How do full-frame mirrorless cameras balance resolution, 4K video and dual slots?

The advantages and the compromises

The key details

Model covered

EOS R5

Sensor format

35 mm full-frame

Effective pixels

45.0 MP

Lens mount

Canon RF

In-body stabilization

Yes — 5-axis sensor-shift

Stabilization rating

Up to 8 stops with compatible-lens/CIPA qualification

Maximum internal video

8192 × 4320 DCI 8K

Mechanical burst rate

12 fps mechanical

EVF resolution

5.76 million dots

Rear monitor

Vari-angle touch LCD

Card slots

2: CFexpress Type B + SD UHS-II

CFexpress Type B

Yes

Body-only weight

650 g body-only

Still battery estimate

320 EVF / 490 LCD (CIPA; mode-dependent)

Animal/bird AF

Yes — animals, including birds

Weather protection

Not established in checked spec

45 MP full-frame and RF system

Canon identifies the original EOS R5 as a 35 mm full-frame RF-mount body with approximately 45.0 effective megapixels. That is the core system choice: it suits a buyer who wants the RF lens family and detailed still capture, while the body’s resolution does not by itself guarantee a particular amount of usable detail. Lens performance, focus, shutter speed and output size remain part of the result. Confirm that the product is the 2020 EOS R5 and not the R5 C or R5 Mark II, because model names that differ by a suffix refer to distinct cameras.

Stabilization with lens and test conditions

Canon describes five-axis in-body stabilization that can coordinate with optical stabilization in compatible RF and adapted EF lenses. Its up-to-8-stop figure is a qualified maximum, not an unchanging rating for every lens or exposure. The profile preserves that qualification rather than turning it into a general promise. Body stabilization addresses camera shake; it does not freeze a moving bird or sports subject. Buyers comparing systems should check the lens-specific combination and the test conditions behind the figure, then separately consider the autofocus mode and shutter speed needed for their subject.

Action rate and animal detection

Canon lists up to 12 frames per second with the mechanical shutter and up to 20 fps electronically. The mechanical value is the relevant one for this finder. Canon also documents animal detection that can track the body, face or eye of cats, dogs and birds. This makes the R5 relevant to buyers who need an explicit animal-recognition claim, while neither the frame rate nor the detection feature guarantees focus on every frame. Read the selected shutter, focus and media settings together before assuming that a particular high-speed workflow is available without trade-offs.

Vari-angle display, viewfinder and media

The R5 combines a 5.76-million-dot OLED EVF with a 3.2-inch vari-angle touch display. Canon specifies two card slots: one for CFexpress Type B and one for SD UHS-II. That is useful for parallel recording or a planned overflow workflow, but the two slots accept different media families. The camera’s high-resolution video modes can place demanding requirements on card speed and remaining capacity, so a buyer should verify the exact mode against the card table. The display hinge and EVF provide different framing positions; neither specification describes how comfortable an individual finder will feel.

8K ceiling, battery and weather unknown

Canon lists internal DCI 8K at 8192 × 4320, a body-only weight near 650 g, and CIPA still estimates that vary by viewfinder, screen and power setting. The representative profile value uses the standard EVF estimate of about 320 shots; the screen estimate is higher and economy settings change both. 8K and other high-bitrate formats have recording-time and media conditions, and should be planned deliberately. The checked exact-model source set does not establish a weather-resistance field, so that value remains unknown rather than a negative claim.

Before you decide

The advantages and the compromises

The key details

Model covered

Z 7II

Sensor format

FX / 35 mm full-frame (35.9 × 23.9 mm)

Effective pixels

45.7 MP

Lens mount

Nikon Z mount

In-body stabilization

Yes — 5-axis sensor-shift

Stabilization rating

Not stated in checked US product page

Maximum internal video

4K UHD up to 60p (8-bit in FX format; 93% sensor coverage)

Mechanical burst rate

10 fps maximum (about 9 fps for 14-bit RAW)

EVF resolution

3.69 million dots

Rear monitor

Tilting touch LCD

Card slots

2: CFexpress Type B or XQD + SD

CFexpress Type B

Yes

Body-only weight

615 g body-only

Still battery estimate

No still-shot figure stated in checked page

Animal/bird AF

Not documented in checked source

Weather protection

Not documented in checked source

A high-detail full-frame capture choice

Nikon identifies the Z 7II as an FX-format body with 45.7 million effective pixels. That makes it the highest still-resolution option in this three-camera group on the manufacturer figures recorded here, which can matter when the buyer expects to crop or produce large images. The specification is not a direct image-quality ranking: lenses, focus accuracy, exposure, processing, and output size all affect the final result. A buyer who does not need this resolution may reasonably give more weight to carrying size, video workflow, or an existing lens collection. Nikon’s 45.7 MP figure should be treated as one documented capability, not as evidence of a guaranteed result.

A deliberate two-slot media workflow

Nikon provides two slots: one accepts CFexpress Type B or XQD, and the other accepts SD, including UHS-II SDHC and SDXC media. Nikon describes using both slots to separate file types, create a backup, or add onboard storage. That flexibility is useful for a photographer who has a clear card plan, but the unlike slots mean a spare SD card alone does not cover both positions. CFexpress Type B and XQD media also differ from ordinary SD cards in cost and reader compatibility, so confirm the exact format and camera recording mode you intend to use. The historical title’s FTZ II bundle is unrelated to and does not prove the included card setup.

The Z system and adapter boundary

The Z 7II uses Nikon’s Z mount, and Nikon says F-mount NIKKOR lenses can be used with a mount adapter, with restrictions. That provides a path for some Nikon DSLR lens owners, but it is not a promise that every lens retains every feature or that an adapter is included. Check the exact lens compatibility entry and adapter before treating an existing kit as ready to use. A new buyer should compare native Z lenses and system needs as a whole; a body purchase can set the direction of future lens spending and carrying weight. The camera specification establishes mount compatibility, not a seller’s package or the condition of any used accessory.

Stabilization, focus, and burst pace

Nikon lists five-axis image-sensor shift, a 493-area autofocus system, and a top full-resolution rate of 10 frames per second; it also describes Eye-Detection AF options. The electronic viewfinder is specified at approximately 3.69 million dots. Together these are substantial stills-oriented specifications for portrait, event, landscape, and some moving-subject work. They should not be collapsed into a blanket claim that the camera always tracks a subject or delivers a sharp frame. Movement, lens choice, focus settings, shutter speed, card speed, and file settings can change the practical result. Nikon notes a lower approximate rate for 14-bit RAW in the detailed frame-advance specification, so high-resolution bursts need a workflow check.

Video resolution with a format qualification

Nikon lists 4K UHD recording up to 60 fps and Full HD up to 120 fps. Nikon’s product material qualifies 4K60 as 8-bit in FX format with 93% sensor coverage. That qualification matters to a video editor planning color grading or framing, and 60p should not be read as every bit depth or crop mode being available at once. The 3.2-inch monitor tilts and supports touch operation, which helps with framing from above or below but is not the side-hinged movement of a vari-angle display. Before a paid shoot, verify the exact recording settings, media requirements, heat conditions, and monitor position in Nikon’s manual.

Before you decide

The advantages and the compromises

The key details

Model covered

ILCE-7M3

Sensor format

35 mm full-frame

Effective pixels

24.2 MP

Lens mount

Sony E-mount

In-body stabilization

Yes — 5-axis sensor-shift

Stabilization rating

5 stops with Planar T* FE 50 mm F1.4 ZA; CIPA qualification

Maximum internal video

3840 × 2160 4K

Mechanical burst rate

10 fps continuous shooting

EVF resolution

2.36 million dots

Rear monitor

Tilting monitor

Card slots

2: SD UHS-I/II + SD or Memory Stick Duo

CFexpress Type B

No Type B support listed

Body-only weight

Body-only value not stated in checked page

Still battery estimate

About 610 EVF / 710 LCD shots

Animal/bird AF

Not established in checked source

Weather protection

Not established in checked source

Full-frame capture and E mount

Sony identifies the ILCE-7M3 as a 35 mm full-frame E-mount camera with approximately 24.2 million effective pixels. This makes the lens system a central part of the decision: buyers should check their current E-mount lenses, intended focal lengths, and any adapter plan before comparing the body alone. The sensor format and pixel count are documented attributes, not a forecast of image quality in every light or a guarantee of usable focus. For a hybrid kit, the 4K recording modes and card arrangement also shape the practical fit.

Five-axis stabilization with lens context

Sony lists five-axis sensor-shift stabilization and a 5-stop CIPA result when the Planar T* FE 50 mm F1.4 ZA is attached. This qualification is part of the fact: it is not a blanket gain with every lens, movement or shutter speed. Stabilization can reduce camera shake when photographing a stationary subject, but it cannot freeze subject movement. Buyers should compare this rating with the lenses they will actually use and distinguish the body’s stabilization from optical stabilization in a lens. The source does not provide a body-only weight on the checked US page.

10 fps and a flexible card workflow

Sony lists a maximum continuous shooting rate of 10 frames per second and two memory-card slots. Slot 1 supports SD UHS-I and UHS-II cards; slot 2 accepts UHS-I SD or Memory Stick Duo. The camera supports recording modes that can duplicate stills or movies across the two slots, but a photographer cannot assume both slots take the same card family. The rate is useful for general action comparisons, yet focus, shutter selection, card speed and buffer behavior still affect a specific sequence. Check the exact recording mode before relying on a backup plan.

Viewfinder, monitor and 4K

The electronic viewfinder is specified at 2,359,296 dots, while the rear monitor tilts upward and downward. Sony lists 3840 × 2160 XAVC S 4K modes as well as Full HD choices. The monitor movement is not described as a side-hinged fully articulating screen, so buyers who need to face the display while recording should confirm the hinge suits their position. The 4K width is a clear documented capability, but the exact frame-rate, crop, bit rate and card combination should be checked in the mode table for a production workflow.

Battery and focus information

Sony estimates about 610 still images using the viewfinder and 710 using the LCD, with CIPA conditions applying. The checked specification gives a combined weight with battery and card, so a body-only comparison remains unknown here. Sony documents face detection but the checked source does not establish animal or bird recognition, and it does not establish a weather-sealing value for this profile. Those unknowns should not be interpreted as proof that a feature is absent. If either is a hard requirement, compare a manufacturer page that names the exact model and the relevant claim.

Before you decide