Q: photos

If you mean how do you export photos from the photos application, then you should use the export option from the photos file menu.

Assuming you did not have an *ancient* version of iPhoto. Photos should be able to open your iPhoto Library. If not something like iPhoto Library Manager should work.

iPhoto was replaced by Photos app. Launch Photos and it will migrate all your iPhoto files to its own library. Depending on the size, this migration might be a lengthy period, but you should not "loose" anything.

Which version of OS X and iPhoto do you have?

If you are now running el Capitan or OS X 10.10.3 Yosemite or newer, you would need iPhoto 9.6.1.  You can only update to this version by reinstalling iPhoto from the Purchases tab of the appStore, and and only under certain conditions. see Barney's user tip:

I'd try to update iPhoto, even if you migrate the iPhoto Libraries to Photos.  YOu may need iPhoto to repair the library before you migrate it, or to be able to compare the migrated library to the original iPhoto version. Some content cannot be migrated, so you will need to recreate it.  See this document:  How Photos handles content and metadata from iPhoto and Aperture - Apple Support

And also:  Updating from iPhoto to Photos for OS X - Apple Support

I have lost photos that have gone unsupported by Apple -- iPhoto will not open and the apple download doesn't work. I want to permanently save my photos a on an SSD.

You need Photos 9.6.1 - see Can't Update iPhoto because it is not available in the App Store - or better yet just migrate them to Photos.  When you migrate from iPhoto '09 (version 8.x.x) or later you simply drag the iPhoto library to the Photos icon in the Dock and it migrates intact per theses rules - How Photos handles content and metadata from iPhoto and Aperture - Apple Support

If your old library was made by iPhoto '08 (version 7.x.x) or earlier you first have to download and run the library upgrader tool then migrate to Photos as above - Using the iPhoto Library Upgrader tool - Apple Support

As to keeping your own copy - I see no point - I do two daily back ups (Time machine and a daily clone) for my system with two libraries totaling about 100,000 photos - I have never lost a photo or even had to go back to a backup except for stupid human error which has made me do a restore of yesterday's libary

If you want to simply select them in Photos and export (file menu ==> export  --  Probably the unmodified originals)  either automatically using the Moments structure or manually using your own structure and put them anywhere you want

LN

Aperture 3.6 and Photos 9.6.1 both run under El Captain and both can export to an event structure - Aperture may have more options even - I seldom use it

As to why you have many libraries I have no idea - when I do an option launch of Photos I have two copies of each of my libraries - one on my Mac disk and one on my clone disk

All Photos is just that - All Photos - it you have duplicates in your library then you will have duplicates in All Photos

LN

Charlie,

? I must have 500 total libraries!! Do you have any suggestions on how to straighten out this mess?

which version of Aperture do you have?  Aperture is the only Apple application I kow, that can merge Aperture libraries and iPhoto libraries, without losing the edited versions or the originals.  But the versions of iPhoto and Aperture need to match. All other tools will force you to decide between the edited versions or the originals. See this link:  Aperture 3.3: How to use Aperture to merge iPhoto libraries - Apple Support

But you need matching versions of Aperture and iPhoto, so update to iPhoto 9.6.1 and aperture 3.6 if you can. It may not be possible, if your versions are not AppStore versions.

. I can't tell what version of iPhoto I have since it is grayed out. I wanted to keep all photos in one large library, then create others as needed.

To find out  the versions of your applications, you can select the application in the Finder and use "File > Get Info" . In many cases, the info panel will show the version.

If the Info panel is not showing the version, use the -menu in the upper left corner of the main menu bar.

 > About the Mac.

In the About panel click "System Report". In the System Report panel scroll down in the sidebar to "Software" and select "Applications". Wait for the list of all applications to appear and look for iPhoto and Aperture. The list will show the version numbers.

Can you tell me why I have over 250 "Photos" libraries when I attempt to choose a library (by holding down the option key) and starting Photos? I must have 500 total libraries!!

Do you have backup drives connected, when you select libraries? Photos, iPhoto, Aperture will show all libraries you have, even the librares on connected drives, if the are not time machine drives. It is easy to accidentally open the wrong library, and if do not have the drive connected, when you launch Photos the next time, it may simply create a new library, if it cannot find the last library you opened.

Especially when they are all named "iPhoto Library"!

When I merge iPhoto lib and Aperture libraries I will have a ton of duplicates -- is there a safe way to dispose of these? Any good software that you know of?

There are a few third party applications to detect and remove duplicates, that are safe to use. Don't use apps that directly modify the library, only applications that gather the duplicates in an album, so you can delete them using Aperture or iPhoto.

if you need to purchase a duplicate detector, I would wait with the duplicate detection until after you migrated to Photos, so you can buy an app that you can use after the migration that will work with Photos for Mac.

Photo Sweeper is safe, Power Photos, or Duplicate Annihilator.

I have tested Photo Sweeper and Power Photos.

• Photo Sweeper is very good, if your duplicates are different versions of the same photos in different states of edits or different sizes. It can compare the actual photos based on histograms or bitmaps. Also, it can search duplicates across several libraries.
• Power Photos is the successor to iPhoto Library Manager for Photos. It can find duplicates based on file attributes - filenames, file size, etc. You can also use it to move photos between libraries or to merge Photos Libraries.