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How to Cull and Rate Photos on Your Synology NAS

By Ingo D ·

You bought a Synology NAS because you wanted your photo library on hardware you own. No monthly cloud fees. No upload queues. Just your RAW files, on your drives, on your network. It is a brilliant choice for storage.

And then you try to cull a shoot on it.

Why can’t Synology Photos cull or rate photos?

You come home from a job with 1,400 frames. You need to get to 80 keepers before you open Lightroom. You open Synology Photos. You start scrolling. And you realise the problem: Synology Photos cannot rate photos. It cannot reject them. It has no culling workflow at all.

The Synology Photos mobile app shows your library, yes. You can browse and you can scroll. It will even sort by faces and subjects. But there is no star rating, no reject flag, no keep-or-discard gesture, and no way to write that decision into a file your editor can read. The web UI is not built for rapid triage either: every frame loads like a file browser, not a review tool. You are stuck clicking through one image at a time with no way to mark your decisions.

So the workflow becomes: copy everything to a laptop, import into Lightroom, cull there, export your selects, and somehow sync the metadata back to the NAS. That round-trip can take hours. For a shoot-heavy photographer, it is the slowest part of the week.

Should I connect over SMB or the Synology Photos API?

CullKit can reach a Synology NAS two ways, and they suit different setups:

  • SMB — the standard network file share. Best when your RAWs live in a normal shared folder (for example a photo share or a dedicated shoots share). You browse the real folder structure, exactly as it sits on disk. This is the most universal option and the one to use for working RAW folders.
  • Synology Photos API — connects to the Synology Photos app itself, letting you browse Personal Space, Shared Space, and Albums directly. Best when your library is already organised inside Synology Photos and you think in albums rather than folders.

Both write the same XMP sidecars and run the same culling session. If you’re not sure, start with SMB pointed at your photo share.

How do I connect CullKit to my Synology NAS over SMB?

Your Synology NAS exposes your photo folders over SMB, the standard network file-sharing protocol. Every DiskStation does this: it is how your Mac finds the NAS in Finder, and it is how any SMB client can reach your library without proprietary integration or special plugins.

  1. In DSM, open Control Panel → File Services → SMB and confirm Enable SMB service is on.
  2. Confirm the shared folder that holds your photos. Synology’s default photo share is named photo (lower-case); you may also have a custom share for RAWs.
  3. Find your connection address. You can use the local IP (Control Panel → Network, e.g. 192.168.1.15), the Bonjour name (diskstation.local), or your QuickConnect ID for access from outside your home network.
  4. In CullKit, add an SMB connection: smb://diskstation.local/photo (or smb://192.168.1.15/photo) with your DSM username and password.
  5. Browse to your shoot folder and start a culling session. The connection is saved securely in the device Keychain for next time.

Nothing is copied to a temporary location. Nothing is uploaded anywhere. Your photos stay exactly where they are, on your drives, on your network.

CullKit is an independent product. It is not affiliated with or endorsed by Synology Inc. It connects to Synology NAS devices via the standard SMB protocol, the same way any other SMB client does.

How does the culling session work?

CullKit is a dedicated culling and rating app. You browse, rate, flag, tag, and organise. You do not edit or develop images in CullKit; that job belongs to your editor of choice. Think of it as a first-pass tool: it sits between your memory card and Lightroom, and it does one thing quickly.

The culling interface is full-screen and gesture-driven on iPhone and iPad. Swipe right to keep a frame; swipe left to reject it. Tap a star icon to assign a rating from 1 to 5. Use the quick-access bar for colour labels and tags. On Mac, the workflow is keyboard-driven: number keys for star ratings, P to pick, X to reject, 0 to clear, arrow keys to move through frames. Auto-advance carries you to the next frame the moment you decide.

A session runs in three phases — start (all frames, unrated only, or a filter), rate (the main pass), and batch review (confirm selects before writing). That structure lets you cull in passes: a fast first sweep to drop the obvious discards, then a focused second pass to star-rate the survivors. For a wedding photographer with 1,800 frames, or a travel photographer reviewing a week’s worth of shooting, the time saving is immediate.

How do my ratings get into Lightroom?

Every star rating and reject flag you assign in CullKit is written to an XMP sidecar file, stored alongside your RAW files on the NAS. XMP is the open metadata standard that Lightroom, Capture One, and Darktable all read natively.

When you open your working folder in Lightroom after a culling session, your selects are already there. Five-star keepers are marked. Rejects are flagged. No re-import. No manual metadata sync. RAW and JPEG pairs share a single sidecar, following the Lightroom convention, so nothing is duplicated. If a folder is already in your catalogue, use Library → Synchronize Folder (or Read Metadata from Files) and Lightroom pulls in the new ratings.

This is what closes the loop. You cull at the source, on the device in your hand, and your editor inherits the result automatically.

Can I cull my Synology library when I’m away from home?

Yes. If your RAWs are in a Synology Photos library, the Photos API connection works over your QuickConnect ID, so you can browse and rate from anywhere with an internet connection — useful for reviewing a shoot from a hotel or a client’s office. For SMB, remote access depends on your own setup (a VPN back to your network is the common, secure approach). On your home network, though, a direct local-IP or diskstation.local connection is always fastest, because it skips any relay. Either way, full-resolution previews stream on demand, so you’re not waiting for an entire library to download before you can start.

Troubleshooting Synology connections

  • NAS not found / “connection refused”. Confirm SMB is enabled (Control Panel → File Services → SMB) and that you’re on the same network. If you use the IP and it stopped working, your DHCP lease likely changed — assign the NAS a static IP or use diskstation.local.
  • Credentials prompt won’t accept your login. Check the DSM account has permission on that shared folder (Control Panel → Shared Folder → Edit → Permissions). 2-step-verification accounts may need an app password.
  • QuickConnect is slow. QuickConnect relays through Synology’s servers when a direct connection isn’t available; on your home network, the local IP or diskstation.local is much faster.
  • RAW previews load slowly. Full-resolution previews stream over the network and render progressively. A wired NAS or a 5GHz Wi-Fi client makes a noticeable difference on large RAWs.
  • Ratings not showing in Lightroom. Run Read Metadata from Files on the folder, or check that “automatically write changes into XMP” / read-XMP behaviour is enabled in Catalog Settings.

Why does a local-only workflow matter?

A cloud photo app would ask you to upload your library before you can review it. For a working photographer with terabytes of RAW files on a Synology NAS, that is not realistic, and it defeats the point of owning a NAS in the first place. CullKit processes everything locally. Your photos never leave your network. Credentials are stored in the device Keychain. There is no third-party server, no additional storage subscription, no privacy trade-off. (More in the privacy FAQ.)

You bought the Synology to own your data. CullKit keeps that promise.

Getting started

CullKit runs on iPhone, iPad, and Mac. It is available exclusively on Apple platforms; there is no Android or Windows version. You can also point it at a local folder or external SSD if you want to try it without connecting your NAS first. A built-in demo mode lets you explore the full culling workflow on sample data before you connect any real library.

Browse is free. The Pro subscription (with a seven-day free trial, then monthly or yearly) unlocks culling, star ratings, XMP metadata, move, and delete. Download CullKit from the App Store or learn more at cullkit.com.

CullKit is an independent product. It is not affiliated with or endorsed by Synology Inc.

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