Transferring photos from iPhoto and Photos to Lightroom
I had all my photos in iPhoto and then when Photos came along some of them, but not all, were transferred (or copied?) to the new Photos library. the reason given for not all going over seemed to be that i didn't have enough iCloud storage space. Anyway in future I'm wanting to use Lightroom to handle and edit all my photos because of all its features. An important one of these is that I'm told that it doesn't keep the original versions of photos that have been edited in Lightroom as iPhoto does, instead holding an XML file of all the changes that have been made so that you can go back to any earlier version, saving a lot of space.
What I want to do now it to transfer all of my photos from the iPhoto and Photos libraries into a new one I'm going to hold on an external hard drive. Where a photo has been edited in iPhoto I just want to take the latest version and delete all earlier versions. How best can I achieve this?
iMac, OS X Yosemite (10.10.5), MacBook Pro. iPhone 6, iPad Air 2