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Trattamento d'Immagine XXII: Prima e Dopo
In Microscopia e Ottica
EBo
May 22, 2021
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Trattamento d'Immagine XXI: Inserimento di una scala di riferimento
In Microscopia e Ottica
Trattamento d'Immagine XV: Fotografia macro estrema
In Microscopia e Ottica
Trattamento d'Immagine XIV: Fotografare foraminiferi (Macro spinta)
In Microscopia e Ottica
Ambra screpolata
In Preparazioni paleo
EBo
Feb 11, 2020
Riprendo qualche commento che ho ricevuto su FB e che copio di seguito. Lorenzo T.: Va rilavorata. Va abrasa per bene tutta la parte microfratturata fino a raggiungere la resina fresca e poi va rilucidata. Se ne resta anche solo un po' si rovinano molto più velocemente. Infatti ne avrei qualcuna da fare sistemare ma, essendo cosa molto invasiva, attendo il più possibile. Soluzione temporanea potrebbe essere un immersione in olio: riempie le crepe e si vedono meno, ma è una soluzione lenitiva solo dal punto di vista ottico. Ho parlato con un conoscente e si stava vedendo se si potesse fare un'impregnazione di resina, tipo con un'epossidica trasparente. Un po' di letteratura a riguardo esiste, si stavano valutando pro e contro effettivi. Sam H.: We embed our amber for a number of reasons, primarily for conservation. Over time, amber will oxidize, becoming crazed and developing cracks. Embedding in a synthetic resin prevents this from happening. It also helps to support the specimen which makes cutting, grinding, and polishing much easier. The resin we use is very high quality (called EPO-TEK 301-2) and has excellent optical properties which often aids in imaging. All that being said, sometimes all that's needed are a few drops of glycerine and a coverslip :) The amber is embedded under vacuum. This has the dual purpose of removing any air bubbles from the resin and also pulls it into any cracks in the amber, thereby consolidating and stabilizing it. Tre pubblicazioni assai interessanti sul soggetto mi sono state consigliate da @Lorenzo Tettamanzi (che ringrazio): The Conservation of Amber: https://www.jstor.org/stable/1506496?seq=1&cid=pdf-reference Conservation of amber at the Metropolitan Museum of Art, New York, USA: Regalrez® 1126 as a consolidant and adhesive for amber and copal: https://www.tandfonline.com/doi/full/10.1179/204705814X13975704318317 Variation in the Deterioration of Fossil Resins and Implications for the Conservation of Fossils in Amber: https://doi.org/10.1206/3734.2
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Trattamento d'Immagine XIII: Focus stacking e macro estrema
In Microscopia e Ottica
EBo
Feb 07, 2020
Riprendo di seguito una discussione avuta su FaceBook con un Ilya Minaev (ha una carriera alle spalle di acquisizione fotografica di insetti in ambra). I suoi input (e spero di altri specialisti nel settore) credo che saranno utili a tutti quelli che, come me, si lanciano nella fotografia marco estrema. Your photo turned out to be very blurry, although the quality of the optics and the camera allow you to take high-resolution photos. In this case, the spider is quite large. I also do a lot of photographing beetles in amber, I can give advice. 1) As I understand it, your shutter speed is set to 1/3? It is very small, very small. Your tripod is not stable enough, there is movement. With such exposure, the photo will be soapy. When shooting 1: 1, you need to have a shutter speed of at least 1/60. When I shoot a macro with a 3: 1 lens, I use a shutter speed of at least 1/100. This leads to problem number 2 2) bad light. its not enough. And a very bad light source. Mercury lamps are weak and have a low flicker frequency of 100Hz. Need to use LED sources with constant light 3) The third possible problem is the stacking program. I tried different programs with the same frames. Photoshop 6 gave the best result. And some programs made a much worse picture, the same "soapy" as yours. the result in photoshop from the same frames was clear 4) 4 reason is commonplace, but unlikely in your case. This photo can be obtained by stacking, when the surface of amber above the insect is spherical. but this effect is not noticeable on macro 1: 1. To avoid it, I grind amber over the beetle on a piece of sandpaper on the table to get a perfectly flat surface
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EBo

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