When I render my bubble texture out, the image in the image editor after rendering is correct, but the saved image is not, as it is missing the light I added to the top of the bubble. After reading the other comments on this lesson, another person in march had the same exact issue I am having, but the solution to it was never mentioned in the thread.
What makes this even more bizarre, is that when rendered in open exr, the render saves as expected.
What are the steps to take so that the PNG I see in the image editor matches the one I see saved to my computer?
If I remember correctly Paul had the light move a little towards the camera on the y axis.
Hi Andrew,
Stupid question, why don't you use the OpenEXR Format then, as that works as expected?
It is much better than PNG and usually even smaller in file size.
The main issue would probably be, that PNG format doesn't handle Alpha's very well.
The only reason to use PNG's, would be, that they are more generally accepted. But if it's for use within Blender, there is no reason to use (some people would say: 'cripled') PNG's.
I'm on 4.2.0 and I have the same issue. My thumbnail renders out correctly, and the render that blender shows me is also correct, but the image file produce by it is different.
I think the lighting is getting rendered but it is very very very faint, even though it looks fine in the render view in blender and the thumbnail image saved in the folder.
I think it's some alpha issues? if I save the file as RGB the values of the lighting looks correct, but then it isn't transparent anymore.
I tried updating to Blender 4.5.3 LTS but the problem persist.
So I'm not sure if I missed some of the steps or anything, but the problem for me indeed was the alpha channel. It seems that the alpha wasn't including the lighting that I put in, so the image saved ends up different.
Here's how I fix it, I just used one of the color channel as the new alpha and the saved image is fine and dandy. 
You can see the alpha in the bg here and how it doesn't have the lighting on it.
What's weird is that it looks correct in the render result in the image editor and in the 3D scene view.
Would appreciate a more proper fix if anyone comes across it or know why this happens.
