Best low light prime lens for Sony FX30 video?

Question

I’ve been using the Sony FX30 for a few months now and I absolutely love the image quality during the day. However, I’ve started doing more event work lately—think dimly lit wedding receptions and moody indoor interviews—and I’m really starting to feel the limitations of the APS-C sensor when it comes to low light. I currently have the 18-105mm f/4, but it’s just not fast enough when the sun goes down, and I’m seeing way more noise than I’d like even with the dual base ISO.

I’m looking to invest in a solid prime lens that can really help me push this camera in dark environments. I’m debating between something like the Sony 15mm f/1.4 G for those wide venue shots or perhaps the Sigma 30mm f/1.4 DC DN for a more natural look. Sharpness is important, but I’m mostly concerned with how the autofocus holds up in low light since I’m usually a solo shooter. My budget is around $500–$800, though I could stretch it for the right glass.

For those of you filming on the FX30, which prime has been your go-to for clean, low-light footage? Should I strictly stick to f/1.4 glass to compensate for the crop sensor, or do f/1.8 lenses cut it for you?

XtrapSmoth · Accepted Answer

Yo, I feel u on the low light struggle with the FX30—it's a beast during the day but that f/4 lens is definitely holding u back. Honestly, I've been shooting events for years and you really need f/1.4 glass to keep the ISO down and the noise manageable. Here's my comparison: the Sony E 15mm f/1.4 G is the winner for AF reliability, which is HUGE for a solo shooter in dim rooms. The Sigma 30mm f/1.4 DC DN Contemporary for Sony E is incredibly sharp for interviews but might feel a bit tight for crowded receptions. I'd lean toward the Sony 15mm or even the Sigma 16mm f/1.4 DC DN Contemporary for Sony E for those wide venue shots. Quick tip: Stick to f/1.4 glass cuz f/1.8 often isn't enough to compensate for the crop sensor noise... u basically need every bit of light u can get!! gl

tank_akOi · Answer

I've been shooting with Sony for a long time and I'm honestly super happy with how the FX30 handles when you give it the right glass. For event work, reliability is everything. You really want to stay at f/1.4 or f/1.8 to ensure you're hitting that second base ISO without adding too much digital gain, which is where that grain soup comes from.

Sigma 16mm f/1.4 DC DN Contemporary is a beast for wide venue shots and the AF tracking is very reliable for solo operators.

Sony E 35mm f/1.8 OSS works well because the built-in stabilization helps a ton when you're handheld in a dark room and starting to get a bit shaky. I actually used that 35mm at a wedding last summer where the venue lost power during the toasts. We had to finish the shoot using just the light from the catering staffs lanterns. It was actually kind of magical, reminded me of this old indie short I worked on back in the day where we used literal flashlights for key lights because we couldnt afford a proper kit. We spent like three hours trying to rig a flashlight to a C-stand with duct tape... it was a mess but we had a blast. Anyway, those two lenses should definitely get you where you need to be with the low light stuff.

Alexzsqueks · Answer

I went through this last year too. Honestly, that f/4 lens is killer for daytime but it LITERALLY falls apart in dark venues. I found out pretty quick that on an APS-C sensor, you really wanna stay at f/1.4 to keep that second base ISO (2500) from looking like grain soup. I ended up grabbing the Sigma 30mm f/1.4 DC DN Contemporary for Sony E because the value is just insane compared to the Sony G glass. AF tracking is actually solid on the Sigma stuff nowadays, which was a huge relief cuz I'm usually solo too. I also looked at the Sigma 16mm f/1.4 DC DN Contemporary for Sony E which is way cheaper than the Sony 15mm mentioned before if youre trying to save cash for a cage or extra batteries. Just be careful with f/1.8 lenses... they're okay, but that extra bit of light on an f/1.4 actually makes a huge difference when you're pushing the sensor limits. gl!