Nikon Raw vs Adobe DNG

I’ve been doing a lot of looking into converting my Nikon camera raw nef images to Adobe's dng format. I decided to educate myself and perform a few comparisons. Here’s what I have so far.

There are many points that favor dng which you can read about all over the internet and of course on Adobe’s site. Looking at the many pros and cons of nef vs dng the issue for me has boiled down to these last points which might favor not switching to dng.
1 Nikon has a proprietary algorithm that eliminates chromatic aberration (CA) when using their lenses on a Nikon camera.
2 Nikon has its own proprietary noise reduction.
3 In the future there may be improved technology in the software that does the raw conversion on the original Nikon nef's.
4 Saving the files as 16bit tiffs.

I’m going to address the issue of saving tiffs first. A tiff is not a camera raw format file so it's not really up for consideration. It is popular so it deserves mention. The tiff format was created by Aldus for use in their desktop publishing program pagemaker to standardize the scanner image file format. Tiff is now under the control of Adobe as of 2009; they bought Aldus many years ago. The tiff format is loss less, compressable, generic and probably has the best chance of being read far into the future. The big problem with archiving a tiff or any completed image file as opposed to raw data off the sensor is the fact that you don’t have the ability to natively go back and change many of the shooting parameters after the exposure. You also give up the ability to ever reprocess the file through a new raw converter that might be developed in the future.

I’m not too concerned with noise reduction because most of my images are shot in conditions where the exposure isn't pushing the sensor’s limit. If it does there are excellent software noise reduction filters for PS. Whenever I read camera review comparisons between 2 high quality pro cameras, one camera has higher optical resolution than the other because the manufacturer has decided to use more or less in camera noise reduction. Noise reduction is essentially blur so it cuts down on sharpness/ resolution. Of course this only applies to the in camera jpg’s.

From my standpoint Adobe probably has more motivation to keep improving their raw converter for a particular camera than Nikon. I doubt Nikon will spend the money, time and trouble to improve software for discontinued cameras. Adobe’s main business is selling software to users of many cameras, most not current models so they have the motivation and economics to keep improving their raw converter I also think Adobe just may have better engineers doing this work. I think raw conversion is pretty good right now and many of the nuances are in the ‘art’ decisions, not in the technical realm. In this respect Adobe might have it over the camera manufacturers when it comes to working with artists. I’ve carefully watched Canon and Nikon over the last 5 years and both these companies have exhibited an almost adversarial attitude towards their customers.

I decided to do a comparison test to see if the Nikon proprietary Raw converter is really any better than Adobe Camera Raw / DNG. Essentially, any manufacturers raw files that are directly viewed in any Adobe software are being processed by ACR. If you are going to compare raw conversions you have to display the raw file in the manufacturers supplied software. The comparison also has to be made on the same monitor, preferably color calibrated. I’m using a wide gamut NEC 2690wuxi.

I’m using Adobe CS4, Adobe Camera Raw 5.5 and ViewNX 1.4; all the latest versions as of 10/9/2009

Raw files by their nature can’t have any corrections what so ever because they are raw sensor data in need of software to convert them to a useable image file. The only thing determined in the process of creating a raw file is ISO sensitivity. When the pixels are being read off the sensor they are amplified by the electronics in the camera. The more you turn up the volume the higher the ISO and, by the way more distortion is introduced creating high ISO noise.

During the image creation process the raw converter software can perform it's magic and create a new image file of the user's choice and either 8 bit or 16 bit format. This is where you choose a color profile, saturation, sharpening, perform noise reduction and CA correction, etc. Raw files are used to create new jpg's, tiff's etc to be used for the myriad of print and web display possibilities.

You can drag the box around the image. If you click and drag you change the magnification.

The jpg’s from my Nikon D300 would already have all of Nikon’s in camera noise corrections, sRGB curve (set in the camera), the Nikon CA eliminator, and camera styles (set in the camera) applied to it. Since noise wasn't a big concern and wouldn't be as easy to see I figured I’d compare the CA in the images processed in camera by the Nikon (the original jpg) and compare it to the raw nef processed by Adobe camera raw.

I then figured I’d compare these with an image brought up by Nikon’s ViewNX raw converter which I assume also processes the image with the proprietary Nikon CA filter and noise reduction.

The picture to the left is an extreme example of what CA or purple fringing is. This is a section out of a picture I took in 2004 with a Sony 828 which was known for it's terrible CA. Look closely and you will see the purple fringing surrounding the branches of the tree.

I brought up the jpg in PS and zoomed 100%. Then I brought up the nef version in adobe camera raw, made no corrections and clicked on ‘open image’. Then I brought up ViewNX with the same nef. I arranged the 3 images on my monitor all at 100%. Doing the comparison the image brought up under Adobe Camera Raw (ACR) had the least purple of the 3. The ViewNX was 2nd and the Nikon processed jpg was the worst. Then I realized that the camera has a ‘picture style’ setting which lets you choose between vivid, portrait, landscape, normal etc. The camera was set for vivid which added saturation to the purple making it look bad. I played with the picture style in ViewNX and discovered that it has a major impact on the look of the picture. Setting it to vivid it matched the jpg. Setting it to normal made it equal to the ACR version. Then I went back to ACR which now has the Nikon camera picture styles and found that it was in fact set to normal.

I also played with the CA reduction built into ACR, PS and Lightroom. Frankly, they didn't seem to make any improvements. In fact, the changes that occurred while using the CA reduction software made the images worse. Because they didn't make any improvement I was starting to doubt if the purple problem wasn't something else. I have no idea what else it could be but I do know that manual CA methods simply desaturate the area. When I was comparing ViewNX with ACR the ViewNX images looked a little ‘snappier’ probably because they had a bit more sharpening.

I attached a screen shot of the final comparison. Look at it at 100%. I can’t see that the Nikon raw version is any better than the Adobe conversion. I can’t even see that the Nikon version is reducing CA at all.

I decided to do more research to see if someone had developed custom curves in LR or ACR to match the Nikon camera output. I ended up on Adobe labs site (search on "adobe labs camera profiles") and after reading through the information on camera profiles it became evident that solving my problem was the reason for camera profiles in LR and ACR's existance. I must be doing something wrong since my test showed a difference.

After reading through the whole FAQ on the Adobe Labs page it turns out that the camera profiles supplied by Adobe are probably a little outdated. I found that the latest Nikon Vivid profile (2009) is not = to the Adobe profile (2008).  The other thing that made a difference is the color space.  I have the colorspace in my camera set to sRGB.  The Nikon software is picking this up when it converts and or displays the nef files.  I have LR set to convert the color space when the file is exported to 16bit proPhoto RGB which is a wide gamut space. 

Here what Adobe says right off the FAQ:

What are Camera Matching profiles?

These profiles match the color appearance produced by the camera vendors' software, under specific settings (described below). They are intended for photographers who appreciate the workflow and toolset provided by CR (camera raw) / LR (lightroom) but prefer the color rendering provided by the camera vendors' own software.

All CM profiles are identified with the prefix Camera in CR / LR's Profile popup menu.

Please note that the CM (camera matching) profiles are NOT expected to match the embedded in-camera JPEG, especially if you have established custom in-camera settings. To understand the abilities and scope of the CM profiles, please read the following description carefully.

As of July 29, 2008, we have created CM (camera matching) profiles for Canon and Nikon DSLRs only. Photographers who want CM profiles for other cameras are encouraged to use the DNG Profile Editor.

In general, there are 5 CM profiles per Canon DSLR, one for each of the default Canon Picture Styles. These five Picture Styles are called Standard, Portrait, Landscape, Neutral, and Faithful. The CM profiles will match the Canon Picture Styles with all Canon sliders (i.e., Contrast, Color Balance, and Saturation) set to their default values of 0.

Similarly, in general there are 8 CM (camera matching) profiles per Nikon DSLR, one for each of the Nikon Picture Controls. These Picture Controls are called Standard, Neutral, Vivid, Landscape, Portrait, D2X Mode 1, D2X Mode 2, D2X Mode 3. The CM profiles will match the Nikon Picture Controls with all Nikon sliders (i.e., Saturation, Tone Compensation, etc.) set to their default values of 0. Note that the D2X name is applicable to all Nikon DSLRs, even non-D2X models. This is not a bug.

Are the new profiles camera-specific?

Yes. Every profile that we build is camera-specific. Even the older profiles (e.g., ACR 3.3, ACR 4.4) are camera-specific. In fact, the profile menu in CR/LR will only show profiles for your camera. Note that the profiles you see in the profile menu do not include the camera's model name (e.g., Canon EOS 40D). This is intentional (for several reasons).

Why are the new profiles called "DNG camera profiles"? Can they only be used with DNG images?

The name "DNG camera profile" is used because (1) the underlying camera profile format comes from the DNG 1.2 specification and (2) these camera profiles can be embedded in DNG images.

The name does not mean that these profiles can only be used to process DNG images. In fact, the new AS (adobe standard) and CM (camera matching) profiles can be used to process both DNG and non-DNG images.

In terms of the DNG 1.2 specification, what makes the new camera profiles technically different from the old ones?

Our earlier camera profiles (in CR 4.4.1 / LR 1.4.1 and earlier) only use color matrices to perform the colorimetric characterization of digital image sensors. One set of matrices is optimized for standard illuminant A (~2850 K) and another set of matrices is optimized for illuminant D65 (~6500 K). CR / LR automatically interpolate between these two sets of matrices based on an image's white balance.

The DNG 1.2 specification expands and formalizes the concept of a camera profile. In addition to color matrices, profiles may now contain a set of color lookup tables and an optional tone curve. The new AS and CM profiles are using these additional features to improve color rendering in CR 4.5 / LR 2.0.

What exactly goes into one of these new DNG camera profiles? Descriptions of color, tone, noise, detail, etc?

DNG camera profiles only describe color and tone. Other aspects of an imaging system's behavior (e.g., noise, detail, geometric distortions, etc.) are not stored in these camera profiles.

Technically, a DNG camera profile contains a set of color matrices, an optional set of color tables, an optional tone curve, and some metadata (e.g., embed policy and copyright information).

What is the DNG Profile Editor?

PE is a new standalone application for Mac and Windows that can be used to edit DNG camera profiles. It can be downloaded from this page.

Here are some cases in which PE may come in handy:

• Making adjustments to existing camera profiles. If there's something specific about an existing profile (e.g., yellow saturation) that you don't like, you can use PE to make your desired changes and save the results to a new profile.
• Optimize profiles for infrared-modified cameras and unusual lighting situations, both of which might cause an image's white balance to fall outside of CR / LR's standard range. See Tutorial 4 for details.
• Optimize colors for specific applications (e.g., studio portraits, fall foliage colors, etc.).
• Get multiple cameras to produce similar colors. Useful if performing a shoot using multiple cameras (e.g., a main camera and backup camera).

 

Next I’m going to compare a high quality image to see if there is any difference.

I took a technically very good image and brought it up with ViewNX and LR. I made sure that the Picture controls were set the same in each program. I then dragged the ViewNX window over to my Nec monitor and compared sections of the image at 100% next to each other. There’s not really much difference, but there is some. LR isn't as sharp and the lit area around the window is darker in the LR sample than in the ViewNX sample. The wood around the window has a bit more red than the LR version. The rocks and the rust colored roof in the upper right are a bit darker in the LR version. At this point I like the ViewNX version better.

I adjusted LR to match the the ViewNX image. I had to sharpen the LR image to 90% with a radius of 1.6 and added about +25 saturation. I probably should have kicked the exposure up a bit more to match the sunny area around the windows.

From what I can see there is nothing in the Nikon software that makes the image intrinsically any better. Since I’m able to match the Nikon ‘look’ with LR controls it means that Nikon is using regular everyday curves, saturation and sharpening to personalize their image. There doesn't seem to be any deep dark secret science going on.

I decided to do more research to see if someone had developed custom curves to match the camera output. I ended up on Adobe labs site and after reading through the information on camera profiles it became evident that solving my problem was the reason for their existance. I must be doing something wrong.

Turns out that the camera profiles supplied by Adobe only work correctly on dng files.  I was looking at the nef files in LR when I should have converted the files to dng.  The other thing that made a difference is the color space.  I have the colorspace in my camera set to sRGB.  The Nikon software is picking this up when it converts and or displays the nef files.  I have LR set to convert the color space when the file is exported to 16bit proPhoto RGB which is a wide gamut space. 

What I did was to convert an image to dng and assign it the vivid profile to match the one set in the camera.  I exported it to PS and converted the color profile to sRGB.  I brought up the same image in ViewNX and they finally were very very close.