How to get a sharp shadow line with a flag

<p>Hello, did some searching around the forums and didn't seem to come across anything with this subject. I've been working with flags lately trying to get various effects with shadows in portraits. What I'm trying to achieve is a very definite shadow line, something like you can see in this image as an example. <br>

http://danwintersphoto.com/#/P%20E%20O%20P%20L%20E/P%20E%20O%20P%20L%20E%20%20O%20F%20%20I%20N%20T%20E%20R%20E%20S%20T/45/thumbs<br>

For my shots, below, I used a 7-inch reflector with a 30-degree grid camera right about six feet away and had a 20x30 flag literally just out of from on camera right. (Also had a large umbrella on-axis for fill.) Figured a larger source like a softbox wouldn't create as much shadow as a small source. I realize one pose is looking in the opposite direction as the example, but you can see on the shirt that the shadow line isn't as defined as the example. Any thoughts on how to get that crisp line? I wasn't able to move the light farther away; it's already up against a wall, but maybe that's the answer ... making the main source even smaller?<br>

<p>Thanks in advance</p>

<p>Move it closer to the subject?</p>

Three things to try:

 

Move flag closer to the subject

 

Use two flags with some seperation between them. One closer to the subject, (its an old physics trick at work)

 

Try either or both of the above with a light that optically focuses, in essence a spotlight but a parabolic reflector can work

as well. If you use Paul C. Buff lights the retro-laser reflector is a good place to start or with any lights, a grid spot plus

flags.

 

 

In other words you are trying to make the light stream more in a straight defined line.

 

One last thing if you are going to use grids: I really like the Plume, ltd. Chimney reflector over every other grid holding reflector I've tried from virtually every lighting manufacturer.

<p>If you haven't yet, you need to read Light: Science and Magic. It will open up your world. And explain everything you want to know about this specific situation.</p>

<p>The above advice is incorrect. It's all about the relative size of the light source / the distance between the light source and subject. The closer the source, the larger it appears to be, and with respect to diffusion, the more indirect the light rays that fall on your subject. If you want more direct rays. you have to move your source <em>away</em> from your subject. The result is that the light rays falling on the subject are more parellel, which will allow you to create sharp shadows such as you describe. In addition, you want your flag far away from the source, closer to the subject. All of this can be enhanced using a light source that can be focused, adding a grid, and careful use of any diffuser on the source.</p>

<p>Thanks for the feedback. Gary, I do have the book you mention. I'll have to get it off the shelf again and check it out. I remember reading it cover to cover when I first bought it. And based on what you said, it kind of confirms what I thought -- that I needed to make my smaller in a relative sense. Unfortunately, in this setup, my light was all the way back against a wall (not a very big room), and I couldn't move it back any farther. I'll have to give it another shot in a larger space and still keep the flag as close as possible but still just out of frame. </p>

<blockquote>

<p>...it kind of confirms what I thought -- that I needed to make my smaller in a relative sense. Unfortunately, in this setup, my light was all the way back against a wall (not a very big room), and I couldn't move it back any farther.</p>

</blockquote>

<p>Actually, you can make the light smaller by masking it off with cardboard. If the opening is a vertical slot, you won't lose quite as much light. Another option, if your studio walls are not too light (reflective) is to lose the reflector and shoot with a bare bulb.</p>

My advice is actually sound and is borne out through about three decades of professional practice, playing and

experimenting, and studying some physics before that.

 

I thought I was pretty clear about getting the <I>flag or gobo</I> closer to the subject, not the light source. You can test

that by shining a light at a wall and using your hand as a gobo. Notice that when your hand is closer to the wall the edge

of the shadow is more crisply defined? That is the effect he is going for - a crisply defined edge.

 

You are correct in pointing out that the relative size of the light to the subject plays an important role in defining how the

defined the shadow edge is as well as the size of the highlights, but what a flag or gobo is doing is changing the apparent

size and shape of the source from the subjects perspective so having a flag or layers of flags close to the subject makes

for a better defined edge.

 

Working in a small space adds lots of room for inadvertent fill light to infiltrate the the set as well. Dan Winters usually

doesn't have to deal with that problem but he knows what to do when he does.

Sorry, Ellis, I meant my thank you for the feedback to all who contributed, not simply to Gary. I'm actually

very eager to try out your recommendation on the two flags as that completely hadn't occurred to me. And

yes, I'm trying to get the flag as close as possible -- while still keeping it out of the frame (or easy to clone

out). And definitely agree with you. I'd much rather try and figure out the situation given my current space

limitations rather than just thinking, "Oh well if I had tons of square footage it'd be no problem." Problem

solving like that is half the fun.

Yes it is. For some jobs it is almost as much fun as getting paid.

<p>Don't forget that the longer the focal length, the more easily you'll be able to keep that up-close flag out of the shot. Also a challenge in tight quarters, of course. But remember that you can "thread the needle" of a complex set by backing up and using a longer lens. Of course that changes the perspective, and flattens faces in portrait situations, so you have to watch for the sweet spot.</p>

<p>Ellis, perhaps the word "incomplete" would have been a better choice. With expansion, it seems that we are all on the same page. I felt is worthwhile to point out that this issue is clearly discussed in "Light" and that the book is an excellent resource. No slight intended, only seeking clarity.</p>

<p>I hope that Gregory posts some results shots after working through this.</p>

<p>Ellis is spot on as usual. 2 controls with flag placement is first, move the flag closer to the subject or wall to harden the shadow edge transfer. The closer the flag, the harder the shadow edge transition. Move the light away from the subject makes the light relatively smaller. Use a flooded Fresnel. It produces razor sharp shadows not just kind of sharp like a grid. Finally, be sure you have enough dof that your lense isn't softening the shadow edge transition. Shallow dof can be used to soften shadow or specular edge transitions so be sure you are closed down a bit and be careful where you place focus. </p>

<p>Using gobos (i.e., flags, solids, cutters, cookies, etc.) with standard strobe reflectors isn't very effective--you need more focused light. The two most common focusable lighting instruments are: A.) Fresnels B.) ellipsoidals (also referred to as "projectors"). These are available as either attachments, or as complete housings.</p>

<p>I don't know why Profoto and others charge such insanely high prices for their Fresnel-housed strobe heads. If you're willing to shoot using continuous light, you can buy a brand new Arri 650W Fresnel for only $379. For laser-sharp, focused patterns or shadows, choose an ellipsoidal. The popular 750-Watt, ETC Source 4 ellipsoidal sells for only $349. While the Source 4 is capable of producing sharper shadows, the Fresnel will tend to be more versatile.</p>

<p>Also, note that the objective isn't necessarily to make the light source <em>smaller</em>. Your objective is to make the light rays <em>more parallel</em>. Yes, moving a source further away is one way to do this. But, using either a Fresnel-lensed instrument, or an ellipsoidal/projector attachment is simply a much more efficient way to do this. Also, note that grids do <em>not</em> affect light quality; i.e., they don't make the light harder or softer (they simply act like a hundred tiny flags).</p>

<p>Am I missing something here? I've looked at those two example pictures, and while a flag or barndoors might have been involved, I really can't see any remarkably sharp shadow lines attributable to a flag.</p>

<p>In the first shot, there's top and slightly camera-right lighting raking down and across the face. There's also a kicker across the shoulders - which may be a separate light or just the overhead key extending backwards. The light has been well-controlled to not spill on the background - or the BG has simply been PhotoShopped away. However I really don't see any sharp flag shadows there at all. Just hard lighting with plenty of soft fill from front camera left.</p>

<p>The second example has a very similarly positioned key light, which I agree has been flagged off from hitting the subject's left shoulder. Yet again, the feathering isn't particularly hard. It's just what I'd expect from a barndoor or flag swung across the camera-right side of an open reflector light. That's about all. There's no discernible fill, just a snooted down BG light.</p>

<p>Gonna have to keep experimenting. Moving the source farther away has helped a little, but now I'm definitely interested in the Arri Fresnel Ralph mentioned. And no, Joe, you aren't missing something. The example shots do show evidence of a flag, but not nearly like the sharp shadow I was hoping to produce.</p>

<blockquote>

<p>Gonna have to keep experimenting.</p>

</blockquote>

<p>Hi, sounds like you didn't try masking down the light yet, 'cuz you probably would have been done by now.</p>

<p>If you don't know where to start, try this: put the light 6 ft, and the flag 2 ft from the subject. This makes the shadow line on the subject 1/3 the width of the masked slot on the light. For example, a 1 inch wide masked light source makes a 1/3 inch wide shadow line (expect to lose a couple stops of light).</p>

<p>Regarding the lights Ralph mentions, if I'm not mistaken these will use tungsten-halogen bulbs, meaning their color is way different from the studio flash I presume you're using. Certainly you can work with them, but if you filter so as to match strobes, you'll lose a couple stops or so of light.</p>

<p> We got a lot of good advice from different people who all have different thoughts on this but did anyone actually think about what Greg did? Greg used two light sources and only one flag. He placed the one light source on the side the flag was on and the second light source was place on axis as fill which cancelled out or minimized the effect he was going for. <br>

One light source is best at camera axis. Using a bare bulb (small light source) will help with your distance problem and will also define the shadow lines better but it will still have a soft edge transfer. Using a focused head in my opinion is not a very flattering look for this type of shot. Dan Winters example that you like is much more flattering than if it had razer sharp edges. But for purposes of experience you need to know how to do both so follow all the above good advice. Good luck</p>

<p>What's wrong with using a little speedlight (or speedlite, if you prefer Canon)? A little hotshoe gun at it's shortest "zoom" setting gives a very hard light. Set it two or three metres away from the subject, with your gobo a lot closer, and you'll get as hard a shadow as you could wish for. Basically these things are just mini Fresnel spots, but a lot cheaper and easier to come by.</p>

<p>Excellent suggestions, ie., the speedlight rather than a strobe and the masking, and yes, the Arri lights would be tungsten, so some matching would have to be accounted for. In reference to Michael's comment about the fill light basically canceling out the effect of the flag, that was in fact something I noticed. Thus, I removed the fill for the second example, but still didn't notice quite as distinct of a shadow line as I was expecting, the reasons for which have been pointed out through the many helpful answers. Still experimenting with placement and masking and hope to have some examples up soon.</p>

<p>Yes, both Arri 650W Fresnels and Source 4 ellipsoidals are tungsten instruments (3200° Kelvin). If mixing tungsten with strobes, it's more effective to correct the strobes to tungsten, rather than the other way around (since the tungsten sources are likely lower-output). However, this may be easier said than done--full-CTO is too warm, half-CTO, too cool. The SB-600/800 Nikon Speedlight correction filters are definitely too warm (I have to set my in-camera color temperature to 2500° Kelvin to match these). An all-tungsten set would make things easier, and would facilitate easier gobo positioning for a precise cut.</p>

<p>Yes, light source farther away and flag closer. Another try may be to play with a beauty dish to see if you can set the edge. I think you can get a pretty distinct edge with those by angling the light and playing with where the penumbra falls, but it would probably be a curved edge.</p>

<p>All flag related posts (small light source/reflector at maximum possible distance from subject as well as flag as close in as possible) seem sound. It seems, however, that your lighting ratio is too low, i.e. your fill light is too powerful relative to your (flagged) main light. Using your original set-up, maybe using above comments to fine tune it, try reducing the power of the umbrella light or moving it further away. This might achieve your objective without investing in new gear.</p>

<p>Chris</p>

<p>FYI, not all true fresnels are tungsten. I use a Hensel Starspot fresnel ($1,300 new) which is a self-contained pack head with focusable strobe light. Hensel also makes much larger units which are ARRI conversions to strobe, and they didn't even bother to remove the ARRI logo.</p>

<p>If I recall correctly, there is a source that has Bowens mount fresnel attachments, however I've never used one and do not know how effective they are or how much you can focus the light like you can with a self-contained fresnel. </p>

<p>I also have a Elinchrom focusable gobo box that acts like a smaller fresnel when no Gobo insert is used. Nice spot light type effect. Very easy to make a hard edge at any distance with a cutter gobo inserted and the fresnel focused on the subject ... total control of the edge hardness.</p>

<p>I mention these because Ralph is correct in how well these work for controlling exact placement and edging of light. I also have a relatively small studio where distance can sometimes be an issue, and while there is always a solution using other methods, none of them quite do it as precisely or as fast as a tool made for the purpose. The addition of a fresnel has been one of the best moves I've made since my studio isn't going to get bigger any time soon.</p>

<p>Of course, it depends on whether you need that type of control frequently, or it is just a one time thing. I use it a lot for various type shots, so it was worth it. For a one time gig, I'd rent one.</p>

<p>- Marc</p>

 

<p>This is a compact and effective solution.<br>

<a href="http://www.visualdepartures.com/dedolight-imager-projection/">http://www.visualdepartures.com/dedolight-imager-projection/</a></p>