Projector Reviews

ViewSonic PX727-4K Projector Review – Calibration Settings

ViewSonic PX727-4K Projector Review – Calibration Settings: Calibration Presets Notes, Best Mode Calibration, Brightest Mode Calibration & 4K Calibration

ViewSonic PX727-4K Calibration Notes

Note: The projector had over 53 Hours on the lamp before I calibrated it and took the light measurements. A brand-new bulb may have slightly higher measured lumens.

ViewSonic has included 5 picture preset modes for the PX727 (Bright, Standard, Movie, User 1 & User 2). I spent most of my time with User 1, User 2 & Standard modes. All of these modes have the same controls, what sets them apart is how these controls are preset. They all offer 3 color temperature options (Normal, Cool & Warm) 2-point white balance adjustments, gamma presets and full CMS (color management system).

Best (dark room) Mode Calibration for 1080p and REC.709 – User 1 Mode

ViewSonic P727-4K User 1 Mode Post-Calibration RGB Balance GrayscaleTracking (target D65)
User 1 Mode Post-Calibration RGB Balance / Grayscale Tracking (target D65)

For my Best/Dark Room calibration I used User 1 and renamed it Best/DARK. I kept the lamp on normal and would have kept Brilliant Color off but oddly the PX727 lacks the Brilliant Color feature which is found in most DLP projectors in this price range. With the default contrast set to 58 the projector clipped whites around 228, but thankfully lowering contrast to 48 corrected this. I kept color enhancement and skin tone off. I recommend you keep sharpness to 6 or lower and super resolution to 4 or lower for 1080i/p content.

User 1 out of the box with it’s bright gamma and blueish white balance showed DeltaE ranging quite high form 5 on the low end of the grayscale to +12 on the high end. The average color temp was 7100K range, a bit cooler than our target of 6500K (D65). After my white balance calibration, I was very pleased to see the DeltaE shrink to 1.25 or less across the board.

I usually target a 2.4 (BT.1886) gamma for my Best/Dark calibration but found that the projector is really tuned to a 2.2 and trying to calibrate it to a 2.4 yielded poor results, so I used 2.2 as my target. The default gamma setting of 2.3 actually measured an average of 1.95. After calibration resulted in a fairly flat 2.25 average.

ViewSonic P727-4K User 1 Mode Post-Calibration Gamma Log 2.05 Average Gamma (target 2.10)
User 1 Mode Post-Calibration Gamma Log 2.25 Average Gamma (target 2.20)

IRE Pre-Calibration Post-Calibration
10 IRE 6857K 6220K
20 IRE 6992K 6417K
30 IRE 7059K 6450K
40 IRE 7117K 6559K
50 IRE 7171K 6500K
60 IRE 7160K 6488K
70 IRE 7120K 6449K
80 IRE 7216K 6384K
90 IRE 6992K 6454K
100 IRE 7084K 6375K

Measurements taken at Mid Placement with Normal Lamp.

Average Gamma Pre-Calibration: 1.95

Average Gamma Post-Calibration: 2.25 @ 1119 Lumens

Type Pre-Calibration Post-Calibration
Contrast 50 50
Brightness 58 48
Color 50 50
Tint 50 50
Color Temp Normal Normal
Gamma 2.3 2.3
Type Pre-Calibration Post-Calibration
Sharpness 6 6
Color Enhancement 0 0
Skin Tone 0 0
Super Resolution 4 4
HDR Auto Auto
EOTF n/a n/a
RGB Gain Offset
Red 98 250
Green 102 249
Blue 95 250

White Balance calibration settings for Best/Dark Room (user 1 mode).

ViewSonic-P727-4K-User-1-Mode-Post-Calibration-DeltaE-2000-(target-below-error-of-3)

DeltaE is a metric for understanding how the human eye perceives color difference. The term delta comes from mathematics, meaning change in a variable or function. The suffix E references the German word Empfindung, which broadly means sensation. Simply put, look at DeltaE as a measure of grayscale/color accuracy. 3 and under is considered ‘Excellent’ and imperceptible by the human eye.

Bright Room/Quick Cal Mode Calibration for 1080P and REC.709 – Standard Mode

Next up I did my Bright Room/Quick Cal calibration using Standard Mode with normal lamp. After some experimenting I found doing the white balance calibration worked best from the warm preset. By doing this it helped to keep the lumen output a little higher than if I had used normal. I compromised on lowering contrast to just 49. Had I lowered it further it would have improved the rather large DelatE error I was getting at 100% IRE but at the cost of lumen output which Is important for a bright room calibration. As with my Best/Dark Room I kept color enhancement and skin tone off and sharpness to 6 and super resolution to 4.

ViewSonic P727-4K Standard Mode Post-Calibration RGB Balance GrayscaleTracking (target D65)
Standard Mode Post-Calibration RGB Balance / Grayscale Tracking (target D65)

My target gamma for Bright Room/Quick Cal was 2.10. I was having problems with obtaining a flat gamma using the usual 2.0 or 2.2 presets. I discovered that custom 2 gamma preset helped with this issue and I was able to get a fairly flat gamma response with a 2.05 average. With the brighter gamma I found turning brightness to 48 preserved shadow detail without the blacks looking washed out.

ViewSonic P727-4K Standard Mode Post-Calibration Gamma Log 2.05 Average Gamma (target 2.10)
Standard Mode Post-Calibration Gamma Log 2.05 Average Gamma (target 2.10)

IRE Pre-Calibration Post-Calibration
10 IRE 7572K 6469K
20 IRE 7634K 6475K
30 IRE 7564K 6522K
40 IRE 7618K 6544K
50 IRE 7307K 6566K
60 IRE 7321K 6533K
70 IRE 7354K 6501K
80 IRE 7455K 6474K
90 IRE 7390K 6317K
100 IRE 7141K 5921K

Measurements taken at Mid Placement with Normal Lamp.

Average Gamma Pre-Calibration: 1.95

Average Gamma Post-Calibration: 2.05 (target 2.10) @ 1462 Lumens

Type Pre-Calibration Post-Calibration
Contrast 50 49
Brightness 50 48
Color 50 50
Tint 50 50
Color Temp Normal Warm
Gamma Custom 1 Custom 2
Type Pre-Calibration Post-Calibration
Sharpness 6 6
Color Enhancement 0 0
Skin Tone 0 0
Super Resolution 4 4
HDR Auto Auto
EOTF n/a n/a
RGB Gain Offset
Red 100 258
Green 98 255
Blue 111 250

White Balance calibration settings for Bright Room/Quick Cal (standard mode).

ViewSonic-P727-4K-Standard-Mode-Post-Calibration-DeltaE-2000-(target-below-error-of-3)

4K with HDR – User 1 Mode

Lastly, I did a 4K/HDR calibration. Any of the 5 modes can be used for 4K/HDR, I used User 2 and renamed it 4K/HDR. I kept the lamp on normal. Contrast is defaulted to 58 in User 2 and I kept it there. I lowered gamma from 2.3 to 2.2 and kept the color temp at normal. Pre-calibration white balance showed a small plus blue and minus green errors stating at the low (dark) end of the grayscale and getting progressively worse as it got brighter.

When it comes to trying to improve these (HDR) errors with calibration you kinda ignore 60-100 IRE. It may be possible to improve those higher IRE’s by lowering contrast but you lose those precious lumens that we re so desperate to keep for HDR content. With 1080p content I was able to keep Super Resolution at 4 but using the new Ghostbusters UHD as my reference I observed noise in the image especially noticeable on some of the sweaters worn by some of the ladies in the film. Turning Super Resolution off eliminated the noise.

ViewSonic P727-4K User 2 Mode (4K) Post-Calibration RGB Balance GrayscaleTracking (target D65)
User 2 Mode (4K/HDR) Post-Calibration RGB Balance / Grayscale Tracking (target D65)

Most DLP 4K/HDR projector that I have calibrated have swapped out (or re-named) their gamma control setting when fed an HDR signal. So, Gamma becomes HDR Brightness for example. Well with the PX727 you actually get 2 gamma controls for HDR. It keeps your traditional (power) gamma control and adds an HDR gamma control called EOTF. ETOF does effect both the high and low end of the grayscale while Gamma effects mostly the low end. I seemed to get the best results on my screen with gamma set to 2.2 and ETOF set to low. I wished there was a position between low and mid as I felt there was a big difference between them with mid looking washed out on my screen. Now your settings may be different depending on your screen size and gain.

ViewSonic P727-4K User 2 Mode (4K) Post-Calibration Gamma Log 2.05 Average Gamma (target 2.10)
User 2 Mode (4K/HDR) Post-Calibration (Electro-optical Transfer Function) aka gamma. EOTF set to Low

IRE Pre-Calibration Post-Calibration
10 IRE 6452K 6143K
20 IRE 7004K 6632K
30 IRE 6943K 6591K
40 IRE 7198K 6593K
50 IRE 7195K 6573K
60 IRE 7315K 6707K
70 IRE 6960K 6848K
80 IRE 6947K 6905K
90 IRE 6974 6924K
100 IRE 7127K 7019K

Measurements taken at Mid Placement Normal Lamp.

ETOF (gamma) Post-Calibration: Low tracked fairly flat except for the low end which was slightly brighter than the target and the high end rolling off. 1192 Lumens.

Type Pre-Calibration Post-Calibration
Contrast 58 58
Brightness 50 50
Color 50 50
Tint 50 50
Color Temp Normal Normal
Gamma 2.3 2.2
Type Pre-Calibration Post-Calibration
Sharpness 6 6
Color Enhancement 0 0
Skin Tone 0 0
Super Resolution 4 0
HDR Auto Auto
EOTF Mid Low or Mid
RGB Gain Offset
Red 100 248
Green 101 255
Blue 97 256

White Balance calibration settings for 4K/HDR (user 2 mode).

ViewSonic P727-4K User 2 (4KHDR) Mode Post-Calibration DeltaE 2000 (target below error of 3)