When it comes to the cameras, the OnePlus 7T and the 7T Pro are nearly identical. Both phones have a triple camera layout on the back, two of which are identical on both devices. On the front is a single selfie camera and while the mechanism is different, the camera itself is again identical on both. So really, the only difference between the two phones is the telephoto camera and that the 7T Pro has a laser AF sensor, which the 7T doesn't.
To list off all the modules, we have the now famous Sony IMX586 as the primary rear camera on both phones, with 48-megapixel resolution, 7P lens, f1.6 aperture, and optical image stabilization. Complementing it is a 16-megapixel ultra-wide camera with f2.2 aperture, again common on both phones. The third camera is the one that differs on both phones; the 7T has a 12-megapixel f2.2 camera without stabilization that offers 2x optical zoom over the standard wide-angle lens. Meanwhile, the 7T Pro has an 8-megapixel f2.4 camera that has OIS and provides 3x optical zoom over the standard wide-angle cameram with a clever trick.
You see, the 7T Pro - like the 7 Pro before it - has a 13-megapixel sensor for the telephoto camera. This lens provides roughly 2.2x the optical zoom factor over the standard wide-angle lens. To achieve the 3x zoom, OnePlus only uses the center 8-megapixel portion of the lens, which has a field of view roughly 3x narrower than the main wide-angle lens. However, when you shoot portrait images with the telephoto camera, it captures a 12-megapixel image, meaning it uses more of the sensor. The field of view is obviously wider but that's fine for portrait images.
Earlier, with OxygenOS 9 on the OnePlus 7 Pro, the telephoto camera captured the full 13 megapixel resolution in portrait mode. However, with the OxygenOS 10 update, that camera has now been slightly downgraded to only capture 12-megapixel images in portrait mode on the 7 Pro. Since the 7T Pro ships with OxygenOS 10 out of the box, it has only ever been able to capture 12-megapixel images in portrait mode and the standard 8 megapixels in telephoto mode.
The point of all this is that while the 7T and 7T Pro don't have the same sensor for their respective telephoto cameras, they have roughly the same specs and the 7T Pro is merely cropping the image to achieve the extra zoom factor. You can probably crop the 12-megapixel 7T image to 8 megapixels manually and get roughly the same field of view as the 7T Pro but that's obviously extra work. Both cameras capture Portrait mode images in 12 megapixels but while the 7T does it at 2x the main lens, the 7T Pro does it at around 2.2x.
Lastly, the front-facing cameras on both phones are identical, with 16 megapixel resolution and f2.0 aperture. There is an electronic image stabilization but no autofocus. The 7T has the camera placed inside the notch while the 7T Pro has it in a sliding mechanical module. The mechanical module does give the camera some additional protection as a scratch or a smudge on the display doesn't end up hurting the camera performance. Also, in the year since we have had these sliding cameras, we haven't heard of any widespread terminal failures with them so maybe they aren't such a bad place to put the front camera.
Moving on to the camera software, both phones ship with the same version of the OnePlus Camera app (v3.8.69 at the time of writing). The OnePlus camera app has gone through a few iterations over the years but the current one is easily the best with very well laid out options and camera modes. The app puts the most used modes within direct access and others are in a slide-out tray at the bottom. The zoom controls are also within each reach whether in portrait or landscape mode. You also get all the features, including HDR, Nightscape, panorama, slow motion, time-lapse and a pro mode.
The 7T series also adds a new macro mode, which uses the ultra-wide lens to capture really close images of subjects. The only thing missing right now is a hyperlapse option and a super slow-motion mode. The latter is expected to arrive at a later date, so we will have to keep an eye out for that.
Winner: OnePlus 7T Pro. While both phones have nearly identical cameras, the 7T Pro has a longer 3x optical zoom that provides better reach and it has OIS.