Photographs by Frank

14 June 2010

The Dragonfly Rig

Filed under: Odontates,Other Insects — Tags: — Frank @ 12:00 PM

Warning… photo geek talk below!!!

A number of people have asked me about the tools I use to shoot odontates (i.e. dragonflies and damselflies). So here is the answer!

The  basic “problem” is that these critters are relatively small and somewhat wary. Thus one needs significant magnification and decent working distance.

In the past I have used the Sigma 50-500 mm zoom to make photos of dragonflies… this lens has a short (for a long telephoto) close focus distance which allows for modest magnification so some cropping is needed to make a “frame-filling” image. This lens is also large and heavy and therefore it needs a tripod (or monopod) which limits mobility.

In looking for a better solution, I switched to a Nikon 70-300 VR mm lens with a 36 mm extension tube. This combination often allows one to make frame-filling images of dragonflies and it is much lighter, allowing one to hand hold the rig (the VR helps here too).

I have been using this rig for about a year now and have made many nice photographs with it. But… isn’t there always a “but”… this spring I decided to go further!

Shooting at high magnification leads to a small depth-of-field. I’m not going to try and explain the physics of the situation… it is just a fact of life… the higher the magnification the small the depth of field.

The way to get more depth of field is to decrease the aperture (i.e. increase the f number).  Of course, this leads to less light reaching the sensor and that needs to be compensated for with a longer exposure or a higher ISO both of which cause their own problems… life is tough!

Adding some extra light (from a flash) into the picture (pun intended… go ahead and groan!) would help to mitigate these problems. However, the quality of the light is important … direct flash coming from directly over the lens is, to put it simply, ugly!  The flash needs to be off camera and it will need some diffusion.

Adding off camera flash to the mix introduces a problem that comes with having only two hands… one of which is usually in use to trigger the shutter and the other of which is usually in use steadying and operating  the long lens! There is no hand “left over” to hold a flash nearby. Thus one needs to tie the camera and the flash together.

So here it is (click for a larger view)… everything all in one unit:

This unit is, to put it simply, large and unbalanced! As most people do, I usually use my left hand to steady a long lens and my right hand to work the camera controls and trigger the shutter. This was impossible to do with this rig… the flash hanging way out on the left really unbalances things and I could not hold it steady.

The solution… use the flash bracket as a handle. By gaffer taping my cable release to the flash bracket, I can now trigger the shutter with my left hand (which is also supporting the heavy side of the rig) and use my right to operate the lens. With this system, I’m going to have to stick auto exposure since the other camera controls haven’t moved. This is not a big deal for me as I usually use matrix metering in aperture priority mode anyway.

The total unit is still large, heavy and unbalanced enough to cause pain in my wrists and elbows on my first few outings.  The torque it puts on ones joints while in use is significant. I have diminished this problem in two ways… by remembering to let the rig hang from the neck strap between shots and by supporting the rig with a monopod when possible. Of course the monopod limits my mobility a bit and needs to be removed to get a really low perspective. But life is full of compromises… isn’t it?

One last comment… the magnification provided by this rig is just not quite there yet when it comes to damselflies, so I am still resorting to cropping in order to “fill the frame” with these critters. The solution, of course, is more magnification (attained by adding another extension tube). I have my doubts as to the ability to get a crisp image at even higher magnifications without resorting to a tripod, but I will be experimenting over the summer and time will tell.


12 June 2010

Ants Herding Aphids

Filed under: Other Insects,The Yard,Wildlife — Tags: , , — Frank @ 9:11 AM

Yesterday after work Joan went out to inspect her vast flower beds. At one point she stuck her head back in the door to say “There are ants herding aphids out here.”

I have learned over the years that when your wife spotter announces a find I am required go get the camera and investigate.

For those of you who have not heard about or seen ants herding aphids, it is an example of biological mutualism. You can read more about it here.

As you know, ants are very small (these were about one quarter of an inch long) and (most commonly) black. This makes for a difficult photographic subject. Thus,  I had some experimenting to do.

To get high magnifications, I used my extension tubes… this was the first time I had a need for all three at once.  The camera was mounted on the tripod… no hand holding at this magnification.

Light was provided by an off camera flash diffused with a soft-box. This was lying on the ground off to one side or hand held off to the side more-or-less at the level of the subject.

This  photo was taken using my 70-300 mm lens with three extension tubes (36 + 20 + 12 = 68 mm):

[singlepic id=85 w=300 h= mode= float=]

For this photo, I switched to the 90 mm macro lens and ended up using just the two larger extension tubes… all three tubes gave too much magnification:

[singlepic id=86 w=300 h= mode= float=]


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