Next ??? - Convergence

[TheBigE]

Convergence...how often, why, how do you know when, etc.
WHEN I get my HD RPTV I WILL have it professionally calibrated after a break-in period. But, having said that, I am curious as to the ins and outs of each TV's convergence settings.
I understand the basics of when convergence is obviously off but am not sure of 3 things....which are, in no particular order:

1) Is there any REAL notocable difference between some manufacturer's 9-pt and another's 56-pt convergence features? I ask cuz I never really hear much about "my 56-pt smokes your 9-pt"

2) If you find yourself needing to run convergence every so often, with no obvious cause of shift (such as moving the set)...is there a time period frequency that tells you "something else is wrong, you are doing this too often"?

3) Given that you have an RPTV prof calibrated and you don't move the set to throw convergence off...should you even USE the factory convergence feature?
By this I mean - does the ISF tech do such a wonderful job of converging that running the factory convergence will negate what they have done...or will the ISF convergence make it so that factory convergence "tune-ups" will perform that much better?
or maybe neither absolutely applies in truth?

I guess there is one last item...does DIGITAL convergence really mean anything? Are they all digital convergence or is this just a whiz-bang term that sounds cool in the brochures?

Thanks guys - you're helping SO much :D

[zarlor]

Hmm, well let's see if I can provide a few answers, althought I brook no gaurantees that these are 100% correct, only what my experience can offer.

1) A 56pt convergence can make a HUGE difference over a 9pt convergence, especially if you are having problems in a specific are of the set. And if my set is any indication you WILL have some off areas on your set either between those convergence points or outside of them, especially if you try to reduce overscan on your set by pulling all those points in so you see more of the picture that is normally projected outside of your screen area (very useful for those of us using PCs with our sets.) If you really get into converging your set believe me when I say the more points you have, the happier you will be. Nothing worse then having an in-between point that can only be converged by fiddling with all the other points around it.

You probably don't hear how someone's convergence is better than another's because most people don't ever deal with convergence, only technicians and maniacal tweakers like some of us around here, despite the improvement it could make. ;)

2) Well I tend to try and converge every 3 months. It's never very far off, but there is usually some minor convergence around the screen. Once you set convergence it is already on the long, slow road to drifting. Some factors can contribute, though. Like do you live near an interstate or road where big enough vehicles pass by that you can feel that ever so slight shake of the floor as they go by? Is the set on the second floor of a building where it is more likely to pick up vibrations even from folks walking across the floor? Ever get earthquakes? If the set is in a rock stable environment, or even in an only gently swaying one, I'd guess that if you have convergence problems (fairly noticible drift) after only a few day or weeks, then it's probably worth calling in on your warranty for and having a tech look at it.

3) I have found, thorough experimentation, that if you converge a set very nicely and then use the factory convergence it will quie probably undo your convergence and make it worse. I think the reason is that the convergence algorithm cannot see any anomolies in the screenthat is projecting to. It can only estimate where that screen is and assume it is completely flat. Most screens will have some anomolies in them, im my experience, and they'll also over a longer period of time deform slightly from their own weight and especially from accidental bumpings into the screen. So it is my feeling that an auto convergence will never get you as close as doing it by hand, but I can see if you had some very gross convergence errors how it could at least get the set back into the ballpark.

[TheBigE]

thanks zarlor - that ties up a lot of the other stuff I had read too.

I suppose temp changes could also somewhat cause convergence to drift

[zarlor]

Yeah.. doh! Can't believe I forgot that. After all everytime you turn your set on and off you are sending it through a slew of thermal changes which will, over time, affect many parts of your set over time. Don't know why I didn't think of throwing that into the list.

[kevinw]

When setting up my TV, the 56pt was what made my tv go from good to great! If I could recomend anything to anyone about TV's - it is Tune it up with something like AVIA(my choice) and do the convergence. Also NEVER EVER do a 9 point again..It really throws your convergence out of whack-I know I did it:mad:

[ZeroDegreeK]

Never use the automatic convergence feature that comes with some sets. It is always best to do it manually. Also do the 56 or 64 point and not the 9 point, like kevinw said, it could ruin all your hard work if you go back to the 9 point convergence.

Do a manual touch up every 3 months becasue there is some drift due to many factors like age and movement.

Always let your set warm up at least an hour before doing any type of convergence adjustment.

[ZeroDegreeK]

Also, let me add a caution about adjusting convergence. Remember in your quest for perfect convergence and geometry it may take you a while to adjust, and that convergence grid is high contrast. I know more than one tweaking genius that has caused permanent burn in while trying to attain perfect convergence.

[TheBigE]

oh man - and I am a perfectionist!!!
Thanks ZDK - I feel much more at ease now!!! :eek: