On Friday, January 21, 2022 at 6:33:52 PM UTC-5 [email protected] wrote:
> > Hugin will by default map the exposure of the photos to the scene, > meaning that it will brighten your sky image and darken your ground > image so that they match the exposure of the middle image - the end > result (if you stitch to an 8bit format like JPEG) is that you may as > well have taken the photos on the middle exposure in the first place. > That is what I most want to avoid. It would ruin the panorama. > > Actually most of the time this is wanted, most panoramas I shoot these > days are taken with my phone on auto-exposure, and I don't worry that > the individual photos have different exposure times, Hugin blends them > together seamlessly. > Maybe you mean horizontal panoramas, for which I can see that what you usually want is to undo what the camera did with varying auto exposure. That is harder to believe for vertical. I don't think this exposure issue I have is at all uncommon within vertical examples. for this you need tonal range compression - > That is also something I want to avoid. Compressing the tonal range is not nearly as bad as clipping the range (undoing the auto exposure) would be. But it is still bad. I want to leave the well chosen exposure choices made by the phone roughly intact, but somehow avoid the problems that implies for seams. In fact, for this specific panorama, I think with a lot of tedious work I could mask to boundaries at which a shift in exposure would look like something legit rather than like a defective seam. I might even try that. But I'd rather learn a better and more general method. > Select > the photos in the Photos tab, edit the Eev and set them all to the > same number. I hadn't thought that was needed. I don't really understand other choices. I thought I could opt out of any exposure correction more directly than that. But if I misunderstood other choices, thanks for the reminder of a clean way to disable exposure correction. > > what you probably want is Transverse Mercator, this projection is > designed specifically for tall and narrow panoramas. > Bruno > Thanks. There were so many choices and names in a terminology I don't know. It helps a lot to know the likely best to try and if necessary compare to turning the whole project sideways. I still think that what I want for the main problem is to pre-shift the exposure within each photo based on relative (within each image) vertical position. I think I know which open source tool will make that fairly easy (once I learn how to use it). So I'll reread that documentation and experiment a lot (documentation makes it easy to see such effects are supported but hard to see exactly how you ask for them). I'll assume you know hugin well enough that your not mentioning anything about doing that inside hugin implies it isn't there. I don't mind using multiple tools. I'd want to learn the purely-in-hugin way if it exists. But otherwise whatever works. -- 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/86c2241e-92d1-4f73-865e-8172452761f6n%40googlegroups.com.
