Question Lens Coating on the Takumar SMC 50/1.4

[Uncle Bill]

Dumb question of the day, the coating on the Takumar 50/1.4, is it an amber colour? I am well aware of the problem of lens yellowing due to the use of "rare earth" in the manufacture of the lens glass. I showed my lens to my camera tech when I dropped the spotmatic off for CLA and seal replacement, he is an allumini of both the Leica and Pentax service departments, he said it was the coating. For piece of mind on my part what tone of yellow should I look out for on my lens?

Bill

 

[titrisol]

If it looks yellow-orange when you look thorugh the lens then IMHO it has turned yellow.
I noticed that on mine when I shot some color film and it looked as if I had a 81 filter on it.

While your camera is in CLA it wouldn;t hurt to leave your lens in a window sill and see if it changes

Dumb question of the day, the coating on the Takumar 50/1.4, is it an amber colour? I am well aware of the problem of lens yellowing due to the use of "rare earth" in the manufacture of the lens glass. I showed my lens to my camera tech when I dropped the spotmatic off for CLA and seal replacement, he is an allumini of both the Leica and Pentax service departments, he said it was the coating. For piece of mind on my part what tone of yellow should I look out for on my lens?

Bill

 

[josephaustin]

A faint yellow color, no orange in it. If you shoot a roll of color film you should not see any color cast from the lens, I know you already know that just an easy way to check.

 

[Donald Qualls]

The test for me is to hold the lens in front of a sheet of white paper and compare the color as seen through the lens against that seen alongside. If they match, you're seeing the coatings. If not, your lens needs a sun bath.

The Super Takumar and SMC Takumar lenses do, however, both have a brownish/yellow coating rather than the blue, green, or pink coatings we're more familiar with.

 

[Ian Grant]

This Pentax lens is not that exotic, glasses had progressed by the time of its manufacture. Looking at the colour of the multicoating is actually too ambiguous, as long as the glass & coatings are in good condition you have a lens made to far tighter tolerances than many manufactured today.

Pentax Spotmatic cameras & lenses were wonderfully over engineered and possibly only Leice cameras are on a similar par with regards to build quality.

Ian

[QUOTE)]he is an allumini of both the Leica and Pentax service departments, he said it was the coating. For piece of mind on my part what tone of yellow should I look out for on my lens?

Bill[/QUOTE]

 

[Uncle Bill]

Phew!

My 50/1.4 lens only has a faint amber cast not the orange-yellow, at least I know what to look for now.

Bill

 

[gma]

I think that all the earlier coated lenses had the blue-purple cast. The multi-coated tend to appear amber and purple at the same time, almost irridescent. I have seen some lenses that have somewhat of a blue-green reflection. The reflected color you see does not color the image as far as I can determine. When you look through the lens you see a clear image and not the color tint that is so obvious in the reflection.

This is way over my head.