The "top of the range" model seems to be the Black Rapid Sports-RS, but at £75-80 it is ridiculously expensive just for a strap! Whilst investigating alternatives, I came across the Focus F-1. This seems to be a Chinese made copy of the Black Rapid and prices on eBay or Amazon were around £17-20, which seemed a much more reasonable price for a strap. I found a number of reviews which said it was comfortable, well made and good value, so I bought one. That was in Feb 2016. I have used it a great deal since then, including on several field trips when I have worn it pretty much continuously for periods of one to two weeks.
|Canon 60D with 100-400mm lens on Focus F1 sling|
|Note the damage to the hook caused by the steel ring of the Manfrotto quick release plate - and the fact that the hook has pulled out of the swivel in the D-ring! The cut in the D-ring was done by me with a hack-saw to remove it from the strap.|
I decided to replace the fastening with a small, steel, screw-gate carabiner bought from Amazon for £2.35. (Stainless Steel M7 70mm Length Spring Snap Hook Stainless Steel Climbing Gear Carabiner Quick Oval Screw Gate Rock Lock).
|Manfrotto quick release plate attached with a steel screw-gate carabiner.|
In summary, the Focus F-1 strap itself seems fine, but the attachment supplied with it is not really strong enough - at least not for a camera and lens combination weighing in at about 2.3Kg.The substitution of a steel carabiner, which is sold as climbing gear and is rated for far more load than this, should fix the problem.