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08-21-2008, 07:34 AM   #16
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K20D, FA43mm Limited, HOYA R72



f9.0, 30 seconds, ISO 100

You can see the full sized image here

http://farm4.static.flickr.com/3194/2783490315_dd6c8cc9a4_o.jpg

Here is a 100% crop, randomly chosen.



A few key things to note about these.

First, they are based on 6Mp JPGs as my larger card junked out and I'm waiting for a new one. Currently, I'm reduced to a 16Mb card. So, No RAW file exists.

Second, The WB HAS to be set with the filter in place. This is the hardest part of the entire process. Set the camera for some long wide open exposure or boost the ISO way up. Put the filter on the camera, press the FN button. Go to the the icon for WB that looks like a computer screen (does to me anyway). Point the camera at some neutral object, close up so to fill the frame (manual focus please) and focus to long distance (infinity). Take Press the shutter release. If you see an image on the screen (takes just as long as taking a photo), you're all set. Pick a clean area using the 4 way controller, press the OK button and you're ready to go.

If you skip this step, you'll end up with something like this and post processing is an exercise in futility.



Third, the sun really should be at a higher angle for something like this. These photos were created in response to this thread. Also note that with a 30 second exposure, Wind is the enemy, unless you want the blurred look. Take the photo using a rock solid platform, and for longer exposures, cover the viewfinder (I was a doubter until I tried it myself).

Good luck.


Last edited by JeffJS; 08-21-2008 at 07:41 AM.
08-21-2008, 11:22 AM   #17
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QuoteOriginally posted by JeffJS Quote
Second, The WB HAS to be set with the filter in place. This is the hardest part of the entire process. Set the camera for some long wide open exposure or boost the ISO way up. Put the filter on the camera, press the FN button. Go to the the icon for WB that looks like a computer screen (does to me anyway). Point the camera at some neutral object, close up so to fill the frame (manual focus please) and focus to long distance (infinity). Take Press the shutter release. If you see an image on the screen (takes just as long as taking a photo), you're all set. Pick a clean area using the 4 way controller, press the OK button and you're ready to go.

If you skip this step, you'll end up with something like this and post processing is an exercise in futility.

Or shoot RAW and pick your white point in Post. Even using JPEG, you can correct the color using Levels.
08-22-2008, 03:45 PM   #18
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QuoteOriginally posted by alohadave Quote
Or shoot RAW and pick your white point in Post. Even using JPEG, you can correct the color using Levels.
It's never worked that way for me. Best to just get it right to begin with.
10-19-2008, 10:01 PM   #19
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It may be more than a digital filter...

QuoteOriginally posted by vizjerei Quote
actually there is a setting in K20D that it will output the picture as infrared picture, but of course it is just a digital filter.
Yesterday (Oct 18) I was at a seminar put on by the Abbotsford Photo club.
APAC Seminar Home While there, I had a chance to speak with a Pentax rep who was displaying demo images from the K20D (IR included). From his description some infrared light passes the filter which is built into the camera. For normal pictures this remaining infra red is removed electronically. However when you set the K20D to the infra red setting the infra red which makes it through they physical (in body) filter is extrapolated to recover an accurate infra red image.

I had some time this evening to play with it, and there may be something to what he had to say. I set my K20d as follows. 18-250 F3.5 - 6.3 locked at 18mm. F4 2 Second Exposure, ISO 200 Auto White Balance, No flash. As the image will only be posted here, I set the camera to record a 2 megapixel jpg. I then resized it 800X600 with the Microsoft "image resizer" powertoy. Microsoft PowerToys for Windows XP

As a test, I just did a quick hand held shot of my TV remote in a dark room (no visible light at all).

As you can see from the attachment the K20d did record some of the IR light that the tv remote was emitting. Not sure how well this will work in the field, but I will do some additional testing with it. The demo shots the Pentax rep had were quite impressive.

To complete the test, I repeated it with the K20D set to "Natural" It did pick up some light from the remote which shows red in the picture, but was invisible while doing the test.

To set the K20D to IR:
- Press Fn
- Press OK
- Move left or right until you get to BW
- Move down and change the filter effect to Infrared Color
Press OK to complete the change.

To change back set the filter to Natural rather than BW.

Attached Images
View Picture EXIF
PENTAX K20D  Photo 
View Picture EXIF
PENTAX K20D  Photo 

Last edited by pureluck; 10-19-2008 at 10:14 PM. Reason: Added info on setting camera to IR
10-20-2008, 12:11 AM   #20
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QuoteOriginally posted by pureluck Quote
For normal pictures this remaining infra red is removed electronically.
I seriously doubt that is even possible.It's just bits and pixels, and none of them have "Hey, I'm infrared !" written on them. Infrared light just adds signal to red channel. After the sensor readout no electronics can know what caused this signal - visible or infrared light or mix of both. And if they really remove some data from even the RAW file then that would be really disappointing.
10-21-2008, 11:30 AM   #21
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My understanding of everything I have read is that the 'IR' setting in the camera is just a way of processing the RAW image, nothing more.

I eventually purchased an IR converted K100D and I've been very happy with the results.
10-21-2008, 02:39 PM   #22
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I used to use an istD and R72 filter and at F8ish my setting used to be around 1-3 seconds aswell. My same settings on my K10D were about 25 seconds or so.

Gave that up right away..

In June i bought a Canon G3 converted off of ebay for $250. It performs great. Came preset with custom WB and i shoot in B&W mode. Auto tone in LR 2 sets up a nice shot.

I'm still mulling over converting my old D1, and then i'll have a bunch of telephotos to use.

Dave
11-05-2008, 02:07 PM   #23
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Hi

Infrared pictures can be taken using a k200d ?
If so, how ?

Thanks in advance

11-05-2008, 03:45 PM   #24
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QuoteOriginally posted by jfsavage Quote
That's interesting! You're using 1-3 seconds at f11-13, I'm looking at 5 minutes at f4! So either the K20D has a much stronger hot mirror, or the problem is with my cheap Opteka filter.
There are many factors influencing IR performance. For once the Pentax cameras got less IR sensitive one model after the other. The K10 was already hardly useable and the K20 is even less so.

But the lens has an influence on the results too. If you search on the web, you will find some nice comparissons on the influence of different lenses and their IR opacity.

The filter is the third variable and it might well be, that your Opteka, which is a cheap modell, has a bad influence on the image, but I doubt another filter will really remedy the situation. An older istDS is a much better choice for IR. When I still had mine, I compared the istDS against the K10 and the expsoure times with a Hoya filter were at least four times shorter on the istDS.

Ben
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