CCC Forum

Jus had my Nikon camera converted to infrared this my first run with the camera.

I sill need to work on my Infrared skills any advice would be appreciated.



Thanks
Keith

Hi Keith

Is this with a custom white balance OOC? There are some odd colour casts, which you can avoid either by converting to mono post capture or applying a red/blue channel swap for a false colour effect.

Hi Mike

Thanks for you response, the picture was taken using auto white balance.

I tried to create a present WB using a patch of grass. I kept on getting "No Good". My camera does allow a picture to be set as a WB will this work
just as good any opinions on this will be appreciated.

Thanks
Keith

keithash wrote:Hi Mike

Thanks for you response, the picture was taken using auto white balance.

I tried to create a present WB using a patch of grass. I kept on getting "No Good". My camera does allow a picture to be set as a WB will this work
just as good any opinions on this will be appreciated.

Thanks
Keith

My IR camera is a Canon 450D which left to its own devices produces images with a strong red cast. This can be sorted out in post, but does make assessment of shots at the time of taking somewhat tricky. If the AWB on your Nikon D7100 is giving you this, then I would say result.

The thing to remember with IR is that you are using the equipment outside of its design spec so you will need to experiment to find out what works best, which is all part of the fun if you enjoy mucking around with gear. For me, the camera's WB and metering are both problemmatic. The WB I resolved by using a custom WB and when I shoot the camera's suggested metering is usually a starting point. Having taken a test shot and reviewed the histogram, more often that not I find myself dialling in some exposure compensation which can be anything up to two stops either way. Which is handy, as two stops is all the camera has when shooting with semi automatic exposure. I find that on a sunny day, I need to increase exposure and decrease it for dull ones. That too is convenient and preferable to being the other way around.

Lenses have different issues as they are designed to transmit and focus light in the visible spectrum, where wavelengths are shorter than IR. The problems tend to come in the form of flare, especially if the camera is pointed anywhere near the direction of the sun, and hotspots. Some lenses perform better than others, but once again you will not know until you try.

The forum has a thread on IR photography which you might find useful if you have not already seen it.

viewtopic.php?f=10&t=243

What wavelength did you convert it to?

Also I think you have dust on your sensor. I can see dust-like spots to the right of the spire, on one of the gravestones and a few other suspect locations.

One way to find out is set your camera to the max f-stop (e.g. f/22), turn of AF and put it on low ISO. Point it at a white wall and take the shot - you will see any dust spots clearly.

When mine was messy this is what I got -

davidc wrote:What wavelength did you convert it to?

720 nm, i.e. just above the top end limit of the visible spectrum which tends to run out at around 700 nm, although some reports suggest it can go as high as 730 nm. Maybe there is some variation in human physiology?* 720 nm is the most popular choice as it allows both the high contrast IR monochrome effects and false colour options such as the red/blue channel swap.

One thing I am thinking about doing is having my Panasonic G3, with which I have a love hate relationship due to its susceptibility to inadvertent button presses, converted to have a clear filter over the sensor. That would allow all wavelengths the sensor is capable of recording from UV to IR to be captured. In that way I can control filtration on the lens and get the benefit of different types of filter without having to use multiple cameras. There are a whole raft of weird and wonderful filters out there if one wishes to experiment. It would include using the camera conventionally with a UV/IR cut filter which would only allow light from the visible spectrum to pass. With the Lumix CSCs, AF with different wavelengths of light is not a problem as focussing is done by analysing data from the sensor, rather than using a different optical path as happens with DSLRs. How that would work with a filter which passes both UV and IR, but cuts the visible spectrum in between, will be interesting to say the least. It might be a case of relying on DOF and stopping down, but the smaller sensor size of a m43 camera would be an advantage in that situation.** Whether it would result in an aesthetically pleasing image is a completely different matter, of course.

* Or, shock horror, incorrect information on the interweb.

** And one in the eye for the Internet equivalencists*** who insist that a m43 f/2.8 is really f/5.6 or some such nonsense.

*** Yeah, I made the word up.

davidc wrote:Also I think you have dust on your sensor. I can see dust-like spots to the right of the spire, on one of the gravestones and a few other suspect locations.

Quite surprising, especially given that the sensor (or more accurately the new IR pass filter in front of the sensor) should have been cleaned as part of the conversion process. It shows just how susceptible to crud our ILCs are.