Aerochrome: Back to Foveon

Emulating Aerochrome is a long and winding road. Anyone who has read my previous blog posts on Aerochrome has probably seen my frustration in achieving an authentic look.

At first, I dabbled for a long time with the Foveon sensor, which produces a pseudo-Aerochrome look right out of the camera when you remove the IR blocking filter.

With the emphasis on pseudo: whether using the Hoya X1 or an orange filter, red filter or no filter, every look has a drawback. Sometimes the sky is too green, sometimes the contrast is too weak, sometimes the tones of the vegetation are too uniform. And in each of the cases one of the decisive features of Aerochrome is missing – the color changes. Red to yellow, yellow to white, green to purple, and so on.

After the Foveon came several tests with CMOS cameras, primarily from Nikon.

First with the Nikon D700 and a combination of X1 and Orange 16, then with the Triple Bandpass Filter, which lets green, red and IR pass. There, too, some things fit, but others did not.

Now I am back with the Foveon and have tested with the Triple Bandpass. And suddenly I achieved an in-camera look that is actually not bad at all. But beware, I don’t want to sound too euphoric for now. There are still problems, but the signs are good.

The magic phrase is FOV Classic Blue. This is an in-camera preset that exists in the Sigma SD1, like “neutral”, “landscape” and so on. What it does? I don’t know. Like much else about Sigma’s Foveon sensor cameras, it’s a black box.

But in any case, it results in getting red-pink trees and green-blue skies right out of the camera with the Triple Bandpass filter from Midwest Optics. The color changes were unfortunately not there yet, with the exception of yellow to white. But red was still reddish, or let’s say at least orange.

But if you install an additional filter that flattens the transmission curve of green (in the 550nm range), then it becomes good. Why? I do not know. Maybe someone can enlighten me. The best result I got so far was with a Lee filter called Pretty n Pink.

Here are some results. Unfortunately I did not get a Custom White Balance with both filters together. That would be necessary to get a convincing result. But maybe it works with a related filter.

What I will do now: optimize and test with other filters. And then also see if an inefficient hot mirror, which also reduces the IR influence, could also help.

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