Optoma HD91 Plus Review



  • Beautiful, cinematic picture quality
  • No need to change lamps
  • Runs very quietly


  • Slow dynamic contrast system
  • Expensive
  • Slightly high input lag

Key Specifications

  • Review Price: £3499.00
  • DLP projector with LED lighting
  • Full HD native resolution
  • 20,000-hour claimed lamp life
  • PureEngine processing system
  • 1.9x optical zoom

What is the Optoma HD91+?

As its name suggests, the HD91+ is an improved version of 2014’s HD91 projector.

It keeps the key LED DLP lighting system that made the HD91 so unique

for the sub-£5,000 projection market, but delivers enhancements to its

predecessor’s brightness and contrast. But do the changes do enough to

elevate the HD91+ from the HD91’s “good” level to excellent?

Optoma HD91+ – Design and Features


HD91+ looks identical to the HD91. This is no bad thing: Its elongated

shape, liberal use of angles, curved bodywork and large, centrally

mounted lens make it more attractive than most projectors on the market.

It even manages to inject a dash of colour in the form of a red ring

around the lens.

It’s promising to note, too, that the bodywork

incorporates what appear to be large venting “wings”. Experience

suggests these will prove helpful in keeping a lid on the projector’s

running noise.

See also: Best projectors 2015

Optoma HD91+
Connectivity is fairly strong. The two HDMIs are built to the HDMI 1.4

spec; this is a Full HD projector rather than a UHD one. There are two

12V trigger outputs for driving, say, motorised screens and curtains,

plus a component video input.

You’ll also find a RS-232 for

integrating the projector into a wider home-entertainment system, a USB

port for applying potential firmware updates, and a jack for attaching

an optional extra 3D transmitter.

The HD91+’s unique selling

point is its DLP LED lighting system. While normal UHP projection lamps

tend to last between 2,000 and 4,000 hours, the LED lighting in the

HD91 Plus is rated at a mammoth 20,000 hours. That’s long enough to watch

10,000 two-hour films, and effectively means that you’ll never need to

change the bulb throughout the projector’s working life.


isn’t the only benefit of LED lighting. It should also enable you to

continue watching the HD91+ for every one of those 20,000 hours with a

minimal loss in picture quality. Traditional lamps, by comparison, lose

brightness and colour response quite dramatically in the course of their

operating lives.

LED lamps should also deliver more stable

colours than normal lamps. In addition, since they’re much easier to

keep cool than normal lamps, turning the HD91+ on and off is pretty much

an instant affair, with no warm up/warm down process required. The

relative heat efficiency of LED lighting should also help it run more

quietly than rivals.

The HD91+ boasts a light output of 1,300

lumens and a contrast ratio of 600,000:1, versus the 1,000 lumens and

500,000:1 of the original HD91. These represent surprisingly large

on-paper improvements for a projector that adds only a “+” sign to the

name of its predecessor, and they immediately raise hopes of a

significant performance boost.

Optoma HD91+
The final noteworthy features of the HD91+ is its PureEngine

video-processing engine, which includes tools for enhancing motion, colour and

sharpness. It also offers a huge suite of picture setup tools that mean

the projector is able to support a professional installation by a

trained Imaging Science Foundation (ISF) calibrator.

Optoma HD91+ – Setup


original HD91 was a tricky beast from which to get the best; I

certainly struggled to find an out-of-the-box setting that I liked.

Fortunately, perhaps because of its brightness and contrast

improvements, the HD91+ delivers far better instant results – although

the comprehensive nature of its adjustments is nonetheless welcome.


many users the Cinema or, more likely, Film picture presets will be the

best starting point, although there’s also a Reference mode that turns

off all the projector’s processing for AV fans wanting the “purest”


Personally, I was surprised to find that I quite

liked using the PureEngine system. I generally left Ultra Resolution on

and both PureMotion and PureColour on their lowest power setting. The

only exception to this was gaming, where you need to turn off as much

processing as possible to try to minimise the amount of time it takes

the HD91+ to render its images.

Optoma HD91+
I also found it was necessary to use the colour-management tools to

reduce a slight infusion of reddish-pink that creeps into very dark

scenes. However, by far the most important setting to learn your way

round is the Dynamic Black feature.

This adjusts the picture’s

luminance continuously based an an analysis of the picture being shown –

but, for reasons I’ll get into in the Picture Quality section, I found

the Dynamic Black 2 and 3 settings pretty much unusable. As a result,

I’d suggest using the Dynamic Black 1 setting, since turning the feature

off entirely reduces the projector’s contrast performance to a point

where it doesn’t quite hit the spot for a projector costing £3,500.


you find even Dynamic Black 1 uncomfortable, then I’d suggest using the

non-dynamic LED Brightness feature set to around 60% for a dark room or

around 70-75% if there’s some ambient light with which to compete.


it comes to the physical side of setting up, the HD91 Plus is pleasingly

flexible. It sports a 1.9x optical zoom – more than you customarily get

with DLP projectors – and there are simple wheel adjustments for

optically shifting the image horizontally or vertically. This means you

shouldn’t have to distort the image with digital keystone correction.


and focus are achieved via simple, reasonably taut rings around the

lens. However, the thought did occur to me that a motorised system might

have been nice on a £3,500 projector.

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