Buying new macpro - External drives from PC to mac

Still in my planning stages for the purchase of new macrpo - currently working on PC tower.
As a pro photographer, I just realised that all my external harddrives have been formatted for PC. Will i have problems plugging them into the Mac and be able to read and write to the externals?

Or will i have to copy data to spare drive and then reformat?

Thanks

It depends on what file system the drive is formatted for. If it is FAT32 then you will have no problem reading or writing. If it is NTFS you will be able to read but not write to it from OS X without a utility like Paragon NTFS for OS X.

If you don't plan on using a PC anymore then I would just copy them to another drive, reformat, and copy them back just to make life easier. Of course Windows can't read HFS+ (the OS X file system) without a special utility either. But with FAT32 both can read and write without issue.

Hope that helps clarify things!