Where is the border between raw developing and photo manipulation?

by Skippy le Grand Gourou   Last Updated August 24, 2015 17:08 PM

Raw images are supposed to be detailed output from the camera sensor(s), with more details that what can actually be printed or displayed on a screen. Effects like exposure compensation or white balance could be achievable with on-camera settings, or filters, or lights, or during developing. On the other hand I doubt advanced functions like noise reduction, local contrast or edges could be obtained through traditional film photography — and it seems quite easy to fell on the "too much" side of photo editing.

Hence my question : which tools (and/or ranges) of raw editing software have (or do not have) an equivalent in film photography/developing ?

NB : I understand that the JPG output of a camera has already been altered, maybe in a way which could be considered as photo manipulation.

NB2 : I am not really a purist, I'm asking out of curiosity.

NB3 : This question and this other question sound similar, but the first focuses on philosophicals aspects while the second focuses on ethics. None of both questions addresses the technical side of raw vs film developing equivalence — though the questioner of the second one mentions some relevant technical criterions, which is a nice first step.

NB4 : I feel this information is of little pertinence here, but FWIW I'm using rawtherapee.



Answers 3


Actually local contrast / edge enhancement can and was done with film.

https://en.wikipedia.org/wiki/Unsharp_masking#Photographic_unsharp_masking

Other processes that could be done with film include: cropping, contrast enhancement, rotation, colour manipulation, selective brightening/darkening, gradient filters, image compositing, dust/spec removal / airbrushing.

Matt Grum
Matt Grum
August 24, 2015 15:11 PM

One big one you can do digitally that was very hard to do with film is color correction at more than one place along the dark/light range. Unless you were doing very complicated, time consuming, and difficult masking, you could only color correct a photographically processed (as apposed to digitally processed) image at one color point.

Color enlargers had filter dials that would change the color mix, but these adjustments applied to the whole image. Getting the color balance right was laborious due to the turnaround time between trying a set of exposures and seeing the results. At best you could get the color right in one place of the color space, and the rest came out as it came out.

A common example was sunlight-balanced film used to take pictures under incandescent lighting. Corrected for sunlight, the whole image would look orange. You could pick a mid-gray spot somewhere and make it look gray, but then dark areas would have a bluish tinge.

Digital sensors are usually linear, so one correction for the lighting color actually works, and it's easy and normal to map the output image from the darkest to lightest area of the raw image.

Olin Lathrop
Olin Lathrop
August 24, 2015 21:48 PM

On the other hand I doubt advanced functions like noise reduction, local contrast or edges could be obtained through traditional film photography — and it seems quite easy to fell on the "too much" side of photo editing.

There is no doubt that digital files allow much more processing flexibility than traditional silver halide film. But in this particular case, grain reduction, local contrast and edges could be controlled (up to a point) during development. These techniques are available only in B&W photography, though.

MirekE
MirekE
August 24, 2015 23:08 PM

Related Questions


Image correction

Updated April 01, 2018 08:18 AM


How are these "wiggling" 3D images made?

Updated July 07, 2016 08:07 AM


Can deconvolution help mirror lenses?

Updated July 22, 2017 14:18 PM