A 4,000-ANSI-lumen BenQ is a reasonable starting point for a home golf simulator with controlled light, but the lumen rating alone cannot confirm the finished picture. Screen area, light falling on the screen, image settings and installation geometry all affect the result. LK830ST, AK700ST and AH700ST share the same published 4,000-ANSI-lumen rating; their main buying differences are elsewhere.
Use this guide to decide whether one of these three belongs in your room before spending more on brightness or buying a projector that cannot sit where the room needs it.
A useful lumen range starts with the room
BenQ's current lighting guidance uses approximately 3,000 lumens as a starting point for smaller screens and recommends considering 4,000–6,000 lumens for larger screens or more ambient light. Treat those as planning ranges, not promises that a particular ceiling light, window and screen combination will look a certain way.
| Room situation | First buying check | What it means for a 4,000-lumen shortlist |
|---|---|---|
| Darkened screen wall, modest image size | Check picture mode, source and projection fit. | LK830ST, AK700ST and AH700ST are sensible candidates to evaluate. |
| Lighting needed near the golfer | Keep required task lighting directed away from the image where practical. | Evaluate the picture with the lighting you will actually retain. |
| Daylight or a fixture falling directly on the screen | Assess blinds, fixture direction or screen location. | Do not assume the shared 4,000-lumen rating will overcome that light. |
| Large image with lighting that cannot be reduced | Assess a higher-output installation against the actual screen and use case. | The three models may not be the right shortlist; resolve the room before ordering. |
The screen-area calculation most lumen comparisons leave out
For a simple comparison, keep the same image shape, screen material, projector settings and projected light output. Increasing both image dimensions spreads that output over more area. The resulting average illumination changes with the area, not just the screen's width.
| Image width × height | Image area | Average illumination relative to the 8-foot-wide example |
|---|---|---|
| 8 ft × 6 ft | 48 sq ft | 100% |
| 10 ft × 7.5 ft | 75 sq ft | 64% |
| 12 ft × 9 ft | 108 sq ft | 44% |
The calculations are 48 ÷ 75 = 0.64 and 48 ÷ 108 ≈ 0.44. They illustrate the effect of area; they are not measured brightness figures for a BenQ projector. Real delivered output can change with settings, optical position and digital adjustments. Screen reflectance and ambient light also affect what you see.
This explains why a recommendation from someone using a smaller screen may not transfer to your larger build. Record your planned viewable image width and height before comparing lumen ratings.
All three BenQ models are rated at 4,000 ANSI lumens
| Model | Published brightness | Resolution | Optical throw ratio | Reason to shortlist it |
|---|---|---|---|---|
| LK830ST | 4,000 ANSI lumens | 4K UHD | 0.496:1, fixed | 4K from a closer lens position, when its vertical geometry also fits |
| AK700ST | 4,000 ANSI lumens | 4K UHD | 0.69–0.83:1 | 4K with optical zoom and Auto Screen Fit in the longer mounting range |
| AH700ST | 4,000 ANSI lumens | 1920 × 1080 | 0.69–0.83:1 | A Full HD build with optical zoom and Auto Screen Fit |
Moving from AH700ST to AK700ST buys a different resolution proposition, not a higher published lumen rating. Moving from AK700ST to LK830ST changes the mounting geometry; it does not increase that rating either. Equal specifications do not prove identical measured performance in every picture mode.
If all three meet the lighting requirement, prioritize the one whose placement, source resolution and setup features suit the room. Our AK700ST versus LK830ST guide handles the close-placement decision, and the AH700ST versus AK700ST guide handles the resolution choice.
Why more lumens do not fix every washed-out image
Room light reaching the screen raises the brightness of areas that should appear dark. Adding projector output can improve the bright parts of the image, but it does not remove the room light from the dark parts. Direct light control is therefore part of the display design, not a finishing touch after the projector arrives.
Keep enough light for the golfer, safe movement and any equipment requirements. Separate that task lighting from the screen wall where your room allows it. Check the launch monitor's instructions; the lighting needs of one tracking system should not be assumed for another.
A gray impact screen is also a trade-off. It can change the appearance of the image under ambient light, but it reflects less projector light too. Do not use its color as a substitute for evaluating the projector and screen together.
A three-scene test for the actual room
If you can evaluate a candidate in the room before final installation, use the same screen area, source and picture mode for each comparison. Keep a simple record:
- Golf scene: inspect fairway texture, darker trees and the edge of the projected image with your usual room lighting.
- Data screen: check whether the smallest shot numbers and menus are readable from the hitting position.
- Light-control comparison: repeat after reducing light that falls on the screen. Note which change improves the picture before deciding that more projector output is necessary.
Use the picture mode you expect to play in, and note any economy or light-output setting. A maximum brightness specification is not a measurement of every operating mode. Phone photos can be misleading if automatic exposure changes between shots; use them as notes, not as calibrated light measurements.
Close projection is useful, but it does not replace a lighting plan
LK830ST can be valuable when the projector must sit closer to the screen. Check its lens height, mount, ventilation and light path as well as distance. Short throw can help position the projector relative to the player, but the room's geometry still determines whether someone or something blocks the image.
For square and 4:3 screens, plan the intended image inside the native 16:9 optical frame. Digital resizing and correction do not add light output. Use the projector planning calculator and the model's installation instructions before fixing a mount in place.
Make the final choice
If your lighting and image-size checks support this brightness class, compare LK830ST for close 4K projection, AK700ST for 4K with Auto Screen Fit, or AH700ST for Full HD with Auto Screen Fit. If strong light or a large screen remains unresolved, send us the room and screen measurements before committing to one.
Checked October 19, 2026 using BenQ's current US specifications and lighting guidance. The area table is a stated mathematical illustration, not a photometric test. No model-specific measured brightness or contrast result is claimed.
