Help fixing panoramic picture

Question

Hello, the above picture is taken in panoramic mode from Olympus TG-2.
It's made up of three pictures each one having a little different exposure because of the sun angle.
The camera automatically stitches the photos in the one JPEG
Does anybody have any suggestions on how to fix this?
Any help would be appreciated…

Answer 1

That's still doable, but will need a bit of work.  I don't know what version of Photoshop you are using, so the following is for CC. 
Open the image, and drag a selection across the the central darker area. Make the selection the full height of the image, and try to intersect the transition from light to dark.  Feather the selection.  This is just a starting point, but something like 5 pixels would work.
Now open a Curves Adjustment layer.  The layer mask in this layer will automatically have a suitable mask in place from your selection.
Click on the hand icon top left of Curves Properties panel, and click in the image on the dark blue of the sky dragging upwards until you get a reasonable match.  Note you need to match the darkest area, which is on the left.  The right edge will be too bright, but you'll fix that later.
Unlink the layer mask in the Curves Adjustment layer. (click on the chain icon to the left of the layer mask.)
Make sure the layer mask is selected (it should have a heavy white outline), and nudge the mask left or right to get the best seamless transition.  You will also need to adjust the feather.  If you click between the mask and curves icon on the layer, it will change between Curves and Mask properties.
When you get the left edge as near as possible, you are going to have to fine tune the right edge using the paint brush in the layer mask. Set brush opacity to 10%, and with black as the foreground colour, and using a fairly large fully soft brush, build towards the best match a stroke at a time.  If you go to far, swap to white and reverse it.
You can improve the result of the above process using the Patch tool.
Select the highest layer in the stack, and add a copy merged layer (Shift Ctrl Alt e or Shift Cmd Opt e)
Select the Patch Tool and make sure it is set to Source in the Options bar.
Make a select around the transition from light to dark, but just of the sky.  Don't get too close to the horizon.
Now drag the selection to the right, keeping it abutted to the upper frame edge, and let it go.  This will merge the selected area.
Note: your selection will have needed to cover a reasonable area each side of the dark to light transition.
To fix that huge step in the horizon on the right, drag a selection around everything to the right of the step,, and copy to a new layer (Ctrl j or Cmd j)
Now use Free Transform, or Liquify to match the horizon as close as possible, so you can finish off with the Clone tool.
Note: If you use Free Transform, hold down the Ctrl (Cmd) key while dragging handles to give best control.  If this leaves a gap in the sky, select it and fix with Content Aware Fill (Shift F5)