I use photoshop elements on the mac. I will be color correcting photos for a project and must convert to CMYK format. Elements does not have a CMYK option for photos. Can I purchase an upgrade of Photshop Elements, or do I need to upgrade to full Photoshop?
"And, BTW, why do you need to convert to CMYK?"
My main commercial client likes their imagery in CMYK, so I sell them that using PS's default US SWOP color space. I outline this default in my scope of work and everything works out just fine...
The OP’s wording
must convert to CMYK format.
seems a bit suspicious, though.
In my opinion it is better to deliver RGB images instead of images in the wrong CMYK space.
Edit: Profiled RGB images that is, naturally.
My experience is that the main reason a client (publisher) wants a image in CMYK is so the artist/photographer can see prior to publishing all their beautifully subtle shades of green die. And not blame the publisher for "ruining" the image.
And, for whatever reason, there are still some sadly mistaken people that think you need to convert an RGB file to CMYK before printing to an inkjet printer.