Q&A: Avoiding Cross Shadows When Rim-Lighting
Strobist reader Ed Roper asks:I've been using a three-light setup, but running into a pesky shadow problem. Below is an example setup shot with the shadows highlighted. As you can see, I'm already using grids to try to cut down on the spill.
Are these cross shadows just a fact of life when trying to wrap full body like this?
The good news, Ed, is that you have exactly the light mods you need to do this well. And the fix is easy…
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First, a note about Ed's strips. He is using two Paul Buff 10x36" soft boxes with grids. These are great strip lights -- well-built, open like an umbrella and offer a lot of bang for the buck. The mounts are speed rings, which allow interchangeable inserts. I used to use them with AB's and then swapped inserts when I switched to Profoto.
At $119.95, they are reasonable enough to cough up an extra $29.95 for the matching grids, which are very helpful for controlling spill. And that is is exactly what you would want to do here.
Simply put, if you do not want the cross shadows (which Ed has circled for us above) you have to keep the rim light from reaching the ground. There are three ways to do this: feathering, gobo'ing or a combination of the two.
Easiest way is to feather the lights. And in this case you would feather them up. You are gonna have to do this to a greater degree than you think. If you are doing it right, it will look almost comically overdone. The idea is to rim light your subject with the diminishing edge of the beam. By the time it gets down to his feet, it is all petered out.
For even more control I would physically lower those rims a little before feathering them, too.
Most of the time, this will work. But if you need absolute control of weird ground shadows, you'll want to gobo the light off from the bottom. With a bare speedlight, you might use something like a Honl Speed Gobo or even a piece of cardboard on the flash itself. But with a light mod of this size, you'll need something bigger.
In this case the gobos would be large cards, clamped to stands and placed between the rims and the subject. Geometry should tell you exactly how high to place them. The top of the gobo would exactly hit a straight line between the top of the strip box and the bottom of the subject's feet. As you moved up the subject's legs, they would see more and more of the strip box.
Now, no cross shadows on the ground will also mean no light on the ground. Which could be a problem in this case. You'll either have to make that happen with your key light (feather it up for foreground control, too) or scrape another light across the background.
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Posted at 4:30 AM.
28 Comments:
brilliant - I have frequently suffered these odd-looking rim shadows in the past and never worked out how properly to eliminate them. now I know. thank you!
I'm not really sure the gobo part will be much help: seing the subject's shadow on the ground means that the light coming from the flash hit the subject before it hits the ground. Goboing this light means blocking this light before it reaches the ground, sure, but it also means blocking it before it reaches the subject ! So goboing the light responsible for the shadow means casting a shadow on the subject, imo. Based on the setup shot, that would mean leaving the model's legs in the dark.
Lowering the flash heads and using some feathering as you first advised seem much more efficient to me to reach the goal : the subject keeps well lit, but his shadow has been "moved" out of the frame.
Spica-
True -- and I see what you are saying. But by gobo'ing the rim from the top edge of the light to the bottom of the feet (top of gobo intersects with a line between the two) a few things happen.
1. Obviously, the shadow on the ground won't connect to the feet. The light is fully gobo'd there.
2. As you move up the legs, the light will progressively begin to be visible to the legs. So, a little at a time, the shadow would start to become visible, if not connected.
3. But as you work up the body, the light (think, overspray) has further to go after it passes the legs before it reaches the ground.
So not only is it disconnected, but a couple of other factors are working to minimize it. You can tweak this with a feather of course, as noted above.
In both cases (feather and/or gobo'ing) distance of rims from subject is a further variable/tweak.
IMO, feathering is a better way to do it, with a gobo being a good way to seal off the feathered edge if you need to.
Hi everyone,
I would shoot this frame with a tripod, then move him out of the frame and reshoot it, and then composite them in PS. It gives the best of everything: light on his whole body, no strong shadows on the ground (or at least controllable shadows). It would probably take less time then setting up gobos and testing the results.
Eric
Aren't these solutions all compromise and won't they change the personality of the photo? I like that pic pretty well, just the way it is, shadows or not.
Either way, why not just take the shadows out in post? A little lightening or cloning, 2 minutes and it's done.
That's prolly what I would do.
Is that heresy???
Thanks, Sensai. This is timely as I had the same issue shooting team photos last season and will be tapped to do it again this year.
I've also had good luck shooting the scene on a tripod and having the subject step out of the scene for a couple of fully lit shots. I overlay those shots in Photoshop, hide them with a layer mask and reveal the layer where I need to erase or diminish any shadows cast by my subject. I hate shooting on a tripod, so I save this technique for problem scenes, but when I need it, it's almost always faster, and yields far more control, than trying to balance the compromises of solving the problem with light modifiers alone.
Here's my $0.02 worth--gobo or feather only one of the lights. Leave the other one exactly like it is and let it cast light and shadow at his feet. That, to me, would result in a more believable image--the subject will be more grounded, and you won't need a third light to scrape the background.
Here's my half-nickle's worth: gobo or feather just one of the lights. Leave the other one exactly like it is. This way you'll have it cast light and shadow on the ground, which looks better and more realistic to me. And you won't need a third light to rake the background.
Would it be ok to gobo only one strip bank? Let the other strip bank create the directional shadow on the floor. Do you think that would look ok?
Great article as usual David! Could you recommend a place to actually see this gobo setup as you describe? In action? I am having the damnedest time visualizing it from your paragraph that I included below. Thanks as always!
-"In this case the gobos would be large cards, clamped to stands and placed between the rims and the subject. Geometry should tell you exactly how high to place them. The top of the gobo would exactly hit a straight line between the top of the strip box and the bottom of the subject's feet. As you moved up the subject's legs, they would see more and more of the strip box."
I think maybe instead of saying "gobo", maybe "flag" is a better word?
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Yep, feathering can look comical. I brought a friend along on one of my car shoots recently and he wanted to know whay I was trying to aim the lights at the sun...
don't forget that this is a three light setup, so he has the front light as an adding factor to help reduce the cross shade effect.
Sorry. but the only way for me to reduce those unwanted shadows without the intervention of a third light is by modified the modifiers to the lower third of the grid. doing this will create a biggest light source below that in turn creates a more involving kind of light killing the shadows on the ground.
forgiveness for my horrible English
Sorry. but the only way for me to reduce those unwanted shadows without the intervention of a third light is by modified the modifiers to the lower third of the grid. doing this will create a biggest light source below that in turn creates a more involving kind of light killing the shadows on the ground.
Forgiveness for my horrible English
I'm very much a newbie would be very interested in seeing the effect of this suggestion in a sample shot -- that is, have a shot similar to this before and after adjusting the lights to prevent the shadows. I have a hard time visualizing how this would work...
Either ignore the shadows or increase the size of the modifiers, while at the same time reducing the directionality of them. translation: ditch the grids.
The resulting image will be softer. If you don't like that, accept the shadows or change the point of view. A lower camera angle would diminish the shadows as a part of the image.
I would welcome a picture of that gobo as well. It's a little abstract and I'm not sure how David meant to place them.
rob and kevin, great idea. in hindsight it's kind of a d-oh! i like the idea of a fully lit shot without subject to provide clone material
The shadows are usually the part of rim lighting that add realism... without shadows the light on the subject doesn't make sense and causes the viewer to be disconcerted. In compositing you usually try to do the opposite and add shadows to trick the viewer into thinking the image is real.
Personally I want those shadows, and even create them in compositing to help sell the image as real. People are used to seeing shadows where they see light, and shadows mixing together.
Thanks a lot brother for ur great help.Keep it up.
I agree with Sean McCormack. If there is light on one side of a subject, it only makes sense that there is a shadow on the other. I personally don't have a problem with crossing shadows.
Nonetheless, good point, DHe
Im a strong believer in my speddlites. I have many different modifiers but one I m partial to is my Westcott Apollo 28" softbox. I also have 2 generic softboxes that mimic lastolites Joe McNally EzBoxes 20" that I use constantly. I desperately would love find grids for any of these! Without breaking the bank, or I would have bought Lastolite in the first place. Are you aware of any companies who specialize in (custom) grid making. I've asked Lastolite and a few other to just sell me there grids but was refused. Can you help me?
Long time ready and fellow strobist Nick P.
Im a strong believer in my speddlites. I have many different modifiers but one I m partial to is my Westcott Apollo 28" softbox. I also have 2 generic softboxes that mimic lastolites Joe McNally EzBoxes 20" that I use constantly. I desperately would love find grids for any of these! Without breaking the bank, or I would have bought Lastolite in the first place. Are you aware of any companies who specialize in (custom) grid making. I've asked Lastolite and a few other to just sell me there grids but was refused. Can you help me?
Long time ready and fellow strobist Nick P.
Hi,
I dont't that think feathering or goboing would kill the shadows... That's because when you have light, you have shadow. If you still illuminate the subject with the same light and from the same angle, you will have the same shadow. Additionally, if you feather in such a comical way, as referred, you will make the light source smaller from the subject's point of view and that will cast harder, more intense shadows.
You can reduce the intensity of the shadows by enlarging the light source - bring the soft boxes closer to the subject - thus creating a softer light and less intense shadows. And you can lower the height of the boxes. Then the light hits the subject in such an angle that will spread the shadows a little bit more, thus reducing its intensity.
Nevertheless, I agree with the Photoshop composite option. Easy and clean.
By the way. the photo looks very good to me. I wouldn't worry so much about the shadows.
André P.
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