Eliminating SVM through THEATER Mode Setting
<< Back to General Tips Page
Tip from Michael TLV: Although the set
used for the analysis was a Toshiba, information found most likely applies to most if not
"Errata ... SVM & Toshiba Theater Mode
On a quiet evening last night, I found some time to take a look at my 36" Toshiba
set and tweak the grayscale some more. The set is the CN36G97 unit which is the same unit
as the H97 and the current V71 units.
Moire problems and all, but fortunately, I took care of that problem a long time ago.
I was curious about colour temp readings at the medium and cool settings now that the
warm mode was 6500K. Typically, the medium was 8500K and the cool was 12500K (ghastly to
say the least) and to think some people like this setting. Well, with nothing else better
to do, I reset the medium colour temperature to 6500K too. Why, because I felt like it. No
It was shortly after I did this that I noticed a severe ringing effect on the image. A
horrible edging that made the image unbearable. Was it sharpness? Was it contrast? Nope,
both were under control. I turned the colour down to zero and the edging was still there
and still in colour!!! The image was black and white, but the edging was in colour.
I quickly switched from my Sharp DVD player to my Toshiba 2109 unit, thinking that
there was something wrong with the Sharp DVD player. But when the Toshiba put up the
image, again, the ringing/edging. Good Gawd ... it was the TV ... stupid TV .... Grumble
grumble. This picture was unviewable in my mind. The edging drove me crazy. So in my
momentary fit of depression I switched the image preference setting to Theater mode from
my memory settings. Not too different aside from the contrast going up to 50 from the
previous 30 position.
But with this mode change, the edging was gone ... no more ringing, no more added
colour artifacts. Yes, it was the SVM at work. I remembered that I had reset the unit long
ago and just reset the TV parameters manually, mistakenly leaving the SVM active. I am
kind of ashamed to admit it, but I have never been able to objectively look at the effects
of SVM until this day. When I first got the set, I went into Theater mode immediately,
thus bypassing the SVM. And through all this time, I never ever saw its effect on the
image in real time. And here it was ... I could now objectively turn the
"feature" on and off and the difference to the picture was most
Talk about hiding in plain sight ... it was there all the time and I never bothered to
look at it. But with this little exercise, I was able to confirm that "Yes" the theater mode does indeed shut off the SVM on the
Toshiba directview sets. If there ever was a question of that in my mind, it was
answered. Now what bugged me about the SVM effect was that it was there all the time, even
at low contrast settings. Truly a bad idea for a TV feature.
So what is the best way to test the effect of the SVM circuit? Go to the needle pulse
pattern in AVIA or VE and toggle between Normal mode and Theater mode in the preference
menu. The results should be obvious and startling. The black line in the bottom white
field literally thickens to 3x when the SVM is engaged. The KeohiHDTV site has a wonderful
presentation/illustration of what this SVM
monstrosity does to the image.
It not only distorts geometry, it adds colour artifacts, it creates artificial edging.
And this is a good thing right?
So if you ever wondered, this is a way to see the effect first hand and decide for