you insane - endlessly spotting prints, or being willing to be hyper-diligent to keep your negs and work space, and masking equipment, as free from dust as possible? Quality masking requires one to be a clean freak, at least in the darkroom whenever that kind of task is involved. There are only two suitable current films I can recommend for large format originals: FP4 and TMax 100 (only TMax for small roll film images, due to its finer grain). A good developer needs to obtain a long straight line at very low gamma. That can be described later if necessary. Conceptually, basic contrast masking is not that difficult, but the devil is in the details, and it does take some experience to get a good handle on it. It's easy to overdo it. A good magician never shows his hand. Now the applicable negatives: depends. What are your trying to do? Automatically do complex dodge and burn operations with an attached mask, rein in highlights and open up shadows in otherwise difficult to print negatives, enhance edge effect and midtone microtonality? All this is possible with even a basic unsharp contrast mask, the most elementary kind. But I don't do it very often anymore with black and white work, mostly just with color images. Let's face it; Tmax sheet film is expensive; and if there's an easier route, I take that first.

[Pere Casals]

I've been researching this technique and have come to some conclusions regarding which mask film to use and which developer.

I've only limited experience in masking, I'm a rookie in that, but let me say my view...

Well, a ortho film is nice for that, as you may use safelight as you work the thing. ROLLEI Ortho 25 also provides a fine grain. Anyway as we use a diffuser layer then the grain in the mask is a minor issue.

An interesting effect is if toe/shoulder of the mask matches in shape/exposure the curve in the original negative, this allows for a wide range of effects.

or is it just a matter of experience?

in my particular case it is a matter of luck !!

My view is that USM is also by-product from CRM, SCIM, etc I'm still learning the basics of all that, so...

In other words, when is it not worth the effort?

Unsharp masking is a sharpening technique: USM. Photoshop does the same with digital images, it just subtracts a blurred negative image from the original image, with balanced factors in the convolution mask.

As with Ps, some images do not react much to sharpening because there are no hard edges in the image that would show the accutance increase, IMHO.

I guess that the regular Ps control factors, radius and percentage, are controlled in the film mask with the mylar diffuser thickness and with the mask contrast. Probably the optimal diffuser nature dependends ub the ebnlargement factor and viewing distance.


is it not worth the effort? USM/CRM/SCIM/Etc... this is not for the faint of heart. Not worth if the image is not sound... well worth for an image we love if we want a supreme analog crafting.

USM/CRM/SCIM/Etc is both a tool to solve problems in a negative and a powerful image manipulation technique, but I would consider USM as an integral component of the masking work which has a wider scope that includes advanced tonal mapping.

____

Way Beyond Monochrome book and Alan Ross pdfs (color Selective Masking, https://alan-ross-photography.myshop...ective-masking) can be recommended.

[Pere Casals]

Of course, you can learn the basics without needing to hunt down the relevant punches and registration frames,etc. But it's difficult to do this kind of thing accurately or in volume without specialized gear

Punches etc are convenient but not necessary, see here how Burkett aligns a mask with a binocular loupe in the glass carriers, min 11:39 :

https://www.youtube.com/watch?v=doNGi8HeKQ4&t=7s


I use a variant: As I've not a bino then I use the GG x8 focusing loupe, effect is easily seen, when aligned I place the ANR glass on the sandwich. This is a nice way if not wanting to insert xenogear (register) in the enlarger.

[Drew Wiley]

Once again, Pere, you're showing a bit of ignorance of what is really involved. But once again it's also nice to hear from you and know that you're beginning to seriously think things out. As far as I'm aware, Chris B. only masks relative to Cibachrome for sake of contrast reduction as well as certain hue repro issues inherent to that particular medium. He and I have quite different protocols even for Ciba. There is more than one way to skin a cat; and I don't like the sloppy way he tapes the films together, or the dimensionally unstable type of tape he uses. If your punch and registration steps are correct, then there's no need for optical alignment en route; it's automatic. There are a few tricks to doing it right in the first place. But the inherent difference with black and white work, unless you're just talking about broad area control like Alan Ross does, is that unsharp masking with film can do very subtle things for microtonality and precise edge effect that involve, first, reducing the overall contrast via the inverse density of the mask itself, then raising it back up via a harder paper grade. That means any potential misalignment or excess diffusion halo is likely to be more apparent and annoying in a black and white print than in basic color masking applications which end up with reduced overall contrast instead. And of course, small film sizes are much harder to align over a lightbox than large sheet film. Sharpening is controllable by the degree of diffusion. And just like over-sharpening in PS, overdoing it via a film mask can lend a harsh unrealistic look, a common mistake among beginners. So bingo, you have correctly assessed that it is based upon the thickness of the frosted mylar, or by how many sheets of this are involved in between. But you also have to consider the angle of light incidence from the enlarger lens as a point light source up above your masking contact frame. That's why I like to use a long lens at a fair degree of distance, and have the masking frame very precisely centered below it. But for beginners I do recommend trying to do alignment visually over a light box before going nuts hunting for specialized gear or having a machinist make it. It takes a bit of experience to recognize just exactly what gear you personally need, and if the expense it worth it to you. ... I won't comment on ortho films here, except that if you learn masking on pan film instead, then it will be easier to transfer some of that learning curve to color masking too, which obviously requires pan sensitivity.

[Pere Casals]

As far as I'm aware, Chris B. only masks relative to Cibachrome for sake of contrast reduction as well as certain hue repro issues

Yes, but he makes a precise mask totally pro alignment with no punch, no register, no etc.

Also a tinny reticle (cross hairs) can be placed in the original neg borders to allow an easy/precise alignment.

But you also have to consider the angle of light incidence from the enlarger lens as a point light source up above your masking contact frame. That's why I like to use a long lens at a fair degree of distance

Not necessary, while this is benefical for a regular contact print a collimated light source is irrelevant for USM masking, you don't need total sharpness in the mask as at the end you will use a diffuser between the neg and the mask, so a diffuse illumination works perfect to expose the mask.

But for beginners I do recommend trying to do alignment visually over a light box

Also using a bino loupe would make it easier.

[Drew Wiley]

He spoke about a punch in the flick. And I know that he sometimes uses a set of matched registered neg carriers for pre-punched film. The video has been simplified to the very basics of technique, not what he routinely does. Sometimes multiple masks are necessary for the same image, and it's just about impossible to do that right without punching. I've done this kind of work for decades. The whole point of a matched punch and register system is so that you don't have to visually register things - a big headache! Nor do you need to spend anywhere near the amount of money on enlarging equip as he did to obtain equally high quality results. What an $11,000 super rare 360 Apo EL Nikkor lens gives you, versus a 360 Apo Nikkor process lens one can find in immaculate used condition for around $300, besides bragging rights, is just one stop of extra speed. Ciba is a very slow printing medium, so that might be a luxury in that particular case; but it's relatively meaningless with much faster RA4 and b&w papers. Ciba is basically obsolete anyway. I doubt anyone would even spot the difference in a huge print if even the fast 360/5.6 ordinary EL Nikkor were used. These optical niceties are a very minor issue compared to depth of field issues in 8x10 photography to begin with. The faster 5.6 option is nice when trying to compose and focus through the orange mask of a color neg. But I prefer the slower Apo version for black and white printing and certain technical applications with color film. The relation of light source diameter and its angle of incidence, sharpness, precise edge effect, and specific means of diffusion is quite complex. Don't underestimate it. You really have to test to get a good idea. And dye clouds in color film behave quite a bit differently than silver grain clusters in this respect. Even the type of b&w film can be an
issue with what degree of diffusion is optimal. It's a short step from a very subtle etched effect to something annoyingly obvious.

[Pere Casals]

Sometimes multiple masks are necessary for the same image, and it's just about impossible to do that right without punching.

O course... if stacking masks then a register is essential.

But a simple USM or USM/CRM is easy to align with a bino or loupe.

[Drew Wiley]

Well, keep on plugging along. It would be truly helpful to fine-tune some masking tricks before exposing that stash of CDU you got ahold of, unless you've gotten good at an alternative flashing technique. I recently printed an 8x10 interneg that involved nine film steps ahead of it. In this case, it was worth it. But more often than not, a single mask does the trick.