The Quick Verdict
Get the BenQ LK830ST 4K Short Throw Laser Projector. It lists at $2,499, which is $400 under the AK700ST at list. BenQ rates its input lag at 16.7 ms at 1080p 60Hz, against 33.4 ms for the AK700ST. Otherwise the two line up closely: both list 4,000 lumens, both have a golf mode, and both state 4:3 and 1:1 among their modes. The BenQ AK700ST 4K Short Throw Laser Golf Simulator Projector earns its extra $400 in one case: you need a zoom lens for mounting slack, or you want a warranty term BenQ actually publishes for the model.
What They Have in Common
Both are BenQ, both released in 2025, and both are short throw by the numbers. They share a 3840x2160 resolution, a native 16:9 shape, a golf picture mode, and a laser light source rated at 20,000 hours. Both list 4,000 lumens. BenQ doesn't state the measurement standard for either figure, and since the numbers match there's no gap to talk about.
Where They Differ
Throw and image size
Image width = throw distance divided by throw ratio. The LK830ST has a fixed 0.496:1 lens. From 10 ft back it puts up a 20.2 ft wide image (10 ft ÷ 0.496). The AK700ST zooms between 0.69:1 and 0.83:1, so from the same 10 ft it gives 12.0 ft to 14.5 ft wide (10 ft ÷ 0.83 to 10 ft ÷ 0.69).
Turn it around for a 10 ft wide image. The LK830ST sits 5.0 ft from the screen. The AK700ST sits 6.9 ft–8.3 ft from the screen.
The fixed lens matters as much as the short ratio. With the LK830ST, your screen width sets the lens position, and there's no zoom to adjust it. The AK700ST's range lets you slide the mount a bit and still fill the same width. Measure the distance from where the lens would hang to the screen, then check it against those figures before you choose.
Input lag
The LK830ST is rated at 16.7 ms at 1080p 60Hz and the AK700ST at 33.4 ms. That's a 16.7 ms gap in the LK830ST's favor. My read is that this, together with the lower list price, settles the pick when everything else is this close.
Zoom, lens shift and keystone
The AK700ST has a 1.2x optical zoom and no lens shift. The LK830ST's zoom is 1, meaning a fixed lens. BenQ doesn't publish a lens shift spec for the LK830ST, so I can't tell you whether it has any.
Keystone differs too. The AK700ST lists 3D keystone: ±30 degrees vertical, ±30 degrees horizontal and ±30 degrees rotation. The LK830ST lists 2D auto keystone at ±30 degrees vertical and ±30 degrees horizontal.
Screen shapes, resolution, warranty and the rest
Both state 1:1 and 4:3, which covers the common impact-screen shapes. The LK830ST also states 5:4. That shape isn't among the AK700ST's stated modes, though that's not the same as saying the AK700ST can't do it.
On resolution, BenQ says the AK700ST's 4K is pixel-shift. It doesn't say how the LK830ST produces its 4K.
The AK700ST carries a published warranty: "3 years parts and labor from purchase date (original retail purchaser), US." BenQ publishes no warranty term for the LK830ST.
Size and weight are close. The AK700ST weighs 7.48 lbs and measures 11.94 x 4.43 x 9.23 in. The LK830ST weighs 7.93 lbs and measures 10.99 x 4.74 x 9.03 in, so the AK700ST is 0.45 lbs lighter.
Who Should Buy Which
Get the BenQ LK830ST 4K Short Throw Laser Projector if:
- You want the lower input-lag figure: 16.7 ms against 33.4 ms at 1080p 60Hz.
- You want the projector closer to the screen. It needs 5.0 ft for a 10 ft wide image.
- You'd rather keep $400 at list for the rest of the bay.
- Your screen is 5:4, which BenQ lists among this model's modes.
Get the BenQ AK700ST 4K Short Throw Laser Golf Simulator Projector if:
- Your mount position isn't flexible and you need zoom slack. It fills a 10 ft wide image from anywhere between 6.9 ft and 8.3 ft.
- You want 3D keystone with rotation correction listed.
- A published 3-year parts-and-labor warranty matters to you. BenQ publishes no term for the LK830ST.
- You want BenQ's stated answer on how the 4K is produced (pixel-shift).
The Bottom Line
The two match on lumens, golf mode, resolution, laser life, and the 1:1 and 4:3 screen shapes. That leaves price and lag to decide it, and the LK830ST wins both: $400 less at list and a 16.7 ms lower lag figure. The AK700ST's zoom and published warranty are real advantages, so if the mount can't move, that's your exception. For everyone else, I'd guess the fixed lens is a fair trade, but I don't work at BenQ.