Make your own IR Chrome

Yes, I made a mistake. I have unfairly praised and promoted the IR Chrome filter in the past. Kolari Vision’s filter, designed by a French IR fan named Yann Philippe, is meant to mimic the Aerochrome style. And yes, if one is satisfied with red-orange trees, it is quite sufficient. But Aerochrome is more, much more.

And so it is a bit presumptuous to advertise the IR Chrome filter as Aerochrome for the digital age, as Kolari does. And moreover to sell it at exorbitant prices. Especially since it can be built relatively cheaply by yourself.

Today, I don’t use the IR Chrome at all – it sits in a box gathering dust.

Why the IR Chrome filter actually has nothing to do with Aerochrome:

– Trees/vegetation are not red, they’re orange-reddish. You can make them red in post-processing, but I can do that with other filters.
– The colors are too uniform. Typical Aerochrome colors like pink or a rich deep red are missing.
– The sky is too bright, even with polarizing filter.
– The color changes typical for Aerochrome (for example car taillights) are missing.
– The look seems kind of dirty, it’s hard to describe. Those studio-like light and shadow effects typical for Aerochrome are missing.

The reason is simple. Unlike Aerochrome, IR Chrome lets through large amounts of the blue spectrum and only a small amount of infrared. The infrared is blocked somewhere between 700nm and 750nm. Actually it is a blue filter and a bad hot mirror filter in one.

Aerochrome, on the other hand, works by blocking out blue. In RGB composition, this means that blue contains only IR. The blue channel is shifted to the red channel. Red becomes green and green becomes blue. This is the only way to get the typical color changes, the typical red tones and the typical illumination.

This color/light distribution is valid for the analog original as well as for the digital version. The best way to get authentic digital Aerochrome is to use this triple bandpass filter.

So how can IR Chrome be imitated? Relatively simple.

Buy a Swatchbook from Lee Filters and pick out number 115, Peacock Blue. You also need an “inefficient” hot mirror – ideally this Chinese one.

IR Chrome Filter

Combine them (you can cut the Lee filter and stick it behind the lens) and you get the following look. Straight out of the camera it looks even a bit better than IR Chrome in my eyes. Above always IR Chrome, below Peacock Blue plus Hot Mirror. Only White Balance on asphalt and “Landscape” preset. Almost the same, right?

IR Chrome Filter

IR Chrome Filter

IR Chrome Filter

IR Chrome Filter

I’m not a fan of devaluing the work of others. And that’s not what this post is intended to be. It’s simply to demonstrate that IR Chrome has little to do with Aerochrome and is easy to create yourself.

However, the numerous photos on the web made with this filter show that the IR Chrome filter is relatively popular and pleases many people, even those who had nothing to do with infrared photography before. And getting more people interested in IR photography – no matter how – is certainly a good thing.

7 Comments

Hello and thanks for your research and input. I would have been very keen to discuss all the issues you pinpoint in your blog post before making it a definitive assertion 🙂 All the best,
Regards

Yann, the “IR fan”

Don’t take it too personally, Yann. This is all just my opinion, but as you rightly say, it’s based on a little experience and research. Feel free to add or correct if you think I’m withholding important info. But promoting “IR Chrome” as an “Aerochrome for the digital age” is not right in my eyes. Orange-red trees can be obtained relatively quickly by using a blue/cyan filter. You see for yourself – the result above is almost 1 to 1 the same.

No no, no problem, I’m totally open to critiques and discussion ! I know that IRChrome is far from perfect. With Kolari we had to make a lot of compromises to make the filter work for a wide range of different sensors and, more importantly, without any post-processing step (outer than RAW development) and fully in glass with available material. And “scientifically accurate” lies in a galaxy far far away from “marketing”. And of course IRChrome can be reproduced in cheaper versions.. but with gels, not glass. My validated prototype had 4 layers of glass !! But that was way too much for a retail version. Compromises..

I think it’s a cool product for someone who wants something easy and quick to buy from a store that also works relatively well. On the other hand, depending on the camera, the look really doesn’t come “out of the camera”, but a lot of post-processing with a lot of moving sliders back and forth is necessary to get a reasonably good result. I think I would have liked something else from Kolari (or LifePixel): A filter that doesn’t generate a pseudo-Aerochrome look “out of camera”, but one that makes a “true” Aerochrome emulation using channel mixers, i.e. a filter that produces dark blue trees and green sky “out of camera”, that creates an authentic look when “switching” the channels without further adjustments – like with my Orange-Green-method or with the Triple Bandpass (I mean, actually all IR filters work like that). I think the contamination problem could be fixed…. Have you tried this way as well? Or was the goal from the beginning to get an Aerochrome-like look in the camera?

Hi,

Actually, I’ve just managed to create a really similar effect with two layers of glass that fit inside a single ring. I worked with a filter factory for a few weeks, it was not hard, but the process was quite fun. Not every blue filter will fit the purpose of course.

My “True Color Super-red” filter (that’s the silly name I gave to it :P) makes for a cheap option for those who live in Europe. Kolari’s filters sent to the old continent are way too expensive for many enthusiasts. I had been using a 52mm ring of Kolari’s IR Chrome that cost me around 200€ after tax and shipping! The Lite version is, to me, still too expensive. The 72mm True Color SR is not even half the price put at home.

Well, sorry for the marketing here. Christoph, I guess that some of us like to play with the colours direct from the camera. Also, channel shifting sometimes gives a fringe on the trees, which is mainly avoided with SOOC versions. I am with you, that selling the filter as Aerochorme is not fair since the results are far from its original film version.

My version of the filter is not for everybody either, I guess, it is a step between high-quality end product and a DIY product.

I have a Fuji Xs10. I believe this in not a full spectrum camera. But will the hot mirror filter combined with just a cyan tinted lens produce that effect? Will i still need a IR filter for a non-full spectrum camera

No, you need a full spectrum camera, so the IR cut filter must be removed. There is no way around that. Full spectrum camera + inefficient hot mirror (so that a little bit of IR gets through) + Peacock Blue filter.

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