PIX 2015

Severe contrast enhancements: on 45% rule — and cats

Started Jun 28, 2013 | Discussions thread
Shop cameras & lenses ▾
ilza OP
Regular MemberPosts: 107
Re: Changing contrast without distorting colors: 45% rule and another cat
In reply to knickerhawk, Jul 13, 2013

knickerhawk wrote:

I rarely bother with gamma adjustments (too blunt).

The only reason I used gamma adjustment in my examples is because it is so easy for other people to reproduce (just type-in one number instead of mouse-dances with defining a tonal curve).  But gamma adjustments are relevant: look at an S-curve.  Its left third (foot) and the middle (spine) form an almost exact copy of the curve corresponding to gamma-adjustment with γ>1 (to match exactly, the only fix needed is to increase brightness after gamma adjustment).

So an S-curve may be considered as a “gamma adjustment with gradual-clipping in whites”.  In other words, gamma adjustment corresponds to the behaviour of S-curve in darks and grays.  By itself, it is pretty useless, but consider it just as a tool to study a part of S-curve.


Reply   Reply with quote   Complain
Post (hide subjects)Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow