Sigma Sd Quattro, applications for Palaeontology

 
 
Sigma Sd Quattro and Ultraviolet light. A chapter apart.
 
Often in palaeontological research may be useful to lighten specimens with UV light (in a dark room where light can be turned off). In some cases the fossils reflects UV light differently from rock matrix, allowing to see much more details than under visible light. It is not a rule, it depends from the characteristics of the fossils and of the rocks, in some case there may be no differences. Better results are achieved if the fossil is made of phosphate (e.g. bones)
 
Anyway, the easiest and more economical method is to lighten the fossil with an UV A lamp, usually of 380 nm wavelength, and take photos with a DSRL and a macro lens . With reflected UV light there is no need of special equipment, given that the sensor and lens do not block UV light too much. I, along with colleagues,  tried this technique with different DSRLs and got different results. And with the Sigma Sd Quattro?  Let me say: mamma mia!
 
To make things even worse for the camera we choose the fossil of an animal without hard parts (usually bones and teeth reflect UV very much), an octopus.
Octopuses are very rare in the fossil record just because they lack shells or other hard parts, thus they are preserved only in very few deposits where conservation is exceptionally good. So their evolutionary history is rather obscure.
 
In short, we take this octopus specimen (the stone slab is about 40cm high) and photographed it under visible light:
 
 

 

Very interesting, good detail,  scientifically significant, but not that easy to interpret.

 

 

Now the photos with the Sigma under UV light:
 

 

Simply stunning. I never saw such details so clearly (you can see gills, suckers, eye caps, ink sac and even the remains of vestigial shells that primitive octopuses retained). 

 

This level of detail obtained without using expensive equipment like a 100mm f4 macro  Coastal Optics, that costs like a small car (at least in Italy). This is in my opinion the strength of the Sigma Sd Quattro.
 
In short,  this camera made me enthusiastic (too much, now I want one)  and I think it is an excellent tool for my work, because it yields professional images at a fraction of the price of equipments that can surely yield similar or even better  results, but are, as said, much more expensive and much less agile to carry around.
Thus the Sigma  Sd Quattro, coupled with a 105 macro Sigma,  may be the dream kit for me,  when I need to take pro-quality  pictures of specimens held in other institutions. 
 
 
All the fossils shown in this article are held in museums,  which Curators I warmly thanks for the kind hospitality.
 
I wish to sincerely thank Mauro Maratta for allowing me to try the camera, it has been a great fun. Only regret, I have to return it.
 
 
 
 
I wish to  thank also The Italian dealer of Sigma, MTrading,that offered to Nikonland the chance to know in depth this unusual but very special camera.
 
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