Re: Flat histogram vs tall

In news:r1kkn1h890ctgb3ad7jg381gqgmof2j913@xxxxxxx,
JPS@xxxxxxx <JPS@xxxxxxx> scribed:
>
> It means that the histogram didn't auto-scale the data to fit within the
> y-axis range; IOW, there were too many instances of the same value or
> values in the image. The software that creates the histogram either
> doesn't change scale, ever, or it has a limit to its scaling range. If
> they used a fixed scaling that accomodated any number of pixels at any
> level without clipping, most images would not show up very well at all,
> like an almost flat line.
>
<snipped>

And if I may, I would like to illustrate just that point with an image I
took recently which contains a very high dark pixel count. The only other
peak of note is in the blue range of colour, as represented by the sky area.
However, as you can see, I have had to manually override the scaling giving
by the software in order to better view the comparative values and
composition of those
lighter pixels.

1. (Default) Auto scaling by software:
http://www.humantouch.pwp.blueyonder.co.uk/Histo_Auto.jpg

2. Manual override selected, with slider adjustment set to reveal uppermost
peak of maximum dark pixel count:
http://www.humantouch.pwp.blueyonder.co.uk/Histo_Manual_Low.jpg

3. And finally here, showing slider adjustment set to weight the higher key
pixels:
http://www.humantouch.pwp.blueyonder.co.uk/Histo_Manual_High.jpg

(The screengrabs shown depict the histogram produced by my preferred RAW
conversion software)

Kind regards
Nigel



.

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