Monday, May 12, 2008
Canon’s MPE-91mm F22 Macro Lens
If you have the camera set to F16 then you’ll actually be at F22 (but the correct aperture won’t show up on the LCD) and you will get a little more depth of field. But diffraction will also be a problem since the lens is stopped all the way down.
You’ll lose a stop of light with the 1.4xTC, so your flash duration will double. Not a big issue at lower magnifications, but freezing motion is more of a problem at 3x and higher. The flash will also take a little longer to recycle as well.
When shooting in bright sunlight exposure can be a problem, especially when shooting against a light colored background (like a daisy). One way to eliminate the ambient light in the scene is to stop down, and the teleconverter helps. I’m also considering a one stop neutral density filter for my MPE-65mm for those times when the ambient light is bright and I want to cut it out completely and just rely on the flash.
I’m not shooting with a 1.4x teleconverter full time, but it is one more trick to use for those situations where there is too much ambient light or I need a little extra depth of field. Unfortunately the teleconverter really doesn’t increase working distance that much –probably due to the MPE-65mm’s unique construction (it’s basically a reversed lens with a variable length extension tube).
The image included with this post was taken at about twice life size with the MPE-65 + 1.4xTC at F22 (F16 on the camera). It’s not as sharp as most of my images, but there was enough depth of field to get the entire shell and the eye in focus…
On my next outing I’m going to set the camera to F14 or F16 between 1x and 2x and see if I can cut out enough ambient light to get good exposures, and get the depth that I want without the 1.4x teleconverter.
Special thanks to Robert Seber who put up with all my stupid questions about shooting with the MPE-65 + teleconverter.