Copsy

The Copsy blog · updated Aug 2, 2026

Field notes on offloading footage.

Guides, honest comparisons and camera-by-camera workflows for getting footage off the card safely. Written by a working DIT.

Overhead flat-lay of card readers, portable drives and cables laid out in a neat row
Comparisons

Best free camera offload software for Mac

Copsy, Ingesto, Resolve's Clone Tool, MhlFileVerify and Terminal checksums ranked, plus why a plain Finder drag is risky.

9 min read
Fingers push a memory card into a laptop-connected reader on a rolling location cart
Guides

How to offload footage from a camera card

Copy the whole card to two places, verify every file with checksums, organize by date and never format until both copies check out.

7 min read
Extreme macro of a memory card's gold contact pins with blue and violet reflections
Guides

What is ASC-MHL?

ASC-MHL is the film industry's standard for proving footage copied bit for bit; here's how it works and why blind copies are risky.

4 min read

Guides

Workflows, checklists and the reasoning behind a safe offload.

28 articles
A smartphone on a chair armrest shows a glowing progress ring, a laptop blurred behind
Guides

Watch your offload from your iPhone

An iPhone and iPad companion in development that shows the Mac's offload progress over your Wi-Fi and can start, cancel or eject.

6 min read
Fingers push a memory card into a laptop-connected reader on a rolling location cart
Guides

How to offload footage from a camera card

Copy the whole card to two places, verify every file with checksums, organize by date and never format until both copies check out.

7 min read
Extreme macro of a memory card's gold contact pins with blue and violet reflections
Guides

What is ASC-MHL?

ASC-MHL is the film industry's standard for proving footage copied bit for bit; here's how it works and why blind copies are risky.

4 min read
Two drives close together on a long table, a third alone by a window
Guides

The 3-2-1 backup rule for video footage

Three copies, two kinds of media, one off-site: what the 3-2-1 rule means for footage and why one drive is never a backup.

7 min read
A jeweler's loupe beside a memory card and a portable drive under a blue lamp
Guides

Checksum copy vs Finder drag-and-drop

A Finder drag never reads files back, so silent corruption slips through; a checksum copy proves every file matches the card.

7 min read
Two crew members seen from behind at a DIT cart on a night film set
Guides

DIT vs data wrangler: who does what

A data wrangler offloads and verifies camera media, while a DIT also handles color, looks, QC and dailies.

6 min read
Glasses beside a laptop reflect the screen's blue glow, a portable drive plugged in nearby
Guides

How to verify a file copy on Mac

What a checksum proves, how to run shasum in Terminal for one file, and how to verify a whole camera card automatically.

7 min read
A thumb pauses above the menu button on the back of a mirrorless camera
Guides

When is it safe to format a camera card?

Format only after a verified offload and a second backup both exist, and always do it in the camera, not on the computer.

6 min read
A thin memory card and a thicker high-speed card standing upright on glossy black acrylic
Guides

SD card vs CFexpress Type A and Type B

SD UHS-II, CFexpress Type A and Type B compared on speed, camera support and what each means for offloading on a Mac.

6 min read
A DIT tent at dusk with a laptop and drives, a camera crane silhouetted behind
Guides

How to back up footage on set

A working DIT's on-set routine: two verified copies, ASC-MHL checksums, labeled drives and no formatting until it all checks out.

7 min read
A card reader in the center with cables running to two glowing portable drives
Guides

Copy an SD card to two drives on Mac

One drive isn't a backup, so copy the card to two destinations at once on a Mac and verify both copies.

6 min read
A drawer organizer with memory card cases sorted into compartments with colored tabs
Guides

Organize footage by date and camera

A repeatable folder structure of ISO date, then camera, then card, and why consistent naming keeps editorial on track.

6 min read
A pen hovers over a clipboard of tick boxes, a memory card clipped on top
Guides

The media offload checklist

Six steps for every card: detect, copy to two places, verify with ASC-MHL, organize, label, and confirm before you format.

7 min read
Light pulses race along a coiled fiber-optic cable, a blue streak ahead of violet
Guides

xxHash vs MD5 for verifying video

xxHash catches a bad copy as reliably as MD5 or SHA and runs much faster, which is why DITs use it to verify footage.

6 min read
A shooter in a parked car at night checks a laptop and drive before leaving
Guides

Did your footage copy correctly?

A finished copy isn't always a correct one; comparing checksums of every file on the card and the copy is the only real proof.

7 min read
A brass stopwatch lying next to a card reader with a blinking blue activity light
Guides

How long does it take to offload a card?

Offload time depends on the slower of card read and drive write speed; here's the math for SD vs CFexpress and how to speed up.

6 min read
A compact card reader linked to a small SSD, blue light streaking along the cable
Guides

The fastest way to offload CFexpress on Mac

The card is rarely the bottleneck: pick the right reader and drive, and avoid software that reads the card twice to verify.

6 min read
A hand swaps card readers on a dark desk scattered with spare cables and adapters
Guides

SD card not showing up on Mac?

A card that won't mount is usually a reader, cable, port or Finder setting; check them in order, then offload before anything else.

6 min read
One person hands a shuttle drive to another across a dark production office desk
Guides

A media management workflow for filmmakers

Six repeatable stages: offload, verify with ASC-MHL, keep 3-2-1 copies, organize, track every card and hand off to editorial.

8 min read
A home desk at night with a laptop, card reader, compact camera and tea
Guides

Transfer footage from an SD card to a Mac

A beginner's step-by-step for getting clips from an SD or CFexpress card onto a Mac, and why a Finder drag verifies nothing.

7 min read
A laptop and portable drive on a hotel balcony at blue hour above city lights
Guides

Back up footage to Google Drive on Mac

Copy a camera card to an external drive and Google Drive in the same offload on a Mac, with ASC-MHL verification.

6 min read
A laptop and portable drive on a night train table by a streaked window
Guides

Back up footage to Dropbox on Mac

Copy a camera card to an external drive and Dropbox in the same offload on a Mac, verified with ASC-MHL checksums.

5 min read
A rugged rubber-armored portable SSD standing on wet black stone beaded with water
Guides

The best drive for offloading footage

What matters in an offload drive: SSD vs HDD, interface speed, ruggedness, capacity, and why you should buy two.

6 min read
A hand waits at a camera's card slot while a small amber lamp still glows
Guides

How to avoid corrupted footage

Where corrupted footage comes from, the habits that prevent it, and how checksums catch a bad copy before you wipe the card.

7 min read
A large hard drive slides into a multi-bay enclosure lit with blue indicator lights
Guides

How to back up 4K and RAW video

4K and RAW fill drives fast; back them up with fast drives, two verified copies on set and one copy off-site.

7 min read
Four card readers on a hub beside a stack of cards and a hand
Guides

Offload multiple cards fast on a Mac

Use several fast readers, queue cards back to back, let each copy verify itself and track which cards are safely backed up.

7 min read
Hands lift a full compartmented tray of memory cards and cables from a hard case
Guides

Copy the whole card, not just the clips

Copying only the clips you can see can break spanned takes, sidecar metadata, audio and the folder structure editors expect.

5 min read
A dim archive aisle lined with shelves of data tape cartridges and sealed drive cases
Guides

Footage archive: cloud vs LTO vs cold HDD

Cloud, LTO tape and cold hard drives compared on cost and lifespan, with a practical long-term archive plan for 2026.

7 min read

Cameras & cards

Camera-by-camera notes on card formats, folder layouts and gotchas.

18 articles
A compact cinema camera on a rig, a memory card half ejected from its slot
Cameras & cards

Sony and CFexpress card backup on Mac

Offload SD and CFexpress Type A cards from Sony FX6, FX3 and A7S III bodies to a drive and the cloud, verified with ASC-MHL.

5 min read
A gloved hand pulls a media card from a boxy high-end cinema camera
Cameras & cards

RED card backup on Mac

Back up RED .R3D footage from MINI-MAG or CFexpress media to a drive and the cloud, with every file verified by ASC-MHL.

5 min read
Overhead view of a box-style cinema camera, card reader and memory card on a case
Cameras & cards

Blackmagic card backup on Mac

Offload BRAW or ProRes from CFast, CFexpress, SD or USB-C SSD media to a drive and the cloud, checksum-verified.

5 min read
An operator films a live event with a mirrorless camera on a shoulder rig
Cameras & cards

Canon card backup on Mac

Back up CFexpress and SD cards from Canon Cinema EOS and mirrorless bodies with the folder structure intact and every file verified.

5 min read
A pilot removes a tiny memory card from a folding drone on a rooftop
Cameras & cards

DJI drone footage backup on Mac

Offload a drone's microSD, verify every short clip with ASC-MHL checksums and sort flights by date and source automatically.

5 min read
Fingers slide a memory card from a field audio recorder in an open sound bag
Cameras & cards

Audio recorder card backup on Mac

Back up BWF and WAV files from Sound Devices, Zoom and Tascam recorder cards with the same verification as your picture.

5 min read
A pro mirrorless camera with a telephoto lens on a ledge facing misty forest
Cameras & cards

Nikon Z9 and Z8 card backup on Mac

Offload N-RAW, ProRes RAW and H.265 from Z9 and Z8 CFexpress Type B cards to a drive and the cloud, verified.

5 min read
A shooter walks a mirrorless camera on a handheld gimbal through a blue-lit night street
Cameras & cards

Panasonic LUMIX card backup on Mac

Copy and verify GH6, GH7, S5 and S5II clips, V-Log included, from SD or CFexpress to a drive and the cloud.

5 min read
A wet action camera on a helmet mount beside a memory card on a dock
Cameras & cards

GoPro footage backup on Mac

GoPro splits long clips into chaptered MP4s; offload every chapter from the microSD, organize by date and verify each file.

5 min read
A retro-style mirrorless camera and a medium-format body on a dark walnut table
Cameras & cards

Fujifilm card backup on Mac

Back up X-H2S, X-H2 and GFX cards, internal ProRes on CFexpress included, to a drive and the cloud with ASC-MHL checks.

5 min read
Hands hold a smartphone in a cage rig, a small SSD clipped to its side
Cameras & cards

iPhone ProRes footage backup on Mac

Offload iPhone Pro ProRes or Blackmagic Camera BRAW from the external SSD to a drive and the cloud, with every clip verified.

5 min read
A small SSD caddy being pulled from an external monitor-recorder mounted on a camera
Cameras & cards

Atomos Ninja footage backup on Mac

Offload ProRes, ProRes RAW or BRAW from an Atomos Ninja SSD or CFast card to a drive and the cloud, verified clip by clip.

5 min read
A hiker holds a 360 camera on a thin stick high above a mountain ridge
Cameras & cards

Insta360 footage backup on Mac

Copy and verify the raw .insv files from an Insta360 microSD before you stitch, organized by date on a Mac.

5 min read
A crew member loads a media drive into a large cinema camera on a dolly
Cameras & cards

ARRI footage backup on Mac

Offload ARRIRAW or ProRes from Codex and CFexpress media to a drive and the cloud, verified with ASC-MHL and sorted by date.

4 min read
A small cube-shaped cinema camera in a cage on a tabletop slider
Cameras & cards

Z CAM footage backup on Mac

Back up ZRAW or ProRes from a Z CAM E2's CFexpress card or SSD to a drive and the cloud, verified and organized by date.

5 min read
A traveler's hand holds up a tiny pocket gimbal camera on a night train platform
Cameras & cards

DJI Osmo and Action footage backup on Mac

Offload Osmo Pocket 3 and Osmo Action microSD cards on a Mac, verified, sorted by date and copied to a drive and the cloud.

5 min read
A folding drone hovers above a coastal cliff at twilight with dark ocean below
Cameras & cards

DJI Mavic 4 Pro footage backup on Mac

Back up Mavic 4 Pro footage from both internal storage and microSD to a drive and the cloud, verified with ASC-MHL.

4 min read
A small SSD from a cinema camera plugged into a laptop beside a backup drive
Cameras & cards

Offload Blackmagic BRAW from an SSD

How to offload and verify BRAW recorded to a USB-C SSD on a Pyxis or Pocket 6K, plus the T7 dropped-frames gotcha.

5 min read

Comparisons

How Copsy stacks up against the paid tools, and where it doesn't.

16 articles
Hands pack a slim drive and card reader into a bag, leaving an old drive
Comparisons

Free Hedge / OffShoot alternative for Mac

Hedge is now the paid OffShoot; Copsy is a free Mac app that copies cards to a drive and the cloud and verifies every file.

3 min read
Two identical rugged portable drives side by side, one lit blue and one lit violet
Comparisons

Copsy vs ShotPut Pro

An honest comparison of ShotPut Pro and Copsy, a free Mac app that copies and ASC-MHL-verifies cards to a drive and the cloud.

6 min read
Two open palms from above, each holding one small memory card over a table
Comparisons

Copsy vs Ingesto: two free offload tools

Both are free and verify every file: Ingesto is open-source and cross-platform, Copsy adds a parallel Google Drive or Dropbox copy.

6 min read
A compact laptop and single drive in sharp focus, a large DIT cart blurred behind
Comparisons

Copsy vs Silverstack for verified offload

Silverstack is a full DIT-lab suite; Copsy is a free Mac app for the copy-and-verify core, with a drive and a cloud copy.

5 min read
Overhead flat-lay of card readers, portable drives and cables laid out in a neat row
Comparisons

Best free camera offload software for Mac

Copsy, Ingesto, Resolve's Clone Tool, MhlFileVerify and Terminal checksums ranked, plus why a plain Finder drag is risky.

9 min read
A card reader and rugged drive on a night location cart, blue haze rising
Comparisons

Offload to a drive and the cloud at once

How to copy a camera card to an external drive and Google Drive or Dropbox in one verified job on a Mac.

6 min read
A hand hovers between two cables plugged into a hub, deciding which one to pull
Comparisons

Copsy vs OffShoot (formerly Hedge)

OffShoot is Hedge's new name and costs about $169–$249; Copsy is a free Mac app that makes verified drive and cloud copies.

5 min read
A brass balance scale weighing a single memory card against a small stack of coins
Comparisons

Copsy vs Tusk

Tusk is a low-cost Mac offload app; Copsy is free and adds a parallel cloud copy, card auto-detect and ASC-MHL verification.

5 min read
A gloved hand inserts a memory card into one of two readers on a cart
Comparisons

Copsy vs Red Giant Offload

How Maxon's paid Red Giant Offload compares with Copsy, a free Mac app that makes verified drive and cloud copies.

5 min read
A light backpack with laptop and small drive, a heavy tape machine glowing behind
Comparisons

Copsy vs YoYotta

YoYotta handles LTO and full DIT work for about $110 a year; Copsy is free and simpler for copy, verify and cloud backup.

5 min read
A card reader and portable drive working on a table in a dark edit bay
Comparisons

DaVinci Resolve Clone Tool vs Copsy

Resolve's Clone Tool verifies copies but lives inside the editor; Copsy is a free standalone app that adds cloud copies.

5 min read
A memory card on a stage floor where a taped line forks in two
Comparisons

Free ShotPut Pro alternative for Mac

Copsy covers ShotPut Pro's core job, a checksum-verified card offload to a drive and the cloud, for free on a Mac.

4 min read
A lone chair and table with a laptop and drive in a vast dark studio
Comparisons

Free Silverstack alternative for Mac

If you only use Silverstack to offload, Copsy covers copy, ASC-MHL verification and cloud backup without a subscription.

5 min read
An open equipment case with foam cutouts holding a portable drive and a card reader
Comparisons

Free OffShoot alternative for Mac

OffShoot, formerly Hedge, costs about $169–$249; Copsy is a free Mac app that still ASC-MHL-verifies every copy.

4 min read
An unbranded cinema camera with a card half inserted, a computer tower blurred behind it
Comparisons

Copsy vs Carbon Copy Cloner for footage

Carbon Copy Cloner is built to clone disks, not offload camera cards; here's how it compares with the camera-aware Copsy.

5 min read
Hands eject a memory card from a mirrorless camera in front of blurred server lights
Comparisons

Copsy vs ChronoSync for footage

ChronoSync is a flexible Mac sync and backup app, but unlike Copsy it can't recognize a card by its content or write ASC-MHL.

6 min read

Workflows

Backup routines for wedding shooters and documentary crews.

2 articles
A videographer moves a camera card into a laptop reader at a night wedding
Workflows

Wedding footage backup workflow

A wedding happens once, so get two verified copies of every dual-card camera to a drive and the cloud before you leave the venue.

7 min read
A laptop and two rugged drives on a camp table in a blue-hour desert
Workflows

Documentary footage backup workflow

For long, remote shoots: verify every card, keep redundant 3-2-1 copies on the road and organize by date and source.

6 min read

Troubleshooting

When a card won't mount, a clip is corrupt, or a card might be fake.

4 articles
A fingertip slides the tiny lock switch on a memory card under a penlight beam
Troubleshooting

Camera card not readable on Mac

Don't click Initialize: the safe order of fixes for an unreadable camera card, and how to offload it before you ever format.

7 min read
A memory card sealed in an anti-static bag beside tweezers on a clean lab bench
Troubleshooting

How to recover corrupted footage

Stop using the card, image it byte for byte and run recovery on the image, then use verified offloads so it doesn't happen again.

6 min read
Fingers hold a memory card up to blue backlight above a pile of cheap cards
Troubleshooting

Test a memory card for fakes and errors

A full write-and-read-back test catches fake capacity and bad sectors on SD and CFexpress cards before they ruin a shoot.

6 min read
Fingers line up three cut segments of motion-picture film end to end
Troubleshooting

Why is my 4K clip split into multiple files?

FAT32 can't hold a file over 4 GB, so cameras split long takes into segments; here's how they rejoin and how to avoid it.

6 min read