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"Capturing Infrared"

Thor Lidasan

New member
Okay folks I need a little help...

***edit*** what I need to wrap my brain around is the WB for full spectrum. Is this a set and forget or will I need to create a new one each time?


Don
Don, on my FS I have several presets loaded for WB. For FS, often I just hit Auto WB. For IR, I have 2 (one for 650nm and another for 720nm). For UV, sometimes I just use Fluorescent, but I also have a preset loaded for macro UV.

What really helps is having a Passport Colorchecker and take a shot on the scene so it is easy to figure out what color cast the filter (UV-IR blocker) on the image.
 

Thor Lidasan

New member
A6000 Full Spectrum Sigma 18-35 f/1.8 on LA-E4 with no filter.
Charleston, Oregon fog
Hi Cindy, that Sigma must have strong IR filtration on the lens coating. There is only a slight hint of magenta cast despite not having an IR-blocker on the lens. Or is this level of IR rejection also same with other lens when you are using the A6000 FS without any filter?
 

Adam L

Member
Hi all. I just love this thread, it's been a source of inspiration for me. I've sent my Fuji X100 out to LifePixel today to have the Super Color 590nm filter conversion. I am now searching for good filters that fit the 49mm lens in 665, 720, and 830 equivalents. I need advice on quality choices that fit this camera. My web searches have not been very good and I'm fearful of making a bad selection. Kolari and MaxMax did not have a 49mm product on their sites.
 

Thor Lidasan

New member
Adam, welcome to the thread!

I use B+W 49mm on my camera. What is important is looking at the spectral response of the filter. There are a lot of IR filters out there that do not publish their spectral response data and those tend to be cheap ones.

B+W and Heliopan are on the expensive side but I like the consistency that I get from them. Here, take a look at the offering from B&H. The Heliopans have the spectral responses along with IR filter that you are interested in:
Infrared & UV Photography | B&H Photo Video

I do have to add that I also dabble a lot in false color IR via full spectrum set-up and I also look for cheap color filters that blocks a certain portion of visible light spectrum and lets in a lot IR (even UV contamination) light.

An example of this is the UV-pass filter from B+W, the UV Black 403. That particular filter is supposed to be a UV-pass filter only. It also passes IR at around 720nm. It is considered an IR-contaminated UV-pass filter. In my case, I like it for creative purposes as I get blue skies with white foliage.

Don't hesitate to play with cheap IR filters. Of course, if you are more interested in technical aspect of IR capture then studying the spectral responses of the filter you are interested in is a must thing to do.
 

f6cvalkyrie

Well-known member
I must admit that I do not shoot in "real' Full Spectrum (without any filter) much. The 'neutral' results are absolutely not pleasing to my eye. Either, I need to apply a lot of PP to obtain visually acceptable results, that are anyway far inferior to results I get with a 'visual' camera, or I need to go down the road of 'false color'. For that, I have not found my path yet ...

C U,
Rafael
 

Thor Lidasan

New member
I don't shoot "full-spectrum" (sans any filter), too. There are too many variables to contend with:

1) UV-friendly lens are difficult to source and the ones that are UV-friendly are on the expensive side. There are cheaper alternatives from the film era and needs some serious rubbing to get rid of the coatings and make them UV-friendly.

2) IR-contamination is also difficult to post-process when mixed in with the visible light spectrum. The result is often an abstract image. Although there are a lot of abstract IR + visible images that I love to look at. In my case, often it is a serendipitous result, a result of keep moving the sliders in post-processing until it gets pleasing to my eyes. The concept of pre-visualization becomes tenuous at best.

3) My favorite for IR + visible spectrum camera is my Sigma DP1. The Foveon sensor has that magical quality (IMHO) of capturing both IR + visible spectrum.

Here are two examples of IR + vis via the Sigma DP1:

The steel is painted yellow (as a point of reference for visible spectrum)



Denim pants via IR, pink shirt + red sweater, the foliage IR:

 

Cindy Flood

Super Moderator
Hi Cindy, that Sigma must have strong IR filtration on the lens coating. There is only a slight hint of magenta cast despite not having an IR-blocker on the lens. Or is this level of IR rejection also same with other lens when you are using the A6000 FS without any filter?
Thor, I don't know the answer to this yet. I just got this conversion right before i left for the trip and have since gotten another CC1, so I always put it on my lens when I use it for regular photography. I will say that it was foggy, so no bright sun. I do think that lens coatings play a role in the color response and will be keeping an eye on that. I'll report back if I find out any more.
 

Cindy Flood

Super Moderator
Adam L,
Welcome.
I use B+W filters for my 770 and 830. I have a dedicated 665nm camera, so I haven't gotten a filter yet for my fs camera.

You might want to just buy one filter until you check your lens for hot spots (unless you already know). Also, step up or step down rings are useful in fitting filters to more than one lens. Buy a bigger filter and use it on more than one lens.
 

Thor Lidasan

New member
Here is the screen grab an IR+visible spectrum image via the Sigma DP1 before post-processing a raw capture (X3F file, Sigma-speak for raw). The Foveon sensor captures both the IR and the visible light spectrum when combined with a filter that attenuates the intensity of IR. It took me several trial and errors to find a filter that decreases the intensity of IR and at the same time let the visible spectrum pass through.

Is this "false-color"? I don't know. By convention, "false-color" IR is a term used during post-processing when we adjust the sliders in the Channel Mixer portion of Photoshop. As you can see in the screen grab, the image is a raw file and all sliders are all in neutral setting:

 

f6cvalkyrie

Well-known member
This for sure is False Color, heavily manipulated in PS.
I like it, because this goat is called 'rosa' :p:p



CU,
Rafael
 

f6cvalkyrie

Well-known member
Infrared ? No, certainly not, this picture was captured with an unmodified E-M5
False color ? For sure : I applied the R/B color switch and a 180° Hue change to a normally edited RAW image ...

Surprisingly, this result came out, and my feeling is that this is very similar to what an IR camera might have given ...





Thoughts on this ???

CU,
Rafael
Rafael
 

steve231

New member
I looks very nice. There are wonderful efforts in finding & reaching the locations where the photos were taken.
 
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