Why won't my DSLR camera focus properly in low light

Low light AF improves with a faster lens. Canon 50mm lens has a bright f/1.8 aperture that feeds much more light to the AF sensors and lets you use quicker shutter speeds, so it locks focus more reliably on dim scenes and moving subjects. The STM drive is quiet and accurate.

Drawback is a tighter field of view for wide star fields and some corner aberrations, but as a budget upgrade it markedly improves low light focusing and image quality.

Low light makes phase detect AF struggle because it needs contrast. Set a single AF point and use the center one & turn off auto area or face detection. Switch to AF-S for static shots and AF-C for moving subjects, and set focus priority so the shutter only fires when focus is confirmed. Open the aperture as wide as your lens allows and enable the AF assist lamp in the menu if your body has one. Big help.

When it refuses to lock, use live view and magnify the preview, aim at a bright distant light or star, tweak focus until it looks smallest and crisp, then switch the focus mode to manual to lock it. For stars, leave it there and don't touch the ring. Bump ISO while focusing to brighten the preview, then lower it for the actual exposure if needed.

To avoid blur from vibration use the self timer or a short shutter delay and electronic front curtain if available. For star trailing use the rule of 500 divided by focal length as a starting point and adjust after a test frame.

Hey, I've run into this exact issue with my own setup during night shoots. First off, try bumping up your ISO a bit to let more light in, which can help the autofocus system grab onto details better. But watch out, too high and you'll get noise in your shots. Also, switch to continuous autofocus mode if you're dealing with moving subjects; it tracks them as they shift.

Another trick is using the camera's live view on the screen instead of the viewfinder. It often focuses more accurately in dim conditions because it uses contrast detection. Works great for starry skies. And for stability, a sturdy tripod is key to avoid blur from shaky hands, especially with longer exposures. Give those a shot and see if it clears things up.

Use manual focus with magnified live view on a bright star, rack past infinity then ease back until it is a tiny pinpoint and leave it. Shoot wide open at high ISO with a shutter from the 500 rule for your focal length and use a short delay to prevent shake, and recheck focus as the night cools.

I treat focus as a two step job at night. Find something with strong contrast that is about the same distance as your subject such as a lit sign or a bright edge and use only the center point, get focus, then recompose. Works great.

For moving subjects use AF-C with the smallest focus area your camera offers, slow down tracking sensitivity so it does not jump to the background, and choose focus priority so it does not fire out of focus. If you keep missing, raise ISO so you can use a faster shutter and reduce motion blur. Also check if your camera offers AF fine tune and run that in daytime on a target so you know the system is calibrated.

Low light focusing can be a real pain, I remember struggling with that on my first night photography attempts and it was frustrating as heck... What helped me was playing around with the aperture settings to open it up wider, letting in more light so the camera could lock focus faster, and then I adjusted the shutter speed accordingly to freeze any movement.

I tried that and it fixed a lot but then for really dark scenes I started using a flashlight to illuminate the subject just for focusing, then turned it off before snapping the pic... yeah, old school but effective. Keeps things sharp without needing fancy gear.