The OnePlus 5’s 2X zoom is not actually optical lossless zoom

June 23, 1:40AM: Updated with OnePlus statement.

The dual camera of the OnePlus 5 is one of the phone’s top selling points, so much so that OnePlus built its marketing campaign around the tagline “Dual Camera. Clearer photos.”

Having two lenses working together – a “normal” wide-angle one and a telephoto one – allowed OnePlus to add several cool features, including Portrait mode and a high-quality zoom feature. As usual though, the devil is in the details.

As noted by Dutch website Tweakers and by users over on Reddit, the OnePlus 5’s 2X zoom is not, in fact, fully optical. Instead, the OnePlus 5 actually uses a combination of optical and digital zoom.

That’s despite claims from multiple reviewers and tech publications from around the world, including Android Authority, that the camera offers 2X optical zoom.

It’s not clear how this misunderstanding became accepted as fact – our theory is everyone assumed the feature works just like on the iPhone 7 Plus, which actually does feature 2X optical zoom. The influential Wired, for instance, makes exactly this connection.

The printed reviewer guide we received with our OnePlus 5 unit uses ambiguous language to describe the feature. The text is technically accurate, but we can see how it could create confusion among reviewers.

To our knowledge, OnePlus did not go out of its way to correct reports and reviews that incorrectly mentioned 2X optical zoom. But after reports about it made the rounds yesterday, Carl Pei clarified – sort of – how zooming works on the OnePlus 5’s dual cameras:

What does this mean for the average user? And is this another case of misleading reviewers and customers, akin to the benchmark manipulation OnePlus has been accused of?

In practice, don’t expect to get the same level of detail when using OnePlus 5’s 2X zoom mode, that you would get from an iPhone 7 or other devices with true 2X optical zoom.

As for the truthfulness of OnePlus’ claims… well, it’s complicated. To be clear, we haven’t seen any OnePlus marketing material or official statement that claims the phone features 2X pure optical zoom. But Carl Pei says the OnePlus 5 features “2X lossless zoom,” which is confounding. How can zoom be “lossless” if there’s clearly a digital component to it?

Pei mentions “SmartCapture multiframe technology,” which is the marketing term for the suite of image processing features in OnePlus phones. OnePlus doesn’t really detail what SmartCapture is, but according to Qualcomm (which makes the image processing chips in the OnePlus 5) SmartCapture helps “deliver a smooth zoom experience between the OnePlus 5’s two cameras for recording high quality videos from a wide range of distances, with greater clarity” – no mention of “lossless zoom” here.

It seems that OnePlus is playing fast and loose with the term “lossless.” In the end, it might turn out to be correct (at least semantically), but the confusion this issue creates is definitely not helping its image. We’ve reached out to the company for clarification. For now, take the “2X optical zoom” and “2X lossless zoom” claims you see being thrown around with a grain of salt.

Update: OnePlus got back to us with a response on how the feature works.

“The OnePlus 5 uses optical zoom to around 1.6x, and then uses multi-frame technology to achieve 2x lossless zoom. It’s not cropped up to 2x, that’s where multi-frame technology lets us go to 2x lossless zoom.”

It’s still not clear what this “multi-frame technology” actually does, but at least we know now that it’s not a simple cropping of the 20MP image.

For what is worth, we enjoyed the OnePlus 5’s camera features, and its Portrait mode won our comparison with the iPhone 7 Plus and HUAWEI P10. But that doesn’t mean OnePlus deserves a free pass when it comes to potentially misleading claims. Let us know what you think.