Digital Emulation of Infrared Film Process

Hi Folks, I'm not sure if this is the place to ask so please bump me over to the relevant forum if it's not.

I used to shoot b+w infrared film, Konica 750NM, and I really liked the effect it could give for certain types of subjects, architecture in the sun, landscape etc. It was also easy film to work with as it didn't need to be loaded or handled in the dark (as with Kodak HIE(?) film) and the filtration used on the camera didn't have to be completely opaque so I could shoot hand-held, composing with the filtration in place. The visual effects of the film were nice without being too extreme, which suited my style better.

However now that I am switching to digital capture, and 750NM isn't made anymore, I was wondering if anyone out there had any good quality techniques for digitally emulating the infrared effect?

I know you can get digital cameras that have been converted to IR wavelength sensitivity, such as Canons, or get your own camera converted, but i'm looking for a higher quality solution that would ideally allow me to use my digital back equipment without having to get it converted (not practical in cost terms).

I've tried the Channel Mixer in Photoshop approach where you convert a colour image to greyscale using the channel mixer and emphasizing one channel over another to give the look of b+w IR but the end result tends to be very 'grainy' as you are effectively taking predominantly one channel of information and making it do the work of three and thus multiplying the 'grain'.

I guess what I'm looking for is the smooth clean tonality of digital capture with the visual effect of IR, black skies, glowing foliage, great textural rendition and so on. Does anyone know of a way to do this successfully? I've heard of Photoshop plugins that mimic the effect but do they do more than the channel mixer? Or is there another technique entirely in the digital workflow that I haven't come across yet?

TIA

Matt

You've got an IR filter, so take your digital camera and go shoot - without converting.

The exposure times are long, often 30 seconds, so you'll need a tripod. Shoot raw, and switch on any long expsoure noise reduction. Nikons tend to be more IR sensitive than Canons, but it varies by model. My D100 was much better for IR than my newer D200. Some examples here.

As for Photoshop IR, the best ways involve channel mixer. Try +200% on red, -100% on blue for the sky. Also use the green channel to select the foliage into its own layer and apply some blur to it (mask out other green objects that wouldn't reflect IR). Add separate layers if you want a grainy effect.

John

So if I understand you right, what you are saying is use my digital camera with the Red IR filter I used to use for shooting IR film (ie deep red) in front of the lens, which would give me a Red RAW colour image and then do a straight convert to greyscale, and depending on the sensitivity of my camera's sensor I'll get what looks like a b+w infrared image? Seems too simple to work but I confess I haven't tried it yet.

I appreciate sensors are sensitive to a wider spectrum than film, and this varies by the sensor, which is why most sensors have fixed IR filters built onto them to cut out the IR portion of the spectrum. Because of these inbuilt IR filters (usually cyan?) I assumed adding a Red IR filter to accentuate the IR would be negated. Obviously not, from the results you are getting.

Can I ask, looking at the results you are getting, do you have an option to shoot directly to greyscale or are you doing the conversion afterwards, in PS or your RAW converter?

As I mentioned I'm not a fan of the PS channel mixer option because of its inherent graininess so the in-camera route would be much more preferable.

Thanks for the suggestion.

Matt

Digital IR

Hi

I have developed a recent interest in this as well and have learned thas some of ther earlier digital cammeras are particulaly sensitive to IR - and work well simply by placing an IR(720) filter on the lens.

I found the following site to be quite useful - even shows how to test you camera to see if has the potential to pick-up IR. All you need is a TV remote control and a digital camera to do the test.

Check this site:

http://www.nature-photography-central.com/DigitalInfraredPhotography.html

I have an old Olympus E20n camera that has been on the shelf for a while - just got back with an IR filter - cant wait to see what happens .....

You understand me correctly - I was surprised when someone showed it to me.

I use a visually-opaque Lee 87 gel filter, another reason for the tripod. Everything comes out purple and on my D200 I do set a b&w conversion, but with the D100 raws I just did a simple desaturation. You can also set a custom WB by shooting through the filter. But this bit really is just a matter of convenience - it's raw data.

We'll have to agree to differ on the channel mixer. Pushing the red channel to 200% can produce graininess but I don't find this often and rarely in 16 bit. The main issue I have is that it is simulating IR, but doing it in camera captures a fundamentally different scene with no haze etc.

As well as switching on any long exposure noise reduction, make sure you close the viewfinder too, just like in night photography.

Have fun!

John

Thanks John, That's good news, exactly the same technique as IR film but doing a b+w conversion later instead of using the film. It will be interesting to see what an Aptus 75's sensitivity is like.

I agree too, doing it in camera is definately preferable, both for the clarity and also because I think simulating it always looks like a simulation, no matter how careful you are.

Sorry I don't mean to be so anti-channel mixer, i have just never been able to get results that pleased me using this technique. However I haven't yet tried it on 16bit digital files (as I'm new to digital capture), only 8bit scanned colour film, which would always come out too grainy so I gave up trying to simulate. As with all things digital I'm only starting to learn the possibilities so thank you for helping to widen those.

Now all I need is some good sunshine up here....

Matt

John Beardsworth said:

You've got an IR filter, so take your digital camera and go shoot - without converting.

The exposure times are long, often 30 seconds, so you'll need a tripod. Shoot raw, and switch on any long expsoure noise reduction. Nikons tend to be more IR sensitive than Canons, but it varies by model. My D100 was much better for IR than my newer D200. Some examples here.

As for Photoshop IR, the best ways involve channel mixer. Try +200% on red, -100% on blue for the sky. Also use the green channel to select the foliage into its own layer and apply some blur to it (mask out other green objects that wouldn't reflect IR). Add separate layers if you want a grainy effect.

John

Click to expand...

I am so impressed with your sandwich technic, John.

I also appreciate the fact that you have explained your methodology. This allows us to experiment.

http://www.beardsworth.co.uk/news/index.php?id=P500

You have created an exceptionally interesting image. The house of God is covered with amazingly poweful clouds, as if daring someone to harm that house. It stands strongly in a place of importance in the landscape.

Blue fringing of the clouds is unimportant, IMHO. This, as art, is well made and successful. Even the blur of the grass in the lower right is fine with me. That blur sends the eye to the left and back to the church. Metaphorically the indistinct foreground grass on the lower right in fact informs me that clarity and truth is found in the house of God.

Not that my interpretation is correct, as it is informed merely by my own education and appreciation.

Nevertheless, this approach to photography, looks at common things in a "new light" that is unique but still understandable as colors are maintained pretty well.

Asher

Matt Laver said:

I appreciate sensors are sensitive to a wider spectrum than film, and this varies by the sensor, which is why most sensors have fixed IR filters ...

Click to expand...

The IR filter is called a hot mirror because it fails to pass thermal radiation (i.e., IR). Or perhaps because it reflects it (as opposed to absorbing the energy).

enjoy,

Sean