# Black Light effect



## mike.strock (Mar 29, 2012)

I have a potential customer that would like to have some photos done with a 'black light' effect.  Can I take a photo and then process it in Lightroom to convey this effect?

I'm sorry, I'm new to this and I apologize for the newbie question.

Thank you.

Mike.


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## Mark Sirota (Mar 29, 2012)

Welcome to Lightroom Forums.  And that's certainly not a newbie question, it's an interesting one.

You might be able to do this with a custom camera profile created in the DNG Profile Editor.

What makes a black light look the way it does is that it emits almost nothing down at the red end of the spectrum up through the blues with the vast majority of its output up in the purples and into the near ultraviolets.  So basically you need to throw away all of the data from the camera's red and green sensels and use only the blues.  I'm not sure if the interface will make such a profile easy to create, and I'm not sure it'll give you exactly the look you want...

It would probably be a whole lot easier to shoot under black lights.  If you do this, you should expect a very very noisy image, since as I say you'll be throwing out 3/4ths of the camera's light-detecting ability.


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## RikkFlohr (Mar 29, 2012)

It might help if you could point us to a link that exemplifies the look you are after.  The new RGB Curves in LR 4 can probably approximate this effect quickly.


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## mike.strock (Mar 29, 2012)

RikkFlohr said:


> It might help if you could point us to a link that exemplifies the look you are after.  The new RGB Curves in LR 4 can probably approximate this effect quickly.



The only image I have is a NSFW image, and since I'm new here, I'd prefer not to be thrown out on day one.  I'll see if I can get a different one that is a little tamer.

Thanks.

Mike.


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## RikkFlohr (Mar 29, 2012)

Well that just makes it more intriguing. :blush:

You can direct message me via the forum with a link and if I have a solution, I will post a Safe for Work image back with the results... Up to you-no peer pressure.


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## mike.strock (Mar 29, 2012)

[Mod Note: Mike's right, it's not safe for work, but I wouldn't call it porn. I think we'll leave it up, and y'all can decide for yourselves]

http://www.myhomeoffice.org/blacklightimage.jpg is a link.  I couldn't figure out how to direct message you.  If it's inappropriate, let me know and I'll delete this message.

Thanks.

Mike.


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## mike.strock (Mar 29, 2012)

Well, I posted a link to  the image in the forum here, but it went to moderation.  Don't know if it'll pass muster or if I'll get deleted.  I couldn't figure out how to DM you quickly, so I tried it the other way.

Let me know if it shows up.

Mike.


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## RikkFlohr (Mar 29, 2012)

You probably don't meet the minimum posts criteria to send a DM.  You can always contact me offline via my website.  I will still post results (SFW) back here for those who are interested in faux Black Lighting.


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## mike.strock (Mar 29, 2012)

Thank you Rick.  I just sent an email.  I appreciate your willingness to point me in the right direction(s).

Mike.


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## RikkFlohr (Mar 29, 2012)

Well, with the exception of the florescent properties of UV light emitted by the black light, I would recommend the following to duplicate the effect in Lightroom based on the sample provided.

Convert image to BW [V]
Split Tone set Highlights to 280 ish and SAT to 100
Same settings for Shadows
Apply a Strong Contrast Tone Curve.

See if that gets you close.


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## mike.strock (Mar 30, 2012)

Thanks Rikk.  I sent you another email with another example that I've converted (I believe) using your instructions.  Please let me know your thoughts.

Mike.


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## erro (Mar 31, 2012)

You american guys are so sensitive...


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## katharineleah (Apr 11, 2012)

Im wondering if you discovered some settings as I was working on a very similar effect today.  I am a medical photographer for a pediatric dermatology practice and we are looking at implementing a whole "UV" system to show sun damage on skin.  Doing true UV photography does in fact show some of the skins damage that isn't visible in regular light, but can be similarly achieved by making some adjustments to the red and orange luminance levels.  I think this is the closest lightroom comes to channel mixing like photoshop? not sure.  Anyhow, I can't post examples as I would be in violation of HIPPA but perhaps can get a nurse to model for me so I can show the UV effect settings I've come up with. I also got some surprising results fiddling around with the chromatic aberrations and cameral calibration settings.  It also makes a big difference if you start with an image that was shot using cross polarization.
My question then becomes- is what you can capture with a true UV photography set up (uv flashes and uv lens-which incidentally isn't even made anymore) actually capturing the same information that can be achieved by knocking out all of those other colors and luminance so that you are just left with that particular wavelength in Lightroom (or photoshop)??
I dont really care if my images are "cool looking" or not- i just need all of the relevant descriptive information about a patients skin to be visible and if my department has to invest in a UV system to do so - we wilL!  BUT-from my experimenting in LR and comparing to true UV images- im not seeing a huge difference!  In face, the information i can pull out of a well exposed cross-polarized image seems even more detailed than some of the UV derm studies i have looked at. 
Thanks for any input or responses!
-kat


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## Mark Sirota (Apr 12, 2012)

Kat, welcome to Lightroom Forums.

It's not the same thing, though your approach may be good enough to show what you want to show.

It's not the same thing because a conventional camera system is designed to capture visible light (over about 400 nanometers in wavelength). Black lights produce light in the UVA range, down to about 315 nanometers. If your camera system can capture light in that range, and if your post-processing tools can handle it, then something captured under UV lights with a UV-sensitive camera system could show something different than a conventional visible-light camera.


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