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Thread: Bounce Flash

  1. #1

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    OK. I must admit that I debated on where to put this for some time before settling here. This discussion seems to be mostly centered on studio lighting and I apologize if I guessed incorrectly.

    My question is on how to effectively use a bounce flash with a rotating flash head on a hot shoe. I can use it effectively when taking technical pictures by rotating the flash head and then using a white peice of paper or something similar to diffuse and reflect the light back onto my subject. My problem is when I try to take a picture, usually of people, without using this method (in other words, bouncing off the ceiling). The rooms are all low ceiling rooms so it isn't like I'm trying to bounce the roof of a gym. I'm using TTL metering so that shouldn't be an issue and I have tried with multiple flashes (SB-50 and SB-80). In all cases, the pictures end up underexposed. On rare occasions, I get good results but I don't remember doing anything different than normal.

    If somebody could provide me with a quick primer and then a couple of excercises (I don't mind burning film to learn), I would appreciate it.

  2. #2
    glbeas's Avatar
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    One thing to remember is a high proportion of these small flashes are rated for more power than they really have. Do some test bracketing to find out its real power for both straight on and bounced and see what you get. And be sure you aren't shooting beyond the flashes range.
    Gary Beasley

  3. #3

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    I thought of that. The SB50 as a GN of 72 at ISO 100 and the SB80 of 125 at ISO 100. I have been shooting a variety of 400 speed print films so the effective GN should be a bit higher. I know that I can light a subject at 50+ feet with the SB50 when shooting straight but have never tested the limits of the SB80 (although I have shot well over 50 feet).

    The typical light path from flash to subject for my bounces is about 10-20 feet. I have a hard time believing that I couldn't bounce either one of the flashes at that distance. I figure I must be doing something else wrong.

  4. #4
    b.e.wilson's Avatar
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    You can try overexposing a bit (to make the flash put out everything it's got), but the reality is these little flashes just don't have much power to illuminate anything but with a directed beam. They absolutely need the reflectors and the lenses (fresnel) to focus the beam tight enough to defeat the inverse square law.

    Picture a flashlight bulb in its reflector and out. The bounced flash is illuminating half a sphere, after ceiling absorbtion. Just isn't enough power to illuminate anything beyond 6-8 feet from the center of the 'bounce'. Even studio flashes get tamed by a 3' x 3' soft box, and they still have reflectors helping.

    If you just can't get the distance you need, find a way of limiting the area illuminated by the flash. The wall+ceiling bounce can give almost a stop more than a ceiling bounce due to the quarter-sphere illuminated, and a corner bounce (tricky to do as the flash is typically shooting over your head, leaving your shadow on the scene) can give a stop more.

    But the best trick is to get more than one flash going. Porters, and I suppose everyone else, sells those cheap little photo flash triggers that fire a flash when they see one. You can buy some cheap, dumb flashes each with a light trigger, and position them strategically (or is that tactically?) around the room to light up the ceiling and walls. The trick is to get the slave flashes nearer the subject than you are, without making the scene look harsh. (Having a digital camera or polaroid to see the overall effect is a very handy thing while setting up.) One method: put a slave in each table lamp in the room pointing at the light bulb. That way of you include a lamp in your shot, it looks normal (and the lamp acts something like a modeling light, previewing the effect for you). Please note that you'll need to take your camera off full-automatic mode to keep the exposure right (unless you have a EOS 3 with multiple 540 flashes, all controlled by the camera). Multiple-flash setups is why they have flash meters.

    Get some old Kodak How To Take Pictures books. They are full of stuff like this.

  5. #5
    David A. Goldfarb's Avatar
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    You might be underexposing those print films, and the lab could be compensating. Try a test with slide film, which is much less forgiving, to determine the real guide number.

    That said, I suspect those units should be able to handle bounce flash in a small room. I do all this stuff manually, so I'm not sure what to tell you about your TTL system, but I suspect that if it's just underexposing, there is a way to fool the system (say by adjusting exposure compensation or the ISO dial either on the camera or on the flash) to get it to put out more power.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
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  6. #6

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    OK. Here is what I'll try.

    First, both flash units will work with a Nikon Wireless flash controller, so that should be relatively easy to set up. I've always kind of wanted to try that anyway so I guess this would be a good excuse to blow another $70 on a new toy.

    Second, and I should have stated this before, the negatives are definitely underexposed (I worked in a photo lab for 4 years during college as well as doing my own developing and printing in High School). When I started getting the dark prints, the first thing I did was drag out the negs and look at what I had done. The negatives that I have tried to use a bounce flash on are consistantly underexposed. That is the problem. For some reason, weak flash, operator error, etc, I am not properly exposing the prints when trying to use the flash off the ceiling.

    I'll try some of the suggestions and let you know.

  7. #7

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    </span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Mark in SD @ Jan 17 2003, 10:18 PM)</td></tr><tr><td id='QUOTE'>First, both flash units will work with a Nikon Wireless flash controller, so that should be relatively easy to set up.&nbsp; I&#39;ve always kind of wanted to try that anyway so I guess this would be a good excuse to blow another &#036;70 on a new toy.
    </td></tr></table><span class='postcolor'>
    OK. I hate replying to myself but somebody with the answer may have already read the above so...

    I went to the Nikon Web Site and read about the SU-4 Flash Controller, got confused, and broke out my SB-50 and SB-80 manuals.

    Now I thought I needed something mounted on the camera to control the remote flash units. From what I am reading, the SU-4 is a device that fits on the remote flashes (not the camera like I originally thought) and triggers the remote flashes at a signal from the camera. That signal appears to be a flash from the main camera.

    Now, both the SB-50 and SB-80 can do this already without the need for the SU-4. In fact, if I use the built in speedlight on the N80, I could trigger both flashes remotely. It also appears as if either the SB-50 or SB-80 will trigger the other using the IR Focusing beams without firing itself.

    Do I have this roughly correct? Is it really true that I can play with this without buying another toy (not that I don&#39;t like toys, but I could spend the money on a different toy)?

    Finally, the exposure here seems to be more complicated than I had thought. The TTL flash control MAY work, but it appears that it will be much safer to use manual calculations. This will definitely take some practice.

    All of which begs the other question I have regarding this operation. How do you mount the remote flashes? Do they make stands or special tripod heads I could use?

  8. #8

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    I bounce a flash with a guide number of 35 (metres... whatever that is in feet&#33; about 115ft if my calculations are right&#33 and it works fine. For 100 asa film it has 3 "computer" ranges of 1-8m @ f4, 0.8-6m @ f5.6 and 0.5-4m @ f8. So, what f-stop are you shooting at?

  9. #9

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    Nige,

    That may be part of the problem. I have been trusting the camera to "choose" the appropriate exposure settings for me. I probably haven&#39;t been paying enough attention to what it is doing. Like I said, it works fine for using diffused and reflected light when I&#39;m doing Macro work. I&#39;m not sure if the problem is weak flash, poor geometry (I&#39;m simply not getting the light to the subject), or poor exposure settings and am unsure how I should go about figuring it out.

  10. #10

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    Maybe it is your geometry. I tend to shoot closer to 90 degrees when I bounce. The "normal" 45 degrees just doesn&#39;t seem right to me. And I have gotten good results with 11 foot high ceilings in my house. I use a Sigma Ef-430 Super and an N80. Nothing fancy there. I just figure that since the subjects are usually pretty close, 45 would be too steep an angle. You might play with that a bit.

    Or, if you want a compromise, try an on-flash diffuser. I use a Photoflex which you blow up. Works with TTL and my AF assist light, and you get a soft light from it. Shadows are still an issue though.....
    Official Photo.net Villain
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