HDR is about Dynamic Range of light, and it's a bit confusing. You can draw a line with a black marker on a white sheet of paper and essentially you've got both extremes, pure black & [almost] pure white. But there's a big difference between looking at that sheet of paper & directly at the beam from a very bright LED flashlight. Turn the flashlight off or look away and in a little while your eyes will adjust and you can see the room around you again. And that's basically the same problem most cameras face -- they can only handle lots of light by closing the aperture, reducing the amount of light that gets through, the same way the pupils of your eyes constrict when you look at bright light, then dilate when that light goes away. And just like when the pupils of your eyes are constricted, when its aperture is almost closed, your camera can't see everything else, because the aperture just isn't letting in enough of the light reflecting off anything that's not so bright.
Now we don't normally look at the beam from a flashlight head on. If we're in a room that's normally lit, if there's a window with Very bright sunlight streaming in, we try to focus on everything else -- we try not to look at that window with all the sunlight streaming in head on. And that's the same approach you would use to take a photo in that room, and it should turn out just fine. But what if you want to take a picture and you can't avoid that window? That's when/where HDR comes in, if your camera can support it -- if not, you simply don't take the shot.
For an HDR photo you would take one shot with the aperture closed down as necessary to accommodate the sunlight streaming through the window. Then you'd take another shot with the aperture adjusted for the rest of the room. Then in special software [Lightroom works very well] you combine the data from both image files. One of the images will show the rest of the room, but with the window blown out because there was just too much light coming through the lens. The other image will show the window, and some of what you could see through that window, but the rest of the picture is way too dark, if you can see anything of the room at all. So you take the window that's properly exposed in one photo, and replace the window in the other photo that's blown out. Done.
Unfortunately the sensors and electronics in your camera are not as good as your eyes, so sometimes, when everything's set correctly for your shot, you might miss some of the details in the darker or brighter portions of the scene. HDR can work there too, taking a photo that's otherwise underexposed, one that's normal, and one that's overexposed, by combining them you *might* be able to capture some of the missing details.
One problem you'll have though, is that almost no image file formats will let you keep all that data in a single file. Another potential problem is that ideally the camera won't move between one shot and the next, so everything lines up. Because that's hard -- just pressing the shutter button can make a tiny movement -- the special software usually tries to compensate for you.
So now HDR projects 5, which has been given away previously -- I have it from 10/15/20. It will do the basics of combining 2 or more photos, but most of its emphasis is on sometimes garish effects, as shown by its wiliness to make it's fake version of HDR from a single image. If you like that sort of thing, cool. You can even call it HDR if you want. Just take care not to embarrass yourself, as many people, most serious hobbyists, and every pro knows the difference.
HDR projects 5 uses files in the program's folder and in files/folders added to the User section of Windows. Like most true Franzis apps, you can copy the program's folder to another copy of Windows, fire it up, activate it, and it works [it'll add the needed User files itself]. The copy I have includes the P/Shop compatible plugins -- they may work if you copy them to the appropriate folder for your preferred image editing app, or it may work better to have the plugins in the program's folder, adding a shortcut in the appropriate folder(s) to those plugins [I've seen both].
