Sylmac,
Thankyou! I get as far as the tonemapping, then I am stumped .... not quite sure what 'tonemapping' is, nor what all the different options contained within that 'step' are ....
And, as I said, 'save as' doesn't give me options I recognise .....
Looking forward to a tutorial! In the meantime, I will try to find a moment this weekend to experiment again.....