Infrared Photography

[idcrewdawg]

I've an interest in infrared photography, and am looking to find out what the most logical entry point would be.

Screw on filters seem limiting because you are limited to lens size, and every single one of my lenses are a different size.

Gel filters though they can go between the lens and the camera seem limiting because the lens must have the mount already.

So what would the experts here at DPS advise? Anyone with experience with either would be fantastic. I would love to know the pros and cons that I haven't thought of.

I haven't done it personally, but I've heard the only way to really do it is to take apart the camera and put a filter over the sensor. You wouldn't want to do this to your DSLR...probably a cheap point and shoot you have lying around the house. You can also buy some modified ones off e-bay, which is where my friend got his.

[Japaslavian]

There are square lens mounts with square filters that can usually attach to several different lens widths. Cokin would probably be your first stop with those.
Otherwise you could pick up the popular Hoya R72 filter that fits your biggest lens and pick up step-down rings for each of your other lenses. They generally run under $25 a piece, many are under $10.

[Raoul Isidro]

The film era IR worked best because film cameras used IR film.
In the digital SLRs, the sensor is the film.
The sensor has to be modified to mimic IR film.
Some modify this by removing the IR filter in front of the sensor.
The Sigma SD14 has an IR/UV blocking filter that can be removed/installed without tools. The result is a very sensitive digital IR camera.
Infra Red images oftentimes render peoples clothing invisible.

[idcrewdawg]

I am looking to do this with a DSLR camera, and so am interested in the prospects of making it happen.

Thanks for the feedback.

[FDCPR]

I have an on again off again relation with IR photography in the digital age. As everyone has stated, to get the best IR photos you really need to have a converted camera. That is one that has the internal IR filter removed and replaced with optical glass. Just removing the filter without replacing with another clear filter results in a camera that won't focus. Also, do some research on lenses used, not every lens is good for IR work. I have a list of recommended lenses somewhere and once I dig it up I'll get it to you. I use the camera mentioned in a previous post, the Sigma SD14 by removing the "removable" filter and then replacing when I want to use it normally. Even after removing the internal IR blocking filter an IR pass filter must be used on the lens or this camera will shoot full spectrum photos.
Now after saying it is necessary to remove the internal filter I have had good success in getting false color IR photos from a unaltered camera just using an IR filter on the lens. For where I live IR is somewhat difficult as it requires long shutter speeds. Here we have an ocean breeze at all times and when shooting vegetation and IR the long shutter speed just has too much movement in the leaves and such. I get a few, but not very often is the wind calm enough to shoot IR.

[inkista]

Actually, it was more of a pain in some ways with film because you had to get IR-sensitive film to do it. Digital sensors are already sensitive to IR. In fact, they're over-sensitive to IR, which is why camera manufacturers put an IR-blocker over the sensor so that visible colors aren't thrown off by the IR sensitivity.

These blockers aren't 100% efficient so you can use an unmodified dSLR for infrared photography, but putting an IR pass filter (like the Hoya R72) over the infrared blocker means you only have a tiny bit of IR to work with. So, you're generally limited to very long exposures and a tripod. Also, IR pass filters typically aren't 100% efficient (they usually let some red light through) so that you can actually see something through the viewfinder.

A modified camera, which has had the IR blocker removed and replaced with either plain glass or another filter that will allow the IR light through, can be used at handheld shutter speeds with an IR filter, but cannot then be used for regular visible light photography unless you put an IR blocker on your lenses. This is why most IR shooters use a dedicated second body for infrared work.

If you just want to get your toe wet and try IR to see if you like it, it's probably best not to get your camera modified (it typically costs around $300 to get it done, and it's not easily reversible), but to get a screw-in filter. And try the long exposure method. The most common IR shooting methods include using a custom white balance setting (off plants that are very green, like grass) and then the channel mixer in post-processing to produce false colors, or processing the image to black and white. Without either of these techniques, the image you'll get out of the camera will have a very strong red cast (from that red leakage the filter lets in).

You do need to know that focusing will shift with the light wavelength so using a distance scale can be tricky and autofocus may be your best friend. Also, composing and focusing will be tough since the filter is so dark; you may need to use liveview with exposure simulation. Also, many lenses may exhibit an infrared "hot spot". On the Canon side, the 18-55 kit lens is notorious for this.

With infrared, the two elements that typically appear very different in IR than they do in visible light are water (which absorbs IR and therefore becomes very dark), and chlorophyll (which reflects IR and thereby becomes very light).

And, of course you don't need a dSLR, a P&S can be used, too.


Canon G9. lensmate+58mm Hoya R72 filter. Ultrapod, timer.
iso 100, f/5. 10s.

[OsmosisStudios]

Originally Posted by idcrewdawg

e.

Screw on filters seem limiting because you are limited to lens size, and every single one of my lenses are a different size.

.

Get 77mm filters and step-up rings.