This movie is just for my spring 2020 students because you're working under difficult circumstances and you may not be able to actually install GIMP on your own computer. So we're going to walk through and make those measurements that you need to use. So again, I've pulled in the images the way I need to and then I'm going to go ahead and zoom in. Now right now I can see all four of the red stars and you should be able to figure out which the blue ones they go with. Just to make this a little bit easier, I'm going to zoom in a little bit more and again locate my one, two, three. And then my other one is up a little bit further for your number four. Starting over here with number one because we're starting on the left side, you would measure from the middle of one star to the pair on the other one. And that's going to give me 5.4 pixels. Now if I were to zoom in a lot, there's some variation involved here and for future semesters I'll let them have a little bit of leeway. If I measure again, I get 5.1 pixels so we're getting about the same here. For my second star, these are a little bit bigger dots but again try and go from the center of one to the center of the matching pair. So for number two, I'm getting 13.0 pixels. For pair number three, going from center to center, we're getting approximately 22.8 pixels. And going up here and over a little bit more, I should be able to find my last one, I may need to zoom out a little bit there it is. And measure it again from about the center to about the center and find that this one is also about 5.1 pixels. So again, just for you guys in spring 2020, if you can't get Gimp installed on your own machine, you can watch this video to actually get your measurements. If you have any questions, let me know.