The difference that matters
The Optoma 4K400STx is brighter (4,000 lumens against 3,500). The Optoma UHZ35ST uses a laser light source; the other uses a lamp. The Optoma UHZ35ST costs $90 less at the prices we observed.
Side by side
| Specification | Optoma UHZ35ST | Optoma 4K400STx |
|---|---|---|
| Brightness | 3,500 lm | 4,000 lm |
| Resolution | 4K UHD (3840 × 2160) | 4K UHD (3840 × 2160) |
| Native aspect | 16:9 | 16:9 |
| Throw ratio | 0.496:1 | 0.5:1 |
| Distance for a 10.5 × 8 ft 4:3 screen | 6′ 11″ | 7′ |
| Brightness on that screen | 31 fL | 36 fL |
| Light source | Laser | Lamp |
| Rated life | 30,000 h | 15,000 h |
| Zoom | Fixed | Fixed |
| Lens shift | — | — |
| Input lag | 4.4 ms (1080p 240 Hz); 16 ms (4K 60 Hz) | About 4 ms (enhanced gaming mode) |
| Price seen | $2,199 | $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 UHZ35ST
Choose the Optoma UHZ35ST if you want no lamp replacements or price leads the decision.
Optoma 4K400STx
Choose the Optoma 4K400STx if your room has ambient light or a large screen.
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