Isf Mt-800/7205  

You know, Mike, I've read the same thing, and I'm also confused by that. I have also read something about setting the RGB gains/offsets to 66/39, so that confuses me even more. I dunno....:confused:

For PC DVI that is correct - if you have DisplayMate on your computer - look at your color ramps - the bright colors will be banded into a solid color rather than a range of bright colors. The reason is that Infocus is optically calibrated at D65 (within manufacturing tolerances) - unlike other projectors that are digitally calibrated to cut back from their optical calibration of 9000-1100K.

Since lamps are usually red limited - if RGB are clipped 100 IRE becomes tinted Cyan. I find the closing chapter of SeaBiscuit a good one for checking out white highlights - also any snow, cloud scenes. There is really not a good RGB range pattern on DVD yet - DisplayMate claims to have one in the works!

For Video DVI you have headroom/footroom remaining in the signal itself so as to stretch the range out on the projector (which is what the 66/39 does to regain contrast/brightness)

Most calibrators trained on CRT are unaware of this - just crank up the guns to get more juice. And even other digital projectors always have more Green/Blue available from the unfiltered lamp. But since Infocus colorwheel is designed for D65 - there is not more Green/Blue to tap into (less space on colorwheel) - so they will clip as well as Red (which is much of the colorwheel to get a Cyan lamp down to D65). They do teach at ISF to monitor colortemp at 100IRE because many displays will go south on colortemp - you are supposed to adjust so it tracks all the way across - and not just calibrate at 80IRE. Some calibrators may like to pump up the brightness/contrast numbers by mistracking highlights - which I find annoying!

Any other projector optically filtered for D65 will have the same problem. I think Sharp and Marantz are in this category - but there was a good thread on D65 spec vs. design vs. marketing and nobody else really contributed their knowledge!

Five years ago I sent my Runco out for professional calibration and it came back with the top third of reds all the same shade. I ended up buying into ColorFacts PowerBuy on AVS to fix it myself. Interesting how things turn out! But this is one of the reasons I try to stress this on the forum -calibration should not be a secret society - the more constructive criticism out there the better everyones displays can get. Either thru individual calibrators or even manufacturers catching a clue at doing it right. Everybody always has something more to learn!

For analog inputs I would have to check the behavior on individual systems - problem is the lack of a good RGB ramp test pattern. My thinking is the circuit flow goes ADC adjustments, color saturation/tint, then RGB - so it seems RGB would be limited because the data is digitized by the time it gets to those controls - but if there is maybe headroom left due to low voltages it might not be a problem. Because of this lack of RGB ramp test pattern I tend to use a little over on one color, then a little under on the other colors to minimize wild swings on anyone one color.

I am sure there might be a pattern buried on AVIA PRO - just have not looked deep enough.

Ok, Kevin, I'm still confused :p

Let me see if I have this straight:

If I connect a PC via DVI, I should set the RGB gains/offsets to 66/39 for that source.
If I connect a video DVI source (like my Voom box), I should leave the gains/offsets set to 50/50, or maybe tweak them a little from that point.

Is that correct?

Now how about gains/offsets on other inputs, like component, vesa, s-video, or composite?

You have it backwards! Also by PC DVI I mean the Windows Desktop - if you use the proper Windows DVD filters you can get Video DVI out of a PC - just like you can your settop box. And the SP4805 setting is different than SP7205 setting. I would presume Toshiba could be different if they tweaked the firmware. Thus I always say calibrate with DVE BTB/WTW signal test patterns.

THe only reason on DVI that gains/offsets are used as a contrast/brightness control is they have more bitdepth than the contrast/brightness control - which is what you are really trying to correct. It gets real complicated when you also try to correct greyscale using the same controls!

For analog inputs correct contrast/brightness with the usual controls, use the RGB controls to correct greyscale - try to minimize swings to avoid banding. Sometimes though I use the RGB controls for contrast/brightness on the analog inputs - on Infocus the contrast/brightness are on the remote - this way I can tell the customer just keep contrast/brightness centered as I fixed it using the greyscale controls.

The reaons all this is confusing - is all the controls interact with each other. They do have different purposes within the video chain though.

Thanks, Kevin, that clears things up! :)

I'm going to go and play with DVE and Avia right now.

AVIA has not the WTW/BTB - I just got the Incredibles DVD - supposed to have a brand new THX Optimizer pattern to try out!

Kras,
Many many thanks for helping us out in understanding the calibration of IF 7205 and other models. I agree with you that calibration should not be a secret society.
For DVD player and Voom DVI I am using 66/39 by switching back and forth because 7205 have just a single DVI input, some time I use Voom's component out put to watch 1080i with same settings 66/39. Does it matter? or it should be at 50 like out of the box. How do I save settings according to the inputs?
By the way, when are you planning to visit Naperville, Chicago to see your relatives? I would very much like to have my7205 fully calibrate by you.
Imagine, make money while on vacation.
Any tips regarding 7205 is wellcome.
www.raoof@myself.com
Thanks in advance.
Iffath

I think both your DVD player and Voom should be Video DVI- but ask in the settop box forums here to verify

The presets menu is where you save or select up to 3 calibrations per input. Use your remote to toggle thru choices once saved

I will keep that in mind if I ever go visit my sister! Though I think she is coming out with mom 4th of July so I am off the hook for this year!

Kras, Iffath, and Bob and whoever else

How does the 800 stack up against the Optoma H77 ?

Or does it at all?

I really like what I'm reading about the MT800, I'm dyin' to pull the trigger here as my new HT nears completion. This is my first FP after leaving my 65" RPTV.....hope I'm not disappointed.......

Any light that y'all could shed on the subject would be greatly appreciated


Texan

Do you value large screen or plasma brightness, do you value calibration out ot the box making ISF optional - or poor calibration making ISF required. (Of course I speak of SP7205 - not the Toshiba OEM - I have no idea if Toshiba uses same calibration or not!)

Probably not the thread for comparison though since this is a projector specific calibration thread - you will not get the other projector specific folks with the contrary opinion poking in with their opinion!

I currently have a the 7205 and I was coming from a ISF calibrated 65 inch RPTV. I promise you will never look back after going Front projection.

Joel

good thread for calibration forum!