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Eric, thanks for doing this, may we see the original D7000 image please?yes of course...below
I am interested why the shadow detail in the dark firs is so different between the two IR images.
This seems to be similar to the apparent loss of highlight detail in the original image Tom posted.
I am guessing its exposure. As you know....but for the benefit of those who havent dabbled with IR .....
With IR you get a fluorescence from the foliage which is in effect extra exposure.
The camera sensor cant 'see' this effect and therefore meters ONLY the visible light.
When the overal scene lighting is high (bright sun) the fluorescence is a minor part and the meter sets exposure for the scene correctly (OK the highlights might be a tad over, due to this extra fluorescence, but that gives the IR some of that hazy dreamy look). But in shadow areas this 'invisible light' is a greater contributor and lightens these areas. The nett effect is a lower contrast image.
The significance of this can be seen when you shoot on a cloudy day. The meter says 'its a bit dull' and opens up the aperture ...but the fluorescence is still there...so the image overexposes! I have to drop exposure when the sun goes in!
This balancing of elements can be critical, as (from whats been said above) the shadow areas on inanimate objects will be darker than the shadow areas of a foliage subject in the same scene! You can see this in the windows of the building on the two IR images, where the D200 has rendered them darker than corresponding shadow areas of foliage in the same lighting.
Of course, ideal exposure depends on what percentage of the image is taken up by foliage. If its only a supporting role ....then the exposure 'error' is less and keeping normal settings works ok.
Which brings me to the second point. For those aspiring to take good IR shots.
One of the most important points about an IR image....is the contribution of the parts that ARENT WHITE.
Instinctively we try to shoot wooded valley, trees by lakes, trees and grass. IMHO this becomes too boring...there is no 'subject contrast'. You NEED inanimate objects...eg...a gate, a wall, a sign, a machine, a (dark) building to counter the overal whiteness. In fact, I feel the white foliage should be a supporting role!
That being the case....when I tried to use a typical scene with a mix of natural and inanimate objects, I found the ACR method didnt recognise them as inanimate objects and rendered them on pure colour. It gave some weird changes to some (eg cars with coloured stickers) that were too distracting. The ACR method simply doesnt differentiate between things that need to be IR and others that are normally rendered just grayscale.
I will now stop rabbiting on.
Attachment: DSCF0962col.jpg (Downloaded 26 times)
Last edited on Wed Apr 24th, 2013 05:15 by Eric
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Eric