PhotoCat Support

Question? Please contact us.

What versions of Lightroom does PhotoCat support?

PhotoCat Viewer works with Lightroom 3, 4 and the current 5 beta. The new Smart Previews are currently ignored.

Can I use PhotoCat to organize my images?

PhotoCat Viewer only allows viewing of Lightroom catalogues. 

Is there a limit on the size of a catalogue?

PhotoCat has been tested with catalogues containing over 100,000 images on the first generation iPad, with very little performance degradation. If you use the “zip” method to import files (necessary on Windows computers), there is a limit on the size of the zip file - 2 GB. We hope (but can’t promise) to remove this limit in the future.

How do I add catalogues to PhotoCat?

Before adding a catalogue, exit Lightroom to ensure it is not being accessed. If your catalogue is large, copying to the iPad can take several hours. Do not start PhotoCat while a copy is in progress.

Using OS X, you can drag a Lightroom catalogue (.lrcat file) and preview directory (.lrdata) into PhotoCat using iTunes file sharing. Once in there, the organizer can be used to import the catalogue. The zip file method recommended for Windows iTunes may also be used. On OS X, Lightroom usually stores its default catalogue in


Using Windows, iTunes cannot import the preview directory easily. Instead, using Windows Explorer, select the catalogue file and preview directory, and create a zip file by right-clicking and select "send to compressed file". Using iTunes fiel sharing, copy this file to PhotoCat. Currently the limit on size of a zip file is somewhere between 2 and 4 GB.

Alternatively, start the FTP server from theFTP view, and use an FTP client on your desktop computer to copy files over the network to the iPad. After copying, use PhotoCat to import the catalogue.

Why are the pictures in my catalogue fuzzy or low resolution?

PhotoCat works with the previews created by Lightroom on the desktop. If Lightroom has generated high resolution previews, then PhotoCat can display them. If you view your photos in full screen in Lightroom prior to export, you may find that you will have better previews for PhotoCat to work with. In the future, we hope to have a desktop application to create previews for you - but no promises...

Why are the pictures in my catalogue sorted differently from Lightroom?

PhotoCat sorts pictures according to date they were taken. We hope to add sorting options in the future.

Do you support all Lightroom smart collections?

Not yet, but we support most. If there’s one you’d specifically like to see, please contact our support department.

Do you support Lightroom slide shows?

Yes, as a type of collection. Transitions, etc are not supported.