Is there a way to make a collage of a very large amount (500+) images?

[Nicolas5FB1]

Id like the files to be overlapping, as shown in the attached image:

[Trevor.Dennis]

If you intend working with rectangular image elements as per your example, then it would not be too terrible a task doing it manually.  The layers are delineated with a simple drop shadow and you can fine tune positions using Ctrl (Cmd) Auto Select to drag the layers.

I've done irregular montages using layer masks, but that was quite a lot of work.  It would be easier nowadays though, as Photoshop is way better at making selections than it used to be

To make a collage automatically, forum regular JJ Mack has a script on his Mouseprints site.  If JJ happens along, he can maybe help you with that.

Free Photoshop Packages (mouseprints.net) 

[JJMack]

My Collage templates and scripts only suppot up 53 Images in a collage.  Mockup templates can have as many smart objects layer  as you need . The Past image roll scripr can tile any numen of image. Creating a tenplate with 500 images is quite a bit of work and take a large abount of time to batch populate.

[Bojan Živković]

There are a couple of ways:

• Manualy creating template and manualy populating it one by one. 
• Using script or action if you plan to repeat collage or to share with others to quickly create collage and to have help to place images
• Using Data sets what is reusable template that can be automatically populated with images for what is needed additional setup and file renaming.

what are your plans? Do you need collage only once or more times? If you need it only once then manual method may be most appropriate.