Jump to content

File:Yellowing of thorium lenses.jpg

This is a file from the Wikimedia Commons
From Wikipedia, the free encyclopedia

Original file (4,734 × 1,702 pixels, file size: 4.32 MB, MIME type: image/jpeg)

Summary

Description
English: 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
Please note: Not all lenses that appear yellow do so because of “yellowing” – many lens coatings do look golden/yellow/brown as well.
Date
Source Own work
Author El Grafo

Licensing

El Grafo, the copyright holder of this work, hereby publishes it under the following license:
w:en:Creative Commons
attribution share alike
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
Attribution: © El Grafo / CC-BY-SA-4.0
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.

Assessment

Featured picture

Wikimedia CommonsWikipedia

This is a featured picture on Wikimedia Commons (Featured pictures) and is considered one of the finest images. See its nomination here.
 This is a featured picture on the English language Wikipedia (Featured pictures) and is considered one of the finest images. See its nomination here.

If you have an image of similar quality that can be published under a suitable copyright license, be sure to upload it, tag it, and nominate it.

VI seal
Valued image

This image has been assessed under the valued image criteria and is considered the most valued image on Commons within the scope: Yellowing of Takumar lenses. You can see its nomination here.

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

inception

4 January 2015

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current13:09, 22 February 2015Thumbnail for version as of 13:09, 22 February 20154,734 × 1,702 (4.32 MB)El Grafominor background fix
17:20, 13 January 2015Thumbnail for version as of 17:20, 13 January 20154,734 × 1,702 (4.22 MB)El Grafomove that yashinon a bit to the right
16:24, 13 January 2015Thumbnail for version as of 16:24, 13 January 20154,676 × 1,702 (5.75 MB)El GrafoVicuñaUploader 1.20

Global file usage

The following other wikis use this file:

Metadata

This file contains additional information, probably added from the digital camera or scanner used to create or digitize it.

If the file has been modified from its original state, some details may not fully reflect the modified file.

Retrieved from "https://en.wikipedia.org/w/index.php?title=File:Yellowing_of_thorium_lenses.jpg&oldid=894603138"