13.2 - PRECISION FOCUSING: A RECOMMENDED PROCEDURE
This procedure follows Sony's method fairly closely because it works very well and takes into account Sony's wisdom about its own products. In particular, focusing is a balancing act between optimizing fine mid-brightness detail and avoiding blooming (bloating) of the scanning spot in very bright areas. Attached are recommended patterns that can be loaded via memory stick, played from a DVD player as JPEG-on-CD, or displayed via HDMI from a computer. Important: You want to get the vertical pixel-count right: 1080 for MS and maybe computer, and 480 for JPEG (or maybe computer - experiment). I don't know a single pattern on DVE that will work as well as the MS patterns for the fine-pitch CRTs in the XS and XBR sets. HS420 sets and the like will have to use what you can find or use the DVD/CD images.
We're going to work simultaneously with service-mode codes and with the physical Focus control. We'll be using a green-only display to eliminate any confusion possibly caused by misconvergence.
(1) With power OFF, insert the screwdriver into the Focus control knob, as described in the first part of this article. Leave it in place. Unless you have very long arms, a small hand-mirror will be a helpful asset. If you knock the screwdriver out of whack while working with it, just get the flashlight and reinsert it. No need to power down and lose whatever youve done up to that point.
(2) Load the test images onto a memory stick if you have that feature, or onto other media, and verify that they display properly. (You can try the patterns on DVE or Avia for white crosshatch and focus. Watch out: I note some of the patterns on DVE are NOT sharp as recorded!)
(3) Put the TV into service mode. Go to 2170D-4 and WRITE DOWN the existing settings for #0-8, QPAM thru DQP.
(4) Display the CrosshatchPlusDots pattern. Set Pro picture mode, Sharpness = 15, Picture = 40, ClearEdge OFF, and adjust Brightness for a very slight glow to the black background (i.e. a normal black level). Go to 2170P-2/#1 RGBS, and set it to 2 for a green display. Use the pattern PlugePlusExtremeGray to help with black level, if necessary.
Dynamic focusing of the beam apparently uses two mechanisms. Sony would have us completely disable the Dynamic Focus (DF) mechanism by shorting a pair of contacts on the main deflection board, and then adjust the Dynamic Quadrapole (DQ) settings; but we can't do that. Since the two mechanisms interact almost completely, compensating for each other, we are going to set DF according to suggested defaults from the manual, and proceed with Dynamic Quadrapole Focus adjustments.
(1) Look at the figure Table1_DQPData and at the column for your set. If your existing setting for DF is within 5 of what is listed, leave it alone. Otherwise, set it to the listed number (40 or 36). You can reconsider this later, if need be.
(2) Display the image CrosshatchPlusDots for your set's profile (4:3 or 16:9). Gently grab the Focus-screwdriver, push inward gently, and turn it all the way to the left (counter-clockwise) until it stops. Brace yourself! The display is now completely blurred. Adjust 2170D-4 #8, DQP until vertical line widths at equal distances from center are balanced. I.e. the 8th line to the right of center should be equal in width to the 8th line to the left. You should also note that the dots should look like what is shown in the figure DotShapes. The goal is to achieve good left-right symmetry. (See Note #5, below.)
(3) Turn the screwdriver-Focus control to the right (clockwise) until the screen is approximately focused again. Display the pattern FocusMatrix for your set. Go to 2170D-4 #3 QPDC, and set it to 31. Adjust the screwdriver Focus adjustment for sharpest focus in the *center* of the screen. Turn the control back and forth a bit to see what it does. You'll be choosing a compromise between the black-cloverleaf-on-white and its reverse. When you think you have it just right, stop. (See Note #1.)
(4) Now look at the screen center, and adjust 2170P-4 #3 QPDC for an even better focus. Again, you can increase QPDC and decrease it until you are satisfied - it's not a very sensitive adjustment.
That's the fundamental whole-screen adjustment. Now let's fine-tune the rest of the screen.
(5) Look at the top-most focus pattern and adjust #4 QPDV to see if you can improve on the focus up there. You may end up with QPDV = 63 (max) and it's still not perfect, but them's the breaks! Also check out both top and bottom, and use #5 QPDP (a top/bottom balance adjustment) to make them look about the same. You can keep diddling back and forth until you've got it as good as it gets.
(6) Look at the focus patterns at the middle of the left and right edges of the screen, and adjust #0 QPAM for best focus and #2 QPAP for best balance between left and right. (It's a miracle that the beam is focused at all at these extremes, so don't expect the same clarity as the center!)
(7) Check out the extreme corners, and adjust #1 QPAV for best focus. Just do the best you can.
(8) WRITE the settings (press Mute, then Enter). You should write the settings on paper, too. Depending on what source you used for the pattern, you have to transfer your settings once. According to Sony, there are *two* separate dynamic-focus settings (a) for 1080Vcomp/480Vcomp, which are the vertically compressed modes for 4:3 sets, and (b) Others. While your new settings are still on-screen, you should see if you can find a video source that causes *different* values to appear in 2170D-4. If so, change them to match what you've written down, and WRITE. I can't predict how this will go for sets other than 4:3. But this will cover all bases.
PAUSE FOR A BREATHER. You're done . . . at least in theory. But you can go back through these steps any time. (I would write down what you get each time.) You can also set 2170P-2 #1 RGBS to 7 to get full color back to check out real program material.
Here is an overview of what you've done, now that you've seen the result:
The goal was to minimize the effects of dynamic focusing at the screen center first, then defocus and balance the beam width with DQP. Then you (a) focused the center of the screen with the Focus control and (b) perfected the center focus with the QPDC setting. The rest of the settings just balanced the focus over the extremes of this wide-scan screen; just don't expect the beam (the dots) to be as round or sharp as they are in the center.
WHEN DONE, gently pull out the screwdriver without tweaking the control. Normal color will be restored when you leave service mode by powering off and on again.
(1) The tiny cloverleaf focus pattern incorporates the best of dots and of vertical and horizontal lines into one shape. You can easily see how you have to choose a focus setting halfway between sharpest horizontal and sharpest vertical features. It's not my invention. I just made up the screen presentations.
(2) You can revisit the focus process using a brighter setting of the Picture control or a dimmer one, depending on what you wish to optimize. Fair warning: optimizing less-bright focus may result in ugly blooming on nearly-white subjects, swallowing up black detail and bloating white text out of shape. I used the Picture = 40 setting, and I'm very pleased. Feel free to experiment with whatever Picture setting works best for you.
(3) You can leave steps 5-7 alone and just re-tweak overall focus (Focus control + QPDC). The balance of all the sides and corners shouldn't change. But make judgments based only on the *center* of the screen.
(4) You can use a high-quality HD broadcast of good mixed brightness and contrast, and touch up the Focus control. If you can't use a memory-stick image, this may be the best way to finalize things. Use that hand-mirror!
(5) If you get a large value for DQP, say over 40, try setting DF a bit higher and redoing DQP. These two settings shouldn't differ by a great deal. But don't obsess - it's a very coarse adjustment, and a whole range of DF-DQP combinations are likely satisfactory. They should probably be within 5-8 of each other. I ended up with DF = 36 and DQP = 37.
IMPORTANT: Please call my atention to any mistakes you find here. A personal message is best, and Ill react very promptly.
Part2_Figs_Patterns.zip 435.087890625k . file
FocusMatrix_4x3_1080.zip 377.583984375k . file
FocusMatrix_16x9_1080.zip 374.51171875k . file