D7 Color

Working with color on the Dimage 7

The question about what to do with color on the Dimage 7 (D7) is a continuous problem for new users. As you will read below, this really should not be called a "problem", but it is something that new users will have to deal with.  There are several different approaches, and everyone seems to have their favorite technique. I'll outline the techniques that people are using here, but I can't provide full step by step details, you will have to visit the forums for detailed information. This is just meant to be an outline to introduce the new user to the various techniques that are being used; each person is going to have to decide which technique they prefer. .

Last update Feb 21, 2002. Version #4

The Dimage 7 color issue.

The color issue on the D7 arises because the camera has a large color space that is not documented at all by Minolta. Although some have called this a color "problem", it is really a color opportunity. The Minolta does not force you into using any particular color space. For example, some popular cameras use the very small sRGB color space, which means that some colors can't be reproduced.  Because it has a very wide color space internally, you can do what you want with it, and achieve very accurate color.. Minolta apparently expects that everyone will use the Minolta Dimage Viewer Utility, but as you will see below there is a critical problem with it that renders it useless at the default settings. Unfortunately, there has been no help from Minolta with this issue. (But I have now fixed it myself! See the DIVUfix page)

When shots directly from the camera are viewed on your monitor or printed on your printer (both of which use color spaces that are smaller, closer to sRGB), the larger color space information of the Minolta shots gets truncated, and the shots appear too contrasty and the colors are washed out.

There are several ways to deal with this.

Approach: Use the Minolta viewer utility.

Most new users will attempt to use the Minolta Dimage Viewer Utility (DIVU). If you check the convert color space box, it can convert the camera's color space to something more useful such as sRGB. However, (and this is the problem), it apparently uses a tone curve that results in shots with WAY too much contrast. Some have suggested that the shots are adjusted for a gamma of about 2.5. There is a way (see below) to use the utility, but it involves working with each shot individually.

Because of this, many people will say that they "threw away" the DIVU utility, or don't use it. There is now a fix for the overly contrasty DIVU defaults, see the DIVUfix page for details.

Approach: Use the Minolta viewer utility with a tone curve:

If the viewer utility is used with a custom tone curve for each shot (and one curve can be used for all shots), the results can look very good. This approach was (I think!) first suggested by "jawed" on the dpreview forum. Here is a link to the original message for the details on how to do this. The unfortunate thing is that the viewer utility can't apply the tone curve to all of your shots in a batch, you have to work with each shot individually. (This is no longer true, see DIVUfix)

Approach: Adjust the camera so that uncorrected shots look better and don't do anything to them.

The color problem arises because the Minolta color space is wider than the color space used for your screen and printer. You can adjust the camera so that the resulting shots look better with no processing, and just skip color correction. Most people like in-camera settings of -2 contrast, +1 saturation, -0.3 EV for this, however some prefer -1 contrast. This will make the shots right out of the camera look less contrasty and have better color.  This approach does not work well if you plan on adjusting the color later using some other method, and I would not recommend that you not do this.

Approach: Use a photo program and the supplied profiles to adjust the color.

The viewer utility ships with two .ICC profiles for the camera. These are located in C:\Program Files\DiMAGE Image Viewer Utility\profiles. The file names are MLTDim7r.icc for RAW files and MLTDim7j.icc for JPEG files. Some people feel that you can use a photo program such as Photoshop or Qimage Pro to convert from the Minolta color space to a more common color space such as sRGB. Unfortunately, there isn't concensus on this, and at the very least using these profiles will result in your having to do some contrast/tone work on each shot. Some feel that the JPEG profile is only intended for use by the viewer utility and has too many tone problems for use by other programs. Some have reported success with RAW files and the RAW profile. In my own tests, the contrast shift is too difficult to deal with.

The problems with the profile arise because of the way that Minolta has embedded a tone curve in the provided profiles that other programs can't read.  It is this tone curve that the DIVUfix utility works on.

Approach: Use a commercial profiler such as Profile Prism.

Using a program such as Mike Chaney's Profile Prism, you can make a custom profile for the D7. You can then use this profile to convert your shots to a more common color space either singly or in batch with your favorite program; I use Qimage Pro. I'm finding that once I have a "good" well lit, well balanced profile, that it works for a variety of lighting conditions, although some say that you have to have a separate profile for each lighting condition. It does take some care to get a good exposure of the test target to get a good profile. With a good profile, the conversion will open up the contrasty shadows, and will not require any further tone curve or contrast adjustment.

What the profile will NOT do is to fix shots where the white balance is wrong; in fact the profile may actually make the shots worse by accentuating any existing color cast.

I like the custom profile approach because although it is often possible to duplicate the results with a photo program, it takes much more time.

 

Approach: use ColorFix from Tamba Ware software

Colorfix is a small shareware program ($17) that just fixes the D7 color space and converts your shots to sRGB. Most people agree that the results are consistantly good, and that if anything it errs on the side of being concervative. This is a quick solution for those that don't want to mess with the color on every shot. It is a quick task to batch process all of the shots in a directory, and the program preserves the EXIF information and the original file. It also has a nice command line facility.

Here is a link to the ColorFix page.

 

Samples:

This album contains some shots converted using some of the techniques on this page. Click here for the album.

 

Summary:

This part is just opinion, but I would recommend the following....

* New users, and beginners should either do nothing to the shots (use them right out of the camera) or use DIVU with a generic pre-made profile "fixed" by DIVUfix to get rid of the extra contrast. (download on the DIVUfix page) The safest thing if you are just starting out is to do nothing to the shots, and make no camera adjustments. Then you can always fix your shots up later if you want to.

* Intermediate users should either use the Colorfix program or use a DIVUfix profile that they adjust themselves for their own taste.

* Advanced users... well, I'm not going to tell them what to do, everyone is going to have their own ideas. I like the Profile Prism program.