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Author Topic: Digital BW Discussion  (Read 2325 times)

Rob C

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Re: Digital BW Discussion
« Reply #20 on: July 25, 2017, 07:28:01 AM »

Well, I do miss the quality of b/w printing, but getting back to a darkroom is no longer a possibility for me. I never felt under any threat in darkrooms, rather did I feel a sense of power.

GrahamBy

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Re: Digital BW Discussion
« Reply #21 on: July 25, 2017, 09:55:56 AM »

Ok, personal practice, works for me and might not for you.

Get your screen something like calibrated, which basically means turning down the brightness. Find an image of a step wedge and make sure you can see most of the steps.

Go into Lightroom. Start with an image for which the raw histogram isn't jammed up either against the left or right margins.
Press the B&W conversion button.

Now spend a lot of time playing wih the curve. Everything about exposure can be learnt by moving that curve around, that's basically it.

You can use the eye-dropper to read the percentage grey on, for eg, the subjects face. Then you grab that value grey and pull it up or down. You can expand the tonal range  in one exposure range and contract it in another, by using a curve that is steep over the range of interest and shallow elsewhere. The only thing to avoid is having the slope reverse, in which case you'll see a solarisation effect (or maybe you want that).

You can also change the relative contribution by colour if you want to change the relative brighness of foliage or a red dress or etc... but first thing is the curve.

I'd also suggest that where possible, you avoid applying local corrections: it's easy to end up with something that looks wrong because of differences in tone which aren't consistent with natural illumination. Classic B&W printing made a lot of use of dodging and burning, but had very limited options for global tone-mapping: a few paper grades, some post-development bleaching.

Leave the local contrast/vibrance/clarity controls alone.
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Deardorff

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Re: Digital BW Discussion
« Reply #22 on: September 21, 2017, 09:41:42 AM »

I'm one of those people with no darkroom experience and when I make b/w conversions I just go by what looks good to me, but it's not a very educated guess. Any suggestions on how to improve my b/w vision? How representative are photo books? I have Nick Brandt's books about Africa and by all accounts those are beautifully printed. Maybe some veteran b/w printer could sell some "this is how good a b/w print can get" technical examples.

One. Set everything for B&W so that is what you see on the back screen of the camera. Don't think in color at all but in tones of B&W. With B&W film we had no color after the original scene or subject was seen. All color was lost. Filters were used for separation of tones and control both in exposure and later in the darkroom.

I have a hard time seeing all in color and 'thinking B&W' and seeing it all as monochrome helps a lot. Might work for you, might not but you won't lose by trying it.
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jmlphotography

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Re: Digital BW Discussion
« Reply #23 on: September 23, 2017, 11:44:01 AM »

But I do notice that if I ETTR there is information lost in the highlights that can't be recovered easily ...

That would be because you are ETFTR (exposing too far to the right).
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David Sutton

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Re: Digital BW Discussion
« Reply #24 on: September 24, 2017, 01:18:26 AM »

That would be because you are ETFTR (exposing too far to the right).
Hmm, according to the histograms in my raw converters, that's not certainly not the case. According to my eyes, that's true.
With a luminance-only histogram you have to be careful with the blue channel in particular, so that's the first thing I look at. I always test a new camera for it's response. How far can I push the iso for a given resolution and how far can I push the exposure and is it worth calibrating for each iso setting.
The Fuji sensor/processing is not at all like the Canon cameras I've used in the past.
David
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