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Old August 11th 14, 04:43 PM posted to rec.photo.digital
Savageduck[_3_]
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Default Lightroom vs. Apertu Curves

On 2014-08-11 14:17:06 +0000, Sandman said:

Here's an example of a feature I'm missing in Lightroom.

I use curves extensively, it's the holy grail of exposure editing. If
you're not using it, start using it!

So here it is in Apertu

http://sandman.net/files/aperture_curves.png

On a slightly (deliberately) overexposed image from Gotland. See the
"Range:" popup? It can be set to "extended", and it looks like this:

http://sandman.net/files/aperture_extended.png

It shows a larger spectrum of image data than can be displayed on your
monitor, i.e. a higher dynamic range. This is only populated if you're
shooting with RAW files of course. You then have more bits of image data
than JPG or your display can show. Using this, I can move the qhite point
*up*:


I am not going to get into a major Aperture vs. Lightroom argument
here, but why on earth would you want to move the white point "up"?
All that is going to do is clip the data on the right.

http://sandman.net/files/apterture_extended2.png

And you can instantly see the result. You suddenly have more image data in
the monitor-visible spectrum! Amazing, isn't it? Now, this may have been a
poor image to show this with since we don't have all that much *useful*
data in the upper range either way. But it's super useful for a lot of
bright images to get more data from the file.


I can see that this might be beneficial in an image with deep shadows
and you might want to artificially stretch the DR, but with the example
you have used all you achieve is clipping. There is no additional image
data visible to me, and I would guess anybody else.

Unfortunately, Lightroom doesn't seem to support this. Default it shows you
a poor-mans version of curves:

http://sandman.net/files/lightroom_poorcurves.png

And at first I wondered what the hell this curve was on about, it had these
stupid limits and regions. So you have to click the bottom right icon to
get to the real curves:

http://sandman.net/files/lightroom_curves.png

But, alas, no extended range here (or with the poorer version of curves) so
no way - as far as I can make out - to actually access all that glorious
image data from within Lightroom.

Anyone knows if I've missed something?


From what I can see you are calling the Lightroom implementation of a
Tone Curves adjustment a "poorer version of curves" because it doesn't
have this extended feature. However, it doesn't really do what you
claim on the right of the histogram where it leads to clipping. It can
help in the shadows and mid-tones, but for the most part there are
other tools which can deal with those issues.
They are two apps with similar goals, but different implementation,
don't expect them to mirror each other in every way. They won't.

--
Regards,

Savageduck