The "camera response function" refers to how the radiance arriving on image film/CCD, after
passing through the lens, is transformed to actual pixel "brightness" values. The easiest and
usual transformation that we apply is the simple brightness+gamma. But in practice, where
photo cameras are involved, a more complex formula takes place usually "coded" from
manufacturer themselves in order to compress a high dynamic range image into a low dynamic
range (usually jpeg) photo.
What the above simple means is that users can now enjoy some realistic non-linear display of
the results - other than standard "gamma" - easily selectable from a drop-down list that
makes the final image matching better the image coming from a real camera.
Here is a series of images that were produced from quick selection in the darkroom panel.
First is the normal image as displayed using Gamma 2.2, which we include for reference.
File comment: Normal image using gamma 2.2.
normal.jpg [ 326.19 KiB | Viewed 2831 times ]
Next, is the same render using Agfachrome-rsx2-200CD response function. It has much
contrast but it is also much darker.
File comment: Agfachrome-rsx2-200CD response function.
Agfachrome-rsx2-200CD.jpg [ 350.93 KiB | Viewed 2831 times ]
A result that has more contrast than normal but uses the black & white film Dscs315B1
File comment: Dscs315B1 response function.
Dscs315B1.jpg [ 239.16 KiB | Viewed 2151 times ]
Finally, including yet another response, the Portra-100TCD, a really nice one. Here, we have
also added some strong glare to make the image even more "sweet".
File comment: Portra-100TCD response function with added glare.
Portra-100TCD-with-glare.jpg [ 310.62 KiB | Viewed 2831 times ]
A complete list of response functions will be available with next upcoming revision to "play"
with. We will be happy to see your comparisons and preferences.