Help! Printing Problems

Hi, I need help! I have a 50D and I recently shot a birthday party for my mother in law.. It wasn't anything big, just random shots.... I burned the pics onto a CD so she could take them to Costco and get them developed to basic 4x6 prints. Here's where my problem came... Costco's computer said they could not print the pictures because the resolution was too high, so basically i need to resize the pictures, but I don't know how to do it without taking up hours of my time. I have a MAC computer, but I don't have Photoshop on it yet.. and I have a Microsoft Laptop that does have photoshop, but its VERY slow, and working with pictures on my laptop takes hours.. is there a program on my MAC computer where I can resize all of the pictures at once to a lower resolution? What size should I put? The size of the prints are like 3000x3000 or something..

I hope someone can help.. thanks in advance!

You can use DPP that comes with your camera, or there are plenty programs that would help.

Basically you will want to resize the images to have 300 pixels per inch (ppi) at 4x6, so you want (4x300) x (6x300) or 1200x1800 pixels. If you use a program with a decent utility you could do all the images as a batch and there would hopefully be the ability in the utility to constrain the sized distinguishing between a "portrait" orientaton and a "landscape" orientation.

Make sure, though, to use a Save As and do this to create a copy of the original if you have any interest in keeping the images with any real quality.

Copy the images to the slow machine with photoshop, put them all in one directory. In photoshop choose files -> scripts -> image processor, enter 1800 in both boxes and check sRgb. Hit go, walk away, come back when it's done.

thanks a lot, I appreciate it! I'll try it out tonight and see if it works

Is it an option to simply upload them to Costco?

The uploader has a "feature" turned on by default that they call the "quick uploader", which resizes the image on the fly during the upload process, so it doesn't matter what the original size is. I find that the 4 x 6's are perfectly acceptable snapshot quality when done like this, and you have just cut out one trip to the store by not having to go down and "drop them off."

Rad