High ISO Digital Monochromic [BW] Imaging

[tonygamble]

Well done for spotting that, Den.

I've installed it and am having an experiment. It seems pretty varied in what it can do.

Initially I felt it might make me a bit lazy. But 99% of my prints are simple improvements and it is rare that I go for special effects - so it will be a good complement to PWP.

I have some boring web images I need to post soon. This might jazz them up a bit!

Tony

[tonygamble]

And by coincidence this thread has just come alive on DPR

http://forums.dpreview.com/forums/readf ... d=34664232


Pointing also to this article.

http://www.prime-junta.net/pont/How_to/ ... tml?page=5

Tony

[tomczak]

Tony, the second technique 'overlays' the grain image over the actual image. The grain image is uniform, but when added to actual image, it seems to be visible mostly in midtones (as I think it should). Am I seeing it right? If so, there were no masks being mentioned - how does the 'overlay' in PS work - is it different from 'blend' in PWP? Cheers.

[den]

MaciejT... TonyG...

...I was able to essentially duplicate the article's "grain.jpg" with no mask by:
(1) downloading the "nograin.jpg" and "t400small.jpg" from the article's web page and opening them in PWP;
(2) clicking on "t400small.jpg" and opening the Composite-HardLight transform and setting the Overlay = "nograin.jpg" leaving everything else at default and clicking OK.

Some interesting things can happen if you:
(1) convert the "t400small.jpg" from 8-bit BW to 8/24-bit Color; (2) apply an 'active' Mask Tool - Brightness Curve [the default diagonal curve for example] to "nograin.jpg"; and (3) use the 'active' mask as the Overlay in the Composite-HardLight transform.

By doing the above, you preserve bit depth [probably an unnessary nuance] and can change the image contrast by clicking on the Mask Tool 'None', form a new curve, and 'lower left Apply - Add'.

Incidently... the "t400small.jpg" grain image is a version of the grain texture tile that I illustrated previously in this thread.

Perhaps the key to adding grain to a digital BW image may be that instead of using the BW image as the Input image of the Composite transform, use it as the Overlay with the grain texture image as the Input image.

[den]

Should add this comment to the above...
...Using a grain image as the Input image to Composite-HardLight with the main BW image as of the Overlay will only work if the grain image has a bell shaped historgram distribution whose peak is at the 50% tone as is the case with the "t400small.jpg" grain image.

[tomczak]

Soft Light Composite, with a grainless image as input and the grain image as overlay, works too, I think, somewhat more subtly.

I also tried producing synthetic grain file with PWP's Texture. Wight Tiles Size set to max, Power set to somewhere between -0.5 and 0.5 and perhaps cutting down a either high, low or both frequencies, there is a variety of believable grain-like textures, some with structure that I can't tell apart from the grain scan file from the article (and with central bell-shape brightness distribution - with the effect of adding more grain in midtones if soft/hard light composites are used; but not with the Filter transform.).

I can't figure out how to possibly automate such effect in a workflow?

[den]

For those who are registered on the DPR forums... free image hosting is available with auto-downsizing for maximum 20 Megapixel jpeg images... click on the small image to 'load' the next larger size... image will appear fuzzy until 'loading' is complete... click on 'Original' to see the full sized image [warning... could be a 2 or 4 MB file size]

[might be a place to temporarily post/exchange/display higher resolution image files for discussion]

A recent posting where grain was added to a BW conversion of a colored image is here:
http://forums.dpreview.com/forums/read. ... e=34853882

The conversion consisted of vignette-ing the background; preference sharpening; extracting the Luminous and R channels; Composite-Softlight the Luminous with the R channel as the Overlay; preference BrightnessCurve adjustments; then Composite-Hardlight the grain image ["grain-tm400.png"] as the Overlay; and Composite-Blend the grain BW image with the non-grain BW image to a preference grain softness....

TonyG... is this approaching your vintage 'film noir look'? I held off on the contrast somewhat thinking the young lady did not need to be 'aged'!