6

Not really. If you want to take a hack at it, the first thing you'll need is the transmittance curves of your (presumably Bayer) color filter. Then,if you're lucky, there's an NIR wavelength at which at least two color filters have some responsivity, and those color filters have no overlap in the visible range. In such a case, you could play with sum and ...


4

If the camera was modified to pass mostly IR light, then this is normal. You need to convert the images to monochrome. Take a picture of foliage outside. Then desaturate completely. If the foliage is very white giving the image a surreal look, then the filter is working properly. There are also IR camera modifications that leave more visible light, if you ...


4

One note: What is meant by "IR filter" depends on the context in which the term is used. When we say the camera has an "IR filter" in the stack of cover glass in front of the sensor, what we mean is that filter cuts IR light. That is, it blocks most of the IR light falling on it. When we talk about an "IR filter" that we put on ...


4

Every field of study and practice has established terminology and usage. It generally does not make sense to apply the jargon of one to another. For instance, suppose you take photos with a "720nm" bandpass filter. "720nm" may be considered a misnomer because some shorter wavelengths and most longer wavelengths are allowed through. But for the sake of ...


4

If you want to use film as an infrared filter, you need to use developed color film. Whether it should be unexposed or exposed depends on whether it is slide or negative film. Regardless, you should not expect great image quality with these materials because they were not designed to be used as filters. Using developed film as an IR-pass filter is just a ...


3

The on-sensor optical filter has an effect on the optical distance between the sensor and the objective. Whenever you remove glass from the space between the sensor and the objective, you are very slightly enlarging the FoV and, what is more important, shifting the range of distances the camera can focus at towards infinity+ - that is, if the camera focuses ...


3

Yes. In fact, every thus-modified camera senses three different bands of near-infrared. (This answer is an expansion of Mark Booth's comment.) In Basics of Infrared Photography, the first diagram's shaded areas show the sensitivity to wavelength of the R,G,B sensors of an unmodified camera. The third diagram (copied in this answer) shows the same for a ...


2

Some photographers put a few different infrared bandpass filters (a), (b), (c), also called infrared transmitting filters, in front of the camera, one at a time, to photograph a scene in a few different bands of infrared light. Some astronomers attach a prism to a telescope (a) (b), smearing out each pinpoint of light from a star into a spectrum with many ...


2

By adding a filter to the front of the lens, you are adding an air-glass interface (between the back of the filter and the front of the lens) that wasn't designed into the camera. This additional air-glass interface can create reflections that are transmitted through the lens and picked up by the sensor as flare, or as a type of flare coincidentally called "...


2

Removing glass from the light pathway would result in the loss of infinity focus unless you can decrease the distance between the lens and sensor "past" infinity. Helicoids, bellows, extension tubes will not be helpful because they increase the distance between the sensor and lens. I suppose what you mean by "short build" adapter is that it is shorter than ...


2

Camera imaging sensors are much more sensitive to longer wavelengths than human vision. The normalized response of the "red" sensitive cone cells drops off rapidly above 640nm. A camera without ir filters will be much more sensitive to red light that contains material percentages of photons with longer wavelengths. Digital color cameras have such filters ...


2

With few exceptions, data for infrared filters are not published for the region from 700 to 900nm. This is because most infrared filters are offshoots of the Wratten gelatin filters recipe. These were made by dissolving dye in gelatin and then floating the liquid gelatin on the surface of water. The gelatin was then allowed to gel and then lifted from ...


2

Typically, digital sensors are sensitive to Ultraviolet , Visible, and Infrared frequencies. A band pass filter is installed in the optical path to eliminate both UV and IR frequencies. This bandpass filter is often called a “hot mirror.” Conversion to “full spectrum” entails removing the hot mirror filter. Full spectrum cameras record Ultraviolet in ...


2

I can only offer some decade old empirical observations and mostly coming from comparing results on film: With longer wavelength, the chances of capturing Wood's effect are better. Longer wavelength also cuts through haze a little bit easier. Shorter wavelengths seem to be more foolproof (less chance for hot spots), focusing distance difference closer to ...


1

You may also find the term 'Hyperspectral' or 'Multispectral' useful. A standard camera producing R,G,B is 'multispectral'. I don't know if you're attempting to generalize a modified camera (such as removal of the IR cut), but if so multispectral may be more useful. There is also a camera modified with a variety of 'cut' filters such that each portion ...


1

Your 590nm filter still eliminates a lot of visible light on the blue end from reaching the camera's sensor. When you try to create a custom WB, though, you're telling the camera you want to end up with a photo that has a fairly even distribution of the entire visible spectrum, a good portion of which the filter is severely attenuating. So even though you ...


1

I'm guessing that you've removed the infrared and UV (lowpass) filters from your camera? The purpose of those filters is to limit the light hitting the sensor to be predominantly in the human visibility spectrum. Without those filters, you have light wavelengths punching through the nominal Red/Green/Blue¹ filters on the sensor elements and activating them ...


1

A normal color balance will produce red/pink images. Perfectly fine. Easiest fix? Get a white sheet of paper outside, hold it up, take a photo. Then use that as the 'custom white balance' (I don't know your camera or how to do it). Now your world will be in B&W... and you'll love it. More custom white balances can be done later with more neutral ...


1

On digital the 720nm and 830nm filters work rather similar. The sky will be about as black on both, the grass as white. Shadows will be somewhat blacker on the deep IR (the longer wavelength, the less your light bends = the deeper are your shadow areas). But relatively speaking this is a minor difference - about as big as using a medium yellow filter. On ...


1

It only makes a difference if your film or your solid-state sensor has reasonable sensitivity between 720 and 830. (and of course that your lens itself doesn't block). The total exposure at a given location, or pixel, is calculated by taking the integral over the wavelength band of the incoming flux (photons) times the film or pixel quantum efficiency as a ...


1

The color filter array is typically right on top of the sensor, under an infrared filter panel. After removing the IR filter, the CFA can be mechanically scraped off of the sensor: Effects of this destructive process are detailed here.


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