There are a number of focus rail systems on the market these days (including Velbon, Manfrotto, RRS, Kirk, Novoflex) and they range in prices from quite cheap to moderately expensive. You really don't want to get a perfect focus set, only then to have the unit move even slightly when you take your finger off the knob, because that sharp focus you just dialed in will now be lost. Ideally, you want the main adjustment knob to be very responsive and to move the camera along in an easy, gradual manner, without any slack or kickback return in the knob mechanism itself. The main thing to look for in a rail is a solid, strong construction and a smooth motion that is free from wobble or jumpy, erratic movement. Focus rails have travel-measurement markings, just like a ruler, so that one can carefully adjust each individual take in an accurate and exact manner. The focus rail unit (my Novoflex Castel-Q which is shown in the pic) simply allows the entire camera/lens combo to be moved, back and forth, in small, smooth, incremental steps, thus enabling one to slightly shift the focus point from front to back (or vice-versa) with each separate image. Here's a link to my tutorial Macro 1:1 for a short overview on the topic which incorporates many of the same basic elements, application techniques, and strategy. All the essential accessories are involved (ie: tripod, geared head, focus rail, shutter release, etc.) with the focus rail now playing the major role. My personal approach to focus stacking is really the same as it would be for any other macro or close-up shot. For example, on my Blood Iris shot shown here, the stacked region is only the front patterned area of the flower, with the background left blurred and completely untouched. Stacking not only allows us to obtain a much greater depth of field, but also one can choose (to a degree) where in the frame the DOF will actually be enhanced. At macro 1:1 distance, using a 100mm lens, even at f16, the DOF is only about 1mm. Moreover, it enables us to shoot each individual image at a more optimal aperture, ie: f8, so that diffraction never becomes an issue.įocus stacking is very well suited to macro 1:1 and close-up work where the regular depth of field is extremely thin. Conclusion Taking a series of pictures at different distances from the subject (without altering the lens focus distance) and stacking them together, will dramatically increase the Depth of Field on your close-up shots.įocus stacking allows us to blend together a set of images that all have slightly different focus points, enabling us to cover a much larger range of depth of field than a single shot.
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