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an additional option for thin section photos

Posted by Frank K. Mazdab  
an additional option for thin section photos
February 21, 2012 07:27AM
I noticed that for uploading thin section photographs, two options are listed: (1) thin section (normal light), and (2) thin section (polarized light). Although I can understand that some thin sections might simply be photographed the way mineral specimens are (hence the "normal light" option), I suspect generally thin sections are viewed and photographed through a petrographic microscope. Hence, I would suggest that the "polarized light" option be eliminated and replaced by two more informative options, one for "thin section (plane polarized light, PPL)" and one for "thin section (crossed polars, XPL)". A similar distinction should be made for photomicrographs of polished blocks in reflected light as well.

As petrographers begin to upload more and more photos of minerals in thin section and polished blocks (particularly those confirmed by microprobe and/or micro-Raman), mindat can become an important visual resource for the optical properties of rare minerals.

Re: an additional option for thin section photos
February 21, 2012 10:05AM
Hi Frank,

you are right that thin sections photographed in PPL vs. "normal light" usually look different and have to interpreted differently, so we should think about better categories here.

But we should watch out that we do not end up with categories like "PPL with filter", "XPL with compensator", etc.
It might be simpler to leave it up to the photographer to add the necessary info to the photo description and just lump all the different thin section photos in a single category.
Re: an additional option for thin section photos
February 21, 2012 10:47AM
We should keep it as simple and as comprehensive as possible ("thin section" might be just enough), otherwise, as Amir points out, we end up with things like "half-crossed polars" etc.
avatar Re: an additional option for thin section photos
February 21, 2012 11:10AM
Agreed, keep it simple, i would prefer to keep all the thin sections in one group, with appropriate descriptions. Though Frank is correct, we should use PPL and XPL in descriptions. Similarly with polished sections - anyone interested in such things will want to see both ppl and XPL images together, not do separate searches.


Edited 1 time(s). Last edit at 02/21/2012 11:13AM by Ralph Bottrill.
Re: an additional option for thin section photos
February 22, 2012 02:32AM
Sounds like from the comments, just having "thin section" is good enough and the onus is on the photographer to adequately describe the settings. That works for me. Thanks for everyone's input.

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