Physlab Loc: Portland, OR

Am I correct in assuming one cannot create an infrared image directly from a color image? To end up with an infrared image one either adds an infrared filter to the lens or uses a camera converted to strictly make infrared photos.

Is my reasoning correct or can one come close to generating an infrared image from a raw color photo?

Lowell

Orphoto Loc: Oregon

You can fake it to a degree, but you are correct.

JohnSwanda Loc: San Francisco

There are apps which will make a fake IR image from a color image, but it isn't considered real IR, and most sites devoted to IR photography won't accept those images.

User ID

You dont ADD anything (e.g. "infrared filter"). You need to REMOVE something, specifically the IR BLOCKING filter built into the sensor stack. After that you would quite likely add something, maybe a blue blocking filter (red, yellow, etc) but thaz optional (altho popular).

Software-faked IR is an aesthetic. See if you like it. No big deal that its banned on "real IR sites" if you just want an effect that YOU like for YOUR reasons. Effects are effects. "Real IR" is also just an effect (except for astro).

If you really wanna "join the cult" and do the authentic IR photography, then youd do well to brush up on a little Jr High science stiff.

JimH123 Loc: Morgan Hill, CA

It's actually a very poor approximation of real IR photography and not something that will fool someone who knows IR photography.

User ID

So, if you will ignore whether or not it looks like what something else looks like, is it an interesting or intriguing editing effect ? IOW forgetting about labels, what about how it looks aesthetically ?

Sometimes a Watercolor or Charcoal filter looks really good even though it wont fool anyone. Effects are effects, for better or for worser, case by case.

JohnSwanda Loc: San Francisco

As long as photographers don't claim fake IR is real IR, we can consider how good it looks.

Scruples Loc: Brooklyn, New York

I have never been a fan of post processing. In part because I am not tech savvy.

I have used Infrared Film with little success in part because i assumed that it was similar to regular film.

I have contemplated purchasing an infrared film for some work. I still need to learn more!

Boris77

It used to be:
That you had to have some familiarity with photo processing programs to create a pseudo infrared picture. So do you enjoy working on the computer? OR
Have a camera converted and get a long way towards the goal.

Now there are a number of choices, which I have found well explained at lifepixel.com, in their now hidden Digital Infrared Filter Comparison Photos section (the site has become quite commercial).
I had the simplest B&W conversion done on an inexpensive mirrorless Panasonic camera years ago, and it was the real deal in output, but limited in quality by the camera and lens.
I would recommend dealing with Life Pixel; they were very helpful and astute when I did, BUT
I wonder with AI construction if this is worth the money anymore?
Boris

R.G. Loc: Scotland

If you like IR because it has a certain "look" you may be able to achieve a similar look using PP. In fact with some experimenting you may find something you like even more than real IR photos. If your editing software has an HSL tool or an equivalent, you can brighten/darken/saturate/desaturate specific colours and target things like foliage and the sky. That includes the option of removing specific colours completely, plus you will also have the option of adding your own colours or tints. You may come up with colour combinations that appeal to you more than those that are common in IR photos. If it's a specific look that you're after you don't have to be limited by what the usual IR processes offer.

petrochemist Loc: UK

That rather depends on the camera. My old Pentax K100d, and the Nikon D70 are both fitted with weak hot mirrors. Add a 720nm filter & about all the camera sees is IR, in some cases the shots will be hand holdable but most of the time exposures will be longer..

Here are a couple of shots with the K100d, with a 720nm filter added:
A hand held panorama (MS ICE & good light )
Infra red Panorama by Mike Kanssen, on Flickr

more typical spring lighting (needing a tripod)
Ghosts of Clacton 1 by Mike Kanssen, on Flickr

Other cameras with stronger internal hot mirrors can usually be made to shoot IR with long enough exposures & a good IR filter, IIRC 2 minutes worked with my K7.

With a converted camera the IR contribution is typically similar to normal visual, so a full spectrum conversion might give shutter speeds around half of a visual only camera (in the same daylight, same aperture & ISO setting).

An action shot via a converted camera:
IR BTCC - Neal by Mike Kanssen, on Flickr

Software based IR is rather like trying to add the blue component of an image based only on the red & green channels. Guessing the sky & water might be practical but the information is not there. Software based IR typically makes green items very bright, as foliage reflects a lot of IR - however I've shot green painted metal items with a converted camera & found they came out near black. The software might get a reasonable approximation for landscapes, but doesn't stand much chance for other applications - such as showing veins in portraits, or viewing through some inks...

All the distracting logo's removed by shooting IR
BTTC grid in IR by Mike Kanssen, on Flickr

Converted cameras vary wildly. All those I've brought have been 'full spectrum' converted removing the hot mirror & replacing it with quartz or glass (quartz allows the camera to record UV, visual & NIR, glass blocks much of the UV) adding filters to these allows combinations not practical with normal cameras as well as options other conversion might not be able to see. I can take images in UV & IR with little or no visual light (some of my filters add blue in the mix), or red & IR ... To date I've not managed UV only as all affordable UV pass filters leak IR (and the camera is more sensitive to this).

Lens can add another level of complication, some of my Panasonic lenses seem to start blocking IR above about 850nm, so see practically nothing on a converted camera when paired with a 900nm filter, converted cameras usually see up to around 1100nm.

sueyeisert Loc: New Jersey

This is also my understanding.

Scruples Loc: Brooklyn, New York

A modest priced used/converted camera can do very nicely for Infrared Photos. Perhaps renting one for a week or two might convince someone who is reluctant like me. IR film was lackluster. Perhaps because I thought my Canon AE-1 could do it justice. Nope!

Scruples Loc: Brooklyn, New York

Ultraviolet photography is a different realm and has yet to be fully explored. Caneras can be modified to photo IR. However, UV light is usually dependent on the elements within a lens. Is this true?

E.L.. Shapiro Loc: Ottawa, Ontario Canada

https://www.iphotography.com/blog/infrared-photography-tutorial/

This link is a great in-depth article on infrared photography with digital cameras. There are explanations of the visible and invisible spectrum and a brief mention of specialized films of the past on which this science and methodology has its roots.

Infrared photography is not only a special effect, trick, or fad. It is used in agricultural surveying, military aerial survivance and detection of subterranean tunnels, underground operations warfare detection, and in certain types of medical diagnosis and documentation. Haze penetration is another aspect.

Artistically and creatively speaking, The IR effect is quite dramatic bithin monochrome and color. The "classic effecIt is dramatic skyscapes, white foliage, and or extreme color shifts when the specialized color film or a converted digital camera is used.

The special effect apps are by no means actual IR photography. It has none of the aforementioned properties but it kind of simulates the color shifts- it is fun and can be used creatively to impart various moods and abstractions.