How do I create thumbnails only in a few selected forums?

[dt~]

Version : Latest (3.6 beta 4)

Hi all,
I wish to display attached images in their original sizes in forum ID 135,
but as a thumbnail in forum ID 246, is there anyway I could do this?

Any help will be highly appreciated. Thank you.;)

[Paul M]

I may be wrong, but AFAIK, you cannot do that.