On Monday I ordered my new stretch frame and "soft egg crate" from Lighttools for my 14" x 35" Elinchrom Strip box. On Thursday it arrived. I use my 14 x 35 strip light (softbox) many times as a rim light. I usually have to flag it off between the softbox and my camera because of the flare cause by the light from the softtbox. Although I will feather the softbox there's still a lot of light going else where.
Today I was at the studio so I set up a quick set-up to see the difference. The first shot is with the Elinchrom RX600 with a 14 x 35 strip light set up on it's lowest setting with the light from the softbox hitting the metal door at f/ 2.8.
I switched out this softbox with my other one that had the stretch frame and the "soft egg crate". Same settings, same distance the light is from the wall. You'll really can see how the off axis light is controlled using the "soft egg crate". This is the 30/50 "soft egg crate".
These "soft egg crates" aren't inexpensive. I think my 14 x 35 softbox runs around $175 and both the stretch frame and "soft egg crate" cost around $325. I wanted to get one for my 53" Octa but I came to the conclusion I could wait after looking at the cost. I don't think I even looked at what the same set-up would cost for the 74" octa....Well, I had to look....I guess they don't have it only for the 69".
If you need to control the light these will do the job.
without the "soft egg crate" from Lighttools
with the 30/50 "soft egg crate, same settings.