Vintage microscopes and the M42 thread as a universal helper (I)
This issue and a few follow-ups will deal with camera adaptations for tardigrade
photomicrography. Solid, not too expensive and portable.
Fig. 1: Leitz dissecting microscope (in German "Stereomikroskop FG II"), heigth 25 cm, weight 2,305 g, 2x objective. This microscope was originally sold with several eye-piece sets (5x, 10x and 15x). When bearing in mind that our little friends are definitely tiny it will become clear that we should choose the strongest eye-piece set in order to search for tardigrades. The resulting overall magnification of 30x is quite perfect for terrestrial tardigrades but will work with the (smaller) marine tardigrades, too. Please note the style mix of this particular instrument which in combinig black tubes with a more modern grey lacquer stand. Alltogether extremely solid and designed for heavy use, possibly over many decades.
As always with internet auctions, you will never know what exactly will be in your parcel. So, when looking at fig. 1 one might ponder some questions like the following:
An old instrument, possibly - will the focus move or be stuck? Well, it does move.
Let's begin with the last issue, the stacking capability. As the tardigrades tend to move during photography we decided to start with a non moving object: the heart of a SWATCH® watch:
Fig. 2: View of the magnetic rotor of a melody alarm clock (model name "Musicall Blue through") built in 1995. As its name "through" does indicate the Musicall has a transparent face. This image was made with the dissecting microscope shown in fig. 1. Stacking was performed by the extremely powerful "Zerene Stacker" software, based on 10 single frames. Of course we are not going to win the Nikon photomicrography contest on this pathway but we think that the result is quite respectable. It documents how the two tiny bolts of the electromagnetic engine are connecting to the central milled wheel of the watch. The diameter of the gold colored cover plate of the engine is about 3 mm, equivalent to the length of 10 Echiniscus tardigrades.
Fig. 3: A total view of the watch, just in order to provide an idea of the dimensions.
Under ideal conditions (without a watch glass!) we can still go further in magnification. This is illustrated by the following 2 mm crop image of an inkjet print head:
Fig. 4: Detail of the print head of an inkjet printer. Cropped image from a bigger image, taken by means of the Leitz dissecting microscope as well.
A further example:
Fig 5: Tiny "dwarf diamonds" (to small for the jewellers). This is a still acceptable image quality but you will note that the it is decreasing towards the edges of the field. Image width ca. 5.5 mm.
And yes, finally we found a few tardigrades (dry state) as well. Just have a look:
Fig. 6: Tardigrade "tun", as photographed by means of the Leitz dissecting microscope. Image width ca. 5.5 mm. The insert box is showing the tardigrade with an additional two-fold magnification. We think that this result is quite okay for a 100 US $ dissecting microscope. It wouldn't be fair to expect more.
In the next issue we will show the simple M42 thread DIY photo adapter
used for those images and we will demonstrate one possibility in order to compensate for the
classical focus level weakness of the Greenough type dissecting microscope.
© Text, images and video clips by
Martin Mach (email@example.com).