You know what's funny? When you start learning, people say don't shoot with light behind it because your subject will be dark and under exposed.
I now practically do the opposite, I chase shooting into light sources, I create them on purpose if I can.
Pentax 67:
Nice,
A guy over on NPN shoots really great stuff in the UK with a Pentax 67II, (Ian Cameron) a great selection of lenses too,
For a good idea of how much it will be let's look at how much more recent unit are vs the Canon competition.
Canon ST-E3-RT:
UK price: £240 (Amazon).
Grey import: £194~.
VS
Yongnuo YN-E3-RT:
UK price: £91 (Amazon).
Grey import: £80.
And
Yongnuo YN565EX II:
UK price: £67.50 (Amazon).
Grey import: £62.
VS
Canon 580EX II:
UK price: £280~ (Google).
Grey import: £244.
So from that I get the idea that the YN-600-RT may cost around the £150 mark considering the Canon 600EX-RT currently goes for £400 or £340 import.
Ah of the flash or the whole kit do you mean?
I have a 580EX MKII and a 430EX MKII, my question is which transmitter is the best to use as Pocket Wizards seem to not be that popularf ! ?
Your 7D has a transmitter built into it