Shooting Macro

Here is an experiment which demonstrates how I take a lot of my macro shots, and what gives those photos such a smooth creamy background. For the most part I take photos with a Sony 24mm-105mm f4 full frame telephoto lens. Mostly because its a really good multipurpose lens to have around.

This lens is not a dedicated macro lens but its able to take pretty decent macros shots without any modifications.

Minimal focal point of an unmodified 24-104 f4 telephoto lens; about 195mm
With no modification or cropping a 105mm lens gets a pretty detailed picture

That looks good but what if I want to make that dime bigger? The easiest way to make something bigger in the frame is to get closer to it. With this lens we cannot get closer to the subject without losing focus, as we are already at our smallest focal length.

This is where an extension tube can help. Extension tubes are very simple and inexpensive additions which sit in between the camera body and the lens. This moves the plane of focus further back from the lens, which results in a shorter focal distance.

My extension tubes.

I have to extension tubes, one 10mm in height and one 16mm in height. My tubes have all the electrical contacts to keep the lens connected to the camera, which keeps auto focus working. A must for fast flying insects.

Lets add one tube extender and see how that changes the picture.

Increase the distance between the lens and the camera by 10mm

Adding one tube extender allows the camera to get closer to the subject which makes the subject larger in frame, with more detail.

Shifting the focal plane by 10 mm, the minimal focal point is now around 125mm
The dime takes up more of the frame, giving a more detailed shot.

The tube extenders shifting of the focal point also has some other effects. With extension tubes added a lens will no longer be able to focus out to infinity, so they cannot be used for landscapes. The shifted focal point also results in less light hitting the sensor, so it works best in bright areas or with good lighting. Lastly the focal shift narrows the depth of field making it harder to keep subjects sharp, but adding an extreme blur to the background.

Adding another 16mm for a total of 36mm

Extension tubes can also be stacked! Adding more space between the lens increase all the effects. So with 26mm of extension we can get the camera even closer.

The minimal focal point is now around 91mm
Subject crisp and large in frame, background completely blurred out.

There are many other components to macro photography and lots of other ways to get similar results. This is the setup I tend to use most often, as with out the extension the 24-105 lens is good to have for wide landscapes or tighter head shots. And now that you know the secret to large detail pictures of bees and spiders is getting as close as possible, you may appreciate the small amount of peril involved in getting some of the pictures I’ve taken.

Inside an Amp

I finally got around to cleaning out my headphone amplifier today. There was some dust in the volume potentiometer which was creating a hissing sound when adjusting the volume. Some contact cleaner has it better than new. While I had it open I thought I would take a picture to share.