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Multi-RAW Processing

Creativity in the Photoshop Darkroom by Harold Davis, September 2009 (updated October 2010)

Intro | Multi-RAW Processing | Creating HDR Images by Hand [Part I] | Creating HDR Images by Hand [Part II] | Sharpening in LAB Color | Converting to Black and White | Using LAB Color Adjustments | Inverting Backgrounds with LAB | Intro to Compositing | HDR in Adobe Photoshop CS5 | Using Image Apply Image | Aging Photos Roundup | Making Colors Pop in Photoshop

My first and biggest “aha” revelation about digital photography took place the day I discovered multi-RAW processing—processing a single RAW photo file more than once. For me, the ability to process a RAW file multiple times—taking the best of each processing job for the final image—is the most important advantage that digital photography has over film photography.

If you don’t multi-RAW process, you can take photos with immediacy—but you are losing out on a great part of the richness of digital photography.

Let me back up a second to explain what I’m talking about. If you have a DSLR, it can probably be set to save your photos as RAW files, as JPEGs, or as both. RAW files have different file extensions (for example, NEF for Nikon and CR2 or CRW for Canon)—what they have in common is that these files store all the information from the time of exposure.

Essentially, a RAW file is a potentiality rather than a final rendition. Ansel Adams said of his work that a negative was a score, and the print the performance. In much the same way, a RAW file is the score, and what you do with it in the digital darkroom is the performance.

Embedded within the potentiality of the RAW file is a vast exposure range—as much as +4 to -4 f-stops in either direction from the exposure you made. If you do the math, since each f-stop has twice the exposure value of the previous f-stop, this represents a 2^8 or 256 times exposure latitude. So you can use RAW conversion to salvage poorly exposed photos—but more importantly, you can process the different parts of the photo to expose properly for each different part. Multi-RAW processing means that you are not stuck with one overall average exposure, which may be good in some parts and bad in others.

You can also use multi-RAW processing to selectively change white balance, saturation, and so on.

Got you interested? The best news is that multi-RAW processing is really a snap once you get the hang of it. Let me show you how it works using an actual example.

Sample File

I’ve provided a low resolution version of the red car reflections (red-car-reflections.tif) in TIFF format for you to experiment with and follow the example in this article. I chose to provide this file in TIFF format because I needed to lower the size and resolution of the file (I’m not about to let high resolution versions of my RAW negatives out into the world on their own!).

This TIFF file has the same settings and characteristics as the RAW file of the image, and you can use to it to try multi-processing and to follow along with the example in this article.

Note: In order to make sure that the TIFF file will open in ACR, check the “Automatically open all supported TIFFs” option in ACR preferences as shown below.

Photographing the Red Car

I recently spent some time photographing at a classic car show. The cars were polished up to the nines; what interested me most were the reflections in polished chrome, including the red car I’ll use as an example.

Unfortunately, I had an exposure problem, as you can see in the JPEG version of the photo shown in Figure 1. A single RAW conversion in ACR with default settings provides essentially the same results.

If I exposed for the sky (as in Figure 1), the reflections in the grill was definitely too dark. Had I reversed this and exposed for the dark grill area, the sky would have looked washed out. If you have this kind of exposure problem, you should be using multi-RAW processing.

Figure 1: Default version of the Red Car Reflections.

Organizing Your Files

Before you can process your files in the Photoshop Darkroom, you need to organize them on your computer. Programs like Adobe Lightroom can help you do this.

My own workflow starts with using a memory card reader to copy the RAW files from my camera to my computer. I store the files hierarchically in a chronology based on the date shot.

Once I have the RAW files on my computer, I can inspect them using Adobe Bridge, as shown in Figure 2.

Figure 2: The RAW file in Adobe Bridge.

Text ©2009 Harold Davis.

Article revised October 2010.

Readers' Comments

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Ben Goren , September 17, 2009; 04:00 P.M.

This is an excellent introduction to the idea. I would add three points.

First, this basic technique is my favorite for HDR: import your different exposures into a single file with multiple layers, and paint the masks to get the end result you want. I’ve never been happy with any form of tone mapping.

Second, when working with a single exposure, you can often achieve similar results simply by careful-but-aggressive use of the sliders in ACR. Drop the exposure to control the highlights; boost the fill to bring up the shadows, and finally adjust the midtones with brightness as necessary to correct what the first two have done. Go back to the highlights, repeating the entire process a few times until you get the look you want. Use the contrast slider to add “punch” or reduce blocked details.

Last, I’ve recently fallen in love with the adjustment brush in the latest version of ACR. I’ll start with the above technique to get the image as close as I can, and then I’ll “dodge and burn” with the adjustment brush — including the kind of selective darkening of skies, etc., as described in the tutorial. For me, at least, it’s much easier, faster, flexible, and intuitive, and I’m much happier with the results.



Thomas McInnis , September 17, 2009; 08:44 P.M.

Great tutorial - it will push me to do this more often. I often overlook some photographs because I am still stuck in a JPEG mindset!

Multi-RAW processing is also spectacularly simple using Lightroom where you can make infinite 'virtual copies' of the same file. After processing them in as many ways as I want, I then use the 'open as layers in Photoshop' command. I work on a rather aged laptop so I prefer this method where I don't have to move back and forth between programs repeatedly.

Emil Ems , September 18, 2009; 02:42 A.M.

This is an excellent approach. However, I wonder, whether it would be preferable to save the first version of the picture as SMART OBJECT and to continue by copying it. The copy (a layer) can then easily be reprocessed in ACR and the same results achieved as by the author's approach. Is there a drawback with using the SMART OBJECT approach?

François Dugas , September 18, 2009; 06:17 A.M.

I agree that the ajustment brush in ACR will do pretty much the same thing but much faster! You can also use masks and gradients... I would use your technique for subjects where precise selection is necessary (i.e. object against blue sky) but even that, the auto mask fonction with the adjustment brush could work well...

Harold Davis , September 18, 2009; 10:27 A.M.

@Ben, @Thomas, @Emil, @François: I'm glad you've enjoyed my article. These are all very good comments and tips.

@Ben, @François: Very good point about the ACR adjustment brush in CS4.

@Thomas: Your approach with Lightroom works just as well.

@Emil: Yes, you could use a duplicated Smart Object rather than multiple passes through ACR.

Photoshop is a huge program, and there are always more than one way to do anything. My approach is functional, and not always aimed at the latest bells and whistles. I like to present multi-RAW processing in the way this tutorial does because exactly what is going on is clear to even a Photoshop "newbie." Also, I want to show techniques that are the classic approach, and don't need the "latest and greatest" (many schools are still using CS2 for teaching).

That said, thanks for great suggestions of refinements of my approach!

Justin Weiss , September 30, 2009; 02:54 A.M.

How is the multi-raw approach any better than simply adding exposure gradients to, and burning/dodging certain areas of, a single photo in Lightroom?

In your example, I could simply slap an exposure gradient across the photo and then use the brush tool to lighten particular areas further, all using a single copy of the photo in Lightroom.

Does multi-raw processing get better-quality results?

Harold Davis , September 30, 2009; 12:35 P.M.

@Justin - I believe that adding an exposure gradient in Lightroom is a good approach. There are always many ways to "skin a cat." However, I think multi-RAW processing gives you access to the entire range of possibilities in the RAW file, as well as allowing you to change the exposure and white balance (for instance) at the same time in a given layer. So I think it is the more powerful approach, but obviously more labor intensive---so if what you are doing in Lightroom is working for you, by all means keep it up!

Best wishes,


Dien Duong , October 02, 2009; 01:12 A.M.

Harold, I certainly appreciate your efforts and time to prepare the instruction and willingness to share your knowledge. I've read only half way and feel the complexity, but I believe that your procedure covers more extensively. However, one of my professors advised that once should know the proper way and the "quick" way to solve/ finish a task; although the "quick" way might/might not provides a less satisfied result. By saying that ...


Would you please share your procedure?

Arnav Mukherjee , February 01, 2010; 12:28 P.M.

Hi Harold, Thanks very much for the articles on multi-RAW processing and HDR. I have started using some of these techniques thanks to your article. It does help make a picture much nicer most of the times.

One comment in general on software for everyone: since I am not a professional I cannot think of investing on Adobe Suites. I looked around for something that was free. The two software that works for me are Picasa and Gimp.

Picasa reads RAW formats and is useful for quick viewing, mass sort and tag, mass resize etc. And since it is from Google, it is of good quality. It is also available on the MAC.

Gimp, well it is not Photoshop (Adobe products has one of the best user experience in the industry). But Gimp for free is pretty nice. I did complain to myself about the UI at first. But it grows on you after a few hours. Gimp is also available on the MAC and it can open and process RAW images. Now (after 3 weeks) I prefer Gimp over PaintShop Pro which is not a freeware.

For automatic HDR, Photomatix Light for $40 is worth it if one is going to do auto-HDR.

So, if you are a professional or quasi-professional, Adobe is your friend. For the rest, my 2 cents may be useful.

Thanks Arnav

David Kenny , February 10, 2010; 09:48 P.M.


Roger Beltz , March 18, 2010; 10:06 P.M.

Thanks Harold. Excellent tutorial and very comprehensive.......so comprehensive, in fact, that I sure wish this could be downloaded as a PDF.

Lex Molenaar , June 25, 2010; 06:00 A.M.

Hi There,

A very quick and good way for me is in ACDSee Pro 3 is the Light Equalizer (\Process\Lighting\Light EQ). With sliders one can boost or temper dark or light areas of your photo similar as the sound equalizer on an amplifier.  Fast, so you use it more often. And I never use RAW since I prefer the in-camera chromatic aberration reduction of my Nikon D90.





Marco Garrone , July 08, 2010; 08:10 A.M.


thanks for this smart article. Being a Lightroom aficionado I'm very uneasy on PS and wouldn't even rate myself as a "newbie", but still I'd like to practice it more. just one question: I have only a licensed copy of Photoshop Elements 2.0. I reckon the pull-down menus are different, do you think however the  processing (i.e. blending layers with a single mask for each layer) is possible all the same?

thank you very much


Harold Davis , July 09, 2010; 09:21 P.M.

Marco, Photoshop Elements does not support layers and layer masking. My understanding is that it does support adjustment layers and the related layer masking facilities, so you can do some of things you can do with regular layers in Photoshop itself---but not easily the techniques shown in this article, unfortunately.

Best wishes,


Tomek Gooseberry , May 23, 2011; 12:37 P.M.

For those interested in the subject, I'd also suggest Mathias Vejerslev's Expanding the dynamic range of a single RAW file tutorial.

...and should someone want to get more fancy with luminosity masks, Tony Kuyper offers some great advice (and throws in Q&As :)


A fellow photo.netter contacted me because the links I had embedded in my post above didn't show or work on his browser.  I wouldn't have a clue why this might have happened, but just in case his wasn't an isolated incident, thought would provide actual URLs folks can cut 'n' paste, so here they go:

  • Mathias Vejerslev's simple yet effective Expanding the dynamic range of a single RAW file tutorial @ http://imagingpro.wordpress.com/2008/12/03/expanding-the-dynamic-range-of-a-single-raw-file/
  • Tony Kuyper's excellent Luminosity Masks tutorial @ http://goodlight.us/writing/luminositymasks/luminositymasks-1.html (and if, after perusing the above, you still need some clarification, ref. Q&A on the subject matter @ http://www.goodlight.us/writing/questions/questions-1.html)


Frank Klein , June 25, 2011; 09:51 P.M.

I just sent you an e-mail, then starting looking around your blog and came across the multi-raw processing article. Same procedures. Here is my e-mail:

I have three of your books: Creative Lighting, Creative Composition, and The Photoshop Darkroom. I have run into a problem with trying to  apply your procedure for multi-raw processing. You use the same procedure in all three books but I cannot make it work. I am using Photoshop CS5 on a MacPro computer. I have read the books then went back to start the tutorials, and I can't make the multi-raw processing one work. For example, in the Photoshop Darkroom, the one starting on page 33. ( I downloaded your images from the book). I hope you can shed some light on what the problem might be. 

Page 33 - It says, go back to Bridge and double click the same image again tp open the same RAW file a  second time.  DOESN'T HAPPEN, it opens in Photoshop instead. (I'm using Photoshop CS5). My solution, I click on the on the original image and go to File menu to open it in Camera Raw.

Page-35 It says hold down the Shift key and use Move tool to drag SKY image onto Hills image window, then release Shift key. Then the book says, now there are two layers, SKY and HILLS, and it shows two thumbnails in the layers palette. DOES'T HAPPEN. I just see one thumbnail.

Page 37 - After adding the layer mask, and clicking on SKY layer, and setting foreground color to "white", drawing the gradient, I get a fine matrix screen on my screen covering the image.

I've tried the prescribed procedure about 10 times and can't make it work. Am I doing  something wrong? Since you use the same procedure in all three books, I conclude the must be some setting in Photoshop which is preventing the procedure to work. Can you shed any light on this problem?

I would greatly appreciate any assistance you could provide because I think it is a very worthwhile procedure I would like to use a great deal.

Incidentally, I just signed up for your blog and look forward to exploring  all you have on it. 



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