On 5/31/2013 7:10 AM, Bruce Walker wrote:
Thanks, Bob.
Although, strangely enough, there's no ISO scale on the flash as far as I
can tell. None of the function buttons on the back seems to bring up any
indicators. I'll have to do a little digging around to see if there's
something I'm missing.
Hmmm.
Nothing's missing, Walt. Modern flashes don't come with the exposure
guide Bob described. I don't know when they stopped adding that, but I
suspect whenever the fancy *-TTL flash automation became standard.
Neither the Pentax AF540 or AF360 have it.
The guide is also a simple mechanical thing and couldn't take into
account the zoom setting in the flash head. The Guide Number is always
quoted at full power at one particular zoom, eg 50mm, and it reduces
as you zoom the head wider.
If you set the flash manually to the same setting as the Guide Nimber
is quoted for, eg ISO 100, zoom 50mm, then you can determine the
aperture for a given distance from the subject with this formula:
aperture = GN / distance
--
-bmw
Thanks, Bruce.
This is where having an actual class in photography would be helpful.
Being self-taught, I've relied on my ability to stumble and bumble my
way into learning "new tricks" -- which means I have to relearn them
several times before they ever sink in. I really don't know what I'd
have done if I hadn't subscribed to PDML when I got my K-x. I get to
crib a lot from people who know what they're talking about.
-- Walt
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