Yellowing of thorium lenses
© El Grafo / CC-BY-SA-4.0
Autor/Urheber:
Shortlink:
Quelle:
Größe:
4734 x 1702 Pixel (4526030 Bytes)
Beschreibung:
Some older photographic lenses were produced with glass elements containing small amounts of thorium. If stored in the dark for prolonged periods of time, these lenses can undergo what is commonly called “yellowing”. While some photographers enjoy the effect the yellowed glass has on their photographs (it acts similar to a weak yellow filter), others prefer to reverse it by exposing the lens to a UV light source.
- left: a yellowed Super-Multi-Coated Takumar 50mm F1.4
- center: an identical lens that had the same amount of yellowing, but was treated with a LED-based UV-emitting flashlight for several days until the yellowing almost disappeared.
- right: an Auto Yashinon-DS 50mm f1.9 that showed no signs of yellowing for comparison
Lizenz:
Relevante Bilder
Relevante Artikel
ThoriumThorium ist ein chemisches Element mit dem Elementsymbol Th und der Ordnungszahl 90. Im Periodensystem steht es in der Gruppe der Actinoide. .. weiterlesen