Using "Rosco Diffusion Kit" papers on a vertical camera stand setup.
Rosco company offers many excellent diffuser products (see
HERE). A "Rosco Diffusion Kit" (contains 24 pieces of letter-sized diffuser papers, costing about $30 from a local retailer) makes it easy to experiment with many different strengths and kinds of diffuser materials (pieces can be combined--so the possible number of combinations is very large). My current favorite paper is "Tough Rolux #3000" but I have only tried a few combos so far! The following shows some simple ways to utilize these diffusers on a vertical camera stand.
First attempts were to use step-down and step-up adapter rings to fix diffuser to a Canon Macro Twin Lite. A 15mm high ring of poly plastic was cut from a shallow container and "sandwiched" between a 72-67mm and 58-72 ring (the Twin Lite mounting base has a 58mm thread on the outer face). A long piece (20cm) of transparent mylar was rolled into a double-walled cylinder, with a 10cm length of diffuser paper lining the inside, and this is placed into the plastic ring (67mm diam., using friction-fit only, so the cylinder can be rotated, to avoid the seam interfering with the flash, and to make it easy to switch papers). This worked OK (very easy to switch around paper types, etc.), but I still preferred a pingpong ball setup! The plastic bottle on the left is the basis for the next (and better) arrangement.
Cutting the neck and most of the bottom off the bottle leaves a cone-shaped piece that that can serve as a "holder" for diffuser paper made into a cone (using a pattern similar to the one for the inside of a Beljan RMS adapter cone discussed
HERE). Two methods of attaching the plastic cones are shown: one that fits snugly onto the tip of the lens (left), the other loosely around the base; the shape of the lens determines which is best. The tight one must be cut very carefully to fit properly (a Dremel rotary tool is helpful here). In each case, the diffuser paper cone must be in place before the plastic part is attached. The notches in the cones on the left are to accomodate insect pins, which sometimes interfere with close focusing (working distance with the Minolta is 6-8mm).
The loose plastic cone in place (without the diffuser paper).
Complete diffuser cone setup shown on stand. Placing the Twin Lites on flexible arms was the initial reason I tried the cone setup, but I've now come to prefer this system for small subjects. I believe the cones make a better diffuser than the bigger cylinders; more like a pingpong ball diffuser, but many more options possible with different diffuser papers. Of course, many other materials (even Kleenex tissue!) could be used on top of the plastic cones.
Shot of a small robber fly (Atractia sp.) using #3000 "Tough Rolux" cone diffuser. Shot at 9X--head is 0.5mm wide. [Minolta 12.5 @ f2.8, 40 @ 0.02, ZS]
My thanks to Craig ("augusthouse") for introducing us to Rosco products on photomacrography.net.
