CHDK Forum

CHDK Development => Feature Requests => Topic started by: rocketjam on 30 / January / 2008, 15:20:12

Title: uv/ir
Post by: rocketjam on 30 / January / 2008, 15:20:12
I read today that Fuji has issued a firmware update for some of their cameras that enables "the camera's UV and/or IR wavelength sensitive CCD". I'm pretty new to CHDK so I don't know if this has come up before, but if any of the Canon CCDs have this capability, it would be really cool to have that enabled via CHDK.
Title: Re: uv/ir
Post by: GrAnd on 30 / January / 2008, 15:28:41
I've checked S3 with a remote control from TV. The sensor is sensitive enough to see the blinking of IR LED.
Title: Re: uv/ir
Post by: carlos on 31 / January / 2008, 11:38:06
I've checked S3 with a remote control from TV. The sensor is sensitive enough to see the blinking of IR LED.
A640 also ... very bright image.
Title: Re: uv/ir
Post by: jetzt on 31 / January / 2008, 13:51:22
I also have a bright point on my A710IS with my ir-remote. (Seems to be RC-5 XD, quite fast :D)
But it's somehow mapped as violet, not BandW like in ir photos,
any way, to create a custom filter and map only the frequencies in ir range?

Title: Re: uv/ir
Post by: zdravko on 31 / January / 2008, 14:01:19
In order to take "real" IR photos, you should filter out most (if not all) of the visible light. As far as I know this can not be done with software. Using a "hardware" filter works very well. I am using a HOYA R72 infrared filter with my S3IS camera. A little disadvantage is that you can not take handheld shots with the infrared filter, because too less light is reaching the sensor. But with tripod you can achieve wonderful results, look at this sample photo:

http://www.flickr.com/photos/epitti/280309607/

Regards,
Zdravko
Title: Re: uv/ir
Post by: jetzt on 31 / January / 2008, 14:08:12
Ok, I'll try that, when my camera is back on earth, right now I force it to capture form my rc-heli.
But motionless isn't possible how I think, so no ir-in-flight-captures...
Title: Re: uv/ir
Post by: spocket on 31 / January / 2008, 14:24:22
I am using a HOYA R72 infrared filter with my S3IS camera.
I don't know if it really works, cause I haven't tried it. But maybe someone is interested in that link:
Create your own (low cost) IR-Filter (http://www.photocritic.org/2006/create-your-own-ir-filter/#more-50)
Title: Re: uv/ir
Post by: rocketjam on 31 / January / 2008, 17:32:54
Cool photo zdravko.

spocket, after seeing that link you provided, I remember reading that tip elsewhere on the web. I'm going to have to try that.

Thanks.
Title: Re: uv/ir
Post by: PhyrePhoX on 01 / February / 2008, 04:49:32
you can combine the IR Filter with an IR emitting device (not just a remote control). surveillance cameras often have a set of IR "lights" to be able to see the reflecting IR rays (unnoticed by thiefs and such things). afaik they should be cheap to buy.
what i'm asking myself now is this: does the autofocus maybe use IR to focus? this way we could overcome the weakness of the AF at night.
Title: Re: uv/ir
Post by: zdravko on 01 / February / 2008, 07:00:45
does the autofocus maybe use IR to focus? this way we could overcome the weakness of the AF at night.

I do not think this is possible. If you take infrared photos, you will notice that the focus is somewhat different for this spectrum of the light. If you want to have a sharp focus on something which is 15-20 feet in front of you, you will have to set the focus at infinity (or near infinity). It is a bit try-and-guess game to have a sharp focus when shooting in infrared  :)

Regards,
Zdravko
Title: Re: uv/ir
Post by: a710is on 01 / February / 2008, 07:55:30
I once saw some incredible pictures with "white" trees that looked absolutely amazing and the guy said that he had the camera taking pictures in infrared by just basically pulling out some cable from inside some A-series camera. maybe CHDK could "pull that cable out" in software.
Title: Re: uv/ir
Post by: zdravko on 01 / February / 2008, 08:49:36
... and the guy said that he had the camera taking pictures in infrared by just basically pulling out some cable from inside some A-series camera. maybe CHDK could "pull that cable out" in software.

Maybe this guy did not explain well. Every digital camera has a tiny glass in front of the sensor. This glass is an infrared blocking filter - the goal is to block most of the infrared light, because the camera gets confused by it and cannot reproduce the visible light as we see it on the photos taken.
Some peoples are deliberately pulling the IR blocking filter out of their cameras and then using a filter similar to R72 (blocking most of the visible light and passing the infrared) they can take nicely looking infrared photos even with fast shutter speeds.

Here is an example for such a modification:
http://geektechnique.org/index.php?id=254

But it is not for the faint hearted  :D

Regards,
Zdravko
Title: Re: uv/ir
Post by: yeyoungpup on 03 / February / 2008, 21:25:27
If you want handheld IR photos you can take the IR cut filter off of some camera's sensors. One of my students is taking the filter out of a kodak m753 for a school project.
Title: Re: uv/ir
Post by: jetzt on 10 / March / 2008, 13:50:46
I tried that one today:   Create your own IR filter ||| Photocritic blog (http://www.photocritic.org/2006/create-your-own-ir-filter/#more-50)
found a rest of unexposed, but devellopped film, but I think I got the wrong type, there is only a color drift to red,
and that's it. However there are some nice / funny effects in b/w.
(You get the effect of high iso films, perhaps lower contrast, photos look like the old self-developped b and w photos,
an alternative to post processing, with the same better or in that case worse results.)

Any other experiences with that?

Edit: Thanks, had negatives. So dia should be right?.
Title: Re: uv/ir
Post by: Barney Fife on 10 / March / 2008, 16:21:58
Deleted
Title: Re: uv/ir
Post by: dzsemx on 14 / March / 2008, 15:46:23
i tried to make IR images with canon.
the bad news is that canon generally has a real good ir blocking filter :(
even professional ir pass filters doesn't solve situation, u get black image or something brown

my sony ericsson k800 does ir images... so i could make some puple ir pictures on a sunny day with black film (u need 2-3 layers of it, to get ir only image) :)
so you need to remove the ir block filter :) like here:
Canon A70 IR mod (http://www.thustra.com/A70mod/)
canon350d filter removing (http://personales.ya.com/javier_laina/ARTICULOS/FILTRO/filtro350deng.html)


btw... i removed ir filter from my shitty webcam so i made some very very very poor quality pictures with white grass, white trees and purple sky... something like this(not mine, just i didn't keep any of those shitty pictures): IR by ~Fynal666 on deviantART (http://fynal666.deviantart.com/art/IR-59086075)
if you wan't to make a real good quality ir shots, you need to remove ir block filter, use F11-F22 for sharpness, and shoot raw...
Title: Re: uv/ir
Post by: jetzt on 15 / March / 2008, 05:13:12
Did you also try with long expusures? I think with 15 sec or something like that there should be some results.
(I expected the need for long exposures cause of that.)

BTW. Your Webcam seems to be a good one, mine isn't that fine!
Title: Re: uv/ir
Post by: curumara on 02 / May / 2009, 23:47:55
But is there a way to change CDD IR capacibility to on just in firmware ?
Title: Re: uv/ir
Post by: reyalp on 03 / May / 2009, 00:22:47
But is there a way to change CDD IR capacibility to on just in firmware ?
No, of course not. The color response of the CCD is determined by physical filters, not software.