How to assemble by own hands Microscope with using manual lenses.
Collecting information at the web, I came across an interesting article tells of how to use the Soviet lenses and connecting rings can put together a system capable of photographing small objects with a fairly high magnification. I was interested in the option when reversed Helios 44 58mm attached via adapter ring on the Jupiter-9 85mm, with the resulting increase in system - 1.00 / 0.68 (1 to 0.68).
Using transitional Macro Reversing ring 49mm/49mm I decided to take advantage of my favorites: lenses Minolta.
So the system I was using is: camera Olympus E-PL1, which through the adapter MD-m4 / 3 attached Minolta MD Rokkor-X 85mm f2.0 to which, in turn, through the reversing ring is attached upside down Minolta MD 50mm f1.7.
A few words about the system should note. We have two focus rings and two aperture rings. Which is usable and which is not? First, the focus ring of reversed lens does not work! This seems obvious, but it took me a few minutes to understand it. Secondly - the depth of field are mostly influenced by the aperture of the reversed lens. Thus, the system works like this:
1. Align focus - use the focus ring of the base lens (focus ring of reversed lens does not work)
2. Control depth of field use aperture of the reversed lens. The aperture of the base lens should be opened wide.
As already described, Olympus E-PL1, ISO400, naturally tripod. It is a requirement for high illumination: a strong light and a couple of reflectors around.
The object which were used: metal and glass beads. To scale the picture a match was inserted to the photo!
The following pictures are taken with aperture of the reversed lens stopping down from f1.7 to f22. The base of the lens aperture was opened wide.
I liked the result, especially to regulate the depth of field without losing image quality.
Comparison with Extension tubes.
Common sense says that a similar picture may be obtained by using simple extension tubes. Using the same lens Minolta MD 50mm f1.7 and extension tubes I attached ~ 65mm of additional focal length. Below is a comparative picture.
As can be there is a very significant loss of quality using extension tubes, probably due to diffraction or flare.
When using 85mm lens with reversed 50mm lens it is quite easy to arrange a system with a magnification of a 1.00 to 0.60 (counted by the proportion to the size of the diagonal of the matrix) with a decent picture quality. The ratio of 1.00 to 0.60 (1.66 : 1) means that an object the size of 1cm displayed on the matrix as an object ~ 1.67cm, means increases. To get the same image with the same quality using extension tubes is not possible.