Sigma Y52 filter

[enricosavazzi]

Improvised test image with Sony A7 II multispectral, Soligor 35 mm f/3.5 (Kuri clone), rear-mounted Sigma Y52 filter. This filter is from a set of 4 filters in 30.5 mm mounts that used to accompany the Sigma 500 and 600 mm catadioptric lenses. This appears to be a more-or-less standard yellow filter. Manually adjusted WB, but no channel swapping or other processing.

[colinbm]

I like the acid skies these filters give....

[Andy Perrin]

I was thinking this needs some Beetles. Either “Strawberry Fields” or “Lucy.”

[OlDoinyo]

My guess is that it is a yellow filter for b&w film, similar to K2 perhaps. Quite a bit of blue appears to pass the filter, although WB obscures this to an extent.

[ulf]

My guess is that it is a yellow filter for b&w film, similar to K2 perhaps. Quite a bit of blue appears to pass the filter, although WB obscures this to an extent.

How can you see that from just the image?

 

I have measured the transmission on several Y52 filters and so far all of them have been sharp cut long pass filters.

https://www.ultravio...__fromsearch__1

Not sure if I have any of this type from Sigma to measure. If I do I might come back with the transmission graph.

[OlDoinyo]

Looking at the graphs, perhaps I am mistaken indeed, assuming Y52 is a standard. I guess the odd color balance fooled me--when I photograph vegetation through a sharp-cutoff yellow filter, it usually comes out a blue-violet color, so I assumed something must be different. Perhaps just my camera.

[Cadmium]

Impossible to say, the pic doesn't look optimally white balanced.

Run the RAW through Photo Ninja, Color Correction, white balance it that way.

[enricosavazzi]

Impossible to say, the pic doesn't look optimally white balanced.

Run the RAW through Photo Ninja, Color Correction, white balance it that way.

Well, doing that (Color Correction, Light Source=Daylight/Flash, Mode=Automatic) produces a picture with deep blue trees (royal blue, I would say) and violet sky. Not especially pleasing.

 

Manually setting Temperature=3700 gives me something partly similar to the image I posted above. I need to use also the Tint slider to get back the lemon-yellow sky.