Journal Number 106
December 2007


EDITORIAL

Trick Photography
By Ian St George


Here are a few things I am trying. I won't claim I have perfected any of these techniques yet,
but I'd like to discuss them.


1. "High key"
photographs with shadowless white backgrounds (eg, cover photo this issue)
can be stylish in an artificial way.

There are some delightful ones of Australian Pterostylis on the net - eg at www.goldstreetstudios.com.au/MSeyfort.htm

I have taken high key portraits of people in the past, using a big sheet of white paper curved forward to eliminate the shadow at the junction of wall and floor.

Flowers need only a flat white background plane, but shadows from frontlighting (including flashlight) will fall on the background. Anyway, if you use flash, the white comes out grey.

So you have either to use natural lighting, and adjust the exposure to keep the background white, or you have to adjust it later in Photoshop.

Or you use artificial light diagonally from above left, and the white background far enough behind to avoid the shadows.

I tried the white of an empty page in Microsoft Word, but it tended to backlight the flower.
I tried a number of Photoshop manipulations with little success.

I'm working on it.


2.
I have acquired a "Time Machine" from Brian Mumford Photography in the US (http://www.bmumford.com/photo/camctlr.html).

Time MachineThis is a programmable controller and intervalometer for special photographic effects. It allows you to trip the shutter of your camera or fire an electronic flash at regular intervals (time lapse), at specific times of day, or in response to trigger events. These trigger events can be sound, light, motion, or electrical signals. A wide variety of sensors is available for use with the Time Machine.

There is also a motorized rotary table that can be used to create time lapse movies that pan across a scene, or as a motorized indexing table to rotate a subject for "virtual reality" images.

In nature photography the Time Machine can trip the camera shutter, trigger a flash, or start a movie camera when a creature moves - a mouse at night, a bird visiting its nest.

It allows you to take a series of pictures at regular intervals or at specific times of day or night. These sequences can be combined into a time lapse movie on the computer. You can watch speeded up clouds scudding across the sky, plants growing, a building abuilding, a manufacturing process.

For events that are too fast to see normally, you can configure the Time Machine to trip an electronic flash in a dark room while the camera shutter is held open. This will freeze motions like popping balloons or water drops.

You can make "slow motion" movies of high speed photographs. The inventor of the strobe light took amazing pictures of bullets in flight. The Time Machine makes it possible to time exposures on this scale of precision, but you need a very fast flash to freeze very fast motions.

I want to use time lapse to look at Nematoceras opening, and the "Optical interrupter" sensor to trigger a shot when an insect crosses the fine infra-red beam across the labellum of various orchids, night or day.

My puzzle now is how to protect the gear from passers-by and the weather, while still allowing
the insect to approach the flower.


3.
Photography deep in the bush on a windy day can be trying to the point of exasperation.
No suitable natural background, too much wind, reflected light distorting colour, too dark, etc.
The perfect orchid shot - naturally lit, in its habitat - can be difficult.

The easy shots, lets face it, are taken in the studio - ie, at home. Studio backgrounds then become important - I've used bits of blue formica to look like sky, orange bits to look like sunsets, the backs of green clothbound books, lumps of wood, fern fronds - but they all appear a bit phoney.

Here is my latest idea: a photo of the bush on my computer screen as a background. I went to Google images and entered "New Zealand bush" and presto! a wide range of bush scenes. I copied one I liked into Photoshop, enlarged it to fill most of the screen (some pixelation doesn't matter, the background will be out of focus), placed my orchid in front, and took the shot.

Simple? Yes, if you use natural lighting for the orchid, but it will be backlit by the screen to some extent. Flash reflects unpleasantly from the screen. Tungsten room lights make the orchid yellow, unless you correct white balance, when your bush scene will look blue. For tungsten lighting you have to change the colour balance of the bush scene photograph to increase the yellow tones ("image/adjustments/colour balance" in Photoshop).

The photos below show my first attempt - a Nematoceras trilobum agg. The specimen was brought in to my office on 13 August by Pat Enright. The left shot is natural light, the middle photo is tungsten lamp with white balance corrected, and the right photo is tungsten lamp with white balance corrected as well as background colour balance corrected towards yellow.

There has to be a better way.

Nematoceras trilobum    tungsten lamp    tungsten lamp

 

 

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