Miniature Sailboat - clouds missing :(

[avishek24]

I shot this last week at my grandfather's place. In the background is a wall which happens to be lime green color. I have used some post processing to darken the shade but I was wondering if it was possible to add clouds or the sky in the background of this image. I am not that familiar with photoshop unfortunately and there are too many gaps in between the sails to handle. Any suggestions in this regard would be welcome. Please feel free to alter or process the image if you want.

Please find the EXIF info below.
Camera Make Canon
Model Canon EOS Kiss X2
Exposure time 1/6 s
F-number f/5.6
Exposure program Manual
ISO speed ratings ISO 400
Shutter speed value 1/6 s
Exposure bias value 0.00 eV
Metering mode Spot
Flash Flash did not fire, compulsory flash mode
Focal length 32 mm

Thanks!!

[oriolhdz]

Hello avishek24!

I don't know much of photoshop but you can do some color selection to remove background and replace it with any clouds you like or you can use algo alpha channels to do the job! Both ways should give you great results! I'm sure that if you google any tut for alpha channels selection you will find a lot. Below is one that I find pretty use to follow!

Removing the Background - Photoshop Channel Mask

Regards