Shooting in infra-red

Azhrei

I've just invested in a 950nm infra-red filter, only to find that my camera (Fuji Finepix S6500FD) is not ideal for shooting in such situations, being prone to artefacting and hot spots with slow shutter speeds and long exposure times. You can see this clearly in this photograph, with a very prominent hot spot.



It was very sunny when I took this photograph a few hours ago, with no cloud in the sky, and what I thought would be more than enough light. I know this is a boring photograph, but I was just doing experiments with the filter and wanted something static with no chance of movement to ruin the long exposure time. Does anyone have any helpful hints on how to go about photography in infra-red?

Kintarō Hattori

Fenster and FX Meister have both dabbled in this quite a bit I think. Perhaps search some previous posts by them for the moment until you get a few replies going here.

sineadw

are you setting a custom white balance and all that malarkey?

charybdis

I think, given my (limited) understanding of infrared photography, that hotspots like this are a result of lens design in that the optical elements aren't intended to produce uniform results at these wavelengths. I'm fairly sure your camera has a fixed lens, so I don't think there's really anything you can do short of buying a new camera that handles infrared photography better. You could try and take several shots at different focal lengths and see if the changing optical configuration has any effect on the distribution of luminance at these wavelengths, but it probably won't be significant.

jpb1974

Maybe post up what you did to produce the image above and from there we might be able to spot any flaws in the process?

Hot spots are lens related... changing lens can help (assuming that is possible on the camera you mention).

*Edit* Cross posted with charybdis there who also mentioned the hot spots/lens.

Azhrei

Well, being the idiot that I am, I didn't document what settings I was using when taking that photograph (and all the others I didn't post up here), but I did a few tests just now from inside, pointing the camera out. I took a total of ten photographs, all in .RAF (Fuji's RAW format), with different exposure times, F settings, colour and black and white, taken at the lowest possible ISO (100) with auto white balance. I also set the camera for a two second delay before shooting.

I've found that colour is just right out with the filter and my camera, as no matter how powerful the sunlight is outside, as I discovered earlier, all I'm getting is a purple haze. It's slightly disappointing but not too bad as black and white infra-red photography can produce some beautiful results. Out of the ten photographs, the one with the best results was taken at the following settings -

30 stop exposure, F2.8, 1/3 bracketing, ISO 100, Camera B&W

There was no sign of the hot spot or of any artefacting, so I'm delighted my camera can at least produce some nice results with such a dark filter. I'd still be grateful for any further tips anyone could give me, though.

eightcell

I have messed around with infrared for a little bit but with the R72 filter (720nm).
A custom whitebalance is a must. I generally set it to incandescent +3 or tungsten.
You should also try using an aperture of f/8 or above as it tends to yield better results.

Best of luck!

Promac

Can someone explain the IR photography thing?

I've never seen any particularly interesting images (no offence). Is it just for the sake of doing it?

sineadw

I guess its personal taste. I've never seen any sports or landscape images that particularly do it for me.

I want to get into the portrait side of IR things personally. And yep, I guess it is somewhat for the sake of doing it. Sure if you don't try things you go a bit stale IMHO.

Promac

sineadw wrote: »

I guess its personal taste. I've never seen any sports or landscape images that particularly do it for me.

I want to get into the portrait side of IR things personally. And yep, I guess it is somewhat for the sake of doing it. Sure if you don't try things you go a bit stale IMHO.

Absolutely yeah - if no-one did anything interesting or unusual with it then none of us would be doing this. I just wondered if it was particularly difficult or whatever. I don't know anything about how it's done so I can't really appreciate it.

sineadw

I'm only really starting to dabble in it properly (its a total bitch to get the film) but yeah it's not easy. As I'm learning, IR light doesn't take to metering like visible light. Different lattitudes, different times of day can all effect exposure, so you have to bracket bracket bracket. Even focus works slightly differently so you can't trust your eye. You also have to load and unload the film in a darkroom, and block the film window. Mine is covered in tinfoil and sellotape at the moment

It's what it does with light though that interests me. There's no anti-halation layer on the stuff I'm using at the moment, so you get that cool bloom off vegetation. By far the coolest thing for me though is what it does to portraits - it actually photographs under the skin slightly and eyes register black. The teenage goth in me loves that

Digital IR is a bit different in that you're able to more or less see as you shoot so you don't have issues with exposure or focussing once you know what you're doing. But you're usually looking at very long exposure times, with my digital sensors anyway, which kind of rules out portraits.

So there you go. Bet you're sorry you asked now. Sorry OP for going slightly off topic, but I hope some of it suits the more general side of your question.

DaireQuinlan

This being a rather bizarre case in point ...



That was shot using RA4 (colour) paper which, it turns out, is sensitive a little into the IR band, which makes the red component of the print go all funky. This is just the red channel. It's not an extreme example, I've seen far far crazier IR portraiture. OTOH, used subtly I think it could be very effective. Used straight, with maybe just a little filtering, the IR should contribute just enough to a portrait to raise the skin tones a bit and smooth them out and make them look just that little touch translucent. I've messed around a bit trying to do it and never really gotten anywhere. Still ongoing though.

sineadw

And here's one of my son shot in SFX (not as sensitive to IR) with just a normal red filter on I think? I need to take better notes..



OP - can you set a custom white balance from one of your shots on your camera? Take a long blurry shot of some well lit grass with the filter on, make sure the red channel is going to the right or even slightly clipped on your histogram (assuming you can view your histogram in RGB mode?) and set from there

Promac

sineadw wrote: »

Bet you're sorry you asked now. Sorry OP for going slightly off topic, but I hope some of it suits the more general side of your question.

Not at all! Cheers Sinead. And yeah - sorry for the hijack OP.

Fenster

Oh hai! I'm kind of Mister Infrared around here, mostly due to my bordering-on-autistic-obsession with the alternate wavelength.

Hotspots are caused by light bouncing around the lens willy-nilly, especially in cheap and/or wide-angle lens. Consider vignetting in a photograph you shoot wide open: The centre of the image is bright, while the edges are darkened. This is exactly what happens with infrared hotspots, except the effect is markedly more pronounced because you are literally using a wavelength of light for which the lens wasn't designed. Ideally you should browse around to find a suitable lens, although I see that you are using a prosumer camera and therefore (unfortunately) SOL. Your best bet is to 1. shoot at a longer focus length, 2. pump ISO to lower your exposure time and 3. Avoid shooting something that's in full-on direct sunlight.

I have a photoblog, Misadventures at 720nm, that is mostly geared towards infrared photography:

http://www.720nm.com

mdebets

sineadw wrote: »

I'm only really starting to dabble in it properly (its a total bitch to get the film)

Sorry for hijacking this thread, but where is the best place to get 129 IR film in Dublin (or is it off to the Internet) and can they be developed in a normal lab or do they need special treatment?

I asked at Gunns before I left and they didn't had any IR film, but I luckily got a role of Efke 820 and 2 roles of Rollei IR400 in Athens by accident. So I need some more when I come back.

DaireQuinlan

mdebets wrote: »

Sorry for hijacking this thread, but where is the best place to get 129 IR film in Dublin (or is it off to the Internet) and can they be developed in a normal lab or do they need special treatment?

I asked at Gunns before I left and they didn't had any IR film, but I luckily got a role of Efke 820 and 2 roles of Rollei IR400 in Athens by accident. So I need some more when I come back.

It's normal B&W film so it develops up in conventional B&W developers. HAndling can be a little different though. The old Kodak IR films, and the newer Efke films, particularly aura, have to be loaded and unloaded in darkness if possible, as they're particularly sensitive to IR and the felt trap at the entrance to the 35mm cartridge isn't IR proof apparently. In addition, with the aura film, because there's no anti-halation layer, you can get light piping along the film which can fog the first few shots worth of film.

As long as you follow those precautions though they're as easy to dev as normal film.

sineadw

mdebets wrote: »

I need some more when I come back.

Internetz I'm afraid. Although Gunns have a new supplier and are hoping to get some in at some stage.