BenQ TK850 4K DLP Projector Review

TK421 would have made for a much funnier model name and byline...

by Phil Hinton
SRP: £1,359.00

What is the BenQ TK850?

The BenQ TK850 is a 4K DLP projector which uses the Texas Instruments 0.47” DMD chip and with a quadruple flash pixel shift, it creates the perception of 8.3m pixels on the screen. It is not a true native 4K projector as that would cost many thousands of pounds, but it does create the perception of a higher resolution 4K image. 

It is being marketed as a Home Entertainment projector aimed at sports fans as it features frame interpolation image smoothing technology. There is a dedicated sports mode which activates smoothing along with pumped-up vivid colour settings and noise reduction.

It also has HDR-Pro that BenQ describes as advanced tone mapping for HDR10 content, with the BenQ TK850 also supporting the broadcast friendly Hybrid Log-Gamma (HLG) standard. It also features a dynamic iris with three settings to help improve contrast performance and boasts 98% of Rec.709 colour gamut coverage for HD images. Brightness is quoted as 3000 lumens but, being realistic, that will be significantly less when used with accurate picture settings. 

BenQ has also spent some time developing a lens system that can cope with better sharpness and uniformity across the lens and screen. The TK850 sports a 10-element, 8-group lens array which features low-dispersion lens coatings that BenQ claims to minimise chromatic aberration, which when added to the fact there are no alignment issues as it is one panel, gives a sharp and detailed image on the screen. 

The BenQ TK850 certainly has plenty of features that should interest AVForums readers and it does so at a competitive price point of £1359 at the time of this review in May 2020. So let’s find out how it performs. 

BenQ TK850 Video Review

Design, Connections and Control

The design of the BenQ TK850 is the now-familiar office style look, with the lens positioned to the far right with a blue brushed metal front plate with the BenQ logo on the left. Down the left side is the hot air exhaust with intake vents on the right side. 

BenQ TK850
BenQ TK850: Sliding doors

Above the lens is a sliding door that covers the lens focus and zoom wheels, plus on the TK850 we have a vertical lens shift wheel. This allows for more precise projector set up so there is no requirement for using keystone adjustment. You should avoid using any keystone adjustment on any projector installation and make sure you switch it off the automatic setting on the TK850.

 

BenQ has also spent some time developing a lens system that can cope with better sharpness and uniformity across the lens and screen.

Behind the lens adjustment sliding cover are menu and power controls should you lose your remote control. To the rear of the projector chassis are the connections and speakers. 

BenQ TK850
BenQ TK850: Rear connections

Connections wise we have a 12v trigger, RS232C port and mini USB for service. We also have a USB 3.0 media player port and two HDMI 2.0 slots with HDCP 2.2 compatibility. Plus we have USB power port, digital audio out and 3.5mm audio outputs. The HDMI ports will accept 4K video signals with HDR10 and HLG compatibility.

BenQ TK850
BenQ TK850: Remote control

The supplied remote control is the now-familiar BenQ white coloured plastic model with red backlight. It feels cheap but is sturdy and will last the life of the projector, plus the buttons are well laid out and intuitive to use. 

Measurements

Out of the Box

We found the User preset with a 2.2 Gamma and the Normal Colour Temperature settings gave us the most accurate image quality close to the industry standards. We also switched off any image processing or colour enhancement features, including the dynamic iris, for calibrating.

BenQ TK850
OOTB Greyscale and Gamma

Looking at the greyscale first we can see that, as the scale gets brighter, blue dips low with red pushing too high and green remaining around the 100% mark. This means that images on the screen do start to look overly yellow and warm. Gamma is tracking around 2.2 which is good, but because of the errors, we have DeltaE errors well over the visible threshold of three from around 60% stimulus and higher.

BenQ TK850
OOTB Rec.709 Colour Gamut

Our colour gamut results in Rec.709 HD are also affected with white pushed towards yellow and, as such, it takes all the other gamut saturation points towards yellow. This should be rectified once white is aligned properly with calibration. However, we also have saturation issues at 75% green, blue, yellow and red where they are too bright and towards or matching the 100% points. 

 

...the BenQ TK850 was responsive to calibration and we managed to get very accurate results for such a projector at the price point

Overall, the out of the box results are not particularly accurate which is a shame, but at the price point, they sadly will not be calibrated by many owners given the costs of hiring a professional. However, we will see how accurate we can get the BenQ following calibration to the standards.

Calibrated

Thankfully, the BenQ TK850 comes with a suite of calibration controls including a full Colour Management System (CMS) that does work without introducing many artefacts when used correctly.

BenQ TK850
Calibrated Greyscale and Gamma

We used the provided two-point white balance control to flatten out the greyscale (mainly at the high end) and get DeltaE errors well under the visible threshold of three. Thankfully, the BenQ TK850 was responsive to calibration and we managed to get very accurate results for such a projector at the price point. Gamma also tracked well at 2.2 with only slight issues with blue in the tracking, but these did not produce any visible errors seen with TV or film content on screen.

BenQ TK850
Calibrated Rec.709 Colour Gamut

The Rec.709 HD gamut also corrected itself once the white point was corrected in the greyscale, so colour points moved back to where they should be. We did need to use the CMS to correct some issues at 75% stimulus and the 100% points were not perfect, but 75% and below are far more important for correct balanced image quality and we were happy with our results here that had DeltaE errors at two and under. So overall, the BenQ TK850 can get accurate image quality when calibrated correctly.

HDR Results

Like all projectors, the TK850 is not HDR capable as it simply cannot display enough steps of dynamic range to show specular highlights or blacks in the intensity that you would get from a direct view display, such as an OLED or LCD TV. However, it is compatible with 4K HDR10 and HLG sources and it also has dedicated tone mapping and a dynamic iris that can help improve the contrast available. 

BenQ TK850

When it detects an HDR signal it defaults to the HDR10 picture mode and greys out controls you are not able to adjust when using HDR content. It also sets the dynamic iris to high. Contrast measures 2856:1 (115.3 cd/m2 / 0.04 cd/m2) using the DI set to high and fed an HDR signal from our Murideo generator. 

BenQ TK850

BenQ states that the TK850 has HDR-Pro which is advanced tone mapping. Looking at the PQ EOTF tracking ST.2084 chart we can see the lack of brightness on offer, but a tone map that has a gentle roll-off to the peak brightness of 115.3 cd/m2. This the same when fed 1000 and 4000 nit content.

BenQ TK850

The DCI-P3 saturation tracking within BT.2020 also shows that there is no Wide Colour Gamut capability on the BenQ TK850 and what is displayed is only just wider than Rec.709 HD standards for most points. We measured BT.2020 at 61% XY and 64% UV, with P3 at 85% XY and 88% UV.

BenQ TK850
BenQ TK850

We did notice an issue with the TK850 where 4000 nit mastered content could not be displayed correctly and had issues with too much luminance within colours and the greyscale which resulted in images looking terrible with obvious posterisation issues. We had to switch HDR off in the menus to view the content. It is obviously a bug and we have reported this back to BenQ. 

More: What is 4K HDR tone mapping?

Performance

We set up the BenQ TK850 in our Batcave testing room. We used a portable projector stand positioned 10ft 2in from our 120-inch Screen Excellence 2.39:1 Enlightor 4K screen. We had the projector at full wide zoom, producing a 16:9 ratio image that was 94-inch diagonal. 

 

...the HDR performance of the TK850 was just a tad brighter than SDR content with no wide colour gamut coverage

We took all measurements directly from this screen with brightness clocking in at 900 lumens in calibrated user mode. Obviously, with a Dynamic Iris (DI) with three settings, there is a difference in SDR contrast ratio results. With the DI switched off the TK850 measured 672:1, with the DI at Low we measured 954:1, Middle was 1430:1 with High clocking in at 2048:1.

The TK850 is a step up in terms of performance when compared to the TK810 we reviewed a week or so ago. That projector was very much home entertainment and multimedia in its approach and not suited to home cinema use. The TK850 has slightly better black levels, and, thanks to the DI, it produces a much better contrast-rich experience. Blacks are still dark grey but there is more visible detail in the shadows and less crush visible. Just above black is still not there with no detail at all seen but in a normal living room or even a light-controlled environment it performs well, with good contrast for a DLP at this price point. 

 

3D playback benefits here with good motion and a lack of ghosting or crosstalk

Black bars on 2.40:1 movies are dark grey but there is little washout within dark scenes, which stand up much better than the TK810. The BenQ TK850 has a little more detail visible in the shadows which translates to a deeper looking image in those tricky scenes. Below around 5% stimulus, there is no detail and blacks are the same as the black bars, but you can’t expect miracles at this level of the market with any projector technologies.

Motion is good with decent 24fps playback with just the occasional frame skip visible when looking for it. The frame interpolation system manages to smooth out motion to reduce judder, but it doesn’t necessarily add in any detail or reduce blur significantly in operation. DLP manages to produce motion that is more fluid than other technologies. 3D playback benefits here with good motion and a lack of ghosting or crosstalk. We also didn’t notice any issues with motion trailing or rainbow effects when switching to different video content and films. Only when looking away from the image did I notice the odd flash of a rainbow, so it is not significant within viewing material watched normally. 

Once calibrated, SDR content on the BenQ TK850 looks very good indeed with excellent colour accuracy and skin tones being a highlight, Brightness is strong and, while blacks are still dark grey, there is a good contrast to bright scenes with depth and pop. Even tricky movie content fares reasonably well on the TK850 with dark scenes a struggle, but the majority of content looking sharp, detailed and accurate colour and greyscale wise. The motion was good and the image looked sharp. That sharpness was also uniform across the screen thanks to the good quality lens. We didn’t notice any obvious issues with slightly blurry edges or corners of the image. We also didn’t see any issues with colour uniformity across the screen either.

 

Once calibrated, SDR content on the BenQ TK850 looks very good indeed with excellent colour accuracy and skin tones being a highlight

Moving to HDR and we know what to expect from a projector like the BenQ TK850 and that is not a full HDR image. Projectors are not capable of producing enough steps of dynamic range to show HDR content properly, but it is compatible and provides some tone mapping designed to fit 1000 nits content to the capabilities of the projector. We did, however, find a bug with 4000 nits content such as our test disc of Pan where the luminance of the colours was blown out with lots of posterisation. With such discs, we had to switch HDR off in the menu system to restore a watchable image. We have reported this back to BenQ for their attention. 

Overall, the HDR performance of the TK850 was just a tad brighter than SDR content with no wide colour gamut coverage, which we wouldn’t expect anyway at this price point and from a DLP projector. It produces a very watchable image that is very similar to the SDR performance with sharp images, decent, if not entirely accurate colours and good brightness for normal rooms. 

More: What is Wide Colour Gamut?

The BenQ TK850 is being marketed as a projector to watch sports on the big screen and it is certainly capable of doing that. We would stay away from the other picture modes, however, as they are all inaccurate and crush details while greying out some controls in some modes. Set up correctly, the image quality can be very good for all types of content, but black levels, while improved, are still dark grey. But that will not be a big issue for use in a normal living room environment.

 

Overall, the TK850 is a strong multi use projector suited to normal viewing rooms and environments and it adds in some decent features

Verdict

The Good

  • Added contrast thanks to Dynamic Iris
  • Nice bright images
  • Accurate with SDR once calibrated
  • Frame interpolation for those who want it
  • Bright and sharp images
  • Suits a bright room and mixed content

The Bad

  • Dark grey black levels
  • Crushed blacks
  • 4000nit HDR looks very odd
  • Not HDR capable but is compatible with HDR sources
  • Not for critical home cinema viewing

BenQ TK850 4K DLP Projector Review

We were surprised with the performance on offer from this 4K DLP projector at the price point and it will appeal more to AVForums members than the TK810 we reviewed a few weeks ago. That said, the TK850 is still not a machine for critical movie viewing in a Batcave dedicated room. It manages to display most film material with decent calibrated accuracy but blacks are still dark grey and not inky deep. There is a touch more detail in the shadows when compared to the TK810 but there is also still an amount of crush at the low end as well. 

Out of the box could be more accurate for those looking for that kind of thing, but the vast majority of users for this projector will probably end up putting it into the brightest and more colourful modes and use it for big screen sports and gaming, which is what it primarily is designed to do. The input lag measures in at 81ms with all processing switched off.

The TK850 adds in frame interpolation for judder reduction and smoothing and a Dynamic Iris (DI) for vastly improving the contrast performance, but be aware you will see it moving from time to time. The projector is also relatively quiet for such a model, but you should still be placing it away from the viewing position as in high lamp mode it can get loud. We also found a slight bug with HDR playback of discs mastered at 4000 nits and hope that BenQ will fix this issue soon, the work around is easy enough by switching HDR off - you don’t lose much doing this as it is not a projector capable of HDR image quality or wide colour gamut playback.

Overall, the TK850 is a strong multi use projector suited to normal viewing rooms and environments and it adds in some decent features like frame interpolation for those who watch sports, and a Dynamic Iris to improve the contrast performance. It is still not a home cinema model for critical movies viewing in a Batcave, but it does offer good image quality out of the box and very good accuracy when calibrated with SDR content. Blacks are dark grey, but the BenQ TK850 also manages to produce very good colour accuracy, excellent skin tones and good motion for movies, with just dark scenes suffering from the lack of shadow details and black levels. But, with 16:9 TV images, gaming and sports, it lives up to its claims of producing a sharp, detailed and vivid image that can withstand ambient light in the same room, or light coloured walls and ceilings.

If that sounds like it fits what you are looking for, then we suggest you get a demo and we can give it a recommendation for those use cases. 

Recommended

Scores

Contrast/Dynamic Range/Black levels

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.
.
7

Colour Accuracy

.
.
.
7

Greyscale Accuracy

.
.
.
7

Image Uniformity

.
.
.
7

Video Processing

.
.
.
7

Picture Quality Out-of-the-Box

.
.
.
.
6

Picture Quality Calibrated

.
.
8

Features

.
.
8

Ease Of Use

.
.
.
7

Build Quality

.
.
.
7

Value For Money

.
.
8

Verdict

.
.
.
7
7
AVForumsSCORE
OUT OF
10

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