Herman-TLV Maneuver Version 2
(New and Improved)
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"Do you remember the "Picard" Maneuver?
Its nice to see that many more people are implementing this powerful little tweak
on their sets now as compared to when we first talked about it over two years ago now.
(Has it really been that long?) The power of the testimonial is everything. It was also
nice to see that Toshiba as a corporate entity also was quietly monitoring what was going
on and also started to incorporate this tweak into their model lines. And how could one
tell if this were done? Well, the RGB cuts and drivers exhibit a certain characteristic
(look) when the procedure is properly implemented.
As with everything else in this industry, things evolve over time and that is where we
are today. What I am writing about this time is not so much a new way to do things, but an
attempt to address some of the issues that we encounter when we do this tweak and
subsequently rebuild the TVs grayscale. In the normal process of doing the grayscale
on Toshiba sets (sans the Herman-TLV Maneuver) we will invariably end up with a grayscale
that, while better than where we started (a bad place) will not nearly be as linear as we
would like from 100 ire to 20/30 ire. (Oh yes
IRE stands for International Radio
On random occasions the grayscale will come in to be fairly linear for an RPTV
but the greatest trick is to consistently recreate this result from TV to TV to TV. Hard
and it feels more like a crap shoot. Working on numerous sets, I kept finding
significant dips or humps in the mid range of the grayscale. Often, this looked somewhat
similar in shape to the original grayscale curve so it was more like shifting a curve up
and down the Y-axis. How does one go about flattening the curve on RPTVs to get
Presented here is a sequential order of a number of Toshiba RPTVs that I worked
on over a period of two weeks in May. As you look at the grayscale tracking on the sets
done early on to the ones at the end of the tour, you will notice that the linearity of
the grayscale tracking between 100 ire and 30 ire gets better and better every time out.
This is not done by accident. It was based on a deliberate sequence of events that seeked
to achieve the majority of the benefits of the Herman-TLV Maneuver, while at the same time
achieving a far more linear grayscale time and time again.
The method requires a colour analyzer to be used so it is aimed at the really high end
user and/or calibrator. It is what I dubbed as the Herman-TLV maneuver less one third. The
step by step approach is detailed below.
Warning: Not to be applied to
Toshiba sets made after 2001. No H81 or HX81 or higher sets.
- Do the grayscale tracking without any other adjustments and note how linear the
grayscale looks. It will more than likely dip in the midrange ires to something in
the order of 5700K to 5800K when both ends are pegged close to 6500K. This actually
produces a rather pleasing picture as flesh tones mostly fall in this midrange area of
gray intensities. Flesh tones appear even warmer than usual
but not excessively so.
If you look at the split bar grayscale step chart from AVIA
you can actually
visually see where the grayscale dips. The middle ires appear to be reddish/yellow
compared to the gray bars on either end of the screen. (The use of this split bar
grayscale step pattern should only be used after lens striping has been applied to the
- Normally when this dip occurs, you move the curve up the y-axis by pegging the ends at
say 6800K so that the midrange is at 6100K You can stop here, but the next step
incorporates the H-TLV maneuver and takes you to someplace good.
- Have the pluge pattern sitting in the background. Enter the Service Menu and reduce the
screen trimpot intensity for red and green only. Do not touch the blue trimpot. Now the
question is ... by how much? I dont want to give a specific line width because we
are not working with that here so keep reading before you proceed.
- With the red and green pots reduced in intensity, you now have to bring up the BRTC to
compensate for the dramatic decrease in the black level. With the pluge pattern in the
background (remember that?) increase the BRTC until you actually overshoot the optimal
black level location by a bit. The image looks slightly washed out. Blacks are dark gray.
The BRTC setting is now in the high Bs (BFH)
Maybe low Cs.
- After all this, your image is too blue. Now increase GCUT and RCUT to 70s range
and this should tame the blue tint significantly. Now decrease the BCUT to 20s
- Begin the grayscale tracking with the analyzer.
- Here are the target values you will shoot for.
- RDRV-20 to 30s.
The GCUT and the RCUT can range anywhere from 65 to 90, but if you find that you have
to exceed 90
you have turned the green or red trimpot too far so back off a bit. If
the red or green CUT is less than 60, you are too low so turn the trimpot down a bit more.
- After the first iteration to achieve good grayscale tracking, take a look back at the
pluge pattern and the black level will likely still be too high. Now lower the BRTC down
to the As/Low Bs.
- Recheck the grayscale tracking and you will likely have to make minor changes now.
- When completed, you will notice that the grayscale is tracking far more linear than it
normally does. This method can be applied time and again to set after set and the
grayscale tracking literally comes out the same every time. You get the benefits of the
Herman-TLV Maneuver and you also get very good grayscale tracking from 100 ire to 30 ire.
Even 20 ire will now be reasonable as compared to a normal calibration cycle where it is
still outrageously low or high..
- Now bring up the split bar grayscale step pattern from AVIA again and look at the
grayscale tracking from 10 ire to 100 ire. The midrange ires that were yellowish are
now much closer to what a neutral gray should be. Both the analyzer and your eyes will
agree. (The use of this split bar grayscale step pattern should only be used after lens
striping has been applied to the TV.)
- Unlike the original way of doing the Herman-TLV maneuver where we were measuring line
widths on the grid and then concentrating more on the BDRV and how close it got to 00H,
this new approach achieves most of the original results and then some. In many ways, it is
also a much faster way of doing the overall adjustment. It is possible to follow these new
instructions without the aid of a colour analyzer. You just have to eyeball the grayscale
after you dial in the following values.
Here is a comparo of H-TLV results:
Since developing this technique, it has been successfully applied on an
additional 20 odd Toshiba units achieving literally the same results each time.