Author Topic: Questions and Answers on IR  (Read 94107 times)

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Offline Rob aka [minolta mad]

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Re: Questions and Answers on IR
« Reply #105 on: September 17, 2009, 04:18:05 PM »
Look forward to seeing the results when you get the lens.


Rob

Offline hopeless

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Re: Questions and Answers on IR
« Reply #106 on: September 17, 2009, 09:28:28 PM »
For inspiration / jealousy, you might enjoy this article:

20 Stunning Infrared Photographs
http://hopeless.smugmug.com (gallery)
Hot off the memory card (photoblog)
Shutter Scouts (photographer's notebook and forecasting service)

Offline groovyone

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Re: Questions and Answers on IR
« Reply #107 on: September 18, 2009, 05:24:57 PM »
Some very cool shots.

Offline Stef.

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Re: Questions and Answers on IR
« Reply #108 on: September 18, 2009, 05:29:32 PM »
Some really stunning shots but than I have a love-hate relationship with colour IR and hdr. For black and white I do love the effect but when it comes to colour I always wonder why one wants to have these strange colour images???
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Offline Rob aka [minolta mad]

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Re: Questions and Answers on IR
« Reply #109 on: September 18, 2009, 05:33:07 PM »
Some very nice images, but i prefer B/W IR images to colour.


Rob

Offline pcabot

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Re: Questions and Answers on IR
« Reply #110 on: September 22, 2009, 03:16:35 AM »
Hi,

I finally got my Minolta 35-70 F4 with the new Hoya R72 49mm filter!
Wow...!! I am really happy to have it !

I took my first shot quickly today as soon as I received it:
f8, 25s, no saturation, no DRO

Here is the ARW file associated to it:
http://philippecabot.com/infrared/infraredv14.arw

After a few actions in photoshop, I got this:


I am not totally satisfied with the "false color" result.
You can try playing with the ARW above to see if you can succeed obtaining

But I think I know why: I used the auto white balance feature of the camera.... :(
When I saw the result, I remembered that changing the white balance before the shot is necessary in  order to achieve the false color effect.


Next time I go outside, I will try to set it.
BTW, to set the custom WB, here are the steps that I am planning to do:
 0. Set the camera to manual focus
 1. Put the R72 filter on
 2. From the custom white balance menu, select "Custom setup"
 3. Aim at green foliage
 4. That's it.

Last time I try do that, I got "Custom WB error", with the value 6600k G9 ?
Is this normal ? Is this the process you are using to set the WB ?

Thanks for the feedback !
Philippe

PS: btw this 35-70 lens is great for macro shots!! (This is my first macro lens!)

Offline groovyone

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Re: Questions and Answers on IR
« Reply #111 on: September 22, 2009, 04:09:20 AM »
When I tried custom WB on mine I'd get an error, but then I just set it to that same value manually.  Mine is usually 2900 G9 I think.  I posted it earlier.

I am going to take a look at your RAW.  My first guess is it may be a hair underexposed.  Did you have direct sunlight on the trees and bushes?

I played with it a little and I think you ar eprobably 3 stops UNDER exposed.  In similar light try f/5.6 and 30 seconds or so.  If you open your file in IDC, look at your histogram.  You want it to be much further to the right.
« Last Edit: September 22, 2009, 04:15:33 AM by groovyone »

Offline groovyone

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Re: Questions and Answers on IR
« Reply #112 on: September 22, 2009, 04:24:14 AM »
Quick hack at it.  All I really did was stretched the sliver in the histogram out to fill it in better, and clicked trees with the custom WB dropper until I got a look I liked.  For the B&W I added +30 contrast or so.




Take a peek at the histogram when you shoot and see where the data falls.  You want it more toward the right side to get the whites from the trees.  You also really benefit from very direct sunlight.  I find the days where light is too harsh for normal shooting are best for IR.

Offline Rob aka [minolta mad]

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Re: Questions and Answers on IR
« Reply #113 on: September 26, 2009, 05:36:20 PM »
Quote
But I think I know why: I used the auto white balance feature of the camera.... Sad
When I saw the result, I remembered that changing the white balance before the shot is necessary in  order to achieve the false color effect.

That wont cause any major problems, the image above of Bideford was shot with a Custom WB, and adjuated in PS.

Just one quick question, what time of day was the image taken at ???.

I'll try and have a play with some shots at differant angles to the sun, and at differant times, as the sky still isnt coming out like id expect ???


Rob

Offline pcabot

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Re: Questions and Answers on IR
« Reply #114 on: September 27, 2009, 04:46:30 AM »
Hi !

You guys are great !

I finally got the the time to really try the lens, with the proper settings (long exposure and the 2500K G9 white balance).

I am really proud of my first shots !! Thanks for all the help !

Here is the original ARW
http://philippecabot.com/infrared/infrared17.arw

Here is another example:


But, I think since the sun was behind me that the light entered by my viewfinder... I am not sure. Is this why I get the green colors for the trees ? (after swapping channels in photoshop)

If you can convert the first image differently, let me know !
The steps that I do are:
 1. Open the ARW in Sony IDL
 2. Change the white balance using the picker and select something gray
 3. Save the file in TIFF
 4. Open photoshop
 5. Run the false color v2 action( see http://shawn.ocia.net/photos/falsecolors.zip )
 6. Tweak the colors a bit
 7. Sharpen

Let me know if you succeed in transforming the image using a different technique...I would be interested...

Thanks!
Philippe
(which is now a really happy IR shooter!!)

Offline Rob aka [minolta mad]

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Re: Questions and Answers on IR
« Reply #115 on: September 27, 2009, 04:27:57 PM »
Glad that you have finally got there and are getting the right results.

Quote
But, I think since the sun was behind me that the light entered by my viewfinder... I am not sure. Is this why I get the green colors for the trees ? (after swapping channels in photoshop)

The green tree's are a result of them being evergreen and the channel swapping in PS i would imagine. As evergreen tree's dont reflect IR light.

Will have a play with the RAW and see what i come up with.


Rob

Offline groovyone

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Re: Questions and Answers on IR
« Reply #116 on: October 04, 2009, 03:24:29 AM »
Looks good!

Offline groovyone

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Re: Questions and Answers on IR
« Reply #117 on: October 06, 2009, 02:19:20 PM »
I shot a few this past week while in Williamsburg, VA.  Not real happy with most of them, but I got a few decent ones.  I think my 100% A900 VF has spoiled me too, since I kept getting junk on the sides of my A100 shots.  Most of these were shot as the sun was setting, thanks to meetings and tehse are quick edits.










Offline balacau

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Re: Questions and Answers on IR
« Reply #118 on: September 29, 2010, 06:13:10 PM »
A couple of IR-based questions; even though this thread has pretty much answered everything else I could think of.

1) How does the use of artificial light in lieu of natural work with IR photography?  This is of particular interest as some of the photo shoots that I'm involved in are done in multi-story carparks with cars as the main subject.  These locations are usually very well lit with harsh strip lighting.  It may produce some interesting effects if it works with artificial lighting as well.

2) Has anyone ever tried IR photography by mounting a filter on a macro lens (like maybe the Tamron 90mm or 180mm)?  Even the smaller sized ones like Sony's 30mm?  Are macro lenses suitable for this kind of work or perhaps another kind of lens is a better choice?

Its a bit late in the year now to consider macro photography since most of the days its completely overcast now; but something to think about when little else note-worthy is happening during the late spring/summer (if we get one) next year.

Best regards

Gavin
a580 dSLR & a55 dSLT and a bundle of lenses to keep me happy

Offline Rob aka [minolta mad]

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Re: Questions and Answers on IR
« Reply #119 on: September 29, 2010, 08:19:02 PM »
Not entirely sure with how artificial light will affect the 'natural' light.
Personally i wouldnt have thought it would have much effect, but thats just an educated guess rather than anything proven.

As long as the macro lens doesnt produce hotspots, then its prefectly suitable. Though it wouldnt be my first choice lens for IR.



Rob