The new open beta of the Oxygen OS update for the OnePlus 5 and >OnePlus 5T has introduced a few camera improvements, reduced the "oil painting effect" in photos captured using the smartphones and also enabled Google Lens support.
As per various reports, it would seem that some users were not satisfied with the photos being captured by the device. They said that the photos looked more akin to an oil painting than an actual photo. The new open beta update will reduce that effect and also increase photo clarity as per OnePlus.
Google Lens uses the smartphone camera to identify objects using complex machine learning algorithms. Earlier Google Lens was available as a separate app but now it would seem that the update has integrated the feature into OnePlus 5 and OnePlu 5T's native camera app.
As such if you are already a member of the open beta program from OnePlus you will receive this update OTA. In case you wish to download this beta, you would need to flash your device and register for OnePlus' open beta program. A word of caution, however, open betas are prone to bugs and performance issues and as such, they should preferably be downloaded on a secondary device.
Also, you must know that once you migrate to the Beta path, you will no longer receive the regular Official Stable OTAs. Moving back to the Official OTA path from the Beta path will require a full install and clean flash.