Black and white points in the develop persona

[Littletank]

As I mentioned in a previous post, my colour perception is not very good and, therefore, my RAW images are converted to black and white after they have been developed to my satisfaction. I have been using Adobe Camera Raw and it is very simple, to my eyes, to set the black and white points and I would like to know if there is any simple yet accurate way of setting these two points in AP? The training videos have been very helpful in many ways but not on this subject.

[Fixx]

In the Toolbar (at the right end) there are Show clipped buttons which display quite nicely when blacks or whites are clipping.

[Littletank]

Thank you, I have seen those buttons and noted how they show clipped areas on the image. If there are no clipped areas but, from the histogram, there is room to push the highlights and or shadows, would one then use the brightness and blackpoint sliders to do this?

[lepr]

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[Littletank]

You raise some interesting points, owenr and I rarely, if ever, adjust contrast at the develop stage. I think I will be able to get what I want using the AP develop persona but, if and when I get stuck, I'll be back.

[toltec]

29 minutes ago, owenr said:

Develop Persona's Brightness and Exposure currently are exactly the same function but Brightness operates over a narrower range of exposure values.

 

Brightness and Exposure are different things.

 

Brightness is gamma. It is a non-linear adjustment.

 

Exposure is the same as opening the f stop on a camera. The wider the lens is open, the more light hits the sensor affecting all the tonal values.

 

At least, that's the official theory.

[lepr]

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[toltec]

1 hour ago, owenr said:

 

Develop Persona's Brightness and Exposure currently are exactly the same function but Brightness operates over a narrower range of exposure values.

 

The point is, as you say, they are not exactly the same. Similar, maybe, but not exactly the same,

 

 

[lepr]

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[Fixx]

13 hours ago, Littletank said:

Thank you, I have seen those buttons and noted how they show clipped areas on the image. If there are no clipped areas but, from the histogram, there is room to push the highlights and or shadows, would one then use the brightness and blackpoint sliders to do this?

You can use exposure to set white point. Brightness affect more like gamma and generally does  not do so much to white point. (I wish there were simple white point, black point and gamma sliders, none of those "photographic sliders". I have done so much graphic work and prepress that they seem logical, possibly photography only customers find it different.)

You may look for histogram as guidance how much there is room but this is not very accurate. Better to drag sliders until tones clip and then back some. Sometimes it is desired to make some little parts of image clip (deepest shadow, sun and its reflections). And sometimes of course there are no extreme black or white and you have to wing it.

[lepr]

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[Fixx]

10 hours ago, owenr said:

Did you not read anything I posted above?

Yes, but did not bother quote any of it as it is of not much use. I did not say brightness is gamma, I said it is more like it. You can test which tool clips whites easier – usually Brightness does not clip even it lightens image a lot. That happens also in develop module.

[lepr]

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[lepr]

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