The difference that matters
The Optoma 4K400STx throws a given image from closer (ratio 0.5 against 0.69). The Optoma 4K400STx lists higher resolution (4K UHD). The BenQ AH500ST costs $290 less at the prices we observed.
Side by side
| Specification | BenQ AH500ST | Optoma 4K400STx |
|---|---|---|
| Brightness | 4,000 lm | 4,000 lm |
| Resolution | Full HD 1080p (1920 × 1080) | 4K UHD (3840 × 2160) |
| Native aspect | 16:9 | 16:9 |
| Throw ratio | 0.69–0.83:1 | 0.5:1 |
| Distance for a 10.5 × 8 ft 4:3 screen | 9′ 8″ | 7′ |
| Brightness on that screen | 36 fL | 36 fL |
| Light source | Lamp | Lamp |
| Rated life | 15,000 h | 15,000 h |
| Zoom | 1.2× | Fixed |
| Lens shift | — | — |
| Input lag | About 16 ms (fast mode) | About 4 ms (enhanced gaming mode) |
| Price seen | $1,999 | $2,289 |
Highlighted rows differ. Figures come from each product's sources; room depth, distances and brightness are FOREference calculations using the same method for both.
Which should you choose?
Optoma 4K400STx
Choose the Optoma 4K400STx if you need to mount it close to the screen or image detail matters most.
Before you buy either
- Check the room: room size calculator and ceiling height calculator.
- Confirm what each seller includes — accessories, software trials and bundles change often.
- Read the limitations on each full reference page.
FOREference compares published specifications; we have not tested these products side by side. How we work · Disclosure