How can I unwrap a spherical environment in the background?

[pixela]

I have a bitmap applied as a spherical background. I want to be able to unwrap this background and render and paint over it in Photoshop. ( I don't know if "unwrap" is the correct terminology but I want to unfold this map applied to the spherican environment and modify it)
How can I make this- anyone can show me a way?

[Bathyscaph]

Use HDRShop to transform the image. I think you want to convert it to a latitude, longitude format for editing. You can then convert it back.

[pixela]

Thanks for the tip =)

[rivoli]

isn't the panorama you're using already in latitude/longitude format?

[pixela]

No it was a partial sky. Actually I used it for testing purposes and then I saw that it looks great. Moreover after adjusting some U and V tiling, it really added to the composition. But unfortunately it has repetitions. So I thought if I can render this to teture in unwrapped way, I can paint on it in Photoshop.
If I render the background only, I can make modifications but then the reflections and lighting will change.

On CGArchitect and CGTalk, I was recommended to use Panorama Exporter so I am trying to use this tool and see if it fits to my needs.

[instinct]

Create a Camera facing north at 0,0, in the camera settings (render panel) select spherical, tick override and set the fov to 360. Enter desired resolution and render

[pixela]

Create a Camera facing north at 0,0, in the camera settings (render panel) select spherical, tick override and set the fov to 360. Enter desired resolution and render

Thank you for this tip =)
It will be the first time I will try using spherical camera. Never thought of this before!