Quote:
Originally Posted by aliabbasjp
Thanks,
i wanted to increase the default gamma level since the pdf pages appear very light, each time i need to "+" to increase the gamma.I want the gamma to be at max as default
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Increasing gamma lightens dark areas of the image. To darken it you need gamma values less than one. You can also darken light areas (an "S-curve" hack) by gamma adjusting a NEGATIVE of an image, then convert the adjusted negative to a positive, when "photoshopping" an image.
Some content (especially from video cameras) has the gamma pre-adjusted to 0.45 gamma, to compensate for the 2.2 gamma of television CRT phosphors. That would make it look much too bright on a kindle reflective display, and may need to be linearized to darken it, using a gamma of 0.45. However, some adjustment may already have been done when it was digitized, so you really need to use whatever gamma adjustments bring out the most detail in the dark areas without washing out the bright areas, when viewed on your intended target display device.
When doing gamma adjustments on a CRT, it is critical to calibrate the gamma on your CRT. On an LCD, it is hopeless, because LCD gamma cannot be made linear, and varies greatly with brightness settings (but they are getting better).
EDIT: It is possible for software to be misconfigured to make an image darker with a gamma "+" button, but that would be a software bug or a design flaw.
