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How to Connect Your iPad to a NAS for Photo Culling

By Ingo D ·

You want to connect your iPad to a NAS for photo culling. You have a Synology, QNAP, TrueNAS, or UGREEN sitting on your home network with thousands of RAW files on it. You want to sit on the sofa with the iPad, go through the shoot, rate the keepers, reject the discards, and have your decisions carry into Lightroom or Capture One later. This guide covers the exact steps for each NAS brand because the setup is not the same across the board, even though they all speak SMB underneath.

The iPad is a natural culling device: bright, colour-accurate screen, touch-first interface, portable enough to use anywhere. The missing piece has always been the connection. Apple’s Files app can browse SMB shares. It can open a RAW file. But it cannot run a culling session. It has no rating gesture, no reject flag, no auto-advance, and no way to write your decisions to XMP sidecars a desktop editor can read. You need an app that speaks SMB the same way your Mac does and is built for the specific task of rating frames at speed.

CullKit fills that gap. It connects over SMB or the Synology Photos API, presents your folder structure natively, and lets you swipe through a shoot full-screen with ratings that land in Lightroom automatically. What follows are the connection steps, vendor by vendor, plus the networking and troubleshooting details that make the difference between a session that runs smoothly and one that drops halfway through.

CullKit is an independent product. It is not affiliated with or endorsed by Synology Inc., QNAP Technologies, Inc., TrueNAS / iXsystems, UGREEN Group, or any storage vendor. It connects via standard SMB, the same way any other SMB client does.

What exactly do I need to connect my iPad to a NAS for culling?

You need three things: a NAS with SMB enabled, an iPad with CullKit installed, and both devices on the same local network. That is the minimum. The NAS holds the photos, the iPad runs the culling session, and the network carries the data between them.

The connection is direct. No intermediate server. No cloud relay. Your iPad opens an SMB session to your NAS, browses the folder tree, loads thumbnails and full-resolution frames progressively, and writes XMP sidecars back to the same folder when you finish. Nothing is uploaded. Nothing is copied to a temporary location on the iPad. Your library stays where it is, on your hardware, on your network.

On the iPad side, any model from the last few years works. A USB-C port is useful for powered accessories and external drives, but it is not required for network culling. What matters is the Wi-Fi connection, which we cover below.

How do I connect CullKit to a Synology NAS from an iPad?

Synology is the most common NAS among photographers, and there are two ways to reach a DiskStation from CullKit on iPad: SMB and the Synology Photos API.

SMB (recommended for working RAW folders). This is the standard file-sharing protocol. You browse the real folder structure on the NAS, exactly as it sits on disk. It is the fastest option for culling because there is no database layer between you and the files.

  1. In DSM, open Control Panel → File Services → SMB and confirm Enable SMB service is on. Set the minimum SMB protocol to SMB 2 and the maximum to SMB 3 for the best balance of performance and encryption.
  2. Confirm the shared folder that holds your photos. The default Synology photo share is named photo (lowercase). If you created a custom share for RAWs, note that name instead.
  3. Find your connection address. Synology gives you several: the local IP from Control Panel → Network (e.g. 192.168.1.15), the Bonjour/mDNS name (diskstation.local), or your QuickConnect ID for access outside your home network. On the same Wi-Fi, the IP or .local name is fastest.
  4. Open CullKit on your iPad, tap Add Connection, choose SMB, and enter the address in the format smb://192.168.1.15/photo (or smb://diskstation.local/photo). Enter your DSM username and password. The credentials are saved in the iPad Keychain for next time.
  5. Browse to your shoot folder, tap it, and start a culling session.

Synology Photos API (for album-based libraries). If your library is organised inside Synology Photos and you think in albums rather than folder paths, connect via the Photos API instead. This lets you browse Personal Space, Shared Space, and Albums directly. The connection setup is the same server address, but you select “Synology Photos” as the connection type in CullKit and authenticate with the same DSM credentials.

Both methods write the same XMP sidecars to the same file system. Pick whichever matches how you organise your library.

How do I connect CullKit to a QNAP NAS from an iPad?

QNAP enables SMB by default on most QTS and QuTS hero setups, but confirming it takes ten seconds.

  1. Open Control Panel → Network & File Services → Win/Mac/NFS/WebDAV and make sure Enable SMB service is on. QNAP supports SMB 2 and 3; leave the maximum at SMB 3.
  2. Note your shared folder. The default media share is typically Multimedia. If you created a dedicated share for RAWs (a good practice for working files), use that name.
  3. Find your NAS IP under Control Panel → System → Network & Virtual Switch. It looks like 192.168.1.20.
  4. In CullKit on iPad, add an SMB connection: smb://192.168.1.20/Multimedia (or your custom share name). Use your QNAP username and password.
  5. Browse to your shoot folder and start culling.

QNAP path format for SMB: smb://<NAS-IP>/<share-name>. The share name is case-sensitive and must match exactly what you created in the QNAP control panel.

How do I connect CullKit to a TrueNAS NAS from an iPad?

TrueNAS (both CORE and SCALE) does not enable SMB until you explicitly create a share, so there is one extra step compared to Synology or QNAP.

  1. In TrueNAS SCALE or CORE, go to Shares → Windows (SMB) Shares → Add.
  2. Choose the dataset that holds your photos as the Path (for example /mnt/tank/photos), give the share a name such as photos, and save. Start the SMB service if prompted.
  3. Confirm your user account has read/write permission on that dataset. Go to Credentials → Local Users, edit your user, and check the dataset ACL. For culling, the account needs read access to browse and write access to create XMP sidecars.
  4. In CullKit on iPad, connect to smb://<TrueNAS-IP>/photos with that user’s credentials.
  5. Open your shoot folder and begin culling.

Important: the SMB address uses the share name you set in step 2, not the underlying dataset path (e.g. /mnt/tank/photos). The share name is what the SMB server advertises on the network, and that is what CullKit sees.

How do I connect CullKit to a UGREEN NAS from an iPad?

UGREEN NAS models running UGOS also expose files over SMB, and the setup follows the same protocol as QNAP.

  1. Open the UGOS control panel and confirm SMB is enabled (it is on by default for most UGREEN models).
  2. Find your shared folder name. UGREEN typically creates a default share named Public or a user-created share for media.
  3. Locate the NAS IP in the UGOS network or status panel (usually 192.168.1.x).
  4. In CullKit on iPad, add an SMB connection: smb://<UGREEN-IP>/<share-name> with your UGOS username and password.
  5. Browse to your shoot folder and start culling.

UGREEN’s photo app is closer to a cloud-photos clone than a pro culling tool. It does not write reject flags or ratings in a format your desktop editor reads. Connecting over SMB with CullKit bypasses that limitation entirely: you work directly with the files, the same way you would on a desktop.

Does this work over Wi-Fi or do I need a wired connection?

Wi-Fi works, and it is the whole point of culling on an iPad. You are not tethered to a desk. You sit where you want, open the iPad, and go. That said, Wi-Fi quality makes a measurable difference in how fast thumbnails load and how snappy the full-screen swipe feels.

A modern dual-band router with the NAS connected via Ethernet and the iPad on a 5 GHz Wi-Fi channel is the ideal setup. That gives you enough throughput for progressive RAW loading: the thumbnail appears immediately, the full-resolution frame resolves within a second or two, and frame-to-frame swipe latency stays low enough that you never wait.

On 2.4 GHz Wi-Fi or a router several rooms away, thumbnail loading slows down and full-resolution images take noticeably longer to resolve. The session still works; it just feels less fluid. If you regularly cull large RAW files (40 MB or more per frame), plug the NAS into Ethernet and keep the iPad close to the router.

Public or guest Wi-Fi is a different problem. Many public networks block SMB ports (445 and 139) or disable local device discovery entirely. You cannot reach your NAS from a coffee shop unless you use a VPN into your home network or QuickConnect (Synology) with relay. For on-the-go culling, consider copying the shoot to an external SSD before you leave, then connect the SSD directly to the iPad’s USB-C port and cull locally without a network. CullKit handles external drives the same way it handles NAS shares: browse the folder, start culling, XMP sidecars written alongside the originals.

What if my iPad does not see the NAS on the network?

This is the most common connection problem, and it almost always comes down to one of four things.

SMB is not enabled on the NAS. Every NAS brand has its own toggle. On Synology: Control Panel → File Services → SMB. On QNAP: Control Panel → Network & File Services → Win/Mac/NFS/WebDAV. On TrueNAS: Shares → Windows (SMB) Shares and confirm the service is running. On UGREEN: the UGOS SMB toggle. Confirm it is on before debugging anything else.

The iPad and NAS are on different networks. If your iPad is on a guest Wi-Fi network and the NAS is on the main network, they cannot see each other. Most routers isolate guest networks from the LAN by design. Put the iPad on the same network as the NAS.

SMB port 445 is blocked. Some corporate, university, or managed networks block SMB ports. If you are on one of those networks, you need a VPN into your home LAN or a direct connection method (Synology QuickConnect relay). There is no way to tunnel SMB through a blocked port without a VPN.

Bonjour/mDNS discovery is not working. CullKit uses Bonjour to auto-discover NAS devices on the local network. If the NAS does not appear automatically, try entering the IP address directly. IP-based connections bypass Bonjour entirely and are more reliable on networks with multiple subnets or access points.

If all four checks pass and the connection still fails, try accessing the same SMB share from the Files app on the iPad: in Files, tap the three-dot menu, Connect to Server, and enter smb://<NAS-IP>/<share>. If Files cannot reach it either, the issue is on the NAS or network side, not in CullKit.

How fast is culling over a network versus a local drive?

The difference is smaller than most photographers expect, but it exists. Here are the factors that decide it.

On a local network with the NAS on Ethernet and the iPad on 5 GHz Wi-Fi, loading a 45-megabyte RAW frame from the NAS takes roughly one to two seconds for full resolution. The thumbnail loads in a fraction of a second because CullKit reads the embedded preview first. This is fast enough that the swiping rhythm feels natural: keep, keep, reject, keep. You are not waiting between frames.

A local SSD plugged into the iPad over USB-C loads the same file in under half a second. The difference is real but only noticeable if you are trying to cull at a very high pace (a frame every second or faster). For most photographers, network culling is indistinguishable from local culling in practice, especially with progressive thumbnail loading that lets you make the keep/reject decision before the full-resolution image finishes loading.

The biggest bottleneck is not the network speed but the NAS itself: the drive speed, the RAID configuration, and whether the NAS is doing anything else at the same time (scrubbing, indexing, thumbnail generation). If culling feels slow, check the DSM/QTS/TrueNAS resource monitor to see if the disks are busy with another task.

Can I cull on my iPad while someone else browses the NAS?

Yes. SMB is a multi-client protocol. Multiple devices can read from the same share simultaneously with no interference. Your iPad culling session and your partner’s Mac browsing the same folder will not collide.

The one point of serialisation is XMP sidecar writing. CullKit writes sidecars at the end of the session in a single batch. Another app writing to the same folder at the same moment could, in theory, race with that batch, but in practice this is rare because culling happens in sessions and other tools typically read rather than write to the shoot folder. If you do see a conflict, the fix is simple: finish the culling session before running a tool that modifies the same folder.

How do my ratings get into Lightroom or Capture One after an iPad session?

This is the payoff. You finish culling on the iPad. You close the session. CullKit writes XMP sidecar files into the same folder as your RAW images, one .xmp file per frame. Each sidecar contains the star rating, the reject flag, the colour label, and any tags you set during the session.

Back on your Mac, open Lightroom Classic. Navigate to the NAS share or mount it in Finder first so Lightroom sees it as a local volume. Import the folder if it is a new shoot, or right-click the existing folder and choose Metadata → Read Metadata from Files if it is already in your catalogue. Lightroom reads the XMP files and applies every rating and flag you set on the iPad. The same process works in Capture One, Darktable, and any editor that reads XMP sidecars.

The critical detail is that the sidecars travel with the files. They sit in the same folder as the RAWs. If you sync that folder to another drive, back it up, or move it to a different NAS, the ratings move with it. There is no proprietary database. There is no export/import step. Standard XMP, the same format Lightroom itself writes, is what you get.

Is my NAS login safe on the iPad?

Yes. Credentials are stored in the iPad’s Keychain, the same hardware-backed secure storage every iOS app uses for passwords. The Keychain is encrypted and protected by the device passcode or biometric authentication. No credentials are stored in plain text in the app or in a configuration file on the NAS.

The SMB connection itself can be encrypted if your NAS supports SMB 3 (all modern Synology, QNAP, TrueNAS, and UGREEN models do). SMB 3 encrypts data in transit, so your login and every frame you view travel across your local network in encrypted form. On untrusted networks (public Wi-Fi, a shared studio), this matters. On your home network, the encryption adds overhead you probably do not need, but it costs nothing to leave SMB 3 enabled.

For Synology users connecting via QuickConnect from outside the home network, Synology’s relay encrypts the session end to end. The iPad never exposes the DSM login to the wider internet.

Troubleshooting iPad to NAS culling

  • Connection refused even though SMB is on. Check the NAS firewall (Synology: Control Panel → Security → Firewall; QNAP: Control Panel → Security → IP Access Protection). The firewall may be blocking the iPad’s IP. Temporarily disable it to test, then add a rule for your local subnet.
  • Credentials prompt keeps reappearing. The most common cause is a stale Keychain entry. On the iPad, go to Settings → Passwords, find the stored credential for the NAS address, and delete it. Then re-enter it fresh in CullKit. Also confirm the NAS account has SMB access permitted: on Synology, check Control Panel → User → Applications → SMB; on QNAP, verify the user is in the Microsoft Networking access list.
  • NAS found but folder listing is empty. Confirm the shared folder permissions allow the account to read files. On Synology, open Control Panel → Shared Folder → Edit → Permissions. On TrueNAS, check the dataset ACL under Storage → Datasets. The account needs at least read access for browsing and write access for creating XMP sidecars.
  • Culling session drops mid-session. If the iPad goes to sleep or a low-battery warning interrupts the session, CullKit’s crash recovery picks up exactly where you left off when you return. No progress is lost. For long sessions, set the iPad’s auto-lock to Never and keep it on charge.
  • Ratings missing in Lightroom after the session. Run Metadata → Read Metadata from Files on the imported folder in Lightroom. If Lightroom still does not see the ratings, confirm the XMP files are in the same folder as the RAWs and that the filenames match (a DSC_0042.NEF should have a DSC_0042.xmp in the same directory). If you renamed files after culling, re-run the culling session on the renamed folder.

Try it

CullKit is on the App Store for iPad, iPhone, and Mac. The free tier lets you browse any connected library (NAS, local folder, or external SSD) and see your folder structure and thumbnails. The Pro tier (7-day free trial, then monthly or yearly) unlocks culling sessions, star ratings, colour labels, XMP sidecar writing, and folder organisation. A demo mode with seeded sample data lets you try the swipe interface before connecting your own library.

Download CullKit on the App Store

CullKit is an independent product. It is not affiliated with or endorsed by Synology Inc., QNAP Technologies, Inc., TrueNAS / iXsystems, UGREEN Group, Adobe (Lightroom), Capture One, or any storage or software vendor. Compatibility claims only.

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