[Google Pixel 3a Guides, News, & Discussion] quark-lepton:
Hello, I have bought a Pixel 3a. Here's my experience when compared with the camera of the Nexus 5x (Google camera 4.3.016). Nexus 5x was used in HDR+ On mode (technically this mode was comparable to HDR+ enhanced, the Nexus didn't have a zero shutter lag HDR+ mode).

White balance and colors of the Nexus 5x are much, much better. No matter whether the 3a uses Night Sight, HDR+ Enhanced or HDR+, the white balance is nearly always much worse than the Nexus. Indoors as well as outdoors (sunsets as well as normal daylight photos). It's really a noticeable step back and ruins the camera of the 3a. The white balance of the Nexus isn't perfect, but compared with the Pixel 3a it's nearly perfect.

Dynamic range is nearly identical, overall the Nexus is a little bit better. Sometimes the 3a overexposes more than the Nexus when you touch to focus, even in HDR+ enhanced mode. Interestingly the Nexus with camera version 4.1 retains highlights sometimes even better than 4.3 , I have both versions because Google changed the processing a bit with version 4.3).

Furthermore the Pixel seems to have a worse display, the display crushes the shadows more.

In extreme darkness the 3a's zero shutter lag HDR+ mode performs slightly worse than the Nexus 5x HDR+ On mode, but the Pixel's HDR+ enhanced mode is noticeably sharper and less noisy than the Nexus in extreme darkness. HDR+ enhanced is nearly as good as Night Sight, often HDR+ enhanced is even better because Night Sight can lead to blurry photos and Night Sight takes up to 7 seconds (there is a ≈ 1s shutter lag and then Night Sight exposes for up to 6 seconds, for example 12x 0.5s exposures). When you want a brighter photo in HDR+ enhanced mode, you can simply use the exposure compensation slider.

In low-light conditions or average light conditions the Pixel's software zoom can give you noticeably more details and less noise than the Nexus zoom (though not always). The 3a zoom in HDR+ mode works nearly always better than the zoom in HDR+ enhanced or portrait mode, HDR+ enhanced and portrait mode seem to use the old zoom algorithm. The improvement of the tele capabilities are not just due to software. It's also because the Nexus has a slightly wider field of view and slightly smaller effective aperture diameter. The Nexus has a ≈25.9mm field of view, the 3a has ≈27.2mm, therefore the 3a's details are comparable to a 25.9mm field of view with ≈13.5 megapixels instead of 12.2). The effective aperture diameter of the 3a is 2.467mm, the effective aperture diameter of the Nexus is 2.335mm, therefore the 3a captures ≈11.6% more light per time from distant objects than the Nexus.

Nonetheless I wouldn't use more than 1.4x zoom, in some cases maybe 2.0x. At 2.7x zoom there's too much machine learning zoom, which looks artificial. In most cases there's no advantage of using a higher zoom factor than 1.4x (the first big dot is equal to 1.63x zoom, the second big dot is equal to 1.63²x zoom).

In perfect light conditions without shadow areas the 3a zoom is nearly useless. Crops of 1.0x photos look nearly identical to crops of 2.0x photos.

I also noticed that the 3a zoom occasionally produces ugly artifacts. White or blue dead pixels can be visible when you zoom (sometimes also in Night Sight mode without zoom). Sometimes Google's software zoom transforms these dead pixels into white curvy lines. I compared three Pixel 3a, they all had this issue, but with different severity. When I shot in raw with Lightroom mobile, I noticed that the sensor of the Pixel 3a is full of dead pixels. Raw files of a second Pixel 3a had the same issue, even dpreview's studio comparison of the Pixel 3 shows a lot of dead pixels in Night Sight mode: https://www.dpreview.com/reviews/im...=1&x=0.12010144736623733&y=0.5747433399018789

When you zoom, these white pixels will be magnified or transformed into white lines.

The autofocus of the 3a is worse than the Nexus. The Nexus always focused on the center. At first I thought that the 3a did the same thing, but that's not the case. You never know where it focuses on. So I always have to touch to focus (otherwise photos might not be super sharp), but the 3a occasionally overexposes more than the Nexus when you touch to focus (no matter whether the 3a uses HDR+ or HDR+ enhanced).

In extreme low-light conditions the 3a's autofocus struggles more due to the lack of the laser autofocus. Night Sight offers manual focus presets, but I have a Pixel 3a where the focus hasn't been calibrated correctly, so the "far" setting doesn't work with far objects. Another Pixel 3a didn't have this calibration issue.

When you focus on close objects that are very small, the 3a's autofocus is much better than the Nexus.

Flashlight: The flashlight of the Nexus is much stronger than the Pixel's flash. The Pixel's flashlight also doesn't look as neutral as the Nexus. The 3a's light looks slightly blueish or greenish.

Macro performance: When you use the flash and 2.7x zoom, then the Pixel 3a can produce slightly better macro photos than the Nexus.

Selfie camera: The selfie camera of the 3a isn't very sharp in average light conditions, I am not sure whether it's better than the Nexus selfie camera. Also, the selfie zoom has the same issue and can make dead pixels visible.

Overall the Nexus takes better photos unless in not perfect light conditions you prefer details over correct colors or take photos in extreme darkness with HDR+ enhanced or Night Sight. Therefore now I have to carry two phones.