Tungsten film in daylight with thoriated lenses?

[lamerko]

That's interesting! Do you by any chance remember what lens it was, how much yellowing it had, and at what aperture the effect was more pronounced?

The lens was a Canon FL(FD?) 50/1.4. I haven't bothered to clean it - I was pretty cautious with radiation back then. And the yellowing was not much. Now I looked for the shade tests but they are not on my work computer. I had done at different apertures. I subsequently bought a radiometer and... immediately sold the lens
In its place I bought a Canon FD 50/1.2 SCC - (with spot check) which I still have.

 

[Lucius]

The lens was a Canon FL(FD?) 50/1.4. I haven't bothered to clean it - I was pretty cautious with radiation back then. And the yellowing was not much. Now I looked for the shade tests but they are not on my work computer. I had done at different apertures. I subsequently bought a radiometer and... immediately sold the lens
In its place I bought a Canon FD 50/1.2 SCC - (with spot check) which I still have.

I've looked again through the shots I made with the yellowed Takumar -- not a trace of uneven shading that I can see. I wonder if it's down to different lenses, or that it's only under controlled conditions that the effect is noticeable.

But a brownish tint is certainly there. I blamed it initially on expired film and my non-existent scanning skills, but thorium must have been a contributing factor.

 

[mshchem]

Even if I had a Chevy, it'd be a quit feat getting it over across the pond! ;-)

 

[koraks]

Thanks, that's a most instructive (and engaging) read!

Just checked -- my lab's website says they're using ECN-2 chemistry. Though their prices have gone up quite a bit recently, so I'll be trying out a different one, but they too seem to follow the proper process.

Thanks, great to hear! I applaud your lab's choice of processing in ECN2 developer. Some people argue C41 works well enough, but I beg to differ. I really think Vision3 film works best, also for still camera use, in ECN2 developer.

 

[Lucius]

IIRC, the lens radioactive discoloring tends towards yellow/brown. The OP is desiring to use Kodak 500T (tungsten balanced) ECN2 film in daylight and wonders if it would help color balance the use of tungsten balanced film in daylight. No, it would not- you’re going in the wrong direction. Tungsten balanced film is for 3200k light, you need a blue 85 correction filter for 5500k daylight.
Or you can digitally correct in post. I prefer to get it right in-camera, but that’s me.

I think it's the other way round: the blue 82 filter is used for shooting day-balanced film in artificial lighting.

 

[lamerko]

The 500T film is balanced at 3200K. Since we can't change the film balance, we have to change the light. Warming filter 85 which should reduce 5500K to 3200K is orange...