Saturday, August 23, 2008

Post Processing Variations

There are many variations of post processing – including none – a digital image file. This slideshow compares 22 variations of post processing a raw image file. The image was made with a Canon G9 in raw mode, ISO 80, f5.6 and 1/400 second exposure. All the variations were done in Adobe Camera Raw (ACR) with additional processing in Photoshop CS3 for some images. ACR agreed with this exposure setting, i.e., no exposure adjustment required. No noise reduction was applied to any variation. Each slide is numbered on the lower left hand side. Notice that some slides are repeated. The key for the variation is as follows:

1 White balance (WB) As Shot; auto tone in ACR, clarity = 0, saturation and vibrance = 0, linear contrast curve, no sharpening.
2 Same as #1 except Auto WB in ACR
3 Same as #1 except Daylight WB in ACR
4 Same as #1 except Cloudy WB in ACR
5 Same as #1 except Shade WB in ACR
6 Same as #3 except add Clarity = 30; Vibrance and Saturation = +10
7 Same as #3 except add Clarity = 30; Vibrance and Saturation = -10
8 Same as #3 except add Clarity = 30; Vibrance and Saturation = 5; medium contrast curve
9 Same as #8 except strong contrast curve
10 Same as #8 except add sharpening at 50, 0.8, 30,0
11 Same as #8 except add sharpening at 100, 0.8, 30,0
12 Same as #8 except add sharpening at 150, 0.8, 30,0
13 Same as #8 except add sharpening at 100, 0.8, 100,0

All the above slides were processed using only ACR. All the following slides had additional processing in Photoshop CS3.

14 Same as #11 except Auto Levels in CS3
15 Same as #11 except Shadow/Highlights in CS3 = 20 (all settings)
16 This is a blend using Fred Miranda’s DRI plug-in to CS3. Slide #13 was underexposed in ACR by -1 stop; a second file was overexposed by +1 stop. These two files were then blended.
17 This is a blend done manually in CS3 from Slide #13. One layer (for the sky) was at +1/2 stop and another at -1/2 stop for the foreground. The blend was done with a simple gradient mask.
18 Same as #13 except that exposure in ACR was increased by ½ stop; Recovery was manually set to 40 and Fill to 10.
19 Same as #18 except that Fred Miranda’s Velvia Vison (set at 40) was used to simulate Velvia film.
20 Same as #18 except that Pixel Genius PhotoKit Color was used to simulate Kodachrome film.
21 Same as #20 except that Pixel Genius gray balancer was used.
22 Same as #18 except that Pixel Genius PhotoKit output sharpening (medium) was applied.

The most obvious effects are from white balance, exposure, saturation and contrast. Interestingly, quite a few variations that would be visible in prints or full screen views simply don’t show up in the slide show. This is a reminder that there are many details that just don’t matter for small screen shots with high jpeg compression ratios.

I’m not saying that any of these variations are better than the others. Of course there are many, many other ways of processing this image. I even did an over-the-top High Dynamic Range with Tone Mapping based on three separate in-camera exposures. That variation is posted it in my SmugMug G9 gallery.

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1 comment:

Pepako (K) said...

Lovely explanation and great examples.

Best regards from Spain.