Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Optoma - UHD35STx | Optoma - UHZ65UST |
|---|---|---|
| Brightness | 3600 lm | 3500 lm |
| Light source | Lamp | Laser |
Between the UHD35STx and UHZ65UST, the UHD35STx comes out ahead in brightness, while the UHZ65UST wins on light source. Overall, the UHD35STx scores 78.9 and the UHZ65UST scores 78.2 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (78.9 vs 78.2). The decision is not about overall quality — both clear the bar — it is about which specific trade-offs fit your use.
Pick the UHD35STx if you care most about brightness. The biggest gaps in its favor are brightness. The single most decisive one: Brightness — 2.86% more. 3600 lm vs 3500 lm.
Pick the UHZ65UST if you care most about light source. Its strongest claims are light source. The single most decisive one: Light source: Laser (vs Lamp).
Both ship with comparable resolution, short-throw, so those specs do not separate the two — focus on the differences below.
Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity says both are well-rounded; the differences are about trade-offs, not quality.
Which should you buy: Optoma - UHD35STx or Optoma - UHZ65UST?
Optoma - UHD35STx leads the current Mars Score by 0.7 points.The more useful decision is the trade-off behind that result: compare brightness, light source against the way you will actually use the product.
Choose Optoma - UHD35STx if…
Optoma - UHD35STx has the measurable edge on brightness lumens.
Choose Optoma - UHZ65UST if…
Optoma - UHZ65UST has the measurable edge on light source.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why Optoma - UHD35STx wins
- ▲Brightness — 2.86% more. 3600 lm vs 3500 lm.
Why Optoma - UHZ65UST wins
- ▲Light source: Laser (vs Lamp).
Spec comparison
Image
| Spec | Optoma - UHD35STx | Optoma - UHZ65UST |
|---|---|---|
| Resolutionⓘ | 4K | 4K |
| Brightnessⓘ | 3600 lmlead | 3500 lm |
| Contrast | 1000000:1 | 2500000:1 |
| Light source | Lamp | Laserlead |
| Short-throw | true | true |
Smart & Connectivity
| Spec | Optoma - UHD35STx | Optoma - UHZ65UST |
|---|---|---|
| Smart OS | None | None |
| HDMI inputs | 2 | 3lead |
| Built-in speakers | true | true |