Is Fillflash just flash on lowest power?

Discussion in 'Lighting Equipment' started by sarah_michelle_larsen, Oct 20, 2013.

  1. Hi.
    I'm playing around with my built in flashand the SB910 on the D600.
    I don't think I understand the term Fillflash. Is that just the flash on lowest power? (I only shoot manual).
    Or how do I activate it if there is anything to activate.
    Thank you.
     
  2. Gup

    Gup Gup

    Basically, yes. It's just enough added light to fill unwanted shadows or light darkened foreground areas due to strong back lighting.
     
  3. Fill flash is typically about (minus) 1-2/3 stops from the full flash setting, but it depends on the main light. I would start at this setting for fill in frontal and side sunlight.
     
  4. Fill flash is measured f-stops in comparison with ambient light. Setting it properly was very important to me when I did weddings. A usual indoor setting for me to lessen contrast on a face was one or two stops below ambient. It saved me a number of times in difficult light. I used to do weddings in bright noon time sun into backlight. The photographer can't stage the wedding usually so you have to make do with all kinds of lighting situations.. It sometimes took every bit of on camera flash I had to fill faces in that kind of light. When done correctly and properly calculated it's hard to notice flash in the picture when intensity is kept below the level of prevailing light on the subject. Skill with fill helped greatly in my weddings and newspaper work. You need to meter and calculate it for individual shots. The late Nadine O'Hara here on PN knew a lot about if and spoke about on PN. The models below were shot with fill flash as the setting sun was behind them. Up on a roof. I think the fill was between minus two and minus one. It is a great tool.
    00c5QG-543146184.jpg
     
  5. Ok thank you all. I will need to practice a lot. Puhh.. there is so much to learn about flash photography. But I will master it one day:--)
    Dick:
    Yes I will need a lot of routine when shooting in variated light. Nice photo of the girls.
     
  6. "...Fillflash. Is that just the flash on lowest power?" - No. It's flash on whatever power is required to lighten shadows under the prevailing circumstances. In full sunlight at more than, say 20 feet, even full power on your SB-910 may not be enough. OTOH, if you're adding fill to moonlight the lowest power setting on your flash may be too bright. It also depends on what shutter speed you're using, because although the shutter speed doesn't affect the flash exposure, it'll obviously have an effect on the ambient light that you're trying to 'fill'.
    I don't want to appear rude Sarah, but you've now posted several very basic questions about flash lighting. And if you're undertaking paid assignments, this is stuff that you really ought to know already. Maybe you should take a course or read up on lighting for yourself? For example: I just Googled "fill flash" and was immediately presented with a page full of links to explanations of what the term 'fill flash' means, as well as several articles and tutorials on how to do it, including this one and this one. They're not the best tutorials I've ever seen, but they're a good start.
     
  7. The articles you quoted are fine in saying that when using fill flash "both camera and flash try to work together to maintain the exposure in the background and use the flash to light the subject." What they don't say is how are they "working together"? How can you simultaneously have proper exposure for the background and the foreground?
     
  8. ""." What they don't say is how are they "working together"? How can you simultaneously have proper exposure for the background and the foreground?
    -
    Nikon CLS latest flash advances provide lighting patterns, and iTTL/BL balanced lighting, utilizing focus distance information that compatible "D" lens provides to the CLS compatible camera, when available.
    These 2 features mentioned are praised so highly, that some hilariously impressed photography experts call them "defying the laws of physics". - believe it or not, you must try it for yourself - trust none. There are some limitations that you must know to make it work for you.
    Bravo Nikon !
     
  9. "How can you simultaneously have proper exposure for the background and the foreground?"​
    With a well designed auto-exposure system, including auto ISO when appropriate, the camera automagically chooses an appropriate exposure for the ambient lighting (and may adjust the ISO as needed), and an appropriate flash exposure for the primary subject. The primary subject is considered to be the plane in focus.
    So in daylight the camera may choose ISO 100, 1/1000th @ f/5.6, for the available or ambient light - same as if you weren't planning to use flash. Or at night or in dim interiors, the camera may bump the ISO to 1600, and exposure settings to 1/30th @ f/4. The camera and TTL flash choose an appropriate flash level, based on the focus distance. The photographer can override those settings on the fly and nudge either the available light exposure, flash exposure or both, usually with the exposure compensation control. Typically I'll set my flash to -1.0 EV, sometimes less.
    I'm not sure whether Nikon's matrix metering can detect shapes to help determine flash exposure - conceivably facial recognition used for AF could also help determine the flash but I don't know whether Nikon or any other manufacturer does this.
    Nikon also offers a TTL-BL setting, which supposedly nudges the exposures better for balanced daylight flash. There's also FV lock (flash value lock), which helps with recomposing after focusing, including focal length changes with zooming. Very handy and possibly underutilized feature of Nikon's flash system. Keeps flash exposures consistent despite focal length changes or recomposing against a tricky background - as long as the focus remains the same and the camera-subject distance are consistent.
    All of these features work much more efficiently and quickly in actual practice than my description would imply. Or you can meter and set exposure manually, if you're comfortable with that and can do it quickly enough for rapidly changing situations.
    Some current P&S digicams handle this stuff effortlessly. Ricoh and Olympus P&S digicams in particular handle balanced fill flash better than my nearly decade old Nikon D2H and SB-800 flash - and that combination was excellent in its day. Current tech is even better.
     
  10. At the risk of oversimplifying it for the purpose of explaining the underlying principles, there are several factors which combine to make fill
    flash a possibility (ie. exposing for both a darker foreground and a more brightly-lit background):

    - the effect of flash drops off very quickly as distance to subject increases (background is often farther away, right?)

    - flash is quite limited in its ability to have any effect at all on things that are already in bright daylight (in other words, it won't light up an
    already sunlit object much if at all).

    - aperture used by the camera affects flash exposure, but shutter speed doesn't.

    Given the above, and knowing the focus distance to the subject, you or the computer in the camera determine what aperture is required for
    the flash at that distance. Then, being limited by that aperture, you or the camera determine what shutter speed is needed to properly
    expose the background (knowing that it won't really affect the flash exposure - since you're not changing the aperture).

    Sometimes people have problems with fill flash simply because their scene is not really a fill-flash situation, or the main subject they want to fill on is not at the distance focused for.
     
  11. "Is Fillflash just flash on lowest power?"

    No it isn't. It is any amount of light that boosts the brightness (luminance) values of a shadowed portion of the subject or
    another area in the photograph relative to either he overall exposure or to the area lit by the key or primary light source.

    What is your hesitancy to use automation?
     
  12. ." What they don't say is how are they "working together"? How can you simultaneously have proper exposure for the background and the foreground?​

    Well if you're lucky you already have the same amount of light on the foreground as well as the background so it's simple to get proper exposure for both. If the background is darker than the foreground you're out of luck unless you can put a flash or a light source to light up the background and not the foreground. Generally speaking fill flash refers to the situation when the background is brighter than the foreground and you can light up the foreground to about the same level as the background or a bit less to give the impression that the foreground is darker. In such a situation the background exposure is dictated by the amount of light you already have so you need to adjust your flash to light up the foreground but not brighter than the background.
     
  13. Being knowledgeable about lighting is the keys to the kingdom especially so for portraiture. The basics are to set up a “main” some call this a “key” light. While there are no rules in art, you are advised to set the main high and slightly off to the side to simulate afternoon sun. You reposition this lamp based on your subject’s features. Long nose, adjust for short nose shadow. Fat face; light more from the side the other cheek in shadow give an illusion of slimness etc. All this revolves around the notion that the human face is imaged better if illumined by one light.
    Sorry to report that the one light concept has a flaw. Most often the shadows cast by the main will be too deep thus void of detail. We need these shadows to give an illusion of depth to our 2D reproduction of a 3D subject. To lighten the shadows cast by the main we use a fill light or simply a reflector.
    We are filling the main light shadows as seen from the camera’s viewpoint. The fill is best located at lens height somewhere near an imaginary line drawn lens to subject. To preserve the one light illusion the fill is set subordinate to the main.
    Lighting ratios:
    Say the main delivers 1000 units of light on the frontal area of the subject’s face. If the fill is set to deliver ½ this energy than the fill delivers 500 units. The frontal area receives both main and fill for a total of 1500 units. The shadows are only illuminated by the fill thus the shadows receive only 500 units. The lighting ratio is thus 1500:500. This is an awkward fraction so we reduce it to 3:1. The 3:1 ratio is considered the “bread and butter” ratio as it sells best.
    If the fill is adjusted to deliver ¼ of the energy of the main, the main delivers 1000 units the fill 250 units. The frontal areas get both = 1250 and the shadows only 250. The ratio is 1250:250. This reduces to 5:1 and this is more contrasty and often suitable for portraits of men.
    If the fill is adjusted to deliver 1/8 of the energy of the main, the main delivers 1000 units the fill 125 units. The frontal areas get both = 1125 and the shadows only 125. The ratio is 1125:125. This reduces to 9:1 and this is very contrasty. 9:1 is about as high as you can go. The 9:1 is so contrasty it is often termed theoretical.
    To establish these ratios the main is first set in place. If the fill lamp is the same wattage as the main, then measure main to subject distance. The 3:1 places the fill 1.4 times this distance. The 5:1 is 2 times the distance. The 9:1 is 2.8 times the distance. If the main is 5 feet, the fill at 5 x 1.4 = 7 feet, the ratio is 3:1.
    Just some gobbledygook from Alan Marcus
     
  14. Joe:
    Yes I know. I ask a lot of questions (but only in short periods of time and then I reappear again) and I love forums. But it's your fault that I ask all these questions because I get so many useful tips:) And I feel I "know" most of you.
    I spent a lot of time on tutorials on youtube mostly, but there is always some detail I wonder about. But yes I know I have reached the limit with questions about flash in this forum for now:)
    I do make a living of photography, believe it or not. But so far I have used natural light only or just a few lamps with everything on auto. But I want to be good technically as well (Not only aesthetically). I know a lot of guys have the advantage of knowing everything about the tech stuff almost before they pick up a camera. The technical part took me years to learn. Especially light metering and the zone system etc.
    Ellis:
    So basically fillflash is all flash that fills a subject:)
    Thank you all once again. Interesting posts that I need to read thoroughly. (Especially the long posts that are advanced, plus english is not my first language).
    Sarah.
     
  15. Given the above, and knowing the focus distance to the subject, you or the computer in the camera determine what aperture is required for the flash at that distance.​
    Pierre, I was under the impression that, as Lex pointed out, in TTL mode flash power/duration is controlled by the camera to give proper exposure for the foreground while shutter and aperture are determined by ambient light. What you are saying is not exactly the same, is it?
     
  16. That is correct. The meter we can see only measures the ambient, without regard for flash. The TTL flash has its flash power level adjusted to work into whatever aperture it discovers was set, by whoever set it. Shutter speed is not a factor for flash exposure, but there are two conditions... Maximum flash sync speed must be observed (typically near 1/200 second), and in dim light, camera A or P modes will observe a Minimum Flash shutter speed, default is 1/60 seconds. These conditions do not affect flash exposure however.

    Fill Flash - TTL BL mode is called Balanced Flash, which means it is automatically fill flash mode if the ambient is sufficiently bright to need it. Point&shoot fill flash. Meaning, like in bright sun, flash power is decreased a couple of stops, called Balanced flash. Flash models without an overt TTL/TTL BL menu are doing TTL BL mode (SB-700, internal flash, Commander, etc).
    TTL mode (as opposed to TTL BL mode) is Not balanced or fill flash, meaning regardless of how bright ambient may be, TTL mode comes ahead on and does what it thinks the metering says to do for flash (which then the sum of two proper exposures will overexpose the subject in bright ambient). Great indoors, but as fill flash, we have to compensate TTL Mode ourselves, typically near -2 EV flash compensation in bright daylight if we instead want fill level.
    But repeating, TTL BL mode DOES DO this flash exposure pull back automatically, to be balanced fill flash. TTL mode does not.
    Spot metering mode switches any TTL BL mode to be TTL mode, for any flash model. Spot is about ambient, and system does NOT do spot metering for flash, but it does switch flash mode. TTL flash metering does its own thing, resembling Center metering, but not equal to same thing. So, Spot metering certainly can help indoor TTL BL flash mode underexposure (because it is doing TTL flash instead). If your indoor TTL BL is underexposed, try Spot metering then. And of course, flash compensation.
    TTL BL has one more serious quirk (and again, SB-400, SB-700, camera internal flash, and Commander... are doing TTL BL mode).
    Indoor TTL DIRECT flash often overexposes, due to both the metering seeing the inverse square law falloff (metering affected by the dark far backgrounds), or because the metering sees the dark shadows Direct flash can make on near backgrounds. So direct flash metering often sees overexposure. Deer in the headlights, etc.
    Solution: The Nikon D lens data is used (for TTL BL Direct Flash only), and so with the system knowing distance, guide number can compute an exposure for this distance. Guide number is not affected by dark backgrounds or shadows, not even by the subject colors. It definitely is still a TTL metered system (metering preflash), but D lens data can watch, and can say "Whoa, that is too much exposure for this distance", and can cut it back, for reasons above.
    Problem is, D lens distance data is often pretty poor for zoom lenses, and can indicate a false short distance, which causes unrealistic cuts backs, and underexposure (of TTL BL Direct flash).
    It is about TTL BL direct flash. Bounce flash ignores D lens, not a factor. Nor is TTL flash mode concerned with D lens distance.
    TTL BL direct flash is concerned with D lens distance reports. It is TTL metering, but it can be overridden if it thinks overexposure will happen.
    D-lens distance is too inaccurate to be used by the actual GN modes on flash models that have it (we have to enter the distance ourself), but Nikon gives it full run to mess up TTL BL direct flash with inaccurate zoom lenses.
    However, FV Lock will ignore D lens distance (point is to aim elsewhere than where metered), so using FV Lock will often improve TTL BL direct flash underexposure due to zoom lens errors. FV Lock is rarely same flash exposure as without it, but in particular, it can help direct TTL BL mode.
    More on this at http://www.scantips.com/lights/ttlbl-d.html
     

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