Photographing a Wild Cross Orb Weaver
Shooting Spido
by Stacey Falconer
y little Orb Weaver who I have named Spido has been missing for just over a week. You know how it is with a pet—you just get to really know them, and then they are gone. In this case, it was probably natural causes. It was highly unlikely my little arachnid buddy ran away, or was hit by a car.
I had just returned to Victoria from Edmonton, and became intrigued with another Cross Orb Weaver's web that spanned between the roof overhang and the hedge, over ten feet away. It was barely visible in the light, just a gossamer thread barely hinting of its existence by catching an occasional glint of light from the setting sun. This must have been the Golden Gate Bridge of spider web making, but on a miniature scale and constructed by a single tiny creature with only a few thousand brain cells. The web itself was only about a foot and a half in diameter, but the anchor lines and diagonal reinforcing strands were absolutely amazing, continuing a further two feet and then spanning the unimaginable gap between the roof and the bushes.
Unfortunately, such amazing feats in the animal kingdom are seldom witnessed or appreciated, and this poor creature's web disappeared a day or two later, destroyed by all the people walking by, blindly oblivious to its existence. If only I had taken a picture of this amazing construction while it existed.
A 'web' search revealed that these creatures often build a new web every day while alive, and the webs can be up to three feet in diameter. Just after they hatch and break out of their protective egg case in the spring, they start building miniature webs. Orb weavers have even been taken into space on the Shuttle to see how well they build webs in microgravity. Oh well, I guess a spider's work is never done.
Then I discovered a new eight-legged friend, who had constructed a similar web that spanned about six feet between the top of the house wall and the rose bush beneath. The web is still there, though it now appears weathered and worn since Spido left. Every morning I could find Spido, just hanging in there upside down, waiting for the next fast food delivery. When food came along, Spido immediately pounced upon the victim, wrapping it in a cocoon of webbing. At the end of the meal, she would then drop what is left into nature's own ancient bluebox program.
So how do I photograph such a small animal, only about a third of an inch in size? My Olympus 5050z has an amazing macro capability, called super-macro. That was the easy part. What about the exposure though? I come from the old photography school. I am the type who looks at the light and estimates the exposure settings like a Saskatchewan farmer looks at the sun and clouds, and then professes that a storm is on the way because his arthritic hip has just begun to hurt. There are many factors in trying to get a good digital exposure. Experience and the Mark-1 eyeball are vital components. However, some very good in-camera tools can really help with making on-the-spot exposure corrections. But equipment isn't everything. Really 'seeing' and understanding the light is important for almost all aspects of photography. Therefore, I always start by looking at the light.
Real old-time photographers will tell you that in bright direct sunlight and using 100 ASA film (I never got used to the name change to ISO), the exposure should probably be about f-11 at 1/250 of a second. I suppose this is where I should start, though most digital cameras don't have an f-stop above f-8, so f-4 at around 1/1000 and an ISO of 64 was a good starting point. It is often a bit better under exposing a half to one f-stop than over exposing, especially when there is strong back lighting. So I elected to under expose Spido by about a half an f-stop, and to use the camera's aperture priority mode at f/d=4. Why aperture priority? Most photographic objectives will have the highest resolving power when used two f-stops above wide open. A few are designed to resolve best when wide open, but these are usually very expensive lenses. Consumer lenses are usually designed to be fast lenses, but to make them reasonably affordable they allow some photographic aberrations when used wide open, and the best resolution is usually at f/d=4 or f/d=5.6. Digital cameras very seldom have f-stops above f-8 because their angular resolution in seconds of arc is inversely proportional to the aperture diameter, and the acceptable image sharpness starts to noticeably degrade with smaller apertures (higher f-stop numbers). Therefore, it was better to control the aperture in this case, and let the camera take care of the speed.
The first few shots looked at Spido's underside through the web, against the bright side of the building. These creatures seem to build and use their webs this way out of instinct. Shooting against such a bright wall can often cause further underexposure of the subject due to the camera compensating for the all the surrounding brightness. I got a reasonably good though somewhat under exposed photo, and tweaking the levels, curves, and a bit of saturation in The Gimp solved a lot of the under exposure problems, and the deliberate underexposing allowed some of the webbing to show through.
I wasn't happy though, so a few days later I got a friend to hold a piece of black craft paper as a background and tried shooting Spido from the back between the web and the wall, a rather tight fit for the camera and operator's paws. The wind was making Spido's web bounce around and made it very difficult to get a good focus lock. Therefore, I put the camera on manual focus, and eyeballed the sharpness from the LCD viewing screen. This is not the best way of focusing, but you can easily afford to waste digital film. The dark background of the craft paper allowed the web to easily show through, and almost guaranteed a good exposure using the aperture priority system of the camera. The light was also ideal, being diffuse light bouncing off the white wall.
Out of the three exposures of my little feral friend, the last one looked exceptionally sharp and the detail was amazing. This brings in another tool that is often included with digital cameras: the ability to review the exposure histogram on the LCD screen immediately after the exposure. In my case, the 5050z incorporates this function even while composing the shot. This is like looking at the image's tonal range in Photoshop's levels or histogram function, and then adjusting the exposure up or down to get the best dynamic tone range that the camera can record.
Back to Spido though. It turns out that Cross Orb Weavers only live a summer, and once they produce eggs and an egg case, they will die in early fall. I still see a few live ones on the bushes around town, but most of the webs are empty, temporary monolithic testaments to the past existence of amazing little creatures. At least now, this small creature's amazing existence has been captured and will exist for a brief moment in time that we call history.
