Converting to IR with PP?

slackercruster · 04-01-2012, 09:22 AM

Is there a program that can turn photos into IR images?

joe.penn · 04-01-2012, 09:53 AM

Originally posted by slackercruster

Is there a program that can turn photos into IR images?

In short, No! An infrared image is only an infrared image if captured at infrared at time of exposure.

There is however PP that can be applied to "simulate" or "give somewhat the appearance of" IR photog. As a matter of fact, your pentax body has a digital filter to do this for you...

RioRico · 04-01-2012, 10:25 AM

joe.penn nailed it. IR photography works by using filters that block most or all visible light, and pass IR wavelengths. If the sensor doesn't capture the IR energy, it can't be added back in with PP. All the IR 'simulations' I've seen just don't look very IR-ish. At best, such simulations are like deep-Red (#25) filters, blocking all Violet-Blue-Green-Yellow-Orange wavelengths but passing Red and a tiny wee bit of IR, with maybe the addition of a little 'glow' in certain areas.

Figure that a #25 Red filter has a cutoff around 680nm IIRC. The popular 720nm IR filter passes enough visible light to allow composing with the viewfinder. Filters from 800nm onwards block virtually all visible light; my 1000nm filter blocks it all and gives the best IR results. (I use a set of 780-900-930-1000nm filters on my Sony DSC-V1 'Nightshot' P&S.) The visual information in the 700-1000nm portion of the EMF spectrum just can't be seen unless it's captured; it can't be faked.

In case you're interested: Film is normally sensitive to UV wavelengths and blind to IR (except for IR films), so UV filters are needed for much film work. Digital sensors are just the opposite: blind to UV, but so sensitive to IR that virtually all digicams have an IR-blocking hot.filter inside. Conversion to remove the hot.filter is popular but not cheap. Sony 'Nightshot' cams have a switch to temporarily disable the hot.filter. I'll keep my DSC-V1 forever!

stevebrot · 04-01-2012, 11:13 AM

As mentioned above...two things are needed for IR photography:

Film sensitive to IR light
A special filter to block out the shorter wavelengths

You can probably also add a good tripod to the list since the IR filters are generally very dense and exposures are looooong.

Steve

tuco · 04-01-2012, 11:25 AM

Don't forget too when shooting with IR film that you may need to adjust your focus. You may notice a little red tick mark on the lens's DOF scale. That is for IR film. When stopped down it isn't much of a concern but can be a factor when the lens is opened up.

slackercruster · 04-01-2012, 01:09 PM

Didn't know Pentax has a built in filter. Will check it out.

eddie1960 · 04-01-2012, 01:15 PM

the built in filter just emulates I find it hit and miss but it can produce cool images

this one was shot with the K7 IR filter

tuco · 04-01-2012, 01:33 PM

Maybe this tread should be moved to the digital section of the forum if we're not talking about IR film or PP film to look like IR.

eddie1960 · 04-01-2012, 01:37 PM

Originally posted by tuco

Maybe this tread should be moved to the digital section of the forum if we're not talking about IR film or PP film to look like IR.

True.

04-01-2012, 09:22 AM	#1
slackercruster Veteran Member Join Date: Jan 2012 Location: NE, USA Posts: 1,302	Converting to IR with PP? Is there a program that can turn photos into IR images?

04-01-2012, 10:25 AM	#3
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	joe.penn nailed it. IR photography works by using filters that block most or all visible light, and pass IR wavelengths. If the sensor doesn't capture the IR energy, it can't be added back in with PP. All the IR 'simulations' I've seen just don't look very IR-ish. At best, such simulations are like deep-Red (#25) filters, blocking all Violet-Blue-Green-Yellow-Orange wavelengths but passing Red and a tiny wee bit of IR, with maybe the addition of a little 'glow' in certain areas. Figure that a #25 Red filter has a cutoff around 680nm IIRC. The popular 720nm IR filter passes enough visible light to allow composing with the viewfinder. Filters from 800nm onwards block virtually all visible light; my 1000nm filter blocks it all and gives the best IR results. (I use a set of 780-900-930-1000nm filters on my Sony DSC-V1 'Nightshot' P&S.) The visual information in the 700-1000nm portion of the EMF spectrum just can't be seen unless it's captured; it can't be faked. In case you're interested: Film is normally sensitive to UV wavelengths and blind to IR (except for IR films), so UV filters are needed for much film work. Digital sensors are just the opposite: blind to UV, but so sensitive to IR that virtually all digicams have an IR-blocking hot.filter inside. Conversion to remove the hot.filter is popular but not cheap. Sony 'Nightshot' cams have a switch to temporarily disable the hot.filter. I'll keep my DSC-V1 forever! Last edited by RioRico; 04-01-2012 at 10:31 AM.

04-01-2012, 11:13 AM	#4
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	As mentioned above...two things are needed for IR photography: Film sensitive to IR light A special filter to block out the shorter wavelengths You can probably also add a good tripod to the list since the IR filters are generally very dense and exposures are looooong. Steve

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04-01-2012, 09:53 AM	#2
joe.penn Veteran Member Join Date: Mar 2011 Location: Maryland (Right Outside Washington DC) Photos: Gallery \| Albums Posts: 2,902	Originally posted by slackercruster Is there a program that can turn photos into IR images? In short, No! An infrared image is only an infrared image if captured at infrared at time of exposure. There is however PP that can be applied to "simulate" or "give somewhat the appearance of" IR photog. As a matter of fact, your pentax body has a digital filter to do this for you...

04-01-2012, 11:25 AM	#5
tuco Pentaxian Join Date: Jul 2009 Location: Pugetopolis Posts: 11,026	Don't forget too when shooting with IR film that you may need to adjust your focus. You may notice a little red tick mark on the lens's DOF scale. That is for IR film. When stopped down it isn't much of a concern but can be a factor when the lens is opened up.

04-01-2012, 01:09 PM	#6
slackercruster Veteran Member Join Date: Jan 2012 Location: NE, USA Posts: 1,302 Original Poster	Didn't know Pentax has a built in filter. Will check it out.

04-01-2012, 01:15 PM	#7
eddie1960 Veteran Member Join Date: Aug 2010 Location: Toronto Photos: Gallery \| Albums Posts: 13,666	the built in filter just emulates I find it hit and miss but it can produce cool images this one was shot with the K7 IR filter

04-01-2012, 01:33 PM	#8
tuco Pentaxian Join Date: Jul 2009 Location: Pugetopolis Posts: 11,026	Maybe this tread should be moved to the digital section of the forum if we're not talking about IR film or PP film to look like IR.

04-01-2012, 01:37 PM	#9
eddie1960 Veteran Member Join Date: Aug 2010 Location: Toronto Photos: Gallery \| Albums Posts: 13,666	Originally posted by tuco Maybe this tread should be moved to the digital section of the forum if we're not talking about IR film or PP film to look like IR. True.