[commoner]

I personally recommend the first-generation Google Pixel XL (marlin), which costs under $100 used on eBay.

https://en.wikipedia.org/wiki/Pixel_(smartphone)

With MicroG, Google Camera works as it does on stock Android. Most phones on LineageOS aren't able to use their stock camera app, which results in reduced camera quality compared to stock Android. The Pixel/Nexus line, ironically, is the main exception.

Google Camera isn't available on F-Droid or Yalp/Aurora Store, but you can download it from APKMirror:

https://www.apkmirror.com/apk/google-inc/camera

(APKMirror is operated by Android Police, so it's a trusted site.)

[mindslight]

Can you elaborate on this? Is it the app itself needing to do some type of processing for peak performance, or some firmware blob that the app bundles and loads?

Pictures on my S7 herolte (microG+LOS obviously) are grainy, and investigating why is quite far down on my todo list. This wasn't a problem on i9500, klte, or shamu. I had thought the issue must be some missing firmware, either from the OS image or it got wiped somehow. Compounded by being in Exynos rather than more popular Qualcomm land. But not knowing all that much about the Android photo stack, it's interesting to hear you say it depends on the app used itself.

[commoner]

Camera quality depends on both the camera firmware blob and the camera app. On high-end Android phones, the camera app usually makes use of proprietary features on the firmware blob and performs post-processing (such as HDR and bokeh).

Other Galaxy S7 (herolte) users seem to have the same problems as you on LineageOS, but it's hard to tell exactly what causes them:

https://www.reddit.com/r/LineageOS/comments/8awrcz/herolte_g...

Also, the Galaxy S7 is no longer officially supported by LineageOS, since there are currently no active device maintainers:

https://wiki.lineageos.org/devices/herolte/

It's difficult to diagnose issues with unofficial builds of LineageOS, because they most likely don't meet the LineageOS device support requirements:

https://github.com/LineageOS/charter/blob/master/device-supp...

Google Camera's post-processing has been well-received, and the app has been ported to many non-Google devices, including the Galaxy S7. I'm not sure how well the S7 ports work (especially if your S7 has an Exynos SoC) but XDA Developers has a couple of active threads here:

https://forum.xda-developers.com/galaxy-s7/themes

Using one of the ports might improve your camera situation. No guarantees, but it doesn't hurt to try.

I recommended the first-generation Pixel and Pixel XL because they are the only phones that are currently supported by both LineageOS and the latest version of the official (non-ported) Google Camera app. For people who aren't particular about camera features and quality, the Camera app that comes with LineageOS or any third-party camera app would be adequate, and you can use these with any supported device.

[commoner]

A correction: instead of "stock Android", I meant the factory operating system that comes with the phone.

[commoner]

Oops, I missed the "at most 5 inches" part. The first-generation Google Pixel (not XL) has a screen that measures exactly 5 inches, and is even cheaper than the XL.