Dell monitors always seem
to attract a lot of attention, and not without good reason. The original 2405FPW
was Dell's first venture into the 24" market, and was extremely popular. About a
year ago, Dell released the updated 2407WFP model which offered some
improvements on paper, and a change in design. At the time
we discussed the new model which received a lot of attention again. This
year, rather than update the model completely, Dell have updated the screen only
slightly, with the use of enhanced W-CCFL backlighting capable of offering a
colour gamut covering 92% of the NTSC colour space. This new 'HC' (HighColor)
edition of the 2407WFP replaces the standard model, just as Dell did with their
30" display, the 3007WFP. We'll come onto the colour analysis later as well, but
first let's take a look at the listed spec for this screen:
Size
24"WS
Colour Depth
8-bit, 16.7m colours, 92% NTSC gamut
Resolution
1920 x 1200
Viewing Angles
178 / 178
Response Time
6ms G2G
Panel Technology
S-PVA
Contrast Ratio
1000:1
Interfaces
DVI-D (HDCP), VGA, component, composite,
S-video
Brightness
400 cd/m2
Colour
Black bezel with silver stand
Special Features
HDCP support, 92% NTSC colour gamut.
Tilt, height, rotate and swivel adjustments. 9-in-2 card reader, 4x USB 2.0
ports. PiP and PbP options
The spec is characteristically S-PVA, and
indeed the 2407WFP utilises a slightly updated panel from Samsung as compared
with the standard 2407WFP model. The only change on paper, other than the
extended colour gamut, is the 400 cd/m2 brightness instead of the 500
cd/m2
on its predecessor.
Above: back and side views of the 2407WFP-HC
The design of the 2407WFP-HC is sleek and
attractive. The front of the screen shows a nice thin black bezel, with a slight
silver trim at the bottom. The stand is of a matt silver colour, and the panel
itself features a matt-finish AR coating. From behind, the screen is mostly
silver in colour and the stand is thin and well balanced. The materials are all
of high quality, and the screen feels sturdy and well built. There is a very
slight tilt of the screen to the right (due to the rotate function) which some
users have also commented on. This is barely noticeable however, and some users
have had luck correcting this by dismantling the stand and tightening a few of
the joints.
Above: The screen in landscape and portrait modes, thanks to rotation ergonomic
adjustment
The screen offers a wealth of ergonomic
adjustments, with smooth and easy height, swivel, rotate and tilt adjustments
available. I always find that in this size sector, the real usability of a
rotate function is limited, but the ability to rotate into portrait mode (as
shown above) might be useful to some uses. The ergonomic adjustments were
impressive on this screen, something which Dell are very good at with their
premium models. The tilt and height adjustments are particularly useful on a
screen of this size, and afforded me the option to set the screen to a
comfortable position. You can even lower the screen to be pretty much on the
desk!
The OSD operational buttons are inset into
the bottom corner of the bezel and are easy to operate. As shown above, there
are quick selection buttons available for input, PiP / PbP, and the ' + ' and '
- ' buttons also give access to brightness/contrast and auto image adjust (for
analogue signals). The power button glows a soft green colour during operation,
and switches to amber when in standby.
The OSD is well laid out, and easy enough to
navigate. There really are a lot of options and sections, but the interface felt
intuitive.
The back of the screen offers a wide range of
interface options as shown above. The availability of S-Video, composite and
component is a nice feature, and useful for external devices such as DVD players
and games consoles. You can also get an optional Dell Soundbar if you want to
make the 2407WFP-HC an all-in-one multimedia screen.
The back of the screen also offers 2x USB 2.0
ports, as well as an upstream port to connect the screen to your PC. Once
connected to the PC, the ports on the monitor function, along with the
integrated 9-in-2 card reader.
The 2407WFP-HC offers a handy 9-in-2 card reader along with 2 additional USB 2.0
ports on the side of the monitor. The card reader can support CompactFlash type
I/II Card, MicroDrive, Smart Media Card, Memory Stick Card, Memory Stick Pro
Card, Memory Stick Duo (with Adapter), Secure Digital Card, MultiMedia Card and
Mini Secure Digital (with Adapter).
The back of the stand also features a useful slit which can help keep cables
tidy and out of the way.
The stand is detachable and the screen is VESA compliant.
Colour Quality
and Accuracy
The Dell 2407WFP-HC utilises an 8-bit Samsung
S-PVA panel, capable of producing a true 8-bit, 16.7 million colour palette. The
enhanced W-CCFL backlighting used offers a gamut covering 92% of the NTSC colour
space, an improvement over standard backlighting which only really matches the
sRGB colour space, at 72% of the NTSC gamut. An important thing to consider for
most users is how a screen will perform out of the box and with some basic
manual adjustments. Since most users won't have access to hardware colorimeter
tools, it is important to understand how the screen is going to perform in terms
of colour accuracy for the average user. I restored my graphics card to default
settings and set it to its standard profile. The 2407WFP-HC was tested at
default factory settings out of the box using the
LaCie Blue Eye Pro and their accompanying software suite.
Default settings of the screen were 50 brightness, 50 contrast. The 'Colour
Setting Mode' was left on 'PC Mode' and the colour adjustment section showed
that RGB levels were all at 100.
Dell 2407WFP-HC - Default Settings
Default Settings
luminance (cd/m2)
302
Black Point (cd/m2)
0.45
Contrast Ratio
671:1
Testing the screen at default settings showed
some quite pleasing results. You could tell before even connecting the
colorimeter that colours felt even and contrast and brightness felt pretty
comfortable. The main area where the default settings were out was the
luminance, with brightness set at 50 in the OSD, the screen reached 302 cd/m2,
a considerable way off the desired 120 cd/m2 for LCD displays in
normal lighting conditions. Fortunately, this is easy enough to rectify with
manual adjustments, and reducing the OSD setting to around 25 - 30 should result
in a more comfortable user experience, particularly in low lighting conditions.
Gamma was spot on at 2.2 and colour temperature was also very good, at 6596k
(only 1% out from the desired 6500k). From the triangle on the left hand side
CIE diagram of the report above, you can tell that the gamut covers more than
the sRGB colour space, with a particular improvement in the green shades. This
is a wider gamut than regular backlighting can offer, and confirms the screen is
using enhanced CCFL's.
With luminance recorded at 302 cd/m2,
black depth was an average 0.45 cd/m2. This gave a useable contrast
ratio of 671:1, not quite reaching the specified 1000:1 the screen is reported
to be capable of however.
The
graph on the right shows the DeltaE values for colours tested by the LaCie Blue
Eye Pro. As a reminder, the lower these bars down the Y-axis, the better, in
terms of colour accuracy. For reference, LaCie describe the DeltaE readings as:
If DeltaE >3, the color displayed is significantly different from the
theoretical one, meaning that the difference will be perceptible to the
viewer.
If DeltaE <2, LaCie considers the calibration a success; there remains a
slight difference, but it is barely undetectable.
If DeltaE < 1, the color fidelity is excellent.
With an average DeltaE of only 2.6, the
2407WFP-HC is pretty good in terms of colour accuracy, even without calibration.
This is pleasing to see, since it means users can buy the screen and achieve
some decent reproduction of colours, even if they do not have access to hardware
calibration devices. DeltaE only reached a maximum value of 4.9 when rendering
blue, again a pleasing result, and certainly vastly superior to some other
screens we have tested at default settings. For instance, the other wide gamut
screen we have tested recently, the
Samsung SM931C, showed some very poor colour accuracy out of the box, with
an average DeltaE of 9.4. This can be corrected to a point, but most users
aren't going to have access to a colorimeter to achieve this. With this screen,
you don't even need to in order to get some decent performance.
Dell 2407WFP-HC - Calibrated Results
Calibrated Settings
luminance (cd/m2)
120
Black Point (cd/m2)
0.22
Contrast Ratio
545:1
During the calibration process brightness
was altered to 28, contrast was left at 50 and RGB values were changed to 99,
94 and 97 respectively. The results from the tests were again pleasing, with
some marked improvement in areas previously needing correction. Gamma remained
at the desired 2.2, but colour temperature was corrected slightly to 6532k.
The obvious improvement was that luminance was now corrected to 120 cd/m2,
resulting in an improved black depth of 0.22 cd/m2 and producing a
useable contrast ratio of 545:1. In practice, the screen felt more comfortable
and less harsh on the eyes at these settings. I was hoping for a slightly
better black depth from the screen to be honest, since it is based on an S-PVA
panel renowned for decent performance in this area. A level of 0.22 cd/m2
is not bad, but does fall a little behind some other screens we have tested,
including the PVA based Samsung 971P (0.1 cd/m2), and even the TN
Film based Samsung SM932B Plus (0.14 cd/m2). There wasn't really
any change from my personal use Dell 2405FPW in fact, which was tested with a
black depth of 0.2 cd/m2. PVA technology is certainly capable of
producing a decent black level, but it seems perhaps Samsung haven't quite
achieved this with their larger panels yet. At least the calibrated result was
a nice improvement over the default 0.45 cd/m2 level, which is at
best, average.
DeltaE values were also improved nicely,
with an average value of 0.8 being recorded. LaCie would consider the colour
fidelity excellent, and even a maximum value of 2.4 leaves the screen offering
only a barely detectable difference between the colour requested, and that
displayed. Colours still felt even and looked a little better adjusted even to
the naked eye. Without a colorimeter though, most average users would probably
be hard pressed to notice much real difference in colours between default and
calibrated settings. The 2407WFP-HC is certainly capable of offering some
pretty good colour accuracy making it suitable for graphic and photo work if
necessary. There are more professional models available for even better
accuracy, but these will certainly not compete with the Dell from a price
perspective. The wide 'HighColor' gamut is certainly an attractive feature for
those who work with extended gamut content and are looking for the latest
technology from the more affordable monitor range. In practice green shades
were improved and felt deeper, something also noticeable from the CIE diagram
above, where the most obvious improvement in the colour space came towards the
green hues.
Testing the screen with colour gradients
showed nice smooth transitions between colour shades, and no detectable
banding.
Viewing Angles
Above: Viewing angles shown from front and sides, and from above and
below. Click for larger images
Viewing angles of the 2407WFP-HC were very
good, as you'd expect from an S-PVA panel. From the sides, the image remained
good, even at extreme angles, and this was the same when moving vertically. The
screen didn't display the characteristic darkening of the image from below as
you would see from TN Film based models, and although there was evident contrast
shift, it never really proved a problem from any position. There was evidence of
a slight contrast shift as you moved away from a central view of the screen,
something inherent to VA based matrices, and something commonly cited in the VA
vs. IPS argument. In reality, it's very hard to detect this anomaly, and I doubt
it would really bother most users.
Panel Uniformity
Click for
larger image
In our usual testing process I viewed an all
black screen in a darkened room, which allowed me to test the uniformity of the
panel and to examine whether any backlight bleed was evident. There was no
detectable leakage from the backlighting, and the uniformity remained very
consistent. A good performance from the 2407WFP-HC again.
Office and Windows Use
I've always been a big fan of this size
screen since the high resolution of 1920 x 1200, combined with a comfortable
pixel pitch of 0.270mm is ideal, in my opinion, for office use. The resolution
easily affords you enough desktop real estate for side by side working (in fact
I'm using it right now as I write this review!) The text size is a nice
compromise between the slightly too large appearance on 19" and 22" models
(higher pixel pitches of 0.294 and 0.282mm respectively) and the smaller
appearance on 20" models (0.255mm). This is obviously down to personal
preference, but I find it a nice level for regular office and Windows use.
The screen offers both VGA and DVI
interfaces. The image quality was excellent on both, but text appeared slightly
sharper on the DVI interface as you might expect. You will need to adjust the
screen from its standard 50% brightness to around 25 - 30 if you intend to use
the screen regularly for light background office use, or in low lighting
conditions. This will correct the excessive default brightness to around 120
cd/m2
which is recommended.
Responsiveness and Gaming
The Dell 2407WFP-HC was tested using the
chase test in PixPerAn, a good bit of software for trying to quantify
differences in real terms responsiveness between monitors. As a reminder, a
series of pictures are taken on the highest shutter speed and compared. The
images above show the best case example on the left hand side, and the worst
case example on the right hand side. This should only be used as a rough guide
to comparative responsiveness but is handy as a way of keeping a constant test
of each screen.
As you can see from the above images, the
2407WFP-HC performed very well in these tests. It was a little ahead of another
new 24" model, the
ViewSonic VX2435WM, but not by much. It did remain a little behind the
popular NEC LCD20WGX2 however, a screen widely regarded as being one of the
fastest available, and popular amongst gamers. To the eye, you could tell there
was some slight blurring of the moving car, but no obvious ghosting images were
detectable. In gaming, there was some motion blur evident if you know what to
look for, but nothing which is really going to bother most average users I would
suggest.
This good performance is made possible
through the aggressive use of RTC technologies, boosting grey to grey
transitions to a reported 6ms. Compare this with the original 2405FPW model
which featured only slight RTC and a 12ms G2G quoted figure, and Samsung have
clearly made some improvements with their PVA / S-PVA panel technology. In fact,
it is Samsung's 6ms G2G generation which showed the most improvement in practice
compared with the non-overdriven generation of PVA panels. The Dell 2407WFP-HC
is in keeping with this trend.
The Ghosting Issue
Above: the
well documented ghosting issue on the 2407WFP-HC
However....the aggressive application of RTC
is not without it's issues. We have published a
separate article regarding the 2407WFP-HC's unfortunate ghosting issues.
Without going into too much detail here, this issue manifests itself by a
noticeable black ghosting when moving a light coloured object over a dark
background. This was something I was keen to test since there had been many
reports of this issue across internet forums. At the time of this review, Dell
are working towards a fix for this issue, perhaps something which will be
updated in an A01 revision of the screen? We will have to wait and see on that
one.
Above:
Video showing ghosting artefact
In practice the artefact was easy enough to
produce, but interestingly seemed to get more apparent the longer the screen was
left on. Presumably the screen needs a chance to really warm up before the issue
becomes very obvious. By moving a white cursor across a dark grey background,
you could see a black ghost trail behind the moving object. This is most likely
due to the control of the RTC impulse and is something which can be an issue on
other screens where a strong overdrive impulse is used, and control is poor. In
this case it appears that as the liquid crystals are being asked to change from
a light state to a dark state, by changing their orientation, the RTC impulse is
causing them to 'overshoot' the required state, and twist to produce a full
black shade. This then corrects itself to the desired orientation and requested
dark colour, but not without the black state being obvious as a ghost image.
I won't go into more detail here since our
other article covers the issue in full. Updates will appear in that article when
they are available. However, for the purpose of this review I will confirm that
I did notice this strange artefact and it was easy enough to reproduce. I can
confirm that even with correct calibration with a high-end colorimeter, the
issue was still there. However, in gaming I didn't really find it a problem, but
it will really depend what game you are playing. It's not something which every
user notices, but if you are concerned, I would consider either purchasing a
regular 2407WFP model, or waiting for a hopeful fix. Ghosting issue aside, the
2407WFP-HC performed well in terms of panel responsiveness.
One other thing to bear in mind is that you
will need a pretty powerful graphics card to run this screen at its full 1920 x
1200 resolution in modern games. If you can't do this, the screen does offer
hardware level
aspect ratio control, with options for 1:1 pixel mapping, fill, and aspect
available.
As usual I tested the
screen in clone mode with a CRT to determine the level of input lag. This is
something which can put off some gamers and is a delay between graphics card and
monitor output. By hooking up a CRT you can show that the LCD lags behind
somewhat, which can affect users in some situations where they rely on the
screen image being as fast as their inputs (e.g. fast FPS shooting games).
Often, input lag is very low and probably wouldn't represent too much of a
problem in real terms.
The above graph shows
the average input lag across several screens tested at TFT Central (top
section), and also average input lag as recorded from other sources (bottom
section) on some popular and well established models. The Dell 2407WFP-HC showed
some average performance in this test, with an average input lag of 34.3ms. This
is a little behind other screens we have tested, but remains comparable to the
ViewSonic VX2435WM, another 24" screen we tested recently with an average input
lag of 36.3ms. The 2407WFP-HC did reach up to 50ms in some cases, leaving it a
little behind some other screens (including the Viewsonic VX2435WM = 41ms max).
If you compare the HC edition with the standard 2407WFP, you can see the older
version commonly had an input lag of ~23.7ms. As usual, this is maybe an issue
for some serious gamers, but probably not to most normal users.
Movies and Video
When considering whether a display is well
suited for movies, you need to consider a few things. The Dell 2407WFP-HC
offered the following:
HDCP
support over a digital interface is vital for viewing HDCP encrypted content.
Thankfully the DVI interface offers this support. It might have been nice to see
an additional HDMI port included as well, something which is becoming more
common on larger screens nowadays.
Viewing angles must be wide if you intend to have more than one person watching
the video. Thankfully the S-PVA technology is strong in this regard.
Black
depth must be good to allow darker scenes to be rendered correctly, and for
detail to be distinguishable. The 0.22 cd/m2 black depth is adequate
for this and the contrast ratio is decent enough (545:1 after calibration).
Movie
noise must be kept to a minimum, otherwise artefacts and twinkling in large
colour masses can be noticeable. The high resolution of the 2407WFP-HC means
that any compressed or low res content looks a little blocky, and any
compression artefacts are accentuated. Noise is noticeable as well, something
which is common on modern aggressively overdriven PVA / S-PVA panels. However,
if you sit a couple of metres away, which you'll want to with a screen this
size, there is no real issue in practice.
Conclusion
All in all, the 2407WFP-HC is a very
impressive screen. At the time of writing, the retail price in the UK is a very
attractive �447. Cheaper 24" models are beginning to emerge, but the Dell
remains one of the more premium models and does not limit itself to TN Film
technology as some other models have begun to. The display really offers about
everything you could want, with a huge range of ergonomic and connectivity
options. The design is nice and the build quality is excellent. Performance is
very good in all areas, and ghosting issue aside (which will hopefully be fixed
at some point soon), the 2407WFP-HC can offer some impressive performance in
games as well. The addition of enhanced W-CCFL backlighting is a nice touch, and
offers a little something extra compared with many other current 24" screens. I
was impressed with this screen, and would certainly rate it highly in the ever
expanding 24" sector.
Pros
Cons
Good colour reproduction,
even at default settings. Enhanced W-CCFL backlighting offers 92% NTSC
colour gamut
Black ghosting possibly a
problem on current revision