I am so sick of reading conflicting reviews online and just need some straight answers. I have a family portrait shoot for my sister graduation in three weeks here in Chicago and my budget is strictly capped at $350 max. I am shooting on a Sony a6400 and really need a solid portrait lens but I am completely torn between two options.
First is the Sony 50mm f1.8. It is super cheap and fits my budget easily but literally everyone online says the autofocus is slow and noisy and honestly that worries me because I will be shooting kids who do not sit still. The other option is the Sigma 56mm f1.4 which everyone raves about but it is stretching my budget to the absolute limit even buying used on MPB. I also looked briefly at the Viltrox 85mm f1.8 but I am worried that might be too tight for the park we are using.
Is the Sigma really worth the extra cash stretch or can I get away with the Sony 50mm without losing my mind over missed focus?
Saw your post and had to jump in because I have been in this exact spot. In my experience, the bad rep the Sony 50mm gets is usually for the full-frame version. If you grab the Sony E 50mm f/1.8 OSS, which is built for your a6400, it is actually pretty snappy and has stabilization to help with handheld shots. If you really want the f/1.4 look but the Sigma is too pricey, try these:
- Viltrox AF 56mm f/1.4 E is a total hidden gem. It is much cheaper than the Sigma and the autofocus keeps up with my toddlers just fine.
- Hunt for a used Sigma 56mm f/1.4 DC DN Contemporary on eBay or local boards. I've seen them go for $320ish lately if you avoid the big retailers. The Sigma is definitely the sharpest, but dont feel like you have to starve just for a lens. That Viltrox 56mm gets you 95% of the way there for way less cash.
I was in your exact shoes last year shooting my hyperactive nephew's birthday party in a local park. I tried saving cash with the Sony FE 50mm f1.8 first, but honestly, it was a total nightmare with the slow autofocus missing half the shots when he ran around! I ended up swapping it for the Sigma 56mm f1.4 DC DN Contemporary and my mind was blown. Here is how they stack up in the real world:
- Sony 50mm: Super cheap and lightweight, but the autofocus is definitely too slow for moving kids.
- Sigma 56mm: Incredible sharpness even wide open, and the autofocus keeps up perfectly with hyper kids.
- Viltrox 85mm: Way too tight for a park setting, you will be backing up into trees constantly. Seriously, stretch your budget for the Sigma. You wont regret it and the photos will look absolutely fantastic!
Honestly, if you are worried about tracking kids with an a6400, the AF motor tech matters more than the glass quality. I used to run the Sony E 50mm f/1.8 OSS for years and while the stabilization is nice for low light, the micro-stepper motor definitely hunts when the light drops. It just isn't built for high-speed tracking. Coming back to this, you should look at the build specs before buying. Consider these alternatives if you want reliability:
- Tamron 70-300mm f/4.5-6.3 Di III RXD: Sometimes you can find this used right near your limit. It is not as fast aperture-wise, but the RXD motor is significantly more reliable for unpredictable movement than the cheaper primes.
- Samyang AF 75mm f/1.8 FE: This is surprisingly sharp and the AF is generally faster than the older Sony design. It is compact and usually fits well under the $350 mark. If you really want the f/1.4 look, just save the extra cash for the Sigma 56mm f/1.4 DC DN Contemporary. I moved to that lens for events and the linear motor performance is just in a different league for keeping focus on moving subjects. Dont risk the graduation shots on an outdated motor.
Bump - same question here
Honestly, the hunt for autofocus speed on the a6400 is such a headache. I had issues with focus hunting on older glass during a shoot at the planetarium last month, and it was pretty disappointing. The tracking algorithms just struggle when the motors are outdated.
- The internal motor torque in newer designs makes a massive difference.
- Unfortunately, sticking to older budget glass often means missing those split-second expressions.
- Check out the technical breakdowns on dxomark or optical limits before committing cash. Actually, that reminds me, have you ever been to the planetarium? The Zeiss projection systems they use are just mind-blowing pieces of engineering. I spent like three hours just geeking out over how they calibrate the light paths for the starfield. The precision is honestly insane compared to standard optics. Anyway lol, sorry kinda went off topic there. Just save your sanity and get the faster glass.
