Want to turn studio strobe light into spot light

<p>I am using Paul C Buff Einstein's in my studio. They work great with soft boxes, umbrella, etc. for wonderful soft lighting. I would like to use one as a spot light (not with a snoot or hexgrid) so that I can project parallel light rays through such things as lace, mini blinds, lattice, etc. to achieve crisp edge patterns on a nude model. Any suggestions on a "Jerry rigged setup" to achieve this effect. I don't want to spend all the $$$ on actual spot lights, Fresnel if I can help it. The trough distance would be 10 to 20 feet from light source to gobo with gobo to model distance about 6 to 8 feet. I also have Nikon SB-600s available ( once was able to achieve the effect with this unit, but never a second time</p>

<p>The physics says that the farther away the source is from the gobo, the sharper the shadow will be (smaller source) and the closer to the subject the gobo is, the sharper the shadow will be (reduced diffraction). So some combination of small source far away with the subject close to the gobo will get your desired effect. Think of the sun and the window shades.<br>

Hope this helps you figure it out.</p>

<p> </p>

I don't believe there's a good, easy way to do it. If you really need crisp lines, you probably need an actual "projector" system, not just a simple lens in front of the flash unit. If the lines are allowed to be a little fuzzy, then an apparently "small" light source as "seen" from the subject position (this is what Charles suggests.). The problem with this is that you lose a great deal of your light. You could recover quite a bit by placing the right sort of lens in front of the flash; if you have a cheap Fresnel lens, give it a try. Your goal is to 1) project an image of the flash tube onto the subject area (experiment with a white wall), then 2) put it enough out of focus to not be objectionable. The gobo shadow should be about equally blurry in either case. (I'm guessing that you realize that you can experiment in a darkened room, using a CF bulb as the stand in for a flash tube.)

 

By the way, remove the lighthead reflector, so it's essentially a bare bulb source. You can sharpen the shadows further by cutting a smaller hole in a piece of cardboard and letting the light shine through it. This is at the cost of a lot more light.

 

If you can settle for just Venetian blinds, you might want to try one of your SB600 units. If you line up the face of the flash with the slits in the blinds, I expect you would be able to mask off the face of the flash with a slit and sharpen the shadow of the blinds quite a bit. But I think you may also lose angular coverage as well as light. I've never tried it, but think there's a good chance it'll work. This is where I'd start out, anyway, at least for the sake of experiment.

 

If I was going to do a great deal of this sort of work, I'd look for a commercial projector unit, or if just playing around I might rig one up myself. But it's trickier than meets the eye (yep, I have practical experience).

<p>@ Bill C. Thanks so much for your help. What about using a 10 degree hex honeycomb grid light modifier (maybe in a blacked out cone for the surround at the front of the Einstein unit)?<br>

My original shot was with the Nikon SB-600 which I set up 6 to 8 feet behind a flat piece of lace about 3 feet in front of the model (which was a mannequin). Right off the bat it worked! But then when I tried to do it with a live model I could not get it to work again. The first had nice sharp impression on the mannequin, with the model, it was fuzzier than I had hoped. The flash tube on the SB-600 is certainly much closer to a point source light than the donut shaped circular tube of the Einstein. <br>

Further, I have used a computer/DVD projector to cast all sorts of images onto a model. This works pretty well and the images are acceptable. What I am going for though is the main light from the Einstein casting the gobo onto the model and a second fill light from another Einstein giving a more illuminated (not strictly black on white) tough to the model.</p><div></div>

Hi, I doubt that the grid would do any better than a masked off light source, and it would only light up a smallish area. If you were to get a

larger diameter parabolic reflector or Fresnel lens behind the grid, and they are properly focused, the lit area would be larger. But just

masking off the light is probably a better way to go, IMO. The main problem with all of these is the huge loss of light. This is why the slit, in

the same direction as Venetian blinds, is better. The slit is like a couple dozen holes in a line, and can pass a similarly greater amount of

light.

 

Judging by your sample photo, I'm sceptical that you'll get near that quality without an actual projector sort of design. You could rig

something, but it's hard to get anywhere if you don't already understand how they work. The main problem is collecting enough light and

feeding it into the projector lens. You could try rigging up condenser lenses, but they're just not that efficient. By far the most efficient thing

is an elliptical reflector, but it's probably beyond your ability to make one, leaving a commercial unit as your best bet, IN MY OPINION.

 

Much of what I'm saying is educated guessing, so it's worthwhile doing a few actual tests just to confirm. But I have done a few somewhat

crude projectors, so I know something about those issues. Best of luck to you.

<p>The most defined shadow-edges and pattern-projections are most easily accomplished using an ellipsoidal, projector attachment, or a zoom-spot. Most have four metal shutters to create various trapezoidal patterns or "slits," and most can accommodate a wide variety of metal patterns available from companies like Rosco/GAM. You have several options:</p>

<p>• Ellipsoidals (tungsten, continuous): ETC Source Four ellipsoidals are typically lamped at 750 Watts. Choose one of the zoom models (about $600) with a standard Edison connector and a bale-block to enable stand-mounting: http://www.bhphotovideo.com/c/product/435388-REG/ETC_7060A1040_0XA_Source_4_Zoom_Black.html http://www.bhphotovideo.com/c/product/264001-REG/Elinchrom_EL_26481_Zoom_Spot_Attachment_for.html</p>

<p>• Projector attachments: These tend to cost a bit more than their tungsten counterparts, and require using a specific manufacturer's strobe head (typically, a monolight). Here's one for Elinchrom strobes which sells for just over $1,000: http://www.bhphotovideo.com/c/product/264001-REG/Elinchrom_EL_26481_Zoom_Spot_Attachment_for.html</p>

<p>• Zoom-Spots: The Profoto zoom-spot sells for an astronomical $10,000. But the Speedotron Optique (now discontinued) can still be found on the used market, often for only a few hundred dollars. This Speedotron-modified, Strand-Century ellipsoidal is a zoom-spot fixture, similar in design to the Profoto unit. It has a built-in 4,800Ws strobe head, zoomable condenser lens assembly, four adjustable shutters, and a rotating pattern holder. Although it has a built-in strobe head, this unit also requires a Speedotron power pack to operate:</p>

<p><img src="http://studio460.com/images/SpeedotronOptique1542-2.png" alt="" /></p>

<p><img src="http://studio460.com/images/Speedo2401A-1C.png" alt="" /></p>

<p> </p>

<p>All a spotlight consists of is a simple lamp and reflector with a positive lens in front of it at the approximate focal length of the lens. Theatre spotlights just use a fairly crude glass Fresnel, or a plano-convex condenser lens. An old enlarger might be a suitable source for a condenser lens, and an old overhead projector (the ancient sort that you put transparent slides on) has a 12" square Fresnel lens in it.<br /> Other than that, page magnifiers are a good cheap source of Fresnel lenses. A bit of tape to strap a Fresnel across the reflector of a strobe should result in a makeshift spotlight. You might have to add black cardboard spacers to get the focus right.</p>

<p>Or just use a speedlight zoomed out to its narrowest beam angle.</p>

<p>Used leko's are becoming quite common as theatre's convert to LED and moving head type instruments. You may be able to pick up a few fairly cheap. You may be able to mod one to place a speedlight or Einstein in the lamp housing. The reflector shape and lamp filament placement is critical so you might need to fiddle around a bit (and you'd need to disassemble a speedlight but it'd be a fun experiment). An old theatrical beam projector might work as well.<br>

<br /> Older video projectors are dropping in price. A Sony G90 puts out a good chunk of light and has really good blacks. Note that a 3 tube CRT has a shallow focal plane so you can loose a bit of focus on models but usually not so much that it makes much difference. Curt Palme is a good source.<br>

<br /> Check out local theatrical rental houses for both purchase and rental. Their prices are often massively less than photo shops.</p>

<p>@Walker. Thanks so much, just bought an <a href="http://www.ebay.com/itm/221683840512?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT">Century 45° Ellipsoidal Reflector Radial ERS Stage Spot Light 1000w Leko 8"</a> on eBay for $80 with free shipping, says it is in working order!</p>

How did the Leko turn out for you? Are you modifying it? Looks like a good candidate