More pixels. Not a completely different picture.
Megapixels describe the number of pixels in an image. A nominal 2.4MP image contains about 2.4 million pixels; a 3MP image contains about 3 million. That is 25% more pixels overall, but only about 12% more pixels along each dimension when the aspect ratio stays the same.
That extra sampling can help preserve small details during a digital crop. It does not mean a face or number plate will automatically become readable. The subject still needs to be large enough in the frame, in focus, well lit and recorded without excessive motion blur.
“2.4MP” can be a marketing label. Ask for the camera’s recorded width × height and check the recorder settings. For reference, 1920 × 1080 is about 2.07MP, not 2.4MP. A 2304 × 1296 stream is about 2.99MP. Aspect ratios and available modes vary by model.
The practical comparison
| What matters | 2.4MP | 3MP |
|---|---|---|
| Nominal pixel count | 2.4 million | 3 million |
| Digital cropping | Less pixel detail to work with | Modestly more detail under comparable conditions |
| Night-time image | Compare sensor, aperture, lighting, shutter settings and actual night footage | |
| Recording storage | Depends on recorded bitrate, codec, frame rate, scene activity and recording hours | |
| Recorder compatibility | Check supported input format, resolution, frame rate and channel limits | |
| Best way to decide | Test the actual view and identification distance you need, by day and at night | |
What makes the bigger difference?
Lens and camera placement
A very wide view spreads the available pixels across a larger area. Positioning a camera closer to an entrance, or choosing a suitable focal length, can matter more than a small increase in megapixels. Compare cameras using the same field of view.
Lighting and motion
Compare footage with people walking through the scene. A bright still image can hide motion blur. Resolution alone cannot tell you how well either camera handles a dim entrance or a moving subject.
Compression and recording settings
The image on the live preview may differ from the recording you export. Check the recorded main stream, not only the mobile substream. At the same bitrate and recording duration, 2.4MP and 3MP video use roughly the same storage; the higher resolution may need a higher bitrate to preserve its additional detail.
At a continuous 2 Mb/s, one camera records about 21.6 GB per day before overhead. At 3 Mb/s, that becomes about 32.4 GB. These are bitrate calculations, not predicted bitrates for either camera resolution.
Which one should you choose?
When the actual footage meets your needs
A suitable option if it captures the required detail at your viewing distance, works with your recorder and fits your budget. Confirm what the “2.4MP” label means on that model.
When a little more crop detail helps
A reasonable step up if the lens, lighting performance and recording settings are comparable. Verify that your recorder supports the camera’s full resolution and desired frame rate.
For a gate, shop counter or factory entrance, first define what you need to see and from how far away. Then compare sample recordings from the exact models you are considering.
A few common questions
Is 3MP 25% sharper than 2.4MP?
It has 25% more pixels by nominal count. That does not translate directly into 25% more sharpness. With the same aspect ratio, pixel dimensions increase by about 12%, and real detail depends on the whole imaging system.
Will 3MP always use more hard disk space?
No. Storage follows recorded bitrate and duration. If a higher resolution is configured with a higher bitrate, storage increases accordingly.
Does this page show real camera footage?
The slider shows sample stills hosted on this page. Until the sample images load, a clearly labelled computer-generated illustration is shown instead. For the fairest test, compare exported stills with matching scene, framing, lighting and recorder settings.