mr smiff
Mr Smiff, in his FORUM RULES thread pleads with us to use the search feature before posting.
The search feature can be found at the bottom of the main PJ forum screen.
You just type "lens truth" in there and boom in a few seconds you have lots of threads to look at. Some of which contain your answer!
And some of them don't and some of the people contradict each other and add silly comments that don't mean anything, but! with just a little persistance you will have your answer or at least a few things to try. Probably you'll get that quicker than typing in your question. Especially because the same thing will happen in this new thread - lots of answers, more questions, plenty of sillyness and it will take a long time for you to get your answer, if ever.