IR photography problem

[MariaDolore]

Hi

I have a problem with IR photos. I have a Nikon D7200. When I use my IR-filter and shoot the photos just become regular with a red tone. Not that fantastic like I´ve seen others IR-photos can be. I know i can´t use white balance in auto-mode.

Like this for example: http://www.calpoly.edu/~bio/bio161new/images/red_filter_bikes.jpg
So ugly.

 

[petrochemist]

If your cameras not been converted, then monochrome IR is about the best you're likely to get. The 7200 like most newer cameras has very poor IR response, but you ought to be able to get long exposures that show typical IR features such as bright foliage & contrasty skies. I don't think WB on any of the Nikon cameras goes far enough to be right for IR. Nikon IR shooters tend to shoot RAW as this gives them enough control in software.

 

[480sparky]

A lot depends on two things:

1. The frequency the filter is made for (measured in nanometers [nm]). If it designed to pass, say 600-1200nm, then all the blues and greens in the image will be rendered black.
2. How sensitive the sensor is to frequencies beyond 700nm. The further into the IR portion of the spectrum you get, the less sensitive the sensor becomes.

Both of these, combined, may mean your filter keeps the blues and greens from reaching the sensor, and the sensor itself is not registering anything beyond, say, 800nm. Result: Only red light reaches the sensor and that's all that's recorded.

I've not researched how well the D7200 performs with either a filter or after an IR conversion. Perhaps you should check on it yourself. Start here:

Introduction - LifePixel Digital Infrared Photography IR Conversion
Getting Started - Kolari Vision

 

[KmH]

There is an array of filters in front of the image sensor in your camera.
One of them is an IR filter.
The image sensor in DSLR cameras is sensitive to IR light but since people can't see IR light the IR light isn't needed to make a regular photo.
Without the IR filter the IR light getting to the image sensor would over expose a regular photo, whihc is why they put an IR filter in front of the image sensor.

IR light looks red to DSLR image sensors unless a custom (preset) white balance is set all IR images would look very red. Unfortunately some camera models are incapable of setting a proper in camera WB in infrared because they were never meant to “see” IR light as they were designed for visible photography.

A company called LifePixel can modify the filter array in front of the image sensor in your camera so you capture a wider spectrum of IR light frequencies.
However, once converted that camera can ONLY make IR photos.

 

[MariaDolore]

There is an array of filters in front of the image sensor in your camera.
One of them is an IR filter.
The image sensor in DSLR cameras is sensitive to IR light but since people can't see IR light the IR light isn't needed to make a regular photo.
Without the IR filter the IR light getting to the image sensor would over expose a regular photo, whihc is why they put an IR filter in front of the image sensor.

IR light looks red to DSLR image sensors unless a custom (preset) white balance is set all IR images would look very red. Unfortunately some camera models are incapable of setting a proper in camera WB in infrared because they were never meant to “see” IR light as they were designed for visible photography.

A company called LifePixel can modify the filter array in front of the image sensor in your camera so you capture a wider spectrum of IR light frequencies.
However, once converted that camera can ONLY make IR photos.

Thanks! Now I understand. I dont want to convert my expensive camera though, so I might buy a cheaper Nikon camera and converts and shoot IR with that instead.

 

[480sparky]

.............However, once converted that camera can ONLY make IR photos.

Not necessarily. A 'Full-Spectrum" conversion can be done allowing both UV and IR to reach the sensor. Then one uses screw-on filters to block IR to allow one to take UV/visible light images. Or, add IR and UV filters to take 'normal' images. Or, add IR and & visible light filters to take just UV images.

There is also a 2-Spectrum conversion that allows toggling between IR, visible and both.

 

[petrochemist]

Not necessarily. A 'Full-Spectrum" conversion can be done allowing both UV and IR to reach the sensor. Then one uses screw-on filters to block IR to allow one to take UV/visible light images. Or, add IR and UV filters to take 'normal' images. Or, add IR and & visible light filters to take just UV images..

That's the sort I use. I've yet to find a filter that restores it to normal - the best hot mirror I've got leaves a red hue compared with the default WB settings though it transmits very little above 700nm.
On days with overcast skies the images it takes without a filter could be mistaken for normal ones.
This is an example I've not shared here before:
Werewolf 2 by Mike Kanssen, on Flickr

 

[petrochemist]

Thanks! Now I understand. I dont want to convert my expensive camera though, so I might buy a cheaper Nikon camera and converts and shoot IR with that instead.

IIRC the old Nikon D70 is supposed to be fairly IR sensitive without conversion (similar to my old K100d). Not as sensitive as any converted camera, but conversion typically costs $250+
You may find checking e-bay for pre-converted used models enables you to find one that will work for you. My FS model cost me less than a conversion.

 

[JTPhotography]

It is possible to get an ok IR shot by using a screw on filter but not even close to being practical. White balance is your main problem. You have to set a preset WB (reading taken from green foliage works best) for each scene as conditions change. Your shot should have a bronze tone, not a red one. Then the traditional color IR look is achieved in post. Lighting may be a problem too. Full sun is best. I'm using a 720nm converted d3300.

Keep playing, once you figure things out, It becomes addictive.

I've been into photography for 25 years and just recently started playing with IR. I'm like a kid at Christmas. Here's one if my first test shots where I was just getting hang of achieving that classic white foliage/blue sky look.