Help with lighting

MnemosyneMnemosyne Registered Users Posts: 251 Major grins
edited February 18, 2010 in Technique
So I had a few questions about lighting techniques.

1. Feathering. When you feather, is it more of turning the light slightly away from the subject, or just moving the light forward/backward/sideways/etc?

2. Main vs. Fill. I know the ratio is important, but is the angle? If you place them in a mirrored positioning (say for example the main at 7 oclock and the fill at 5), one higher stop than the other, is it the same as placing your main in the same position (7 oclock) but the fill at a non mirrored position (ie 3 oclock)?

3. Light height. Does the height make a huge difference? Obviously it allows for more spread, but does it change the angle of the shadows? Does it help control fall off or direction?

4. Distance. I know that distance can effect the light, the closer it is, the more powerful it is. But does the same occur when you zoom? Technically, you aren't actually closer to the subject and it still needs to travel the same distance.

Ummm, that's all I have :)
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Comments

  • HaliteHalite Registered Users Posts: 467 Major grins
    edited February 18, 2010
    You're asking important questions. Truly, the best way to answer them is to experiment with them yourself. Move your lights around--up, down, and sideways. Change the ratios and distances. Make mistakes, play around and take notes. Lather, rinse and repeat! mwink.gif

    Quick answers to your questions:

    1. Feathering involves turning the center of the light beam slightly away from an object. Can be useful when you are trying to more evenly light a near object and a far object with the same source.

    2. Ratio is important, angle is important. Shadows will not be the same between the two scenarios you outlined. You as the photographer get to decide whether you care about this difference.

    3. Light height matters. General principle: the angle of the light relative to object being lit and the camera is going to affect what is lit and what is in shadow. Think about it: does noonday sun throw a different shadow from late afternoon sun?

    4. Distance matters. Size matters. Not just for power, but for quality of light, shadow and specular highlights. Try playing around with a piece of fruit, such as an orange, and one light. Start with the light fairly far away and then moving it closer in standard increments. Try to keep the exposures the same by changing only one input: light intensity, aperture, shutter speed or ISO. Make a gallery of the pictures with the light distance and settings in the captions. Refer to this often when you are thinking about how to light a new project.

    Good luck. Have fun. clap.gif
  • ziggy53ziggy53 Super Moderators Posts: 23,763 moderator
    edited February 18, 2010
    Mnemosyne wrote:
    So I had a few questions about lighting techniques.

    1. Feathering. When you feather, is it more of turning the light slightly away from the subject, or just moving the light forward/backward/sideways/etc?

    2. Main vs. Fill. I know the ratio is important, but is the angle? If you place them in a mirrored positioning (say for example the main at 7 oclock and the fill at 5), one higher stop than the other, is it the same as placing your main in the same position (7 oclock) but the fill at a non mirrored position (ie 3 oclock)?

    3. Light height. Does the height make a huge difference? Obviously it allows for more spread, but does it change the angle of the shadows? Does it help control fall off or direction?

    4. Distance. I know that distance can effect the light, the closer it is, the more powerful it is. But does the same occur when you zoom? Technically, you aren't actually closer to the subject and it still needs to travel the same distance.

    Ummm, that's all I have :)

    These are all excellent questions, and I'm sure there are many folks wondering similar things. Let me start with an explanation of fill light and the 3 primary considerations of technical, practical and aesthetic.

    Fill light, by definition, is simply using light to "fill in" the shadows, allowing overall scene contrast and dynamic range to fall within the dynamic range of the medium (film or digital, as well as the presentation medium, screen or print) and the requirements of the project.

    Since, from a technical perspective, anything not visible to the lens and camera is unimportant to the purpose of fill light, that would seem to indicate that the best position for a fill light source would be close to the axis of the lens, and in some cases that is true.

    From a practical perspective that is not often possible. For instance if the background is shiny or reflective, or if the subject itself is shiny or reflective, then any light coming from close to the lens axis may be a problem. As such it is often desirable to position the light (or reflector) so that undesirable reflections are eliminated or accommodated. This would normally be a contra angle to the key light.

    In the case of human subjects, as in portraiture, the fill light is often also used as a "catch light" to provide a spectral "glint" in the eyes. In that case the position of the fill light is planned with the particular angle required for the desired reflection. This is an example of an aesthetic use for a fill light.

    "Feathering", by definition, is the use of off-axis light from a light source. This is a valuable technique when you work with subjects spread at some distance from the camera but you want even illumination. For example if you had to shoot a banquet table from the end of the table, you might aim the flash at the furthest end of the table, allowing the off axis feathered light to illuminate the closer items on the table. (Bounced light is another practical approach for this particular application, if possible. In a room with dark or colored ceilings, the feathered approach is more desirable.)

    A group portrait, with the subjects positioned on open stairs might be another good example of a good application for feathering the light source.

    The height of light is extremely important. Key light coming from close to the lens axis gives us little indication about the shape of the subject. Imagine a ball, illuminated from only the camera position. It would look pretty much the same as a disk of the same size.

    Too high and some subjects look unnatural. Human subjects can look like they have "raccoon eyes" and the eyes will seem sunken into the head.

    Flowers and vegetation often look very nice with just overhead illumination, or with just a bit of fill.

    A balance needs to be struck and again, the project requirements will often dictate the best lighting approach.

    Relative size of the light emitter, as well as balance with other lights, is more important than distance alone. A very large diffusion panel close to the subject can make a distant light source, like the sun, appear much more diffuse and yield much more pleasing shadows. Take away the diffusion and the light becomes both hard and harsh.

    Using a bare zoomed flash head will indeed collimate the light and make it seem pretty hard. The combination of a zoomed direct flash and some distance can make for a very unpleasant light, similar to the built-in flash of a compact camera at closer range.
    ziggy53
    Moderator of the Cameras and Accessories forums
  • MnemosyneMnemosyne Registered Users Posts: 251 Major grins
    edited February 18, 2010
    Thanks for the advice.

    @Halite
    I've been meaning to practice, but the problem with practicing is if you don't know how to do it right, it doesn't help. Kind of like learning to drive without knowing how to turn on the car :)

    FILL
    If you're just moving fill, how would the shadow change? since fill doesn't create them. I meant just moving the fill light in relation to the main. Not moving both. Obviously a fill light from behind wouldn't work. But if you move it 5 degrees, it's still just filling shadow and not creating.

    HEIGHT
    I know the angle affects the light, but I meant leaving the angle the same, and just raising the light. Is that changing the angle?


    And thanks Ziggy.

    I ask because I had a project recently, and it was my first serious attempt with my studio lights. They loved the photos, but I'm a perfectionist and I see now, especially after talking Pathfinder, I see now all the things I did wrong. I wish I could have found a way to add my speedlight as a kicker, I should have used fill on some of them, I should check my histogram because many of them were underexposed more than I would have liked and I should have turned up the strobes. I should have used the reflectors to help make the light more directional instead of spread out from the shoot through. That also would have allowed me to raise the light source a little better and avoid the unwanted reflections I was getting in some of the photos, and reduce spill which was probably why they were underexposed more than I wanted.

    I really want to learn, and many of the books and videos I've looked at don't teach you those little things about why. They say they used feathered light, but only in relation to what it did in that specific photo, not what it does in general. So thanks for all your help.
    Audentes fortuna iuvat
  • HaliteHalite Registered Users Posts: 467 Major grins
    edited February 18, 2010
    Mnemosyne wrote:
    Thanks for the advice.

    @Halite
    I've been meaning to practice, but the problem with practicing is if you don't know how to do it right, it doesn't help. Kind of like learning to drive without knowing how to turn on the car :)

    FILL
    If you're just moving fill, how would the shadow change? since fill doesn't create them. I meant just moving the fill light in relation to the main. Not moving both. Obviously a fill light from behind wouldn't work. But if you move it 5 degrees, it's still just filling shadow and not creating.

    HEIGHT
    I know the angle affects the light, but I meant leaving the angle the same, and just raising the light. Is that changing the angle?


    And thanks Ziggy.

    I ask because I had a project recently, and it was my first serious attempt with my studio lights. They loved the photos, but I'm a perfectionist and I see now, especially after talking Pathfinder, I see now all the things I did wrong. I wish I could have found a way to add my speedlight as a kicker, I should have used fill on some of them, I should check my histogram because many of them were underexposed more than I would have liked and I should have turned up the strobes. I should have used the reflectors to help make the light more directional instead of spread out from the shoot through. That also would have allowed me to raise the light source a little better and avoid the unwanted reflections I was getting in some of the photos, and reduce spill which was probably why they were underexposed more than I wanted.

    I really want to learn, and many of the books and videos I've looked at don't teach you those little things about why. They say they used feathered light, but only in relation to what it did in that specific photo, not what it does in general. So thanks for all your help.

    Unlike with driving, practicing lighting isn't really dangerous! eek7.gif Maybe instead, call it "play" or "experiment". Doesn't matter, you just have to dig in and do it. Observe the results. Change things around and observe some more.

    FILL: The fill eliminates shadows. If you move it around enough, it may not eliminate all shadows. This can be considered good or bad depending on your goals.

    Have you read http://www.amazon.com/Light-Science-Introduction-Photographic-Lighting/dp/0240808193/ref=sr_1_1?ie=UTF8&s=books&qid=1266521298&sr=8-1 ? This book is a great source for the why's of lighting.
  • MnemosyneMnemosyne Registered Users Posts: 251 Major grins
    edited February 18, 2010
    Light: Science and Magic, I own it. Have read it many times. The problem is, like G.I. Joe said, "Knowing is half the battle." I've read book after book, watched videos, read blogs, harassed my dad repeatedly with questions and anything I can get my hands on. But I know all this stuff, it's just not habit yet. I know it, but don't completely understand it. Kind of like when I started photography. I knew all about exposure, iso, aperture and shutter speeds, but couldn't just walk into a room and know what I needed. Now it's second nature. Now I'm foraying into studio lighting, and it's confusing at times, even though in print it makes perfect sense.

    Not to use a driving analogy again, but it was like when I was first learning manual transmission. My dad taught me, and I understood, but I was religiously watching the tachometer and RPMs. Eventually I was able to do it by speed. Then just by the sound of the engine. And eventually/now, I can just feel it. I just know by how the car "feels" when to shift.

    Not that I'm trying to jump from beginner to expert in two minutes, but I'm not afraid to ask continuously when I'm confused :)
    Audentes fortuna iuvat
  • pathfinderpathfinder Super Moderators Posts: 14,694 moderator
    edited February 18, 2010
    Mnemosyne wrote:
    Light: Science and Magic, I own it. Have read it many times. The problem is, like G.I. Joe said, "Knowing is half the battle." I've read book after book, watched videos, read blogs, harassed my dad repeatedly with questions and anything I can get my hands on. But I know all this stuff, it's just not habit yet. I know it, but don't completely understand it. Kind of like when I started photography. I knew all about exposure, iso, aperture and shutter speeds, but couldn't just walk into a room and know what I needed. Now it's second nature. Now I'm foraying into studio lighting, and it's confusing at times, even though in print it makes perfect sense.

    Not to use a driving analogy again, but it was like when I was first learning manual transmission. My dad taught me, and I understood, but I was religiously watching the tachometer and RPMs. Eventually I was able to do it by speed. Then just by the sound of the engine. And eventually/now, I can just feel it. I just know by how the car "feels" when to shift.

    Not that I'm trying to jump from beginner to expert in two minutes, but I'm not afraid to ask continuously when I'm confused :)

    How about you, Brendan, me and a few other local shooters get together when it is a bit warmer outside and set up a shoot with a couple models. We should have plenty of gear, lights, reflectors, and then we can crib each others work. Our own Strobist workshop. If you know a make up artist or face painter, that might be a lot of fun to do too.

    PS.... You take too many of my suggestions as criticism, rather than compliments, and suggestions, to make even better images.. I thought you did a bang up job! Your posing was very good, even when the backgrounds you were required to use were tough. I have never shot a session that I did not see how I could have done better after the fact I think that is a given in this type of work, unless you have lots and lots of practice under your belt.
    Pathfinder - www.pathfinder.smugmug.com

    Moderator of the Technique Forum and Finishing School on Dgrin
  • MnemosyneMnemosyne Registered Users Posts: 251 Major grins
    edited February 18, 2010
    @Dad
    I don't know any make up or paint people in TH. And the one who's helping me here is also planning her wedding so she may not be able to help. Although I do know a lot of girls that do modeling, so maybe they could recommend someone. But I'm sure I could find some girls willing to model.

    And I do NOT take everything you tell me as a criticism. If I got annoyed at what you told me, I wouldn't ask you all the time for your advice :) I really appreciate that you put up with my incessant questions. I'm not upset cause of your critiques, I'm upset cause I made stupid mistakes that I know better than to make. Such as trusting the LCD. I told newbies all the time to trust their histogram and not their LCD, and then I made the same rookie mistake. I should have aimed the lights better, I should have lowered the ISO and opened the Aperture, and raised the power of the strobes. And I think the reason I had trouble with the apparent ambient in the pictures may have in fact been because I was using my speedlight to trigger them. I'm not mad at you, I'm mad at myself :) I made stupid rookie mistakes. That's why I'm upset.
    Audentes fortuna iuvat
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