Apple will release Aperture 1.5.1 -- its professional photography workflow application -- later today, the company said from PhotoPlus Expo being held in New York this week. Apple also said it would release a fully functioning demo of Aperture and new camera RAW support.

"The update comes from user feedback on our 1.5 release and focuses on performance improvements related to previews," Kirk Paulsen, Apple's Senior Director Professional Applications Product Marketing, told Macworld. The update also addressed general stability and reliability, he added.

Aperture 1.5.1 will be available later today from Apple's Web site.

In addition to the update, Apple is also releasing a fully-functioning demo of Aperture, which will also be available for download from its Web site later today. The demo allows photographers to try out every aspect of the program, which has not been crippled in any, according to Apple.

If the user decides to purchase Aperture, they can do so from within the application and then just enter the serial number and continue using it. "We want to get Aperture in the hands of as many photographers as possible," said Paulsen.

Finally at PhotoPlus Expo, Apple will release a download that adds camera RAW support to Aperture for the Nikon D80 and the Canon XTI. Unlike other RAW updates that came as part of a Mac OS X update, this will be available as a manual download from Apple's Web site later today.