[Digikam-users] Adjusting Luminescance:

[gerlos]

Il giorno 15/gen/2010, alle ore 11.09, davidvincentjones ha scritto:
> Recently I have been working on a Black and White series where subtle
> changes in the luminescence (akin to burning and dodging in my darkroom) are
> all important and I find in some instances that the degree of control
> afforded is limited (or at least very very hard to control). I think my
> comments below may be more applicable to B/W images than to Color work but I
> may be pushing my luck with this remark.

[CUT ]

> I suspect that most image processing systems were designed for use in the 8
> bit world where the limits of data manipulation were small and the clasicly
> simple 'S' luminescence curve covers most general needs.

AFAIK, in digikam you can work in 16 bits (look for this feature in the menus, just after you opened an image) and using the levels tool instead of the curves took you could do somehow more quantitative editing in the midtones. Is this the problem, or I misunderstood you?

> I need (or would like) to be able to 'tweak' on a much finer scale than I am
> able to achieve on most of today's systems and wonder what thoughts others
> have had in this direction.
> 
> A useful addition that I use in Cinepaint is the ability to move the
> 'mid'gray' position within the "Adjust Levels" ... this allows the retention
> of subtle highlights quite easily. I cannot do this, to the same extent, in
> DK easily

Can you explain a little better the problem with the "adjust levels" tool in digikam? I'm not a great user of cinepaint, so I'm not sure to understand what you mean...

> One competitive Win. program does allow the moving of tonal bands apart and
> together .... could that also be incorporated into the DK "Levels" dialogue.
> I really would like something where potentially I could juggle, together or
> apart, each of the 16 bits, as I see fit with possible the MAX, MIN and MID
> positions being used as 'Master controllers'.

Are you talking of something like the "Zone Mapper" of LightZone? (http://www.lightcrafts.com/) 
I used the linux version when it was free, and I think that is a really useful and comfortable way of editing midtones, like you do with the levels tool or the curves tool, but in a way far more intuitive and efficient
. 
You can see a video of the tool at this address:
http://www.lightcrafts.com/learning/index.html
Click on the fourth video of the list to see it in action. 
I'd really like to see something similar to this tool in digikam... the usual question: should I open a new wish on bugzilla? :-)

More on the zone system here:
http://en.wikipedia.org/wiki/Zone_system

regards
gerlos