For a 4:3 or square golf screen, calculate the LK830ST’s mounting distance from the image height you want to fill. Multiplying the screen’s narrower width by its 0.496 throw ratio can put the projector too close. Screen Fill changes the picture format, but it cannot make the lens cover a taller area from that same position.
This guide covers the BenQ LK830ST specifically. It uses published specifications and original planning calculations, not an in-room performance test. If you are still choosing a projector, start with our AK700ST vs LK830ST room-fit comparison.
Separate the optical image from the picture you want to see
The LK830ST projects a native 16:9 image through a fixed 0.496:1 lens. A 4:3 or 1:1 picture uses a narrower portion of that overall image when you preserve the full height. That is why your impact screen’s width and the width used for the throw calculation may be different.
BenQ’s Screen Fill feature offers formats including 4:3, 1:1, 16:10 and 5:4. Select the format on the LK830ST; do not follow camera-based Auto Screen Fit instructions written for the AK700ST or AH700ST. After changing Screen Fill, check the connected computer and the simulator application separately.
Calculate from height before marking the ceiling
Use the visible image area, excluding the black border and frame. Keep all measurements in the same unit:
- Full optical width = target image height × 16 ÷ 9.
- Estimated lens distance = full optical width × 0.496.
- Check the proposed position against the enclosure, the complete projector body, ventilation clearance and every golfer’s swing.
| Target image height | Full 16:9 optical width | Lens to screen | Same distance in inches |
|---|---|---|---|
| 6 ft | 10.67 ft | 5.29 ft | 63.5 in |
| 7 ft | 12.44 ft | 6.17 ft | 74.1 in |
| 7.5 ft | 13.33 ft | 6.61 ft | 79.4 in |
| 8 ft | 14.22 ft | 7.05 ft | 84.7 in |
| 8.5 ft | 15.11 ft | 7.50 ft | 89.9 in |
| 9 ft | 16.00 ft | 7.94 ft | 95.2 in |
These are geometric starting points for a level, square installation using the full optical height. They are not mounting tolerances or a guarantee of final image coverage. Digital shrink, geometry correction, the actual viewing area and alignment can change the usable result. Confirm the image with the projector before fixing the mount.
Distance is only one coordinate. If the image lands too high or too low, use the LK830ST lens-height and offset examples to check the physical floor or ceiling position before changing the screen format.
Worked example: why a 4:3 screen needs more distance than expected
Suppose the target picture is 8 feet wide and 6 feet tall. Using width alone gives 8 × 0.496 = 3.97 feet. But a native 16:9 image that is 8 feet wide is only 4.5 feet tall.
To reach 6 feet of height, start with a full optical width of 10.67 feet. Multiply that by 0.496 and the estimate becomes 5.29 feet, or 63.5 inches, from lens to screen. The full optical image is wider than the active 4:3 picture. Verify where that unused area lands around the enclosure.
Check the HDMI mode before choosing a resolution
The LK830ST section of BenQ's manual lists different Screen Fill resolutions for Standard and Enhanced. A screen that fills correctly can still be using the lower-resolution setting.
| Format | Standard | Enhanced |
|---|---|---|
| 16:9 | 1920 × 1080 | 3840 × 2160 |
| 16:10 | 1728 × 1080 | 3456 × 2160 |
| 4:3 | 1440 × 1080 | 2880 × 2160 |
| 1:1 | 1080 × 1080 | 2160 × 2160 |
Check HDMI Settings → HDMI EDID for the connected input. Enhanced uses HDMI 2.0 EDID; Standard provides a compatibility option up to 1080p at 60 Hz. Recheck the computer's available resolutions and active signal after changing the setting. A 4K upscaling option does not establish that the computer is sending a detailed 4K source.
Menu reference checked October 17, 2026: BenQ user manual, version 1.1, printed pages 34, 37 and 40. Use the LK830ST column; the other models have different entries.
Match three settings in order
- Projector: choose the Screen Fill ratio matching your intended image area. A square screen calls for 1:1 if filling its full shape is the goal.
- Computer: inspect the display resolution being sent to the projector after the format change. Make sure you are editing the projector display, especially in a two-screen setup.
- Simulator: select a compatible resolution or aspect ratio in the application. Check its menus as well as the course view; one can appear correct while the other remains clipped.
Use a simple circle and a square on screen as a shape check. A stretched circle tells you that filling the border has not preserved the image proportions. Fix the format before tuning picture color or deciding whether the resolution looks sharp enough.
Troubleshoot the symptom you actually see
| Symptom | First check | Next action |
|---|---|---|
| Picture reaches the sides but leaves large gaps above and below | Was distance calculated from screen width? | Recalculate using target height and confirm the optical image can cover it. |
| Desktop fits but course menus are missing | Computer output and application display settings | Check the simulator’s own resolution and full-screen mode. |
| Circles look oval | Aspect-ratio mismatch or forced stretching | Match projector, computer and application formats. |
| One edge is larger than the opposite edge | Projector angle relative to the screen | Square the physical position before applying fine geometry correction. |
| Screen Fill is unavailable | Is Warping enabled? | The manual lists Screen Fill as unavailable while Warping is on. Choose the setup workflow that matches the screen. |
| Picture fits but the club or golfer crosses the light path | Real hitting position and swing path | Reassess placement with every intended golfer; screen fit alone does not approve the location. |
Record the setup so it can be reproduced
Before installation, write down the visible screen width and height, desired ratio, calculated lens distance, actual test distance, lens height and selected Screen Fill setting. Add the computer’s output resolution and the simulator’s resolution. Photograph the final test pattern from the normal viewing position.
Then run a normal session: open the simulator, switch to its menus, return to the course and restart the source. This checks whether the full signal chain returns to the intended format. A successful desktop image by itself does not answer that question.
Questions about LK830ST screen fit
Does a square screen automatically fill?
No. You need sufficient optical height, the correct Screen Fill selection and compatible source settings. A square frame cannot change the format of an incoming widescreen picture.
Can digital shrink fix a projector mounted too close?
Shrinking makes an image smaller within the available projection area. It cannot recover screen height that the optical image never reached. Recheck placement before trying to solve that problem through menus.
Which dimensions should I send for a fit check?
Send the actual visible screen width and height, ceiling height, proposed lens location, enclosure depth, hitting position and projector model. Include a room photo showing beams or other obstructions. For the wider format decision, read our 4:3, 16:9 and square screen guide.
