Home Forums Hunting & Shooting Hunting Optics High End Optics Lenses Turning Yellow?

A good friend of mine prides himself on the high end optics he has, but I asked him why are the lenses turning yellow? Now we’re talking Leica and high end Leupold and Swaros! This past weekend we were out hunting and as he was getting ready to take a shot at a buck it was hard for me to see with that yellow tint. What causes this? I mentioned to him that he should send them in and get them refurbished.

It might be your liver, you should check for jaundice...

I own several European made scopes, a couple 15+ years old. NONE have lens that turned yellow.

I don’t know what the cause is, but I’ve seen it. The worst was on a 7x40-R IOR binocular.

Highly unlikely! Checkups are always good. But when I look thru my Sightron III’s everything is crystal clear which he noticed also. I noticed that a lot of scopes are having the same issue. I know his gun room is not a controlled environment as he only turns on the AC when he is in there. I’ve walked in during summertime when it’s over 100 outside and humid.

Aging balsam glue, from around WWII, would turn the view through doublet objective lens yellow.

I have 2 older, 20 year plus Swaro's, a 1 x 4 x 21 and a 3 x 9 x 36, both have the yellow tint. Still great scopes, especially in bright sunlight, but not as bright as newer scopes of the same quality. They definitely yellowed over time.

FSJeeper,

Do you think it’s the coating changing colors? Just curious.

If you want an expert opinion, try sending a PM Ilya Koshkin.

When I worked in a gun shop in the mid-late 1990's brand new Swaro and Zeiss had a definite amber hue when compared against Leica Trinovids. Leupold Vari-X II's with the blueish lens coating have produced "yellowish" images from day 1.

I recall hunting with a friend from WY in Nov of 2000. There were 3 of us. 2 of us has essentially brand new 10x42 Leica Trinovids, the 3rd had a ~15yr old set of 10x50 Swarovski Habicht porro prism binocs. Those 10x50's were VERY yellow compared to our new Leicas.

Take this for what it's worth as I'm rolling the old noggin's rolodex of useless facts way back into the rusty section. At some point during my gun shop employee days I asked someone (one of the manufacturers sales reps) about the yellow hue on Swaro and Zeiss vs. Leica's truer (to my eyes) color. What I recall being told was something about the technology of the lens coatings. The older lens coatings favored towards producing a yellow/amber final image because that was the way to make the perception of the image through the optical instrument as bright as possible with the technology of the time.

High end or any other optics do not change color with age, that is not true.

Most optics today, are mostly color neutral, with slight differences.

Yes, some older high-end optics acquired a somewhat yellowish cast over the years, but it wasn't the lens coatings.

Instead it was some of the other stuff used inside the binocular.I know for certain that at least one synthetic used inside the binocular "barrels" by an "alpha" company eventually caused a yellowish tint, due to what they called gas dispersion. I know this because the company told me about it, and started fixing the problem when it occurred, both in new binoculars and older ones customers sent in. They fixed mine, and also the exact same model a good friend owned.

JB,

Glad you chimed in! So it was the gas being used? My buddies optics are older models and on one of the Leupolds if you looked into it from the objective end you could see what lookes like dry water spots on the lenses.

Sounds more like he's referencing "off-gassing" by the synthetic material inside the body. Could be the body material itself or it could be from one of the adhesives, or a reaction between the two.

horse1,

Exactly. As I recall, they traced.it to the synthetic armor used to cover the metal frame.

Thank you for clarification. My bud has quite a few with this problem. But since he well off he doesn’t see the need to send them off to get them refurbished until he tries using those particular rifles lol!

No clue if it is the coating. I have a Schmidt & Bender fixed 4x that is older that is perfectly clear, and might be my clearest scope and it is over 25 years old.

I'd say a color shift is the result of climate change - hell it's blamed for everything else.

I’ve got an older Kahles that has a slight amber hue to it. It’s noticeable. I sent it in last summer for a checkup/refurbish. It came back the same color as it left.

borden811,

So when you first bought the Kahles was it nice and clear? Because I remember my friends Leica binos were crystal clear when I first looked thru them in 2009 and just a couple of weekends ago I used them and noticed the yellowish tint!