How does the AF-500FTZ's power compare to the AF-280T? I had thought that the AF-500FTZ was much more powerful since it has a guide number of 164'/50m compared to 91'/27.4m for the AF-280T. But I see on B&H's web site that the AF-500FTZ's 164'/50m guide number applies to its 85mm telephoto coverage, while at 50mm coverage its guide number is 138'/42m.
Since the AF-280T is not a zoom and has a fixed angle of coverage of 28mm, I would guess its guide number of 91'/27.4m applies to 28mm, even though wide angle and telephoto adapters are available separately for it. Correct? Any idea what the AF-500FTZ's guide number is at 28mm? I usually use a Stofen filter on my AF-280T, and I'm not really interested in how powerful the AF-500FTZ is at 85mm coverage. Instead, I'm interested in how much more total light it would put into the Stofen than the AF-280T does -- I'd like to be able to bounce more often and use smaller aperatures. Thanks, Greg
