|
| The physical setup consists of an Olympus E330 SLR camera with the Olympus 35 mm macro lens and EX-35 extension tube mounted on a tripod with ball head and macro rail. The tripod, ball head and macro rail are all made by "Really Right Stuff." This is the highest magnfication that can be achieved with the equipment that photographer owns. Without the extension tube, the maximum magnification is 1:1. Using the extension tube about 1.75:1 can be achieved. Since the image sensor is 17.3 mm wide (about half of 35mm) the maximum "35mm equivalent magnification" is about 1.75 * 35mm / 17.3mm = 3.5:1. In other words, at maximum magnification the field of view is just about 35mm/3.5 = 10mm = 1cm wide. The tripod and macro rail setup serves the purpose of positioning the camera in the right position for the first image image in the focus stack series and then provide the needed advancement of the in-focus plane through the depth of the subject. It is important that this be done precisely. The equipment shown does a very nice job. The images were taken in "B-mode" and thus used manual focus. Aperture and exposure length were set manually and kept constant for all images. White balance likewise was set manually. The aperture was chosen to be f11 to maximize depth of field without introducing unacceptable diffraction blurring. This setting was determined experimentally from test shots taken a long time ago. The small aperture and high magnification necessitated a fairly long exposure, 10 seconds. The macro rail was advanced by about 1/8 turn for each image. This results in about 1/6 mm of travel. The first image in the "Original images" series was actually taken focused in front of the subject and then the camera moved towards the subject. This was done just to be absolutely sure that the all parts of the subject were imaged in focus in some image. The images have a resolution of 3136x2352. Since the field of view is 10mm (= 10,000um) wide each pixel is about 3.2um wide. The first image was taken at the park. The others were taken at home for inclusion in this album. |
|
|
|
|
|
|
| 6 Images | Made with JAlbum & Chameleon | Help |