Well, I finally sealed up the calibration on my 56H80 and thought I would share my results. What follows is a review of the TV itself and the results of the calibration.
As many are aware, the 56H80 is the latest model of Toshiba's 56" 16x9 set. After suffering at the hands of downconversion and an interlaced display, I decided to go the whole hog and enter the 16x9 Kingdom. And what a glorious place it is!
The 56H80 is a very large and heavy TV. If the set needs to be transplanted in your basement or any other difficult-to-reach areas, I strongly advise you to take some measurements first and ensure it will make the journey. My set just made it to its home in the basement.
Out of the box, after getting the set out of its factory-set "torch" mode, the picture was too green. I'm not talking a subtle shade of green as others have reported on their new Toshiba's, but horrificly green. A quick visit to the service mode and a reduction of GCUT was a temporary band-aid to the problem. I knew a full-scale calibration was coming soon, so I was not overly concerned.
After clearing up the green problem, the image was quite impressive. The added detail of seeing anamorphic DVDs undistorted was breathtaking. No downconversion artifacts! Yay! For regular viewing, I find the TheaterWide 1 mode to be the best compromise. A combination of zooming and stretching yields a slightly distorted image but nothing overly distracting.
Confirming that the set was working properly, I began the 100-hour run-in process, anxious to get the set properly calibrated. Then, at last, it was time to get this puppy tweaked.
The usual tweaks applied here - disabling SVM, electrostatic and mechanical focus and optics cleaning. All familiar treatments to readers of this Forum. Electrostatic focus was pretty much dead-on from the factory - this adjustment yielded little, if any, improvement. Mechanical focus was a bit softer. There was a distinct sharpening of the image after this adjustment was made. The optics had a small layer of dust on them which was easily removed.
Having done all the interior adjustments, it was time to tackle grayscale. One immediate problem I noted with my set - the G2 adjustment had not been performed as it had on other Toshiba models. Many are familiar with the "Herman-TLV" or "G2" adjustment on Toshiba sets. The latest models arrived from the factory with this adjustment already complete - except for my set. Perhaps it was a Friday afternoon set, who knows. Anyway, I tackled this adjustment as I performed grayscale.
The chart above contains the numerical data for before and after readings for grayscale. Measurements were taken using the Progressive Labs CA-1 Colorimeter and used the test patterns from the Video Essentials DVD.
The out-of-box readings were not particularly suprising. None of the three colour temperature controls were close to the 6500K standard. The 'Warm' setting was the closest, however, than the other two. Some have noted that 'Medium' on the new Toshiba sets is closer than Warm. With the exception of one TV (out of five), I have found this not to be the case.
In any event, the first step was to perform the G2 adjustment. The procedure went just as advertised on the Keohi HDTV website. Adjusting the screen VR pots royally screws up grayscale and I have no idea how people do this without the proper equipment. I was able to reduce the thickness of my convergence lines from 11mm to 8mm, with blue getting down to 9mm. It is my opinion that the Screen VR pots on my set were not correctly set from the factory.
After performing this adjustment, it was time to adjust grayscale. Using the CA-1 takes a bit of getting used to, but you soon get the hang of it. Adjusting grayscale involves a lot of going back and forth between the low and high IRE test patterns. While the CUT controls are used for the low end and the DRV for the high end, there is definitely interaction between the two and until you get the hang of it you could be endlessly going back and forth between them trying to get the adjustment perfect.
Soon though I was able to bring in the grayscale quite nicely. I followed the excellent advice of Guy Kuo, who pointed out that grayscale cannot be adjusted by number alone. The CA-1 software provides a numerical readout of the colour temperature at the point. However, you should not simply adjust until you hit your target of 6500K. In reality, there are several combinations of colours that would bring you to that colour temperature of 6500K - its deciding which "mix" is the best that is the hard part.
The eye is most sensitive to green in the dark grays. Knowing this, and knowing that its sensitivity lies next with red, one can adjust for an accurate and attractive grayscale. The colour temperature can be adjusted to 6500K and look quite horrendous - if green is prominent in the dark grays. Instead, when errors need to be made (and they have to be - no set can track dead-on at 6500K), they should be made in blue at the low end, since the human eye is least sensitive to blue in the dark grays.
Understanding this interaction between all the colours allowed me to achieve a very accurate and attractive grayscale - there is no hint of green or red in the dark end. My final result is shown in the graph below:
I am very pleased with the result of this calibration. The 56H80 tracks very close to the 6500K standard. It is interesting to note that the final curve is very similar to the pre-calibration curve, in terms of shape.
I made my calibrations in 'Warm' mode. Incidentally, I will point out at this point that my 56H80 did not suffer from the odd bug that other Toshiba models have, namely the default to 'Cool' mode when adjusting grayscale in Service Mode. Since there is no Designer Mode access to this model, I was unable to tailor the grayscale for each of the other colour temperature settings. Some have adjusted so that one offers a colour temperature of 5700K for black and white material and a slightly higher setting (7500K) for poor cable reception. Just for interests sake, I took post-calibration measurements in Medium and Cool mode. Very interesting to note the results, and you can see them in the numerical chart above. In Cool mode, the lowest IRE levels were actually off the scale and unmeasureable. Very odd.
Having completed the grayscale it was time to try lens striping. I was looking forward to trying this as the 56H80 contains no lens striping from the factory and there was a horrific red tint on the right side. The measurements below indicate the drifts in colour temperature before any striping was performed:
Hopefully those numbers are legible. It is quite clear that there was some severe drifts from side to side, with the right side distinctively red and the left distinctively blue.
So I began the process, and it was here that I diverted from the instructions offered by others on this subject. As I understand the instructions I have read so far, the best way to perform lens striping is to bring the colour temperature in as close as possible to the central reading, thus providing a more homogenous colour temperature across the screen. I tried this method and was very disappointed with the results.
While my overall colour temperature from side to side was very similar, I had terrible green tints on both side. It was distracting and unattractive. Back to the drawing board. Then I remembered Guy Kuo's advice about setting colour temperature.
So I thought about this and took some measurements. There are two reasons why the colour temperature on the right is too low, resulting in a reddish tinge on that side:
1. The red CRT is aimed towards the right side of the screen, therefore the output from the red CRT is more concentrated on the right side.
2. The blue CRT is aimed towards the left side of the screen, therefore the output from the blue CRT is less concentrated on the right side.
A lack of blue and too much red creates a dip in colour temperature. However, the correct solution is not to keep reducing red until the colour temperature rises - because red is not the only problem. Instead, I striped the red lens until the excess red was eliminated, but I went no further.
Using one thin stripe and two diagonal stripes, I was able to eliminate the excess red on the right side of the screen. I cannot do anything to increase the intensity of blue, so I will simply accept that the right side of the screen must have a slight dip in colour temperature.
I applied this same logic for the left side, but obviously the rules are the opposite - too much blue and not enough red on the left side. Again, I simply reduced the excess blue with one stripe. I cannot correct red on this side, so I will leave it as such.
The results after this adjustment were much more satisfactory. By the numbers, I still have a small amount of drift from side to side, but it has been significantly reduced. Also, by reducing the red on the right and blue on the left, I eliminated those tints on either side of the screen, but without any ugly green tinge. My final results were as such:
The image is now very homogenous. One must really strain to see the colour temperature changes from side to side - and during normal viewing this does not pose a problem.
After grayscale calibration this set took on a new lease of life. It is amazing how colours will leap out at you once they no longer have to compete with a blueish grayscale. The image now has "snap" and "pizazz". From the bold colours of Toy Story 2 to the stark contrast of fire against a monochrome backdrop in Gladiator's opening battle sequence. Flesh tones have never looked so real and the whole image is so stunning as to grab you behind the ears and give you a good slap. It really is that remarkable.
With all these adjustments done I have sealed up my set and will not touch it for another 6 months. At that time the optics will need cleaning and I will install Duvetyne and a lens hood. I am also considering replacing the screen with a lower-gain model from Da-Lite.
The calibration process was interesting and the results are spectacular. It is amazing the image quality that can be achieved in what is really quite an inexpensive product. My findings have verified my feelings all along - Toshiba RPTVs have some of the best latent abilities - they just a little work to get there.
____
Jeff
As many are aware, the 56H80 is the latest model of Toshiba's 56" 16x9 set. After suffering at the hands of downconversion and an interlaced display, I decided to go the whole hog and enter the 16x9 Kingdom. And what a glorious place it is!
The 56H80 is a very large and heavy TV. If the set needs to be transplanted in your basement or any other difficult-to-reach areas, I strongly advise you to take some measurements first and ensure it will make the journey. My set just made it to its home in the basement.
Out of the box, after getting the set out of its factory-set "torch" mode, the picture was too green. I'm not talking a subtle shade of green as others have reported on their new Toshiba's, but horrificly green. A quick visit to the service mode and a reduction of GCUT was a temporary band-aid to the problem. I knew a full-scale calibration was coming soon, so I was not overly concerned.
After clearing up the green problem, the image was quite impressive. The added detail of seeing anamorphic DVDs undistorted was breathtaking. No downconversion artifacts! Yay! For regular viewing, I find the TheaterWide 1 mode to be the best compromise. A combination of zooming and stretching yields a slightly distorted image but nothing overly distracting.
Confirming that the set was working properly, I began the 100-hour run-in process, anxious to get the set properly calibrated. Then, at last, it was time to get this puppy tweaked.
The usual tweaks applied here - disabling SVM, electrostatic and mechanical focus and optics cleaning. All familiar treatments to readers of this Forum. Electrostatic focus was pretty much dead-on from the factory - this adjustment yielded little, if any, improvement. Mechanical focus was a bit softer. There was a distinct sharpening of the image after this adjustment was made. The optics had a small layer of dust on them which was easily removed.
Having done all the interior adjustments, it was time to tackle grayscale. One immediate problem I noted with my set - the G2 adjustment had not been performed as it had on other Toshiba models. Many are familiar with the "Herman-TLV" or "G2" adjustment on Toshiba sets. The latest models arrived from the factory with this adjustment already complete - except for my set. Perhaps it was a Friday afternoon set, who knows. Anyway, I tackled this adjustment as I performed grayscale.
The chart above contains the numerical data for before and after readings for grayscale. Measurements were taken using the Progressive Labs CA-1 Colorimeter and used the test patterns from the Video Essentials DVD.
The out-of-box readings were not particularly suprising. None of the three colour temperature controls were close to the 6500K standard. The 'Warm' setting was the closest, however, than the other two. Some have noted that 'Medium' on the new Toshiba sets is closer than Warm. With the exception of one TV (out of five), I have found this not to be the case.
In any event, the first step was to perform the G2 adjustment. The procedure went just as advertised on the Keohi HDTV website. Adjusting the screen VR pots royally screws up grayscale and I have no idea how people do this without the proper equipment. I was able to reduce the thickness of my convergence lines from 11mm to 8mm, with blue getting down to 9mm. It is my opinion that the Screen VR pots on my set were not correctly set from the factory.
After performing this adjustment, it was time to adjust grayscale. Using the CA-1 takes a bit of getting used to, but you soon get the hang of it. Adjusting grayscale involves a lot of going back and forth between the low and high IRE test patterns. While the CUT controls are used for the low end and the DRV for the high end, there is definitely interaction between the two and until you get the hang of it you could be endlessly going back and forth between them trying to get the adjustment perfect.
Soon though I was able to bring in the grayscale quite nicely. I followed the excellent advice of Guy Kuo, who pointed out that grayscale cannot be adjusted by number alone. The CA-1 software provides a numerical readout of the colour temperature at the point. However, you should not simply adjust until you hit your target of 6500K. In reality, there are several combinations of colours that would bring you to that colour temperature of 6500K - its deciding which "mix" is the best that is the hard part.
The eye is most sensitive to green in the dark grays. Knowing this, and knowing that its sensitivity lies next with red, one can adjust for an accurate and attractive grayscale. The colour temperature can be adjusted to 6500K and look quite horrendous - if green is prominent in the dark grays. Instead, when errors need to be made (and they have to be - no set can track dead-on at 6500K), they should be made in blue at the low end, since the human eye is least sensitive to blue in the dark grays.
Understanding this interaction between all the colours allowed me to achieve a very accurate and attractive grayscale - there is no hint of green or red in the dark end. My final result is shown in the graph below:
I am very pleased with the result of this calibration. The 56H80 tracks very close to the 6500K standard. It is interesting to note that the final curve is very similar to the pre-calibration curve, in terms of shape.
I made my calibrations in 'Warm' mode. Incidentally, I will point out at this point that my 56H80 did not suffer from the odd bug that other Toshiba models have, namely the default to 'Cool' mode when adjusting grayscale in Service Mode. Since there is no Designer Mode access to this model, I was unable to tailor the grayscale for each of the other colour temperature settings. Some have adjusted so that one offers a colour temperature of 5700K for black and white material and a slightly higher setting (7500K) for poor cable reception. Just for interests sake, I took post-calibration measurements in Medium and Cool mode. Very interesting to note the results, and you can see them in the numerical chart above. In Cool mode, the lowest IRE levels were actually off the scale and unmeasureable. Very odd.
Having completed the grayscale it was time to try lens striping. I was looking forward to trying this as the 56H80 contains no lens striping from the factory and there was a horrific red tint on the right side. The measurements below indicate the drifts in colour temperature before any striping was performed:
Hopefully those numbers are legible.
It is quite clear that there was some severe drifts from side to side, with the right side distinctively red and the left distinctively blue.So I began the process, and it was here that I diverted from the instructions offered by others on this subject. As I understand the instructions I have read so far, the best way to perform lens striping is to bring the colour temperature in as close as possible to the central reading, thus providing a more homogenous colour temperature across the screen. I tried this method and was very disappointed with the results.
While my overall colour temperature from side to side was very similar, I had terrible green tints on both side. It was distracting and unattractive. Back to the drawing board. Then I remembered Guy Kuo's advice about setting colour temperature.
So I thought about this and took some measurements. There are two reasons why the colour temperature on the right is too low, resulting in a reddish tinge on that side:
1. The red CRT is aimed towards the right side of the screen, therefore the output from the red CRT is more concentrated on the right side.
2. The blue CRT is aimed towards the left side of the screen, therefore the output from the blue CRT is less concentrated on the right side.
A lack of blue and too much red creates a dip in colour temperature. However, the correct solution is not to keep reducing red until the colour temperature rises - because red is not the only problem. Instead, I striped the red lens until the excess red was eliminated, but I went no further.
Using one thin stripe and two diagonal stripes, I was able to eliminate the excess red on the right side of the screen. I cannot do anything to increase the intensity of blue, so I will simply accept that the right side of the screen must have a slight dip in colour temperature.
I applied this same logic for the left side, but obviously the rules are the opposite - too much blue and not enough red on the left side. Again, I simply reduced the excess blue with one stripe. I cannot correct red on this side, so I will leave it as such.
The results after this adjustment were much more satisfactory. By the numbers, I still have a small amount of drift from side to side, but it has been significantly reduced. Also, by reducing the red on the right and blue on the left, I eliminated those tints on either side of the screen, but without any ugly green tinge. My final results were as such:
The image is now very homogenous. One must really strain to see the colour temperature changes from side to side - and during normal viewing this does not pose a problem.
After grayscale calibration this set took on a new lease of life. It is amazing how colours will leap out at you once they no longer have to compete with a blueish grayscale. The image now has "snap" and "pizazz". From the bold colours of Toy Story 2 to the stark contrast of fire against a monochrome backdrop in Gladiator's opening battle sequence. Flesh tones have never looked so real and the whole image is so stunning as to grab you behind the ears and give you a good slap. It really is that remarkable.
With all these adjustments done I have sealed up my set and will not touch it for another 6 months. At that time the optics will need cleaning and I will install Duvetyne and a lens hood. I am also considering replacing the screen with a lower-gain model from Da-Lite.
The calibration process was interesting and the results are spectacular. It is amazing the image quality that can be achieved in what is really quite an inexpensive product. My findings have verified my feelings all along - Toshiba RPTVs have some of the best latent abilities - they just a little work to get there.
____
Jeff
