Star trail - Merging layers

[Nelson_A_]

Hi community,

I'm having issues flattening my star trail stack after I apply the Lighten command.  As you can see from my attachments I have all my images stacked as individual layers.  Once I select the first image, shift click the last image, then apply Lighten, I get the star trail with no problems.  The issue I'm having is that once I flatten the image it becomes brighter.  I have no idea what is causing this.  I'm wondering if anyone has encountered this before and what the solution is

Thanks

N

[D Fosse]

You need to view at 100 % to get a correct preview.

Whenever something seems to change when merging layers, it's because you are not viewing at 100%. The merged result is correct! The preview is misleading and incorrect.

100% has nothing to do with size. It means one image pixel is represented by exactly one physical screen pixel.

For performance reasons, all blending and adjustment previews are calculated on the on-screen version of the image. When you are zoomed out, that means a resampled and softened version of the image. Pixel levels are averaged out. You get a lot of intermediate values that aren't there in the full original data.

When you merge, commit an adjustment etc, the numbers are re-calculated on the full original data, pixel for pixel.

Viewing at 100% avoids all this and renders the whole issue moot. You see every pixel before and after, and so nothing changes.

[Nelson_A_]

HI,

Viewing at 100% didn't change anything.  I still come out with an brighter image when flattening or merging