Hazro have given you access to the settings at a controller board level for the digital adjustments of white and black. The brightness control in the OSD menu actually controls the digital white level as opposed to the backlight intensity, which is usually what this control is used for in modern screens.
The contrast setting controls the digital black level. Fear not, you can adjust these to obtain a much better contrast ratio which we will look at in a moment in our calibration section.
There is also a proper backlight control available through the OSD menu but it is accessed through the 'ECO mode' function which has 5 different settings.
More on all this shortly. Hazro have informed us that the screens will actually be factory calibrated before they are shipped out with targets set to 2. The HZ27WA sample we received was sent out before this factory calibration was carried out and so hopefully the default settings will be better from the actual retail stock.
Default colour accuracy was moderate here with an average dE of 3. We will need to calibrate the screen to return more accurate colours and change some settings to address the contrast ratio issue.
The HZ27WC unit which was sent to us for testing has had the factory calibration applied and so these are hopefully a more representative view of what you can expect from these screens out of the box. I have taken these default measurements with the brightness control set at maximum. I am unsure which setting will be used out of the box so this could vary and there's no OSD menu to do a "factory restore". The default luminance could vary as a result so I will disregard this measurement here.
The default gamma of the screen was spot on at 2. The contrast ratio recorded was a very respectable which is excellent for an IPS panel. Even colour accuracy was very good here with dE average of only 1. It's very easy to change the brightness control to return a comfortable luminace and so this performance should be adequate for most users easily.
A very good out of the box performance here. You may not even need further calibration for every day use unless you need higher end accuracy or want to use it for colour critical work.
Calibrated Results. I wanted to see what was possible from both screens with some accurate profiling and calibration. To do this you must alter the controls for digital white and black level using the brightness and contrast controls in the OSD respectively. I ran a series of tests to determine the optimum combination to return the best contrast ratio, without impacting the screen in an overly negative way.
I first plotted the contrast ratio at each combination as shown below:. Brightness 0 10 20 30 40 50 0 93 10 20 30 40 50 60 70 80 90 From these tests I was able to establish the optimum settings for the digital white and black levels.
The highest contrast ratios were returned when the contrast control was set at 90 - When at these settings, brightness had to be below 20 otherwise there was some obvious gamma shift and the whole image became very washed out. I tested each of the maximum contrast ratio combinations in turn to determine how the screen was set up in terms of colour temperature and gamma. At the other high contrast ratio combinations the gamma was quite a long way off from the target of 2.
It had even improved the gamma and white point compared with our out-of-the-box settings, which had returned gamma of 2. The only negative really with this change was that the colour accuracy was not as good as default settings, with dE average of 5.
We will of course be correcting that through further calibration steps. Hazro have informed me that the sample we were sent was delivered without their factory calibration, and that the retail stock will be factory calibrated correctly to address this issue, and also to bring the performance in line with the targets of 2. This is positive news, but even if this wasn't done it is simple enough to correct the contrast ratio through this basic adjustment to the OSD controls.
The HZ27WC sample we had did come factory calibrated which was good since there is no OSD, and no control over the digital white and black levels anyway.
This had returned the best contrast ratio at default settings while also giving an accurate gamma and white point starting point. I also switched here into the 'User' preset mode which allowed me access to the individual controls for red, green and blue RGB.
These were changed to the values shown as part of the calibration process as guided by the LaCie software. The rest of the corrections would be carried out by the software at a graphics card LUT level, and through the creation of the ICC profile.
There is no hardware level calibration available from this screen as you will find on some high end professional screens. The calibration was a great success. Gamma, colour temperature and luminance were all pretty much spot on.
This was pleasing and gave us a reasonably high static contrast ratio of However, this was a calibrated result with correction of grey scale tracking, white point, gamma and colour tones. Colour accuracy was now much better with an average dE of only 0. LaCie would consider colour fidelity to be excellent from this test. Maximum dE was only 0. This screen is a standard gamut model and so for those wanting to work in the sRGB colour space and not have to contend with some of the issues of wide gamut screens, it is an obvious choice in the 27" market.
Of course if you were wanting to work in a wider colour space such as Adobe RGB this screen cannot offer that. Testing the screen with colour gradients showed pretty smooth transitions with some very slight stepping in darker tones. There was no banding evident. Since this pre-production sample unit did not feature the factory calibration I would not recommend using our settings or ICC profile on your HZ27WA model since the starting point is drastically different.
The above tests should still give you an indication of what the screen is capable of however. There is no OSD menu and so there are no hardware changes to be made other than altering the backlight brightness control to an optimum starting point. You cannot control the RGB channels or contrast and so all other corrections would be made at a graphics card LUT level and through the creation of the ICC profile by our spectrophotometer.
The calibration didn't actually need to correct much in terms of gamma which was already spot on out of the box at 2. It did correct the slight offset of the white point, bringing it within 0.
With a black depth of 0. Colour accuracy was also corrected nicely to 0. You can use our settings and try our calibrated ICC profile if you wish, which is available in our ICC profile database. Calibration Performance Comparisons. Keep in mind that this sample unit did not have the factory calibration applied. Despite this, it was pretty comparable to the Dell U 3. This un-calibrated default colour accuracy was pretty good from the HZ27WA but it was unfortunately not great out of the box in other areas, most notably in black depth and contrast ratio.
We found default settings to be very good there, with spot on gamma, very good white point, high static contrast ratio and even a good colour accuracy with dE average of only 1. A great result from the factory calibration there so I would hope you can expect the same from both models from retail stock. Once calibrated, most of the models were very similar in this test.
Some of the professional range models from NEC are even more accurate. Professional grade monitors like the NEC PA series also offer other high end features which separate them from some of these other models, including extended internal processing, 3D LUT's and hardware calibration.
These comparisons are based on a small selection of tests, so it should be remembered that other factors do come into play when you start talking about professional use. For further information and tests of a high end professional grade screen with hardware LUT calibration, you may want to have a read of our NEC SpectraView Reference review. Hazro have made some significant improvements in black depth compared with their older models as well, where the HZ26Wi could only achieve 0.
The modern IPS panels being used in their new range of screens have come on a lot in this regard, not to mention the fact that Hazro have also added a backlight control which was missing altogether from the HZ26Wi for instance. Again pretty good for an IPS panel and certainly a lot better than the older models.
Contrast Stability. I wanted to see how much variance there was in the screens contrast as we adjusted the monitor setting for brightness. In theory, brightness and contrast are two independent parameters, and good contrast is a requirement regardless of the brightness adjustment.
Unfortunately, such is not always the case in practice. As we have already discussed, the OSD brightness control would normally represent a control over the intensity of the backlight on a modern display. However, on the HZ27WA it controls the digital white level and so has a severe impact on the contrast ratio.
We have already compared the contrast ratio results across a range of adjustments in our calibration section. For this test, we used the 'ECO mode' control to adjust the backlight intensity instead. We recorded the screens luminance and black depth at the five settings available, and calculated the contrast ratio from there.
It should be noted that we used the BasICColor calibration software here to record these, and so luminance at default settings varies a little from the LaCie Blue Eye Pro report. HZ27WA Tests. Although there was only a limited number of settings for the ECO mode, 5 to be precise, the control did allow a pretty decent adjustment range of the luminance of the screen.
The black depth ranged from 0. We had a stable contrast ratio across this range of adjustments as you would hope, with an average of It would have perhaps been nice to see more steps available from this ECO mode setting. The HZ27WB had 20 different levels of backlight control, but there are only 5 here. At least it is included though!
We plotted the stability of the contrast ratio on the graph below:. Above: contrast stability of the HZ27WA. HZ27WC Tests. I ran the same tests on the HZ27WC. This model does not have an OSD and so there is no control over the digital white or black levels. We only have control over the backlight intensity so will have to rely on a good factory calibration here when it comes to contrast ratio. Thankfully the screens digital white and black balance has been set correctly from the factory and so we have a decent contrast ratio produced.
There is no OSD and so it's difficult to tell which setting you are in unless you have a colorimeter or some way of actually recording the luminance change in the screen.
However, it does seem that this is a little tempramental and not every press actually results in a change in the backlight. I'll refer to them in this way elsewhere in the review, with setting 10 being the maximum setting, adn setting 0 being the lowest.
The changes at the top end of the scale made smaller differences to the luminance of the screen, and a less noticeable change was made in the brightness that you observe. As you reached further down the scale of adjustments, the changes were more pronounced and obvious to the naked eye, and the difference between each step was larger.
Thankfully this backlight control did offer a wide range of adjustments to the luminance of the screen, and there were more settings available in fact than the 5 from the HZ27WA using the ECO mode control.
Contrast ratio remained static across the range very well with an average of I have plotted the results of the HZ27WC below:. Above: contrast stability of the HZ27WC. This is not available from the HZ27WC.
Dynamic contrast ratio involves controlling the backlight of the screen automatically, depending on the content shown on the screen. In bright images, the backlight is increased, and in darker images, it is decreased.
For this test I would use the colorimeter to record the luminance and black depths at the two extremes. Max brightness would be recorded on an all white screen once the DCR has caught up. Black depth would be recorded on an all black screen.
The DCR feature is available through the 'Misc' sub-menu and it has a simple on or off setting. You can use it no matter which colour preset mode you are in. So where does this 1 million:1 figure come from? This can lead to extremely high levels of dynamic contrast. Figures in the millions are very common now.
But in real applications, for example when watching a movie, there are no absolutely black frames even in the credits.
Most of the time there is something on the screen besides blackness and a monitor with a huge specified dynamic contrast will never have the chance to deliver it in practice. As a result, there is no real practical point in increasing the dynamic contrast higher than about 10, which has already become standard for many monitors, including those with a backlight based on CCFL lamps.
Keep in mind that DCR figures are often exaggerated as a result, and since you will probably never get to utilise the full figure in practice, don't be fooled into buying into the hype too much! The DCR did operate smoothly and offered quick transitions. However, the range of operation was not massive. This gave us a dynamic contrast ratio of which did at least work a little, and improved our static contrast ratio of To be honest this 1 million:1 figure is exaggerated massively anyway. You can see this from our contrast stability tests above.
This would only give you a maximum DCR of anyway so a long way off the advertised figure. This figure would only be produced if the LED backlighting was being completely turned off, something which is possible through local dimming technology but not something which is widely used yet and not available from this screen. Overall it doesn't live up to its advertised spec, but that's normal with dynamic contrast ratios anyway. At least it does something and offers some extension to the static contrast ratio.
Viewing Angles. Above: Viewing angles shown from front and side, and from above and below. Vertically the contrast shifts were a little more obvious and noticeable with smaller movements away from a central point of view. The screen did offer the wide viewing angles of IPS technology and was free from the very restrictive fields of view of TN Film panels, especially in the vertical plane.
It was also free of the off-centre contrast shift you see from VA panels. On black images you could detect a white tint from a wide angle, characteristic of H-IPS matrices. Panel Uniformity. Measurements of the screens luminance were taken at 35 points across the panel on a pure white background.
This is the desired level of luminance for an LCD screen in normal lighting conditions, and the below shows the variance in the luminance across the screen compared with this point. It is worth noting that panel uniformity can vary from one screen to another, and can depend on manufacturing lines, screen transport and other local factors. This is only a guide of the uniformity of the sample screen we have for review.
The uniformity of the HZ27WA was excellent. This was an excellent result from any display, and this is all without the need for additional uniformity correction technologies. Above: All black screen in a darkened room. Click for larger version HZ27WA. As usual we also tested the screen with an all black image and in a darkened room. A camera was used to capture the result. There was very little backlight leakage noticeable to the naked eye in this test.
There was some very slight variation in the bottom left and top right hand corners which was picked out by the camera, but it was very minimal. No real issues at all here with this test which was pleasing. Luminance uniformity of the HZ27WC was very good as well with only minimal variations across the panel.
This was again an excellent result from any display, and this is all without the need for additional uniformity correction technologies.
Click for larger version HZ27WC. Again I tested for backlight leakage. No, not exploding cars. That would be silly. And dangerous. But rather an explosive period of unprecedented innovation. Enjoy the ride. North America. Home Reviews Computing.
But while it's not without its flaws and the odd cut corner, that is exactly what Hazro provides. If you can live with the By pcGameware UK on October 25, What we have to do here is look at what we are getting for our money.
By Wired UK on September 09, 90 Our original attraction to Hazro's monitors stemmed from its price and seemingly comparable performance to Apple's own inch display. By PC Pro on July 27, 83 It has the panel of a top-end 27in monitor, but wrapped in a budget package.
0コメント