The fastest way to cull RAW files on macOS.

Why Lightroom is slow on RAW

A modern RAW file (Canon CR3, Sony ARW, Nikon NEF, Fuji RAF) is 30–80 MB and contains two things: the sensor data (huge), and an embedded JPEG baked by the camera (small, ready to display).

When Lightroom shows a RAW, it ignores the embedded JPEG and decodes the sensor data — applying your camera profile, color science, sharpening, noise reduction, and any develop adjustments. That's 100–300ms per frame on a 6K image, even on an M3 Pro.

At 200ms per preview, scrolling through 3,000 photos is 10 minutes of waiting before you've made a single decision. Photographers feel this as "Lightroom thinking." It's not — it's rendering.

The embedded JPEG trick

Every RAW file your camera produces has a JPEG inside it. It's the image you see on the camera's LCD review. Cameras bake this for free during capture using the in-camera processor.

That JPEG is 2–5 MB, full-resolution-or-near, and decodes in 10–20ms. It's not "develop-quality" — but it's identical to what you'd see on the back of your camera. For culling decisions (in focus? eyes open? composition? exposure?), it's more than enough.

The realization: you don't need RAW-quality previews to cull. You need them for editing. So pick a culling tool that uses the embedded JPEG, then move to your editor.

Setup 1 — A dedicated culling app (fastest)

The simplest path: use a tool built for this. Options on macOS:

Workflow: ingest RAWs → open folder in culling app → use P / X / star ratings → export XMP sidecars → import to Lightroom for editing.

Setup 2 — Force Lightroom to use embedded previews

If you'd rather stay in Lightroom, you can force it to skip the slow render and show embedded JPEGs:

1. Import dialog → "Build Previews" dropdown → choose "Embedded & Sidecar" (not "Standard" or "1:1")
2. After import, go to Library → Previews → Build Embedded Previews if not already done
3. In the toolbar above the filmstrip, click the small dropdown and select "Embedded Preview"
4. Cull using P / X / number keys for ratings
5. When you're ready to edit, switch to "Standard" preview — Lightroom only renders the photos that survived the cull

This is 3–5× faster than Standard previews. Not as fast as a dedicated app, but stays in Lightroom.

Setup 3 — Browse Finder + Quick Look (zero-cost emergency)

Lost in a foreign Lightroom catalog? You can cull using just macOS:

1. Open the folder in Finder, set view to Gallery (⌘5) or Cover Flow
2. Tap space to Quick Look any photo full-size
3. Use Tags (right-click → Tags) to mark picks — these survive in Spotlight + Finder
4. Or: drag rejects to a _rejected subfolder

Slow and clunky for 3,000 photos. Fine for 200 from a casual shoot.

Hardware tips for RAW culling

Speed is software-bound first, hardware-bound second. But hardware compounds:

• SSD over HDD, always. A 7200rpm spinning disk caps you at ~150MB/s. An SSD does 3,000+. For 3,000 RAWs averaging 50MB, that's the difference between 16 minutes and 50 seconds just to read the files.
• Internal > external when possible. Thunderbolt 4 SSD is fine; USB 3 is the floor.
• RAM matters less than people think for culling — 16 GB is plenty. RAM matters for editing.
• Apple Silicon vs Intel: an M1+ Mac decodes RAW 2–4× faster than the equivalent Intel due to the dedicated media engine. If you're on Intel and culling weddings weekly, the upgrade pays itself back in saved hours.

Where to keep working RAWs during a cull

Don't cull from your archive. Keep a working SSD (internal or fast external) for active jobs. Cull there, edit there, only move to long-term archive after delivery.

Reason: archive drives are usually slower (cost-optimized), often spinning, sometimes networked. Culling 3,000 RAWs over a NAS is brutal even on fast networking.

A myth: "smart previews fix this"

Lightroom's Smart Previews are a different feature — they're DNG proxies (~2 MB each) that let you edit when the original RAWs are offline. They do render faster than full RAW previews because they're smaller. But they still go through the develop pipeline. Embedded JPEGs skip that pipeline entirely. Embedded JPEG > Smart Preview > Standard Preview > 1:1 Preview, in that speed order.

Our recommendation

For 3,000+ frame shoots: cull in a dedicated app, edit in Lightroom. The 30 minutes you save per shoot compounds. After 20 shoots, that's 10 hours back in your year.

For under 500 frames: stay in Lightroom but use Embedded previews. The setup overhead of a separate app isn't worth it for small shoots.

Why ShotSelect for fast RAW culling

Built for fast RAW culling on macOS

Embedded JPEG previews, keyboard-first, XMP sidecars to Lightroom. Free, native Apple Silicon.

Download for macOS

Keep reading

• Cull 3,000 wedding photos in 90 minutes →
• XMP sidecars: how ratings sync between apps →
• Keyboard-first photo culling: complete shortcuts guide →