| Joined: | Mon Apr 2nd, 2012 |
| Location: | South Lakeland, UK |
| Posts: | 4066 |
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For close up photography, especially greater than 1:1 (which is macro), AF is useless. You need to concentrate on Manual Focus (MF). Instead of focusing, you need to decide on and set the extension (magnification) you want, then move the camera and lens back and forth to get the focus where you need it. Simple manual focus stacking is entirely possible, with a little care.
I use a PB4 bellows with either a micro Nikkor 55 f/2.8 or a micro Nikkor 105 f/4.0. The PB4 bellows can both set the extension and slide back and forth to focus.
I find using a clean stainless rule with fine graduations a very useful aid to understanding where the depth of focus (DoF) is and placing it to best effect. AF will generally wast half of your DoF because it usually focuses on the closest part of your subject, leaving half of your DoF water with well focused air.
Also be aware that with the micro Nikkor 105 f/2.8 AF-D when you focus, the lens focal length changes, it's only 105mm at infinity. By 1:1 it's somewhere between 40 and 60mm, so altering the inbuilt focus an an AF-D also changes the size of the subject. Which is NOT what I want, especially for focus stacking, it's a right royal pain in the butt.
I have just taken over 9,000 exposures of a bud bursting and leaves unfurling on a small plant, to create a time lapse video with my D300S and a micro Nikkor 105 f/4.0. The sequence started on September 2nd and I turned the camera off yesterday, so close on two months growth.
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Robert.