" I know at least /.../ darktable can output in linear color space without applying a gamma curve " Okay, so part of the solution is to go into Darktable and disable the base curve. This worked, though it's too bad it adds another step to the workflow. Choosing darktable option from hugin import doesn't give any options to specify, like styles that could be used to define linear settings with... does it work well for you? I'd try it but for now it just crashes.
"The response curve is applied to all color channels. /.../ Maybe there is a problem with the white balance instead." Camera manufacturers add subtle changes to the RGB output channels in-camera. It's mostly done to keep a cohesive look to their cameras, like a modern photorapher may use a certain LUT they like so all of their work looks the same. Normally raw files are immune to this because there is no in-camera processing going on, but point here is to check for inconsistencies. It could be anything - sensor age or wear. "Hmm, if you opt for linear color, does color space matter?" Technically those are two different things. A colour space can be whichever coordinate system you can describe within the limits of human visual ability (400-700nm), while linearity is having a constant step "distance" within that coordinate system. I imagine. "What impact would [15bit colour depth] that have on "linear" color space?" More colours between full black (0,0,0) and full white (1,1,1). If the system is new or very uncommon it could cause demosaicing problems, but that is a different topic. On Friday, February 26, 2021 at 6:44:07 AM UTC+1 GnomeNomad wrote: > On 2/25/21 7:49 AM, T. Modes wrote: > > > > > > [email protected] schrieb am Dienstag, 23. Februar 2021 um 21:53:38 > UTC+1: > > > > I want to check if the photo stacks I am working with are linear or not. > > Yes; raw files are supposed to be linear, but Hugin does not work > > with CR2, only tiff. If I convert the cr2 to tiff it will probably > > add a gamma curve, > > > > I know at least dcraw, RawTherapee and darktable can output in linear > > color space without applying a gamma curve. What Adobe does I don't know. > > Hmm, if you opt for linear color, does color space matter? > > Also, I learned something when I changed cameras. I changed from a > camera whose sensor shot 15-bit per channel (each color) to one that I > understand shoots different bit depths per channel. What impact would > that have on "linear" color space? > > > In the attached picture green shift is seen in the cloud. To my > > knowledge this means that the gamma curve has been calculated badly. > > > > Not sure about this. The response curve is applied to all color > > channels. When there is a color shift it is probably not related to the > > response curve. Maybe there is a problem with the white balance instead. > > What happens if the sensor's response curve varies for each color channel? > > -- > David W. Jones > [email protected] > wandering the landscape of god > http://dancingtreefrog.com > My password is the last 8 digits of π. > -- A list of frequently asked questions is available at: http://wiki.panotools.org/Hugin_FAQ --- You received this message because you are subscribed to the Google Groups "hugin and other free panoramic software" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/hugin-ptx/cdfc2f46-0a09-420b-b8d4-17c59b9ab92fn%40googlegroups.com.
