Thanks to everyone that's responded.
jawajohnny - that tutorial was very useful - thanks. I can see that VisionLab Studio is not totally dissimilar to Adobe After Effects, which I used to be reasonably competant with many years ago (when I was involved in video work).
As I didn't know about the limitations of the VisionLab Studio demo (which Mandalorian pointed out) I thought that it might be the product to use, but seeing as it will "put a big 'X' through the frame" I'll obviously want to go down the Photoshop route.
Mandalorian - thanks for pointing out that the VisionLab Studio demo will put a big 'X' through the frame. Your description of the Photoshop method made a lot of sense, especially once I'd seen Ryan Weiber's After Effects lightsabre tutorial. Thanks to Axeman for the link to this.
Once I'd watched this After Effects tutorial, I searched on YouTube for Photoshop lightsaber tutorials, and after finding (& watching) very very many, I found the Photoshop version of Ryan Weiber's tutorial - it's at http://www.youtube.com/watch?v=8gUZt1u9QUw
The 3 photos that I need to add effects to were taken at a Star Wars themed wedding in the summer of 2001 (where I played an Episode 1 era Obi-Wan Kenobi). I want to add the effects so that when I print them out & display them at home, people will go "Wow"!
Given that it's been 7 years(!) since the event, it's hardly a priority to sort these photos out, but when I do get round to it, what would people recommend I use for the colour values to give an accurate blue lightsaber blade, as per the prequel movies? The green & red sabres presumably just require RGB values of 0/255/0 & 255/0/0 respectively, or would that give too harsh results?
In one of the 3 photos, Qui-Gon Jinn's sabre is in contact with Darth Maul's. Try as I might, I can't seem to find anything on YouTube (or elsewhere) that would show me how to create the "flash/clash" pale yellow mini-explosion effect in Photoshop that occurs when 2 sabers come into contact, as per http://www.ferrisshaheen.com/duel11.jpg
Does anyone know of a tutorial for this effect? Or can anyone give me a detailed description of how to achieve this?
Many thanks once again.