I have a Sb600 on my D70 and a pro friend recently tried to explain to me how to match ambient light with fill flash manually so that there is perfect exposure across the frame. It involved measuring incident light with the camera's meter and then somehow meshing that with a manual flash exposure calculation based on distance and guide number. I understand each of these steps in isolation but it's the melding of the two that I can't remember. I tried to replicate it later but haven't been able to and am too ambarrassed to ask him a third time!
Does anyone know the method to which I am referring? He said it was often used by Patrick Demarchelier and other fashion photographers to calculate flash when doing fashion shoots in the field.
I don't want to use TTL because I am trying to be less lazy in my photography and to understand more fully the interactions of ambient and artificial light, distance, and exposure.
#1. "RE: Manual fill flash metering" | In response to Reply # 0Covey22 Charter MemberTue 09-May-06 01:41 PM
Here's a quick try - go to shooting mode M where you pick the aperture and shutter speed. Use centerweighted, meter for the background and do not add any exposure compensation. Put the SB-600 in TTL mode (yes, I know you don't want TTL, but trust me, this isn't a bow to mindless automation per se ) - make sure it's TTL and not TTL-BL (balanced fill). Dial in a -1.0 compensation on the flash. You've now created a fill-flash situation where the lighting is one-stop less than the background. Technically, the background will not be blown out and there should be just enough illumination to "fill" or illuminate the subject in front of you.
For more info, see this Popular Photo Cheat Sheet (Adobe Acrobat Reader required):
#2. "RE: Manual fill flash metering" | In response to Reply # 1Tue 09-May-06 03:11 PM
I think thats close to what was suggested to me. The difference was only that the flash calculation was manual. I am going to try that method this afternoon. I have historically avoided flash like the plague because I hate the hot spots and harsh shadows. When I have used it, I have used ceiling bounce and TTL indoors only, meaning it was essentially useless to me out of doors, even though there were plenty of situations that called for it.
My pro friend pointed out (rightly so) that I was really avoiding getting over my own ignorance and that flash can set you free and open a whole new world of creativity.
Thanks for the advice!
#3. "RE: Manual fill flash metering" | In response to Reply # 2Covey22 Charter MemberTue 09-May-06 04:03 PM
I agree on learning flash basics - your method is admirable and I think other folks would learn a lot from it. But if you're in a pinch, like snap-shooting situations, don't be afraid to use the flash on the D70 in TTL-BL mode. iTTL is one of the reasons why I made the jump away from the D1 and the D100. It really works in most situations, *much more* reliable than D-TTL, more akin to the old Nikon film TTL flash. One thing I've done is lower CSM (17? I think) to 1/30 of a second. This lowers the Shutter speed threshold when firing flash from 1/60th. Couple this with TTL-BL and I get a very properly exposed background and *just* enough fill to get the subject's face illuminated. Works beautifully.
#4. "RE: Manual fill flash metering" | In response to Reply # 0
The issue with calculating manually is that the GN can be quite misleading...Usually manufactures (Nikon included) boast the GN of their flash units by using a using the flash head setting at the longest focal length and shot in a room with a low ceiling to maximize output distance ....
Toss that in with the fact that you can control the flash unit in 1/3 increments from 1/128th to full power and you have a lot of multiplying and dividing to juggle. I say learn the basics behind the exposure and thank god for auto exposure and TTL.
To transfer what I recently learned about the interaction between a iTTL DSLR and the SB600/SB800:
For the greater control of the fill flash shoot in TTL not TTL-BL. The camera's exposure compensation takes precedence. ie. If you set your exposure compensation to -1.0 on camera the combined exposure of ambient AND flash will result in a -1.0EV image. THUS to adjust ambient-to-flash ratio, set the amount of exposure compensation you want for the ambient and then dial the reverse of it on the flash to get a normal flash exposure.
IE. -2.0EV on camera and +2.0EV on flash will give you a normal flash exposure whilst underexposing the ambient by 2 stops. +1.0EV on camera and -1.0EV will give you a one stop boost in ambient whilst keeping the flash exposure normal. Once you get this concept it's pretty easy to figure out how to adjust flash and ambient exposure independently.
RE: http://www.nikonians.org/dcforum/DCForumID71/15876.html Although the camera in question is the D2x, it applies to all iTTL DSLRs + SB600/SB800.
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#5. "RE: Manual fill flash metering" | In response to Reply # 4Chan Tran Registered since 04th Dec 2003Tue 09-May-06 05:50 PM
I think using TTL method is best for simple outdoor shots. Using a flash meter is most accurate but slow. I can handle the GN calculation without a problem but I found that most flash manufacturers inflated their published GN and the 1/3 step manual power controls are not consistent. If you insist on using the GN method I would recommend using either a programmable calculator or a program running on a Pocket PC or Palm or prepare some charts.
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#6. "RE: Manual fill flash metering" | In response to Reply # 0
>I don't want to use TTL because I am trying to be less lazy in my photography and to understand more fully the interactions of ambient and artificial light, distance, and exposure.>
Ok, here is what I do.
First I only do this when I have a static subject who is going to be at a fixed an unchanging distance. Otherwise I use TTL or TTL-BL.
Set your camera to MANUAL mode. Figure out what the proper exposure for the background is before your subject is in the mix.
This really depends on what you are trying to catch.
Lets say youve got a green bush, a blue sky and white clouds. None of these will be lit by the flash.
If I expose for the bush the sky will be white and the clouds will not exist.
If I expose for the blue sky the bush will be dark, the clouds will be all white with no detail
If I expose for the clouds the sky will be a dark blue, the bush much darker but Ill have puffy cloud detail.
It depends on what you want from your shot.
So you set your background exposure.
Next pace the range to target off. Say 12 feet.
With your Flash in GN or Manual Mode (doesnt matter they do the same thing) move your power up or down until you have dialed the range in (say 12 feet and your at 1/64th power or whatever) on the back of the flash. Let it do the math.
This is your starting point. Take a shot and evaluate your exposure on the LCD. You may have to increase/decrease power. Make notes, mental or otherwise about the lighting conditions.
Essentially the higher the contrast of the scene (bright backlit sunny day vs overcast clouds) the more power you are going to have to put into the flash. On the SB-800 each bump is 1/3 of an EV.
Eventually you will learn how much the indicator on the flash is off by. Ive discovered that with rough range estimation (pacing it off) on bright sunny days I have to increase exposure by +2/3 EV from state range for normal skin tones. Really pale people maybe 1/3, really dark +1 whole EV.
Its not something you can always accurately calculate or meter. Consider a person dressed in aluminum foil in the shade. With no direct sunlight on the clothing it will meter and go into your equations the same as some guy in a light gray suit. But it has reflectivity very different from cloth and a standard flash dosage will blow it out. So many things in photography become subjective rather than formulaic.
With time and experience you will develop either notes or memories that in this kind of light we need X compensation from the standard. Thats the main advantage of going manual is that you control the standard. TTL is nice but it can be inconsistent from place to place, shot to shot, subject to subject. In manual mode +2/3 EV up from 12 feet or 1/32 power will always be the output. Its just that you, not the camera needs to decide how much output it should be.
Thats were the beauty of digital comes in, shoot, look, correct, shoot, look, correct etc. Purists might call it lazy but I dont think so, if used properly its accelerated learning. You just have to have discipline to actually LEARN rather than just let the camera do the thinking or shoot away in fix it in post process.
Once youve learned you should be able to find your exposure in 2-3 shots and then you are golden until something changes. Even pros back in the film days would often bracket 3 shots for one scene.