Friday, January 8, 2010

Macro Photography Techniques - Part 2

This is the 2nd technique I've used when taking macro photos (also the one I've used the most).

Macro Photography Techniques
  1. Close Focus Lens
  2. Teleconverters
  3. Extension Tubes
  4. Reversed Lenses
  5. Macro Lens
  6. Combining Techniques
  7. Close Up Filters
Teleconverter with a Close Focus Lens

This technique requires a teleconverter. A teleconverter is an accessory which mounts between your camera and your lens. The effect is increase of focal length. In this case you will probably want a 2x Teleconverter, which is designed to double the effective focal length of your lens. However it does not change the minimum focus distance, so you end up with the same lens, focusing at the same distance, but you get twice the magnification of the image. You can also get Macro Focusing Teleconverters (such as this) which have their own focusing ring, and allow extra magnification, and a good level of control over the magnification.

Drawbacks? Of Course...

The downside of this technique is that a 2x teleconverter, while doubling your effective focal length, it also reduces the effective aperture (incoming light) by 2 stops. So if your kit lens happens to be a Pentax SMC DA 18-55mm f3.5-5.6, and you are wanting to get maximum magnification (55mm @ minimum focus distance) adding a 2x teleconverter will mean that the lens (wide open, where it is a bit softer) becomes 110mm at f11.2. So in order to get a fast shutter speed you will need either high ISO (noisy) or a flash. I have had very good success just using the onboard flash though.

A teleconverter will also exaggerate any quality problems in the lens you are using. If you lens is a bit soft, it will be twice as soft using the 2x teleconverter. So you must be cautious about how you use it. This is where using a flash is also helpful, as it allows you to use a smaller aperture, which will mean the lens is going to be closer to its sweet spot for sharpness.

Another obvious drawback is that you need an extra piece of equipment. I was able to acquire an older 2x teleconverter to fit Pentax K mount on ebay for about $15. It has no "A" contacts (for camera autoexposure) or autofocus. Ideally you would want to have the "A" contacts for auto exposure, however, auto focusing is not required for this technique as you will be using manual focus mode set to minimum focus distance anyway.


The same method for focusing is used as for the previous technique. You can read up on that here, in Part 1.


Here are a couple of photos taken using this technique, including settings.

SMC F 35-70mm @ 70mm (effective 140mm), f11 (effective f22), 1/180 sec, ISO 200, onboard flash

 SMC F 35-70mm @ 70mm (effective 140mm), f16 (effective f32), 1/20 sec (this should be shorter), ISO 400, onboard flash

SMC F 35-70mm @ 70mm (effective 140mm), f11 (effective f22), 1/180 sec, ISO 200, onboard flash

For those of you who already have teleconverters, why not give this technique a try, and post up the results in the comments.

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