8
\$\begingroup\$

I came into some discussion with my friend, and my friend said that age may affect the color produced by the lens, i.e., a newer lens produce better color than an old lens (of the same model). Is this true? And why is it so? What component in the lens that is subject to wear and tear in a way that affects color?

Improve this question
\$\endgroup\$

2 Answers 2

Reset to default
16
\$\begingroup\$

In general, lenses do not degrade in this way. However, some old lenses made up until the 1970s contain elements made of thorium oxide — a radioactive element which yellows as it ages. These were used because they have a different refractive index, with low dispersion — so, generally, better-quality lenses, just as fluorite crystal or other exotic elements are used today. It's also possible that adhesives (used to bond lens elements to each other) or coatings used in older lenses may yellow as they age. In both of these cases, if there's enough effect to make a difference, you should see it when just looking through the lens.

The other difference may be in newer lens designs vs. older ones. This shouldn't affect the case your friend is talking about (same model over time), but may be the source of the confusion. Design of coatings changes, as does the types of glass used. And this can be very strong between manufacturers — for example, while I haven't found this anywhere official, many people believe Sigma intentionally introduces a slight color warming effect in their lenses.

Improve this answer
\$\endgroup\$
1
  • \$\begingroup\$ With thorium lenses, dosing with UV can reverse the yellowing. \$\endgroup\$
    – inkista
    Jan 11, 2015 at 19:53
-3
\$\begingroup\$

Nonsense. Lens glass does not generally discolor over time, and the coating is very thin. Even if some discoloration occurred, you could easily see this simply by looking thru the lens. I have some old lenses, some made before WWII, and none of them are tinted to the point where I can notice this by looking thru them.

Even if some discoloration occurred for some reason, it would be slight enough to be correctable. The difference between lenses would be significantly less than the difference in the color of ambient light. Your existing methods of dealing with ambient light color variations will cover any additional slight shift due to lens discoloration. Take a white or gray reference shot as usual, and all should be well.

Improve this answer
\$\endgroup\$
4
  • \$\begingroup\$ Some older lenses containing trace amounts of rare earth elements do yellow with age. It can be ameliorated by prolonged exposure to UV light (without a UV filter blocking the UV rays, LOL). See camerapedia.wikia.com/wiki/Radioactive_lenses \$\endgroup\$
    – Michael C
    Jan 11, 2015 at 18:51
  • \$\begingroup\$ Also, orau.org/ptp/collection/consumer%20products/cameralens.htm \$\endgroup\$
    – Michael C
    Jan 11, 2015 at 18:52
  • \$\begingroup\$ As I said, lens glass does not generally discolor over time. Some types discolor a little, but the other point is that this is small compared to the variation in ambient light color you have to be set up to deal with anyway. I don't understand all the negativity here. Think of all the lenses you've seen, and then how many of them were visibly discolored. Betcha most people here haven't seen a single discolored one. \$\endgroup\$
    – Olin Lathrop
    Jan 13, 2015 at 13:36
  • 4
    \$\begingroup\$ My "negativity" (read: downvote) was because you used the word "nonsense" about a real phenomenon. Even if you consider it rare, it's certainly not nonsense. Here's a Super Takumar 35/2 that I briefly owned... the discoloration was apparent by looking through the lens, or in shooting with different lenses. dl.dropboxusercontent.com/u/20239870/20140202-K5ii-04903.jpg \$\endgroup\$
    – coneslayer
    Jan 14, 2015 at 14:05

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.