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09-11-2007, 02:58 PM   #16
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QuoteOriginally posted by Duplo Quote
Well I guess those making colour IR from their digital cameras will have to disagree with you, I have seen a few people doing that and with quite impressive results.

Agree with you, Duplo - I don't mind leaving that info in my IR photos




There is a little light that comes through on those channels, and if you pump up the saturation it can really look neat.
Attachment 4807


Last edited by khardur; 01-29-2008 at 02:47 PM.
09-11-2007, 08:08 PM   #17
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The most important thing I find is to get the custom white balance right in order to get the right tones, especially green foliage.

I use the K100D and find that the DA18-55mm kit lens is really very good for IR. Tried the DA16-45mm and found it prone to hot spots. Hot spots can be minimised by using a wider aperture. The K10D isn't so sensitive to IR and requires a way longer exposure whereas it is possible to shoot the K100D hand held in bright light.

Here's some shots hand held:





09-11-2007, 08:49 PM   #18
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QuoteOriginally posted by creampuff Quote
The most important thing I find is to get the custom white balance right in order to get the right tones, especially green foliage.
This was mentioned before - I haven't verified that setting a custom white balance will produce results any better or different from shooting RAW. Why would it?

Anyway, here is my shot from today. Handheld with the *ist D (although it was a very steady hand...1/6th second). You wouldn't guess it was a crappy rainy day today.

09-12-2007, 06:16 PM   #19
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QuoteOriginally posted by Duplo Quote
Well easy now Leo. You come across pretty harsh to me.

I recall two currently running about IR, someone asking for a lighter IR filter than the Hoya R72 IIRC and this thread that I have come across lately.

Well I guess those making colour IR from their digital cameras will have to disagree with you, I have seen a few people doing that and with quite impressive results.

If you are using a stronger filter like the R90 you may be right, but the R72 actually let some green and blue light pass through too, why not use that as part of your Image?

I guess I do not see the point of excluding 3/4 of your imagedata.
-------------

I did not mean to sound harsh, perhaps I should have explained my two points better.

I mentioned it is hard to search for IR threads. I just searched for my name. I've posted in seven IR threads and I'm fairly new at this forum so I'd say there are at LEAST seven IR threads since February. In one of the threads someone mentioned how they could not search for IR because it is too few letters, and Infrared is often not spelled out. Thus, the same questions come up regularly due to no fault of the questioner.

Infrared light, longer wavelength than 690 Nanometers, is on the opposite side of visible red than blue or green. The 720 nm Hoya passes very little visible light, the viewfinder is black on a sunny day. The red pixels respond to IR moderately well, especially in a modified camera like my K110D. The blue and green pixels contribute very little to an IR photo, only picking up a little light that "leaks" through the Hoya filter or, as Andrew suggested, enters the camera without going through the lens. Thus, to me, the Blue and Green are artifacts that are not IR and can not add to the photo. Andrew's original post was about blue streaks that were hurting his otherwise good image. Most IR images either convert to Black and White, use a false red, or use sepia. IR has no color, thus anything other than B&W is not IR but rather the photographers choice to colorize the photo. I happen to like to display IR as red knowing full well it is not.

Thus my suggestion: if you only extract the red pixels from the RAW file then you will have the IR without the junk. This thread was initiated to ask how to fix false blue in an IR image.

The slightly color images added to this thread after my post are the only ones I've seen. No real green trees or blue sky, but some color appears. The Pentax internal filter cuts IR so strongly that the green and blue have some chance to be effective. My filterless K110D is about 300 times better at IR than my K100D, I typically shoot at 1/3000 second on a sunny day.


Last edited by LeoTaylor; 09-12-2007 at 06:32 PM. Reason: Added paragraph about now images in thread
09-12-2007, 06:32 PM   #20
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QuoteOriginally posted by LeoTaylor Quote
-------------

I did not mean to sound harsh, perhaps I should have explained my two points better.

I mentioned it is hard to search for IR threads. I just searched for my name. I've posted in seven IR threads and I'm fairly new at this forum so I'd say there are at LEAST seven IR threads since February. In one of the threads someone mentioned how they could not search for IR because it is too few letters, and Infrared is often not spelled out. Thus, the same questions come up regularly due to no fault of the questioner.

Infrared light, longer wavelength than 690 Nanometers, is on the opposite side of visible red than blue or green. The 720 nm Hoya passes very little visible light, the viewfinder is black on a sunny day. The red pixels respond to IR moderately well, especially in a modified camera like my K110D. The blue and green pixels contribute very little to an IR photo, only picking up a little light that "leaks" through the Hoya filter or, as Andrew suggested, enters the camera without going through the lens. Thus, to me, the Blue and Green are artifacts that are not IR and can not add to the photo. Andrew's original post was about blue streaks that were hurting his otherwise good image. Most IR images either convert to Black and White, use a false red, or use sepia. IR has no color, thus anything other than B&W is not IR but rather the photographers choice to colorize the photo. I happen to like to display IR as red knowing full well it is not.

Thus my suggestion: if you only extract the red pixels from the RAW file then you will have the IR without the junk. This thread was initiated to ask how to fix false blue in an IR image.
I guess you are actually right about the search for IR... Never occured to me. my apologies.

Different approach to different people... that is what makes photography great. personally I like that little visible light that sips through the R72 filter, it works for me, but one have to be careful about blocking the viewfinder etc, otherwise it results in noise.

Again my apologies for misinterpreting you.
09-12-2007, 06:47 PM   #21
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QuoteOriginally posted by Duplo Quote
I guess you are actually right about the search for IR... Never occured to me. my apologies.

Different approach to different people... that is what makes photography great. personally I like that little visible light that sips through the R72 filter, it works for me, but one have to be careful about blocking the viewfinder etc, otherwise it results in noise.

Again my apologies for misinterpreting you.
---------------

No apology needed. I'm sure if we were talking rather than typing we'd understand each other better. Each photographer displays IR differently. Just because I like "pure IR" does not mean I don't enjoy Khardur squeezing some color out of that stone tower.
09-25-2007, 12:45 PM   #22
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How do you set the custom White Balance? I tried using a WhiBal card with my K100D with an R72 on my DA18-55mm and kept getting "NG".
Steve
09-26-2007, 07:49 PM   #23
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QuoteOriginally posted by LeoTaylor Quote
---------------

No apology needed. I'm sure if we were talking rather than typing we'd understand each other better. Each photographer displays IR differently. Just because I like "pure IR" does not mean I don't enjoy Khardur squeezing some color out of that stone tower.
I guess you are right about that.

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