Dabbling with infrared.

greengiant · 9 Jul 2007 at 19:38

Managed to get hold of a cheap Kood IR filter from the bay, so I've had a little play with it on my K100D with 18-55mm kit lens:

Johnny|lucidcomposure · 9 Jul 2007 at 19:56

Whats infrared?

greengiant · 9 Jul 2007 at 20:06

Fstop11 said:
Whats infrared?

What do you mean by whats infrared?

Scuzi · 9 Jul 2007 at 20:06

Fstop11 said:
Whats infrared?

You haven't heard of IR photography? Really?

Johnny|lucidcomposure · 9 Jul 2007 at 20:10

Sorry Greengiant & Scuzi. Yes of course I have.

At the moment I am taking apart a 350D replacing the sensor hot filter with a custom IR one as we speak.

My comment was pure Johnny Sarcasm because I am excited

Your image is nice. Can I ask what shutter, ISO etc details were used as I am not familiar with the camera you used?

greengiant · 9 Jul 2007 at 20:17

Fstop11 said:
Sorry Greengiant & Scuzi. Yes of course I have.

At the moment I am taking apart a 350D replacing the sensor hot filter with a custom IR one as we speak.

My comment was pure Johnny Sarcasm because I am excited

Your image is nice. Can I ask what shutter, ISO etc details were used as I am not familiar with the camera you used?

From the image exif:

Camera Make: PENTAX Corporation

Camera Model: PENTAX K100D

Image Date: 2007:07:09 12:16:04

Flash Used: No

Focal Length: 18.0mm (35mm equivalent: 27mm)

Exposure Time: 1.000 s

Aperture: f/11.0

ISO equiv: 200

and an el-cheapo Kood IR72 filter.

Brave man taking apart a DSLR!

Johnny|lucidcomposure · 9 Jul 2007 at 20:45

So the Pentax takes bloody good IR shots if those are the settings.

I compliment you and encourage you to do more!

Yes Im very brave or very stupid. I guess in a few hours I will know the answer to that!

Just taking the sensor out now!! :O

greengiant · 9 Jul 2007 at 20:58

Fstop11 said:
So the Pentax takes bloody good IR shots if those are the settings.

I compliment you and encourage you to do more!

Yes Im very brave or very stupid. I guess in a few hours I will know the answer to that!

Just taking the sensor out now!! :O

From what I can gather the K10D is less sensitive to IR. It is a cheapo IR filter I have bought, but it seems to work OK with the kit lens.

I'm definitely going to dabble with IR more.

cheers

--
Brian

sean · 9 Jul 2007 at 21:03

Can I ask, did you do any post-processing to the image and did you apply a custom white balance? I ask because the IR filter I ordered should be arriving tomorrow and I've only ever shot IR on modded webcams and cheapo digicams

GeX · 9 Jul 2007 at 21:18

am interested in if any post processing was done there. i have a hoya ir filter that ive only had chance to have a quick play with. and everything was a lot more red!

http://tackycheese.net/images/misc/ir_play/

sean · 9 Jul 2007 at 21:24

GeX said:
http://tackycheese.net/images/misc/ir_play/

I think when that happens you're supposed to take a photo of something which would appear "white" in IR (a big patch of grass for example) then set your white balance off that and possibly swap the red and blue channels in post-processing.

But I wouldn't know.. I've not actually tried it yet

Howski · 10 Jul 2007 at 00:36

Out of interest do you have CS3 yet? It has an IR option in the B&W adjustment layer and I was hoping for a comparison. I'd be real in debt if you could take 2 images of the same scene one with the IR filter and one done threw PS. If you want I could do the PS bit.
-How.

Johnny|lucidcomposure · 10 Jul 2007 at 00:53

I have tried it in CS3. Not that impressed really.

Howski · 10 Jul 2007 at 01:14

I thought that would be the case - looks like there is one more thing to buy!
-How.

MikeHunt79 · 10 Jul 2007 at 01:47

Ok, photography noob here... Does an IR filter let thru only the IR, or block the IR?

I've been able to "see" infrared from my TV remote before on my cameraphone, as it has a cheap lens with no IR filter... but I thought all good cameras already have IR filter on the lens? :confused:

Anyway, cool looking shot.

Johnny|lucidcomposure · 10 Jul 2007 at 01:48

They have whats called a low pass filter inside them that blocks out radiation otherwise known as Infrared.

See my thread on sensor cleaning for a visual example.

Scuzi · 10 Jul 2007 at 01:55

Fstop11 said:
They have whats called a low pass filter inside them that blocks out radiation otherwise known as Infrared.

See my thread on sensor cleaning for a visual example.

You seem to be quite in the know about this. Does the Canon 20Da have the same internals as the normal 20D, only with the low pass filter removed?
Or is there more to it than that?

greengiant · 10 Jul 2007 at 07:41

MikeHunt79 said:
Ok, photography noob here... Does an IR filter let thru only the IR, or block the IR?

I've been able to "see" infrared from my TV remote before on my cameraphone, as it has a cheap lens with no IR filter... but I thought all good cameras already have IR filter on the lens?

Anyway, cool looking shot.

The lens mounted IR filter is really a filter which blocks out visible light. Makes it hard to see through the viewfinder on an slr, so you need to compose then fit the filter.

greengiant · 10 Jul 2007 at 07:43

sean said:
Can I ask, did you do any post-processing to the image and did you apply a custom white balance? I ask because the IR filter I ordered should be arriving tomorrow and I've only ever shot IR on modded webcams and cheapo digicams

Custom white balance (photographed a patch of grass with the filter on)
Then in GIMP, auto levels, swap red + blue channels in the channel mixer.

Pics straight from the cam tend to look like this:

--
Brian

Johnny|lucidcomposure · 10 Jul 2007 at 10:39

Scuzi said:
You seem to be quite in the know about this. Does the Canon 20Da have the same internals as the normal 20D, only with the low pass filter removed?
Or is there more to it than that?

Well the 20Da has a slightly different low pass filter engineered to allow more IR light through which will be enough for astrophotography. It will still let it both normal light and radiation (IR)

The 20Da has been built for the sole purpose of astrophotography.