Thu 13-Sep-12 04:27 AM | edited Thu 13-Sep-12 04:28 AM by jrp
1. Although some logic would lead to prefer a wide angle setting when using it under most conditions, to maximize diffusion; and longer zoom to maximize reach, in my experience the zoom is largely -if not completely- irrelevant when shooting with the Lightsphere on, under A, S, P or M modes. Only when shooting in Flash Manual Mode the speedlight will deliver more light when the zoom is extended (largest effective Guide Number). (See page 42 of the SB-800 Manual)
2. Although I have not made practical test on this particular question of "Raw Power", the SB-910 has in fact a slightly larger Guide number than the SB-800. What the SB-800 has in its favor over the SB-900 and SB-910 is that it seldom overheats. The other thing is that the variable "Illumination Pattern" in the later models may confuse the interpretation of results.
I was given instructions by a professional photographer on using the diffuser. He told me to remove the small plastic Nikon SB800 diffuser before attaching the Gary Fong. More power.
But he didn't say anything about zooming the SB 800. I don't believe zooming makes a difference. And a comparison chart of power indicates that the SB 800 has more power than either the 900. 800=GN 41. 900=Gn36.
>But he didn't say anything about zooming the SB 800. I don't >believe zooming makes a difference. And a comparison chart of >power indicates that the SB 800 has more power than either the >900. 800=GN 41. 900=Gn36. > >That is about a 14% increase.
That's the thing that confuses me. SB-910 has zoom upto 200mm and additional narrow, normal and wide positions.... But i was under impression that SB-800 is the most powerfull Speedlight for GF LS usage or for any soft box or bounced photography application.
Fri 14-Sep-12 01:50 AM | edited Fri 14-Sep-12 01:51 AM by DeanAZ
I have the collapsible model and zooming makes a difference when I have the dome removed and I am bouncing in combination with diffusing. The zoom setting selected depends on the ceiling height (if I bother to think about.) For the standard GF models I doubt the zoom makes a significant difference.
The SB800 has higher guide number but the flash optics don't put as many pixels on target as the SB900 at the longer zoom settings. I would think the SB800 would be the better choice with the diffuser by a small margin.