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Macro photography
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Macro photography1. Introduction, macro photography gallery with testsNow I have the equipment working but need to test different setups and methods. I shall change the following:
It will take some time until I have got through all of these variations. I start with the light and optics. Later when I have the raw images of good quality I start to test different methods to do the focus stacking process. I can already see now that the macro slider I have have some limitations, I need something better when doing more than 2x magnification. A long term goal is to have a macro slider that has a motor, the motor shall be controlled by a software in the computer that control the focus position and camera shutter.
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2. GrapeFrom a focus stack of 40 photos I used 30 to build this image of a grape. Credits to Picolay (focus stacking) and IrfanView (image processing). How I do focus stacking: The focus change along the focus axis is about 6 mm, that make 0.2 mm focus shift per photo. The lens is a Pentacon 50 mm f/1.8 and reverse mounted. With a 28 mm extension it give 2:1 magnification. This is an example how I have it setup when taking a macro photography of the above grape, the size of the grape is about 7 mm. In this setup the object is placed on the macro slider. The contrast in the surface is low, maybe I can change the direction of light and get it better. It look a bit soft also, maybe vibration, I need a support to the front part of the lens. The background is difficult to isolate. I have used a white screen, maybe better with a single color. A lot of things to do experiments on, I have also ordered a set of step up / down rings to have when I setup for different lenses. Next object I will use my Pentax 55 mm f/1.8 lens to see how it behave.
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3. Rose hipFrom a focus stack of 51 photos I used all of them. Credits to Picolay (focus stacking) and IrfanView (image processing). The focus change along the focus axis is about 7 mm, that make 0.15 mm focus shift per photo. The width of the Rose hip is 13 mm. You can see areas where the sharpness isn't very good. After had investigating the object I found that the part out of focus is protruding towards the camera, so long that I started the focus stacking to close to the object. Sometimes it's difficult too see in the display that you are right on the target / focus. The best learning process is when you do mistakes! I expected the Pentax lens to perform better and maybe it is, but the difference compare to the Pentacon is very small. It's a Pentax Super Takumar 55 mm f/1.8 lens. It could be from the 1960s and it have the Pentax M42 screw mount. With 49 mm extension it gives the magnification 1.9:1. This time I used a dark blue background. It worked much better to this object, maybe white that I used earlier is better for other objects. Later I must I have some device that I mount the object on that is possible to adjust the height and rotation with. I changed the angle of the lights to become more from the side. Be careful to not let it shine direct into the optics, it will reduce the contrast. An extra support to the front of the lens is added. I always use mirror lock and delay on the camera otherwise the heavy mirror cause vibration (DSLR). Next time I maybe shall try the flash instead, it has exposure time of less then thousandth of a second.
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