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ceiling bounce flash with or without BFT?

AKfotoAKfoto Member
edited May 2013 in flash & lighting
Question for Neil; when you're in a room where your only option to bounce on camera flash is to bounce to the ceiling, do you use the BFM in that situation?

I ask this because I use the Canon 580 EX II flashes at a lot of weddings. I discoverd that when I bounce to a ceiling and the flash uses al lot of power to reach the ceiling (like in a big church) then despite the fact the flash is pointed upwards (90 degrees angel) there is quite a lot of flashlight going forwards and hit my subject.

This only happens when the flash is at a high power output and at close distances. The pictures look like if I used direct flash instead of ceiling bounce flash. I does not happen a lot but if it happens the pictures look awful.

I wonder if anyone else has experienced the same problem with Canon 580 EX II (or other flashlights)?

I did a test by making pictures of a model in an open space (football field) at night, in a situation where there was absolutly no way the flashlight could bounce from something. I choose camera setting so that my testpictures where 3 a 4 stops underexposed. I put the flash straight up to the sky at 90 degrees angel WITHOUT the BFT. Yes, I just fired the flash into the open air... straight up. And what happens... quite a lot of flashlight went straight forward and hit my model. A lot of direct flash light at top of the picture and almost no light at the bottom. But the picture almost looked like if had I used direct flash. I never knew that the light spill of could be this much!!

Then I made a second testpicture with the BFT to block the light going forward. No light at my model at all (of course).

Since this test, I always use the BFT when bouncing to a ceiling. Never had this problem againg.

But... sometimes when boucing to a ceiling I want some catchlight in the eyes of people and therefore like to send a little flashlight forwards. But I can't use the build in white index card because it's blocked by the BFT. I found a solution for this with the Demb Flash Difuser bouncecard. This bouncecard is sitting quite high above the flash, and when I set my BFT a little lower (but enough to block the light fall of) then I can ad some direct flash with the Demb card because the card is now above the BFT.

This way I have both things I want; using the BFT to block the light fall of (because this light fall of going forward I cannot control and can be to much has I described above) and then use the Demb card to give me some direct light to create a catchlight in the eyes.

I wonder how Neil and others are dealing with this? Does anyone of the same experience had I did?

(sorry for the bad English)





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Comments

  • To me, the answer is obvious, turn your flash power down, or fec. Neil will probably chip in here saying I'm completely wrong. As for catchlights..... that's why I use metz.
  • AKfotoAKfoto Member
    Hello Cakencamera, thanks for your reply. I am afraid you misunderstood the situation a describe a little. This scenario, where I put my flash in 90 degrees angle to the ceiling, and the flash still throws a lot of flashlight straight forward, only happens when the flash output is at a very high level. Almost or entirely at full power.

    The reason why the flash output is at such a high level is simply because it need te be so, because the ceiling is that heigh. So it's simply not an option to turn my flash power down, or use FEC.

    Just to be clear: the flash power need to be high despite the fact that I use high ISO and low F-stops.
  • TrevTrev Moderator
    edited May 2013
    Hi AK,

    The reason it's blowing out too much directly in front of you is you are pointing it straight up to ceiling therefore it's coming back down really directly 'forward' in front of you.

    Simple Physics, light will come back at same angle you shoot it roughly.

    If you were able to magically capture somehow a shot of the scene in front of you and at the same time one directly behind you, you would notice the exact same amount of light coming back almost as to front of where you are shooting.

    Regardless of a high ceiling, still point flash back behind slightly left or right, with just on click up on the flash head behind and you will be absolutely surprised at the amount of light still coming back to evenly light your subject.

    Now you still will have to adjust the Flash Exposure Compensation on the flash to get good lighting with a better fall off in front of you.

    The flash will not be totally accurate at +0- Ev in all situations, in fact I'd be surprised if anyone is able to get correct exposure just relying totally on TTL in zero setting, I ride mine *all* the time, the moment I zoom in or out it will affect the TTL reading.

    Sometimes I get it right at 0, others it can be as high as +1.07 or -1.07 and more, depends on how far I am maybe from a wall, etc.

    So, zoom the flash head in manually to it narrowest which will be 105mm on a Canon 580EX II; point it behind and up say I click on the head, regardless of how open the room is and adjust FEC until happy.

    Regarding catchlights, when bouncing from a large source wall/ceiling, the catchlights will be there in a much better view than using the little white do-hickey mickey-mouse thingymajig that comes with the flash head.
    I've never used that in my life, but, that's just me.

    Let us know how it goes. Oh, yes, do use the BTF anyway regardless of bouncing large or small room, that will definitely work.

    Good luck.

    Trev
  • ZenonZenon Member
    I have adopted the reverse bounce method for ceilings. Wastes a bit of light but I never have to worry about getting the correct distance vs minimal angle if I'm bouncing forward and there is no spill. The red dots show the shadows. It might waste light. Every time I walk into a place I look where I can bounce over my shoulder, ceilings, walls or objects. If not there then the BFT goes into action.

  • TrevTrev Moderator
    Hey Zenon, nice "Picasso" there mate. :)

    Yep, that shows precisely what you are doing with flash straight up instead of bounce.
  • ZenonZenon Member
    Thanks. Too bad I'll probably have to die before I'm famous :). Even though I think it is cool I can't take credit. I member named Smorter at POTN came up with that drawing. Neil has commented on his event photography a few times. I was starting to experiment with something similar before I came across that method.

    Like you said, straight up = shadows. If you don't step back far enough far enough to get the right angle bouncing forward same thing. I believe it is a minimal of 45 degrees.
  • AKfotoAKfoto Member
    Okay, Trev and Zenon, thank you for your replys. I can agree with you both on a lot of things you're saying here. But... I still think you don't understand the problem I try to describe here.

    First of all, for Trev: you write this:

    "The reason it's blowing out too much directly in front of you is you are pointing it straight up to ceiling therefore it's coming back down really directly 'forward' in front of you".

    Did you not read this part I wrote:

    "I did a test by making pictures of a model in an open space (football field) at night, in a situation where there was absolutly no way the flashlight could bounce from something. I choose camera setting so that my testpictures where 3 a 4 stops underexposed. I put the flash straight up to the sky at 90 degrees angel WITHOUT the BFT. Yes, I just fired the flash into the open air... straight up. And what happens... quite a lot of flashlight went straight forward and hit my model".

    So your're explanation can not be correct, because you asume the problem is caused by bouncing straight up to a ceiling. But think a ceiling has nothing to do with this, and I already proved that by doing the test as a described.

    I think you both never had have this problem, because otherwise you maybe would have reconized the described problem. I know it's hard to explain. I don't have the testphoto's anymore but wat I am going to do is make then again and put them here online so that you can see what I mean.

    Maybe this problem only happens with a 580 EX II, I don't know.

    I will post the pictures here in a copple of days.
  • TrevTrev Moderator

    errrr, sorry, but you did mention in a room with a high ceiling; but out in a field with flash straight up, no bounce, you will still get the same result.

    Why?

    well, with the flash straight up, light it still being distributed, and the flash and camera combo, seeing the really dark background is pumping masses of light out to try to light up what "it" sees as a bloody massive black hole.

    That's it. Done.
  • Every time I visit this forum I learn something, Every single time. Thanks Trev
  • ZenonZenon Member
    Sorry. Misunderstood you as well. I think of flash as playing pool with light when bouncing. A bare bulb will throw light in 360 degrees in all directions. A flash head will throw at about 180 degrees in all directions. The outer edges at 180 are a little iffy because it all depends on the flash design, the zoom setting and how high the edge of the flash head is compared to your subject. The outer edges are not as efficient but will cast some light on the subject.



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