Q: Iphoto is distorting RAW images from canon on mac mini

What version of iPhoto? Is OS X 10.7.5 as you state correct? what has changed since this worked? What are the "canon Utilities" being used for?

LN

No - it should work - TD and Léoie are better at RAW - they have posted a few hints on fixing RAW issues including one that is documented for Aperture but is also for iPhoto

LN

You might try downgrading the raw support, that has worked for some.

Have you applied the latest Digital Raw Compatibility updater.  If so try the following;

1. The RAW support files are installed in the System Library in the folder "/System/Library/CoreServices" Folder.
2. To open this folder, use the Finder's "Go" menu. Click the smiling Finder icon in the Dock to bring the Finder forward.
3. Type the keyboard shortcut ⇧⌘G  (for "Finder > Go > Go to folder")  and copy and paste "/System/Library/CoreServices" into the text field. Click the "Go" button.
4. In the Finder window that will open, delete both the files "RawCamera.bundle" and "RawCameraSupport.bundle". You will have to enter your Administrator password. (don't empty the Trash, so you can put the files back, if need be)
5. Boot into the Recovery volume (boot with the Command + R keys held down) and reinstall the system.  That should return the digital raw compatibility to what is included in Yosemite and what is used of your camera.

You could try to revert to the Digital Camera RAW Compatibility Update, that came out in December.

For example, Digital Camera RAW Compatibility Update 5.07

or  to RAW support 6.01. It helped in a similar case:

Re: Digital Camera Raw Compatibility 6.02 - Nikon D800

Any of the earlier raw support versions 5.01 or later should work, since your camera has been supported since Mavericks.

Make a backup of your system and try to downgrade the RAW support to version 6.01

 

To downgrade the RAW Support to the last version from before the last update try this:

• To reinstall the 'RAW Compatibility Update' it is necessary to uninstall the currently installed raw support. Otherwise the installer will rightfully say, that you already have the latest version installed.
• If your tests are showing that the problem happens also in a different user account, try this:

The RAW support files are installed in the System Library in the folder "/System/Library/CoreServices" Folder:

• To open this folder, use the Finder's "Go" menu. Click the smiling Finder icon in the Dock to bring the Finder forward.
• Then type the keyboard shortcut ⇧⌘G  (for "Finder > Go > Go to folder")  and copy and paste "/System/Library/CoreServices" into the text field. Click the "Go" button.
• In the Finder window that will open, delete both the files "RawCamera.bundle" and "RawCameraSupport.bundle". You will have to enter your Administrator password. (don't empty the Trash, so you can put the files back, if need be)
• Download the current RAW support update from Apple's Support Site:
• Digital Camera RAW Compatibility 6.01 http://support.apple.com/kb/DL1777?viewlocale=en_US&locale=en_US

 

In the Downloads folder you will find the disk image with the installer. Double click it to open and run and the installer.

Then restart your Mac.