How Do I Create the Most Specular Light Possible?greenspun.com : LUSENET : Large format photography : One Thread |
How do I create the most specular light possible using regular electronic strobes? I own Dynalite equipment, and have tried using the heads l)bare 2)with silver reflectors of various shapes and sizes 3) snoots 4)bouncing the light off various reflective panels such as mirrors, silver cards, and aluminum , but none of these methods have come even close to producing the degree of specularity I am looking for. I have been recommended to try using a pebbled silver umbrella, but the one I used actually diffused the light! Can anyone recommend a good silver umbrella (please list manufacturer/model) that will produce an EXTREMELY specular light? Or do you have a better method? Thank you.
-- Nick Rowan (Nrowan@vf..com), November 10, 1999
It depends on what are you photographing and what effect you are trying to achieve. Can you provide more information?
-- Ellis Vener (evphoto@insync.net), November 10, 1999.
Basically make the lightsource as small as possible in relation to the subject. try painting the inside of the reflector black (with heat resistant black paint!)
-- Ellis Vener (evphoto@insync.net), November 10, 1999.
i have also seen situations where a lightsource was embedded in the object being photographed and aimed directly at the lens. for REALLY specular, try using a laser :-)
-- jnorman (jnorman@teleport.com), November 10, 1999.
Use a bare tube with no nearby reflecting surfaces.
-- John Hicks (jbh@magicnet.net), November 11, 1999.
Technically speaking specular light can only be had when the subject is metal, because specular defines the way light plays on metal surfaces, which is unique and highly reflective and pinpoint. But I know what you are looking for and the definition has mutated anyway. Specular light, or the appearance of it (harsh, reflective, directional, casting shadows) can be had by making sure your light source is smaller than your subject. It looks more specular the more you diminish the size of the source in relation to the subject. Any umbrella, regardless of material or color, will produce specular-like light if it is appreciably smaller than the subject, but the use of umbrellas is kind of self-defeating because they are large and tend, with many subjects to be diffuse (light source larger than subject). Even bare heads are many times too large to provide specular light because the reflector behind the tube is 6" or so and turns out larger than many subjects. I have used fiber optics to pinpoint light, and lasers might be an approach, depending on your subject. Bare tube might be an option. Bare tungsten is very specular because the filament becomes the source, and this is naturally very small, though even this is diffuse when I shoot something as small as a prehistoric Native American bead. Artful placement, of course, is the key, and distance from subject can very the relative size of the source and subject. The sun itself can be specular because of distance alone, or can be diffuse because of overcast or open shade. Hope this helps.
-- Rob Tucher (rtphotodoc@juno.com), November 11, 1999.
This is a bit vague, but precise solutions depend on the size of the thing you are trying to illuminate, and whether you want the whole object lit or just to create a prominent highlight.If you've got the light source as small as possible, you can make it more directional by moving it futher away from the subject. If the walls of your studio are white, baffle the light with a length of PVC piping to cut down on diffuse reflections. To go beyond that (or if you're losing too much light), place the source at the focal plane of a lens: fresnel lenses or moulded plastic reading aids work pretty well.
If you fail with the strobes, the sun makes a nice, highly-collimated light source. If you have a window in the right place, build a blackout tent and bring sunlight into it with a PVC pipe. Of course, unless you make things adjustable, you'll only be able to take pictures once a year but that didn't bother the builders of Stonehenge.
-- Struan Gray (struan.gray@sljus.lu.se), November 11, 1999.
PS: the above suggestiong were all skinflint solutions. If you are prepared to spend a little money, consider renting a theatrical spotlight.
-- Struan Gray (struan.gray@sljus.lu.se), November 11, 1999.
Re; Struan Gray's suggestion for using a theatrical spotlight. That might work but when you go to purchase one, be sure to ask for an "ellipsoid" or "Lieco" (it may be spelled Leico). Struan mentioned the use of "fresnel" lenses and there are theatrical spots which are commonly referred to as Fresnels but they don't give the sharp edged shadows one commonly associates with a spotlight. Theatrical Fresnels are used for localized fill and the Ellipsoids are used for the hard edged spots. The ellipsoide are also "focus-able" so that you can control the edge hardness (somewhat).
-- Jan Stiff (stiff@ridgenet.net), November 20, 1999.