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Message: <blockquote data-quote="WayneF" data-source="post: 377048" data-attributes="member: 12496">Re: Can 2 AF assist lamps be used at the same time? (on camera & off camera ext' flasOK, sorry, I was just trying to compare the flash powers of the different flash models, but I hit a problem on the 468, and I don't know about it.  I though it was interesting that the manual did not cover that.Well, the TTL flash system does meter itself, so it is almost point&shoot.  Your approach of a wide aperture and ISO 400 or 800 is about what it takes for bounce. The TTL flash system will do what it needs to do to follow your actions.  A stronger flash can do more of it.I was just lamenting that our lenses wide open aperture is not its best aperture, and it can be a bit sharper if we can stop them down one stop. Not a huge thing, but there can be a difference.  But one stop requires 2x more flash power, or 2x more ISO for the flash.  So in that sense, a f/2.8 lens stopped down one stop to f/4, can sometimes be a little better than a f/4 lens wide open.  Or, same f/4 lens stopped down one stop to f/5.6 can be better, but which is more flash power or ISO.The SB-400 is not a strong flash, so there won't be much choice.  Depending on ceiling height, wide open lens and ISO 800 ought to be about the right starting point for bounce.   If a good lower 8 foot ceiling, ISO 400 probably works.A good thing needed to know for bounce flash:  When flash is in TTL mode, then when the camera Flash Ready light (lightning symbol in viewfinder) blinks three times immediately after the shutter closes, that is a warning that the TTL flash limited out on flash power, and picture was likely underexposed for that reason (not enough power).  To prevent hitting that limit, higher ISO, or a wider aperture is required, to make it easier on the flash.  You can force this happen to see it once (to know it next time) by trying bounce at f/16 at say ISO 400.  That can't work, so it will blink, and the picture will be underexposed. And the point is, you see the blink, and know what to watch for in the future.If the picture was a little dark, but no blinking warning, then you just need to add a little +EV flash compensation instead.  But if it blinks, more flash compensation cannot work, the flash has no more power to give.  This is how you know that.  Except my Yonguo flash does not cause that.  The Nikon does.I think the comment about too much flash whitening the childs face too much referred to the severe overexposure problem with the 468?That is abnormal, TTL should not work that way, that should not otherwise happen.  You will like it when it works. Flash is the fun part.  <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile    :)" loading="lazy" data-shortname=":)" />  It is true that sometimes TTL can be slightly off, typically a bit underexposed, typically due to the specific scene it sees in front of the camera - the way that scene meters.   Then we simply dial in a little + EV flash compensation to make it look right, as desired.    Then the rest of the same flash session (in same situation) ought to go much better.  And a little experience teaches us about a good probable starting compensation to routinely start with  (I am speaking of small differences, and small compensations).Flash zoom:  We know that when we zoom in with our camera lens, we get a closer and more narrow view of the subject, a zoomed picture.When we do that, and our flash is still the previous wide angle coverage, we are wasting flash power by illuminating wide area that will not show in our new narrow picture.  Pointless to light the room when the lens only sees the chair.So, many flashes automatically zoom their flash head reflector too, to track the lens zoom.  They concentrate the wide flash power into a brighter more narrow beam, automatically, appropriate for our lenses new zoomed narrow view.  This is more advantage for direct flash than for bounce.  The SB-400 does not do that, it has one fixed wide flash angle, regardless of how the lens is zoomed in ... so, there is no effective flash power increase when the lens angle is zoomed in more narrow.There is quite a bit to pick up about flash, but it is all easy.  If I am saying too much, more than needed, not helping, I can try to tone it down.  <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile    :)" loading="lazy" data-shortname=":)" /></blockquote>

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