Thursday, June 4, 2015

Best Way to Digital B&W


Charley - BW
I've always liked B&W, and grew accustomed to Film Emulation software to make a good B&W out of a colour JPG file. Some of the Film Emulation approaches I'd discovered for free are in GIMP (under Colours > BW Film Simulation) and G'Mic within GIMP (Filters > G'Mic > Film emulation > B&W), not to mention DxO Film Pack (not free). DxO Optics Pro, which in my opinion is the best Raw File Conversion software on the market (also not free, but relatively cheap) offers some B&W presets, as do Opensource (free) Programs like Photivo and RawTherape, with built-in control of some parameters.

But I've only come across one Program which has slider control adjustment available for all parameters you could think of within one control screen, with a good size on-screen preview, and that is also built into the G'Mic-within-GIMP Black and White filter. All within one control box, you can adjust Red, Green and Blue Levels and Smoothness, Hue and Saturation, Gamma, Contrast, Brightness, Grain (Shadows, Mid-tones, Highlights, Grain tone fading, Grain scale, Grain type, Local Contrast with Radius and Smoothing, and as if that's not enough, you also get a Psuedo-Grey dithering control. I created the above file from this original:

Charley, from EOS 5D at ISO 1600, EF 50mm @ f1.8, DxO optics pro
I won't name all the specific actions I took in G'Mic to do the B&W conversion, nor will I mention everything I did with the Raw File within DxO-OP - what's important is getting results you're pleased with. Otherwise, this would be a Tutorial!

So, this is NOT FILM Emulation - rather, this is beyond Film Emulation. The emulation approach is great, as you can get results with one-click (or screen tap). This is Black and White Conversion. As far as a specific film type, there's no way of knowing what I've converted to - this is strictly Digital B&W "Digital Darkroom" stuff. If you were shooting a camera with B&W film, and had a home darkroom, you would be adjusting a lot of the above-mentioned parameters via the film you use, coloured lens filters, type of chemicals, temperature and time. This may sound far more interesting to a whole lot of people, but if you're a digital shooter, and if you want full B&W photography control in one place, this is a great computer app to get.

Although I'm not providing a Tutorial here, some things might need a bit of explanation... lets get the weirdest one out of the way first - "Psuedo-Gray Dithering". What this does is provide an expanded range of "colours" to your grey-scale used in the conversion. Normal B&W conversion (as in the "colour desaturation approach" leaves only 256 values from pure white to pure black. Psuedo-grey adds a whole lot more - up to 1786, by borrowing a wee bit of various colours to mix in with the greys. Depending on your computer screen, or your printer, you may, or may not see any difference. Just a note - my computer screen does not allow me to see this effect make any difference, but my printer actually does. I did not use the effect in the above sample. A film camera equivalent to this might be a form of "cross processing' where you introduce some C-41 chemicals, or use one of the B&W films available for C-41 "drug-store" processing. With film however, there is not much you can do to control the range of the effect.

Next, what is "Local Contrast"? Basically, it is an extremely effective way of extracting more sharpness and detail - but beware - this is best done when converting your Raw File output from your camera to a JPG. Here within GIMP / G'Mic, you  don't have that option, because there is really no extra detail to extract from a file that's already JPG. It is only a "Psuedo - Local Contrast", really no better than the well known "Unsharp Mask". I did add a bit of Local Contrast to the original colour conversion (Raw to JPG) you see above, using DxO Optics Pro. I DID NOT use the Local Contrast slider in G'Mic.

Finally, for a Black and White Conversion, why would there be "Hue and Saturation" sliders, along with controls for Red, Green and Blue?

To answer the first one, Hue and Saturation can provide variable contrast in different parts of your picture. This is normally done within Photoshop (or GIMP) by first changing the Hue and Saturation, and then de-saturating (removing all colour) as a second step. Here within the G'Mic Program, you can do this in one step, while viewing a B&W preview - a real time saver. As for Red Green and Blue, this provides a direct correlation to film photography, where a B&W shooter would use these colour (along with yellow and orange) filters on his lens to provide varying differences in contrast - a very common example was to use a yellow filter to enhance the look of clouds in the sky for a B&W filter. Here (and with many other Apps), you have "digital lens filters". By the way, you should never use a real glass lens filter on a digital camera, unless you know what you're doing and really want an unpredictable result. This is because a digital camera sensor already has millions of tiny coloured glass RGB filters built into it, and interaction between these and a lens filter intended for film will not work the way you think it might. Stick with digital filters for digital cameras.

Finally, just a note regarding B&W photography in general - it retains an enormous popularity, as I notice that my B&W uploads to Flickr usually get double the number of Views and Faves in relation to my colour pics. Also, my B&W shots get far more than double anything I try that looks like an Instagram "nostalgia" filter. What does this suggest? Could it be that we all like the TRUE nostalgia of B&W? Is there some sort of a greater purity? (Because no "Nostalgia" Instagram picture ever really looked like that, right?) What about a B&W-only digital camera, for which only Leica has jumped in so far, with their super expensive "M" - why? A new rumour out there in Blog-Land is that Sony is coming out with a B&W camera - to be announced very very soon. Why not? In reality, a Digital B&W sensor is made by NOT including the RGB coloured micro-lenses I mentioned above, with everything else remaining the same. If B&W is more popular, why don't all camera makers provide us with such a device that's actually easier for them to make, and offer it at a proportionally reduced cost? These days, even the most amateur photographer (like me) owns more than one camera - why not having one of those dedicated to B&W? Surely it would help us learn, as good Photographers once had to, how to "see in black and white"? With colour digital cameras, we don't do that now -- it's more like "maybe this picture would look better in B&W" and so we simply run the pic through one of many device apps to give it a try... this IS NOT "seeing in black and white", the way all film shooters once had to.

Is anybody out there listening??

1 comment:

  1. Hello Dave. Great article !
    Nice to see you enjoy this particular G'MIC filter (I've made it :)).
    Maybe you have some ideas to improve it and make it even more appealing ?
    Just curious.

    Cheers,

    David.

    ReplyDelete

Reader's comments are welcome, and are subject to moderation by the author.