Canon EOS R5 Full Width 8K Video? Yes, Here’s How
The Canon EOS R5 can record full-width 8K video (8192 × 4320 pixels) using the entire width of its full-frame sensor, but only in specific modes and settings. In its standard 8K mode, the camera uses the full sensor width; however, a crop mode (Super 35mm) also exists, which uses a smaller portion of the sensor. This article explains exactly when you get full-width 8K, how to set it up, and what limitations to expect.
What “Full Width” Means on the R5
Full-width 8K on the R5 means the camera reads the entire 36×24mm sensor area to produce an 8192×4320 image. This is different from a “crop” or “Super 35mm” mode, where the camera reads a smaller central portion of the sensor, effectively increasing the lens focal length but reducing the field of view. The R5’s sensor is 45 megapixels, and 8K full-width uses about 35.4 megapixels (8192 × 4320 = 35,389,440), so it’s a near-full readout of the sensor.
When Does the R5 Record Full-Width 8K?
The R5 records full-width 8K only in certain settings:
- 8K DCI (8192×4320) at 24p or 25p – uses full sensor width in ALL-I or IPB compression.
- 8K DCI at 30p – also full width, but only in IPB (not ALL-I) due to data rate limits.
- 8K UHD (7680×4320) at 24p/25p/30p – this is a slightly narrower resolution (16:9) but still uses the full sensor width, just with a different aspect ratio crop on the top/bottom.
When you switch to 8K DCI at 50p or 60p, the camera automatically crops to a Super 35mm (APS-C) area, so it is not full-width. The same crop applies to 4K 120p and 4K 60p in some modes. So, if you want full-width 8K, you must select 24p, 25p, or 30p (DCI) or 24p/25p/30p (UHD).
How to Set Up Full-Width 8K Recording
To get full-width 8K on the R5, follow these steps:
- Set the camera to Movie mode (mode dial on the movie icon).
- Go to the Movie Rec. Settings menu (the camera icon with a film strip).
- Choose Movie rec. size and select 8192×4320 (8K DCI) or 7680×4320 (8K UHD).
- Set the frame rate to 24p, 25p, or 30p (for DCI) or any of those for UHD. Avoid 50p/60p if you want full width.
- Select compression: ALL-I or IPB (ALL-I is higher quality but larger files; IPB is more efficient).
- Use a CFexpress card (Type B) or an SD card with UHS-II speed rating – 8K requires very fast write speeds.
Why Does the R5 Crop in Some Modes?
The crop in higher frame rates (50p/60p) exists because the sensor readout speed is limited. To achieve 8K at 50p or 60p, the camera needs to read the sensor faster, and reading a smaller area (the Super 35mm crop) allows it to do so without overheating or hitting data rate limits. This is a common technique in mirrorless cameras – the Sony A1 also crops in 8K 60p, for example. The R5’s sensor readout is fast enough for 8K30 full-width, but not for 8K60 without cropping.
Overheating and Recording Limits
The R5 is notorious for overheating when recording 8K. Canon has released firmware updates to improve this, but the camera still has a recording time limit. In 8K full-width, you can typically record for about 20 minutes at room temperature before the camera shuts down to cool. The exact time depends on ambient temperature, battery, and whether you’re using the optional cooling fan accessory (which attaches to the back). To avoid overheating:
- Use the camera with the screen open (not closed) to dissipate heat.
- Set the auto power off temperature to “high” in the menu (this increases recording time but may shorten sensor life).
- Use a dummy battery or external power to reduce internal heat.
Full-Width 8K vs. 4K: Which Should You Use?
Full-width 8K gives you the highest resolution and the most flexibility in post-production – you can crop, pan, and zoom without losing quality. However, it comes with huge file sizes (about 1 GB per minute in ALL-I) and heavy processing demands. For most projects, 4K is still the standard, and the R5’s 4K (full-width or oversampled) is excellent. If you don’t need 8K, you might prefer 4K HQ mode, which uses 8K oversampling to produce a sharper 4K image. The choice depends on your delivery format and editing workflow.
Common Misconceptions
“8K UHD is not full-width.” Actually, it is. UHD is 7680×4320, which is 16:9, while DCI is 8192×4320 (17:9). Both use the full sensor width; the difference is the vertical crop. So if you’re shooting for a 16:9 TV, UHD is full-width.
“You can’t shoot 8K without a cage.” The R5 has a built-in cooling system, but it’s not sufficient for unlimited recording. A cage with a fan can help, but it’s not required for short clips.
Frequently Asked Questions
Does the R5 shoot 8K full-width at 60fps?
No. At 8K 50p or 60p, the camera automatically switches to a Super 35mm crop, so it does not use the full sensor width. Only 8K 24p, 25p, and 30p use the full width.
What memory card do I need for 8K?
You need a CFexpress Type B card (or an SD card with V90 speed rating, but CFexpress is recommended). The card must sustain write speeds of at least 400 MB/s for ALL-I and 200 MB/s for IPB.
Can I record 8K without overheating?
Yes, for a limited time. The R5 can record 8K for about 20 minutes before overheating. Using the optional cooling fan, setting the auto power off temperature to high, and keeping the camera at a cool ambient temperature can extend this.
Is 8K full-width better than 4K oversampled?
8K gives you more resolution and flexibility, but 4K oversampled (from 8K) often looks sharper than native 4K because it uses more sensor data. For most viewers, 4K oversampled is indistinguishable from 8K on a 4K screen, but 8K allows cropping.
Does the R5 have a full-width 8K mode without crop?
Yes, the 8K DCI 24p/25p/30p and 8K UHD 24p/25p/30p modes use the full sensor width. Just avoid the 50p/60p modes.
What is the bitrate of 8K full-width?
In ALL-I, the bitrate is about 2600 Mbps (megabits per second), which is roughly 325 MB/s. In IPB, it’s about 1300 Mbps (162.5 MB/s). This is why fast cards are essential.
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