Hi all, I've been here, but off the list for a while. Now I'm outside crawling about taking pictures of flowers, many being only 2-3mm diameter, as usual.
Macro Photography with P30 and P30t: Equipment: Pentax P30 and P30t, Sigma Macro 50mm, several Pentax lenses with Soligor macro converter, small shoe-mounted flash gun (name lost), aluminium reflectors, Fuji and Ferrania negative colour. Processing Tetenal Colortex C-41; s/s tanks in thermostat controlled water-bath. I've devised a new, double, flash reflector. One part goes on top of the flash gun with Velcro and the second part is fastened to the tripod socket - with an adapter so the tripod can still be used. As before the reflectors are made of 0.5mm sheet aluminium polished to remove blemishes and then matted with 'Putkimies' (Pipe-man or plumber) drain cleaner. This drain cleaner contains 10% NaOH and does a creditable job. It takes a little longer than a more concentrated solution, but its right here under the kitchen sink. This time the top reflector is more or less 'T' shaped, extends 130mm from the front of the flash and is directly above the object when the lens is fully extended. The front is bent down and the two 'wings' are curved left and right. The shape is parabolic and I did a lot of calculating to get the angles right. The light is now reflected downwards at about 50 degrees and concentrates (I won't say focuses) on the object. The lower reflector (flat) bounces back some of the light so that the shadows are not as pronounced as they were with only a top reflector. Naturally when I designed this thing I considered only a single ray. The flash, to start with, scatters the light widely. The attached top reflector does more and the light by the time it reaches the object is very diffuse. The light coming up from the lower reflector is much weaker. Using a Seconic flash meter I get a nice f22 at 1:1 with 200 asa film at the subject position. A picture taken with ambient light under these conditions would require four or more times the exposure on a sunny day, even more under cloud. The flash, set on automatic, serves to freeze movement nicely because the ambient contribution to exposure is small. The busiest bees and flies, not to mention wind-blown blooms, come out nice and sharp. I'll be putting a picture of this contraption on my website in a week or so and anyone wanting to see it let me know and I'll give you the address of the directory. Don Dr E D F Williams Author's Web Site and Photo Gallery Updated: March 30, 2002 - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
