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John Rostron

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About John Rostron

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  1. In theory you should be able to use a panorama stack. However you need to ensure that you have covered the entire subject. You will need to use a tripod, and a good tripod head that allows you to take series of images that scan first horizontally, then another series the next row down etc. You need to ensure that your images overlap both vertically and horizontally. Because of the movement of your subject, I would suggest that you take several shots at each position and then select the one with good overlaps with adjacent images. If your subject has too much depth of field, then you could take several shots at each position at different focus points. You could focus merge these first for each group before a panorama merge. As @maspick suggests, it would make your life a lot easier if you could find some means of keeping your subject still. You could use a Wimberly Plamp to hold stems, or use a muslin cage to keep the wind off. John
  2. I have been reading this argument and I have a suggestion. I have argued above that selection is an abstract concept. You could take the Humpty Dumpty approach: "When I use a word," Humpty Dumpty said, in rather a scornful tone, "it means just what I choose it to mean—neither more nor less." "The question is," said Alice, "whether you can make words mean so many different things." "The question is," said Humpty Dumpty, "which is to be master—that's all." Alternatively, you could take the quantum approach. Just as Schroedinger's cat was either alive or dead or somewhere in between, then a pixel can be selected or not selected or somewhere in between. Just a couple of thoughts. John
  3. John Rostron

    Jupiter Moon Wallpaper

    I don't think I would want it on my wall, but this a nice concept. John
  4. I've never thought of Affinity Photo as a replacement for Photoshop. An alternative maybe. Calling it a replacement implies that you want it to do everything that Photoshop does. Plugins that follow Photoshop's correct plugin interface mostly work. But not all do. John
  5. John Rostron

    HDR Artifacts

    I think that you are referrijg to the purple fringing in your highlights. Are you getting these in your street lanterns? They are due to diffraction where different wavelengths of light are bent round the edges of the shutter. They are more marked with a narrow aperture. Wht aperture were you using. They are also exacerbated where you have strong conrrast, as with the specular reflections. Some raw processors automatically apply a correction (defringing). Maybe your Canon program does. Affinity does offer a defringing tool, but does not apply it automatically. This may be all you need to resolve your problem. Search for 'defringing' either in the program help or in these forums. You should apply defringing to the individual images, before your HDR merge. John
  6. Googling "get frames from mp4" gives you a range of possibilities. John
  7. This is why I referred to it as an abstract concept. You propose an interpretation or model that works for you. John
  8. This is what I am referring to when I say that a selection is a more abstract concept than a mask. A seletion can have a fuzzy edge becase of feathering. The pixels in the feathered region are partially selected. The software applies an appropriate feathering algorithm to decide how such pixels are applied. Not a straightforward selected or not selected. A mask can have a fuzzy edge for any number of reasons. In a mask any pixel csn have a (monochrome) value between zero and 255 (for 8-bit masks).1 John
  9. None of the recent postings, including the OP has responded to this question. Masks can have various shades of grey and can be manipulated by the formulae described by @unni above. Selections are more abstract and cannot be manipulated in the same way. I would like to see a response from one of the devs for Serif's take on this. John
  10. John Rostron

    First steps in HDR Persona

    This look good, but we would get a better appreciation of it if we could please see your bracketed exposures. John
  11. I have always understood luminance to be the overall brightness of a pixel (effectively the average of the three pixel values). The Saturation of a pixel is a measure of how much its colour stands out from an average greyness. That being so, how would this apply to an individual colour or hue? Joh
  12. That is because Alfred chooses to be different and make life difficult for us ordinary mortals who use standard glyphs. John
  13. Useful! I much prefer descriptive text to videos. However, I would like to have seen some before and after images. John
  14. I don't see that s appropriate or relevant to apply such boolean operations to pixel images. I am suprised that you were able to do so. I can see that a selection can be seen as a vector shape and that it may be appropriate to apply boolean operations to such shapes. It would seem to me that you should be able to apply boolean operations to monochrome masks. Is that what you are trying to do? John