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Old Apr 12, 2007, 7:45 PM   #1
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If this is something that has been covered elsewhere, I apologize, but I have yet to see any guide to RAW conversion that follows the same methodology I'm going to explain here.

I came upon this technique because I've been doing a lot of shooting in extremely low light conditions and kept finding myself spending far too much time messing with the settings in ACR. I would frequently push the sliders all the way to either extreme and it wouldn't be enough and images would come out very unnatural looking.

Although the instructions I'm giving here deal with the settings in Adobe Camera Raw, I believe the principles of the method should be applicable to a wide range of programs.

So, here's what I started doing. I made a preset in ACR called "flat" that would set all the adjustments to 0, set the white balance to "as shot", and set the curve to "linear".

In details I set the sharpness and luminance smoothing to 0 and chroma noise reduction to 10. Sharpness is 0 because in high ISO shots (or very underexposed shots brightened up) I found that it would tend to sharpen the noise more than the image detail, and I also prefer to tweak the sharpness on a per image basis. Noise reduction is set to 10 because on the K100D that seems to do a good job on nearly every image.

Here's an example of how I would use these settings. This is a photo taken in a cemetery at around midnight. As you can see, with the default settings the contrast and shadows are turned up, which only helps to darken areas that are already too dark.

With the "flat" settings applied, the image loses contrast and brightness;

But now that everything has been simplified, it's a simple matter to start tweaking. I being by dragging the Curves adjustment point on the right to the edge of the image's levels.

In the case of this image, I want to brighten the dark areas and darken the bright areas. Basically, I'm giving this image the HDR treatment. So, I add an adjustment point in the dark area of the levels and raise it, then add one at the high end and lower it;

I tweak those points until the image looks very close to how I want it, then I go back to the adjustments tab to make final tweaks;

Here's another example that is probably a more practical application for most shooters. This is a photo I took of some deer that was shot into the sun. There was an extreme glare that both washed out the image and caused the camera to underexpose;

I again begin by using the "flat" settings;

Then in Curves I bring the adjustment points close to the edges of the image's levels;

I add two more points similar to what I did with the last image, but in this case I want to increase the contrast, so I brighten up the high end of the levels and darken the dark end;

Finally, I go back to the Adjustments tab and make some tweaks, including a slight tweak to the temperatue;

I'm not going to say that this image is by any means a great photo, or that the adjustments I made were perfect (I actually prefer the warmer, lower contrast version), but it does illustrate how quickly a bad photo can be made into something that isn't half bad.

And it's not as if this technique is only meant for poorly exposed photos. The fact is, it's much more quick and effective on well exposed photos;

ACR Default

"flat" setting with basic adjustments

It is quite effective at increasing contrast without blowing out highlights, as well as increasing the saturation levels in a very natural way.

This methodology might not appear to be very quick in some cases, but because you are working directly with the levels and curves to start with, you are applying simple adjustments with a very high level of accuracy. Also, by setting a base adjustment in curves and then applying adjustments using the sliders afterwards, tweaking the image later on becomes much easier as you'll get more predictable results from the sliders.

You may have noticed that on the first couple images there was a very narrow dyamic range to work with in Curve. Sometimes this could be problematic with curves adjustments as even the slightest tweak of an adjustment point can cause drastic changes. There are two ways to deal with this. You can turn up the brightness and exposure settings first to expand the levels across a wider range, but this may affect the accuracy of your changes.

What I prefer to do is get the adjustment points as close as I can, and then start typing in values for the input and output. This is easier than it appears. You simply select an adjustment point and type in a higher input value to move it to the right, or lower to go left. On the output, higher moves it up and lower moves it down. More simply put, higher values will darken and lower values will brighten.
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Old Apr 13, 2007, 2:07 AM   #2
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Nice workflow Corpsy , going to try it as soon as possible.

and keoeeit just downloaded that Raw Therapee to play around with

Thanks Ronny
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Old Apr 13, 2007, 2:15 AM   #3
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Thanks for the link. I'm a big supporter of freeware and I've never seen a free raw converter with noise reduction features.

I downloaded the software and tried it out for about 20 minutes. It looks nice, but that's as much as I can say about it. It took some time to figure out how to actually load an image into it, and once I did, it was extremely slow and not very effective. I don't even understand what it was doing, just that anything I load into it looks like it was shot at ISO 12800. The noise reduction didn't seem to help much at all.

My raw photos actually look cleaner in Picasa which isn't even a raw converter and has no noise reduction. It seems like the free tools from Pentax would be far more effective, and those are definitely nowhere near as good as ACR.

Anyway, the point wasn't that ACR doesn't do things automatically, it does plenty automatically and that was the problem. If I want software to tweak all my photos automatically, I'd shoot JPGs.

There is no curve or setting that does an equally good job to every single photo, and when you've got a preset or auto function that has a dozen different settings all doing different things, it can be difficult to figure out where to begin tweaking. By flattening everything to it's original state and working with the curves directly, you just have to set your highlight point, shadow point, and two more points to brighten or darken the shadows and highlights and you're pretty much set.
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Old Apr 13, 2007, 8:07 AM   #4
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I agree with you in that ACR has a horrible starting point and the ability to save your own presets is not very well highlighted.

Why adobe thought that having all the AUTO boxes checked was a good idea beats me.
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