In a nutshell, the world didn't behave as you expected. But it doesn't
matter. You have the color raw file and can tweak it to maximum effect.
If you had chosen to shoot a JPEG or a film B&W you'd still be
mystified at the result and have no options to recover.
Chuck Norcutt
On 7/18/2012 10:30 AM, Ken Norton wrote:
>> Exactly! Why for any reason accept the camera's version of B&W? It
>> started from the same raw data available to you to process as you desire.
>
> I was home last night and took a few minutes to stare and compare the
> in-camera to an in-computer conversion of the unfiltered shot.
> Something totally strange happened. I'll blame it on the extreme
> temperatures or something, but there was little difference between the
> conversions.
>
> The scene was a bright sunny summer afternoon with puffy clouds. The
> sun angle was high but about 45 degrees behind and to my right. The
> picture included grass, gravel, water, rocks, trees and sky. A classic
> mid-afternoon scene. To my eyes, this was a typical "Sunny 16"
> setting. According to the Sekonic L-508, it was closer to a "Hazy 11".
> According to the image files, it was a "Hazy 11". This is one of those
> situations where a B&W image is definitely enhanced by color filtering
> to counter the haze.
>
> With the normal unfiltered RAW file conversion, I did the monochrome
> conversion in post using the standard red, green, yellow, orange, blue
> and cyan settings. Remarkably, there was little difference between
> the images. This had me puzzled. So, it took a little deconstructing
> to see what went wrong. Usually, selecting a red filter or a green
> filter will yield massively different images, but in this case they
> were almost the same.
>
> We are in a drought here in Iowa. There are places that have gotten
> rains and places that haven't. Within this scene, the green vegitation
> looks green to the eyes, but the camera was certainly seeing the brown
> coming through. The actual percentage of green grass to brown grass
> was such that in the filtered image, they counteracted each other. One
> leaf would darken, while another would lighten, cancelling out the
> overall effect. As to the sky, the haze was great enough that the
> extent of the change from one extreme to the other in the "blue sky"
> was no more than a half-stop. The red filter (either on-lens or
> post-process) had minimal, but visible, difference. Even the polarizer
> had little effect.
>
> I reshot this Monday evening at a different location. Unfortunately,
> the clouds had cleared off, but the haze remained. I got differences,
> but again, they weren't revealing what was expected in the tests.
>
> It's not that I just rolled off the turnip truck last week. I know
> what these filters do. I do know my B&W. But stuff just wasn't doing
> what I expected it to do. So, that's where my engineering mind kicks
> in and tries to figure out what happened or didn't happen.
>
> Several thoughts:
> 1. The haze layer was great enough to minimize the differences.
> 2. The digital sensor has greater or lesser visibility of the UV/IR
> spectrum than film which defeated the effect of the filters.
> 3. The Panasonic DMC-L1 is lousy for B&W conversions.
>
> As to the first point, this is entirely possible. The visiblity
> conditions were less than 10 miles.
>
> The second point is one that we can look at the spec sheets on to
> determine and then speculate on the effect. Testing can confirm.
>
> The third point was easily tested. I pulled up several other pictures
> that were representative of this scene and in the editor, I converted
> to monochrome using various color filters and it responded as we would
> expect.
>
> There may be other causes which I'm open to discussing. Regardless, it
> looks like I'll just have to wait for a better day, which isn't so hot
> and soupy, to prove my theories.
>
> AG Schnozz
>
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|