Aerochrome via Channel Swap & IR Overlay

[bvf]

Bernard: This old thread seemed the most appropriate to add my post to without starting up yet another one ...

Editor: It is quite OK to start new topics. Your IR Overlay with Channel Swap is interesting in its own right. So I have split it off into its own topic.

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I have to say I am not an Aerochrome enthusiast: I find the subject quite interesting from a technical viewpoint and enjoy seeing the images posted on the forum, but it seems a one-trick pony to me. But then I don't get abstract or "modern" art either, so this probably says more about my philistinism quotient than anything else.

 

Anyway I was interested in trying something out. The original Aerochrome/EIR, when used with a yellow (minus blue) filter resulted in IR showing as red, visible red as green, and visible green as blue - with visible blue being lost altogether. So one standard way to simulate this very closely is to overlay an IR image on a visible image and use channel swapping to achieve the Aerochrome effect. This is done in the 2nd image below (the 1st is a normal visible shot). For the IR shot I used a Midwest Optical BP850 - partly to go a bit deeper into the IR than the R72 would go, and because, having bought the BP850 in error, I needed to find a purpose for it to save face.

 

So far, this is all standard stuff. But what about the point that Aerochrome with a yellow filter completely ignores the visible blue region. How about changing the channel swapping such that IR goes to red, red and green each contribute 50% to the green channel, and blue goes to blue? The third shot below tries this out.

 

And finally (and I know this is drifting off topic), what if a similar thing is done with UV? So UV goes to blue, blue and green each contribute 50% to green, and red goes to red? The result of that is in the fourth shot below. (Baader U used for UV; all lighting by flash.)

 

And finally just to round the whole thing off - a pan-spectral image with UV providing the blue channel, visible the green, and IR the red. This is the last shot below - and takes us part of the way back towards Aerochromism.

 

Visible

 

 

IR-->Red, R/2+G/2-->Green, Blue-->Blue

 

Red-->Red, B/2+G/2-->Green, UV-->Blue

 

IR-->Red, Visible-->Green, UV-->Blue

[Andy Perrin]

Very interesting series!

[colinbm]

Very nice collection Bernard.

[Andrea B.]

Ah the glories of Channel Stacking! You never quite know what you're going to get. One of my favorite activities when I have the time.

This is a nice illustration of that from Bernard.

 

[side Note: How I miss using the Breaking Waves software. Someday maybe Ben will revisit and update it.]

 

 

Bernard: I have to say I am not an Aerochrome enthusiast: I find the subject quite interesting from a technical viewpoint and enjoy seeing the images posted on the forum, but it seems a one-trick pony to me.

 

The one-trick pony needs to be pointed and ridden in the right direction. I think our technical experiments get away from good photography. So if you find a fascinating subject and make a good composition from it, then you might find Aerochrome more interesting??? We see mostly trees, sky and grass in current example. That is of course quite understandable from the technical viewpoint. But once the technique has been mastered, then look for the subject, the composition, the light and then let UV or IR or Aerochrome be an enhancement to an otherwise good photograph. Birna is a master of this. And one of the very first things she taught me was exactly that - that the photograph should stand alone regardless of what light it is photographed in.

 

But it is perfectly OK to not like or like some style or technique. We all have our favs and our un-favs.