ISF Calibration

[GregoriusM]

I'm just wondering what a certified ISF technician does that a user such as myself cannot do. I know that he can get into the Service Menu, etc., but take for example the Toshiba 57HX93. It seems to have a nominal 9 point convergence capability and then a more comprehensive 56 point convergence ability.

And then you've got VE and AVIA to check for color, etc.

For what an ISF technician charges, what exactly does he do that can make the picture on the TV THAT MUCH BETTER?

This is a serious question. I'd like to know whether I would really need to get a technician in when I buy my RPTV down the road.

Thanks!

Greg

[Kevin P]

The big thing that ISF techs do is greyscale calibration. Basically adjusting the set to as close to 6500K color temperature across the IRE scale as possible. This requires special equipment (a color analyzer) as it can't be done accurately by eye alone.

Once the greyscale is set accurately this makes colors more accurate since color information is "on top of" the greyscale. Many ISF techs do other things on top of greyscale calibration, such as geometry, convergence, focus, lens striping, centering user adjustments, adjusting color decoder to eliminate red push (if possible), etc. Some charge extra for these services.

It's definitely worth having done if you're a serious HT nut with a decent set. It gets that last ounce of performance out of it.

[Adz]

Is calibration as helpful for a front projector? Does the type of projector matter, say a DLP versus something else?

[Kevin P]

Greyscale calibration can be done on almost any projector. In fact, it's often easier on digital projectors since they usually provide the adjustments right in the user menus, and they're relatively straightforward. Whereas with CRT it can get pretty involved.

[GregoriusM]

Thanks, Kev. I think I know what you mean about that gray scale information. It would need to be very accurate to have a chance of getting better colors out of the set.

Good info.

G. :)

[Kevin P]

Exactly. The gray scale is the canvas onto which the colors are painted. No matter how accurate the color decoder is, if your canvas is too green, or too red, or anything else that skews it off the 6500K norm, it's going to taint the color, and make for a less accurate and less visually appealing image.

I was floored at the improvement I saw in my set after having it ISFed 3 years ago. It still looks fantastic. It's a great investment.

[ThomasW]

If you live near a major metropolitan area, color analyzers can be rented for about $200-250/week. Grap a couple of friends and split the cost.... ;)

[JonMarsh]

All you need to supply then is the expertise...

Not a trivial issue.


I've assembled and setup several FPTVs- literally, Zenith kits. I've also done some fairly reasonable calibration jobs on some RPTVs, using the factory manual as a reference. It is a fair amount of work, and requires a thoughtful careful process- certainly, a good ISF guy earns every penny he charges.

I'm considering purchasing a relatively low buck CRT RPTV to tide me over for the next few years in my bedroom system- but I know right off the bat that I'll have to spend 4-6 hours going through it and re-checking everything, as well as disonnecting SVM, touching up manual focus, etc.

There are resources on the web, as well as factory manuals available, but if you're not already an EE or experienced tech, I'd think twice about doing it yourself. It could get a bit scary if you make a mistake...

OTOH, if you're familiar with doing some methodical technical things, then it's not really a big deal- just don't expect to finish in a couple of hours, and expect that you WILL need a factory manual and I'd also recommend a convergence calibration grid specific to your model. It makes things a lot easier and more accurate.

Best regards,

Jon

[ThomasW]

All you need to supply then is the expertise... Yeap no doubt about that. When Kevin and I do our projectors I'll post the details so people can see what's involved.......... 8O

[aud19]

Good info guys :T I can't wait to get my TV done when I have some spare funds again... :? And as much as I enjoy tinkering with my own gear (I've already got rid of the red-push from my Hitachi and made a few other adjustments in the service menu) I'll be leaving a full blown calibration to the pro's ;)

Jason

[GregoriusM]

Thanks guys. This has really been quite informative for me.

[Sonnie Parker]

Greg... I'm not sure if you've actually spoken with Gregg Loewen but this is what he does during a calibration for approximately $550-$600 which includes 2 inputs:

*Pre evaluation of the viewing environment
*Pre evaluation of the display device, projector, and cabling
*Removal of the protective screen (where applicable)
*Mechanical disconnection of SVM circuit
*Image centering
*Minimization of overscan
*Correction of major geometry errors
*Convergence touch up of all NTSC modes
*Electronic focus adjustments
*Mechanical focus adjustments
*Cleaning of optics
*Herman TLV Maneuver for applicable Toshiba sets
*Grayscale adjustment to 6500 D Kelvin
*Centering of front panel controls when ever possible
*Adjustment of front panel controls from within the service menu
*Color decoder adjustment where possible, either via service menu adjustment, EEPROM Reflashing (I2C Fix), or installation of a red push attenuator.
*Lens striping, when required, to achieve a color temperature variation of less than 500 Kelvin.
*Computer generated report showing pre and post calibration settings

I know he's done a bunch and he travels all over to do them.

[aud19]

Good summary Sonnie, thanks :T

I'll be using that as a check list when my girlfriend lets me spend the money on one... :confused:

Any idea what the average charge for Duvetyne lining is and if it's still recommended? I ask as I've heard varrying opinions that lining RPTV's isn't as useful as it used to be with most manufacturers already making the innards pretty dark.

Jason

[Eduardo]

If I remember correctly Gregg charges $150 for the Duvetyne. I was going to schedule Gregg to ISF my Hitachi but I didn't have a progressive scan dvd player. I will have him scheduled for his next South East tour.

[george_k]

This may seem like a dumb question but do plasma/lcd tv's suffer the same grayscaling, color temp. problem?

[Kevin P]

This may seem like a dumb question but do plasma/lcd tv's suffer the same grayscaling, color temp. problem?Yes, all sets, regardless of technology used, can benefit from a proper grayscale calibration. Although they don't need a lot of the other adjustments that CRT sets require (focus, convergence, geometry, SVM, Duvetyne), they will also benefit from color decoder and Avia/VE calibration of brightness, contrast, color, tint, etc.

ISF calibrations of LCD sets is likely cheaper since the adjustments are simpler and quicker (a lot of LCD PJs have the grayscale adjustment parameters in the user menus).