sky replacement

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    Kirk Osborn

    First of all, please note that AI Sky Replacement is designed to work with skies, so your workflow is not officially supported. Still, there is a workaround that will allow you to use Luminar on images like these: you'll need a consistent bright background of a light gray or blue tone.

    In your image, the background is quite dark and it has almost black areas that can't be recognized by Luminar as parts of the 'sky': https://prnt.sc/u6xzwy

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    Remo Navoni

    Brian

    I filled the background of the image with an even colour in photoshop, then Luminar recognised the background as 'sky'. I was then able to insert the sky background...  This is just a rough and quick test but I believe this is what you want to achieve.

     

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    Ian Murrell

    Brian Lambert

    Brian,

    It is not difficult to get the sky replacement tool active with this photo in Luminar., 

    1. Essentials->Light Set Shadows to 100
    2..Essentials->Color->Advanced - Select blue - Set Hue to 67 and Luminance to 100
    3. Essentials->Color->Advanced - Select cyan - Set Hue to 67 and Luminance to 100
    4. Layers-> Add Stamped Layer

    Sky replacement is now active.

    That said, this photo in my view is not really suitable for a "sky backgroud".
    The lighting has resulted in significant shadows on the original background, which would not exist if the background was really the sky, and unless those shadows were completely removed it  will not be completely believable. Sort of looks like the sky is a just painted background.

    The above process, done completely in Luminar has reduced the shadows but they still cause some discoloration in areas on her right side.

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    Larry Moore

    Why limit yourself to skies? With Sky Replacement I occasionally insert an image other than a sky. The background I used in this example came from Pexels. 

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    Murray White

    this will be comment and questions to Ian, Larry  & Brian. Ian -- love the info you presented for Brian. While I have L 2018 & L3, I have not gotten L4 due to wanting to get the same functionality for the Windows platform as is available for MAC.

    That being said, I have viewed and saved every youtube tutorial related to Luminar that I have been able to find over the past couple years and am fairly familiar with the product.

    1. Ian -- hopefully Brian tries your settings and if he will be using the same background will create a LOOK prior to creating the new stamped layer (so he can still make adjustments to the settings). I would then expect that if he has other backgrounds or the lighting of the background is different, he could then adjust the settings easily after applying the look (saves some time) and then create the stamped layer before changing the sky.

    2. Perhaps Ian you could explain the theory you used to determine the method of creating a way to select the background and adjust it with the settings you used. I think that would be most helpful for those of us not so adept at coming up with the idea. TIA

    I just re-read your comment Ian about the original image with the strong shadow on the background and am not sure how the black area behind the subject occurred as it almost looks like the color of the subject's dress but your replacement did change that area to the clouds. One idea also is that negative structure can be used to the background to soften it down a bit either after or before (save as a new .jpg for future use) adding the new background.

    Just a couple of notes to Brian.

    Because the direction of light is different from the sky to the subject, you could try a flip of the sky and that might even assist the shadow issue on the background. As well as the flip, you might adjust the crop or do as Larry did and use a strong vignette. Note that Larry also used an image where the light more closely represented the lighting done in the studio although the background area near the subjects left could be toned down to not draw the eye to that area.

    Ian -- I liked your idea related to changing the background that is not a sky replacement but simply a background replacement. I think I once viewed a youtube that did something similar but it was not quite the same and seemed a more simple background used in the replacement.

    Maybe you could comment more on your procedure or did you just simply select that background from Pixels (going to have to check out their site -- I take images of the sky all the time and categorize .then based on type and direction of light in folders) and L4's Ai did the rest of the job and then it looks like you added the vignette at the bottom.

    Just a couple of comments on the image that Brian used. One idea is to try to avoid taking an image of a person shooting up into the nostrils as that is one area of that face that is not very attractive and most people when asked about the least attractive part of themselves will say "my nose".

    Keep in mind also, that the feminine pose where the body faces one direction and the head is turned and tilted in the opposite direction creates the nice S curve which is attractive to younger and slender women.

    Also, the other area of the human body that is not very attractive is the palm of the hand. Keep in mind that the best method to use a "show hand" is to make it the one that is closest to the lens. For hands, keep the fingers long and tall and soft and photograph the edge of the hand and not the back or the palm. 

    HTH

     

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    Ian Murrell

    Murray White

    Murray,

    Let me start out by saying that the issue Brian Lambert  raised in his original post was about the Sky replacement being greyed out, and the steps I outlined were primarily to address that. The sky I used for my example was simply one of the standard ones included in the basic package. I made no attempt to select a sky that would properly match the light in the image or even to fully optimize the Sky replacement settings.

    Actually, with this image only step 1 (setting the Essentials->Light->Shadow slider to 100) before creating the stamped layer, was needed to make the Sky Replacement tool active. As an alternative step 1, you could start by adding an adjustment layer, use Essentials->Light->Exposure to around 1.49, and then mask out the effect from the model. The point of step 1 is to brighten up the background.

    My initial reaction when I looked at the image in the post was that the shadows on the background would make any chance of a realistic replacement of the background with a sky problematic. No matter what lighting one uses, the subject would never leave a shadow on a real sky. In addition to the realism issue, from experience I expected that the AI sky replacement would not replace the dark shadow area between her right arm and her body, and even more so the shadow area below her right arm. In addition the shadow above her right arm and behind the right side of her hair would probably result in at least in some discoloration of the replacement sky in those areas.

    Now there are obviously some techniques that could be done in a full blown host editor alleviate the shadow issue, but as this is a forum about Luminar, I kept solely to what could be done within Luminar.

    So to Steps 2 and 3 in Essentials->Color->Advanced Settings.
    I used the luminance sliders for blue and cyan to further lighten the background area and gain some reduction in the shadows, and the Hue slider for those two colors to move the background color more towards blue so it would better blend in with the replacement sky blue.

    So having done steps 1,2 and 3, I created a stamped layer, then selected Bright Blue Sky 3.
    I set Sky local to +150 to force some of the new sky to appear over the shadow areas. The downside is that it then shows to some extent on the model herself, which meant I had to add a mask to remove the sky from the model, but that isn't difficult.

    So all of the above done solely in Luminar 4, and in only a few minutes. It could most likely be improved on, but I doubt it could be made convincing, and I personally would have stayed with the original, maybe just lightened slightly.

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    Larry Moore

    Murray White

    "Maybe you could comment more on your procedure or did you just simply select that background from Pixels"

    I wish I could say it was something more exciting and technical than just choosing an image from Pexels.com. But, that is exactly what I did, indirectly. That image was selected as a background for an image that I was working with to experiment with the latest version of Topaz Lab's Mask AI transparency masking feature. I had picked that one because of the stark contrast between a bride in a very white wedding gown with quite a bit of transparency in the attached veil. I wanted to be sure that the masking of the veil was sufficient for the back ground to show through. I did  do a light vignette on the photo with Brian's image and masked out the upper portion of the vignette. I could have and should have done some darkening around the lower right edge and upper left edge of the young lady to prevent the "glow". this was a quickie on my part to present an alternative to using skies as replacements.

     

     

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    Murray White

    thanks for the comments to both. It is nice to see the process that guys go through in offering assistance and what techniques folks would use related to a specific image and issue. Most appreciated.

    As a retired (20 years) portrait/wedding photographer of the film era and not being a retoucher, I tend to look at the initial image out of camera so many of my comments will begin there. Hope that is ok as time goes on. Even though I have had L 2018, I have not had much success at being happy with Luminar and Windows 10 and hope that things will become more equal if not totally equal (preferred) between  Windows and the MAC platforms. This is my first excursion into the community and have been reading a lot of the comments in a couple of the forum topics.

    I try to view almost everything on YT and from Skylum to learn all I can about the program but don't always remember everything and its location so sometimes commenting can be a problem. Good memory, just short like my hair!

    Again thanks for the info.

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