# question about calibration and clipping! Confused...



## Todd Anderson (Jul 24, 2009)

Curious to hear some responses on this:

I'm using the Spears and Munsil calibration disc.

My setup has an Oppo-93 feeding the video signal via HDMI through my Elite VSX21THX which then is sending the video signal to my JVC RS45 via HDMI.

In following the preparation and orders of operation on the Spears and Munsil website... after making sure all of the settings are as they are called for, I first embark on setting the contrast. Which, I am able to do. A contrast setting of "1" makes it so the highest number white bar on the bottom left hand side is just barely visible.

The next step is to check clipping. When I display the clipping pattern, it appears that red, white, and green blocks are a clipped (the are solid colors) and the blue block has one shaded layer visible.

Adjusting the RS45 contrast control does not change this.

If I, however, go into the Oppo 93's PQ controls... I can eliminate the clipping by setting the contrast to -4 and the brightness to -4.

With those settings intact, tho, when I go back to my contrast pattern a ton of the white bars on the bottom of the contrast pattern are now visible.


I'm really confused here... I would think that the RS45 should be able to display images without clipping. Maybe I'm overvaluing the impact of clipping... but I'm definitely confused.

Is my Elite AVR somehow tainting the video signal during pass through?


I'm hoping mechman... or someone with a lot of PJ experience can chime in and tell me how I should evaluate this and/or tackle the problem.

Thanks guys!


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## mechman (Feb 8, 2007)

27dnast said:


> Curious to hear some responses on this:
> 
> I'm using the Spears and Munsil calibration disc.
> 
> ...



You mean that you are seeing whiter than white? That's usually not a problem. 



27dnast said:


> I'm really confused here... I would think that the RS45 should be able to display images without clipping. Maybe I'm overvaluing the impact of clipping... but I'm definitely confused.
> 
> Is my Elite AVR somehow tainting the video signal during pass through?
> 
> ...


I doubt your Elite is a problem. It sounds like you fixed the problem with your Oppo.


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## Todd Anderson (Jul 24, 2009)

You know... I may have incorrectly adjusted the contrast. I'll check tomorrow and report back. Thanks for reading and responding.


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## Todd Anderson (Jul 24, 2009)

:surrender:Okay... I give up. Little confused. When I put up the contrast pattern, the contrast control on my rs45 has very little impact on it. According to Spears and Munsil's website, a good contrast setting allows you to see all of the white bars on the bottom of the contrast pattern and some of the darker bars on the top.

Well, I can only get my PJ to display about 2 white bars on the bottom and almost no bars on the top.

Now, if I go into the picture settings on the Oppo, I can get the white bars to reveal themselves by turning the contrast all the way down to -15. Hmmm...

When I go to the clipping image, which is what spears and munsil recommends next, three of four colored rectangles show some signs of concentric squares... the red rectangle remains solid red, tho... IF I leave the contrast setting on the Oppo player at -15. If I raise the contrast to 0 on the Oppo player, then all of the rectangles become solid. The contrast control on my JVC RS45 doesn't seem to have any effect on these clipping patterns.


I used this spears and munsil disc to calibrate when I first purchased my projector... I thought in the last week I saw a shift in the picture quality. I'm fairly sure that I didn't have this issue with contrast and clipping when I first calibrated the projector. It has about 70 hours on the bulb --- basically brand new.

Hmmm.....


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## mechman (Feb 8, 2007)

Since the Oppo is in the chain, that could be the issue. :dontknow:


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## Todd Anderson (Jul 24, 2009)

Should I call them? I'm not sure how to proceed... 

I do have another BDP. Maybe u should hook that up and the calibration disc off of it.


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## Todd Anderson (Jul 24, 2009)

Do you think I should be having these issues????


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## mechman (Feb 8, 2007)

27dnast said:


> Should I call them? I'm not sure how to proceed...
> 
> I do have another BDP. Maybe u should hook that up and the calibration disc off of it.


Try the other BDP. See what happens.



27dnast said:


> Do you think I should be having these issues????


Some displays clip. :huh: I have no experience with that particular pj or the Oppo so I couldn't tell you if this is normal or not. I was kind of hoping someone who has a JVC or a calibrator who worked on one would chime in by now. :scratch: 

One thing though, if you're using the Oppo as the source, adjusting it's settings to get the picture correct makes sense. :huh:


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## Joel Barsotti (Nov 26, 2011)

It's the JVC, it clips higher than 235 by default.


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## Todd Anderson (Jul 24, 2009)

Joehl.... Could you elaborate a little?


If that's the case, is there a way to change that? Do I want to change that? And, if that's the case, is there another way for me to set my contrast correctly?


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## Todd Anderson (Jul 24, 2009)

I'm just going to throw out a guess here... Is it that standard video content simply doesn't go above 235?


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## Todd Anderson (Jul 24, 2009)

Mechman - if go under the hdmi settings on the JVC I have 3 selections: standard, enhanced, and super white. I was running it on standard. The enhanced mode really washes out the blacks... But super white, this is the interesting one. Running in this mode slightly darkens the picture. But, it allows me to see all of the white contrast bars on the spears and munsil disc. It also allows concentric squares to be visible on the clipping image on the S and M disc.

Hmmm... Are you familiar with these different modes?


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## mechman (Feb 8, 2007)

27dnast said:


> I'm just going to throw out a guess here... Is it that standard video content simply doesn't go above 235?


There is some content that does go above 235. But not enough to really matter. 



27dnast said:


> Mechman - if go under the hdmi settings on the JVC I have 3 selections: standard, enhanced, and super white. I was running it on standard. The enhanced mode really washes out the blacks... But super white, this is the interesting one. Running in this mode slightly darkens the picture. But, it allows me to see all of the white contrast bars on the spears and munsil disc. It also allows concentric squares to be visible on the clipping image on the S and M disc.
> 
> Hmmm... Are you familiar with these different modes?


No. I see that Joel is here and more than likely he'll respond so I'll leave it to him.


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## Joel Barsotti (Nov 26, 2011)

27dnast said:


> Mechman - if go under the hdmi settings on the JVC I have 3 selections: standard, enhanced, and super white. I was running it on standard. The enhanced mode really washes out the blacks... But super white, this is the interesting one. Running in this mode slightly darkens the picture. But, it allows me to see all of the white contrast bars on the spears and munsil disc. It also allows concentric squares to be visible on the clipping image on the S and M disc.
> 
> Hmmm... Are you familiar with these different modes?


Super white enables WTW content, enhanced enables WTW and BTB content. If you select enhanced, then you'll need to re-adjust brightness and contrast, but should be completely usable once you've reset the brightness level. Once you've reset brightness and contrast they should all effectively give you the same black and white levels, the only difference being the presence or absence of levels >235.

If you want to be able to correctly use the pluge pattern and see to 235, use enhanced and leave your oppo settings alone at default. You shouldn't have to make any changes in the player.


(WTW = whiter than white or values abolve 235)
(BTB = blacker than black or values below 16)


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## Todd Anderson (Jul 24, 2009)

Ah... okay. Thanks for your response.

Just so I understand: I shouldn't use the SuperWhite mode... the better option is Enhanced (considering that I recalibrate to adjust the brightness and contrast)?

correct?


Just out of curiosity... if I use the Enhanced mode and calibrate using the Spears and Munsil disc... will I be gaining anything from attempting to calibrate leaving the projector in Standard mode? The JVC manual is cryptic, of course. I **think** it says to leave the projector in Standard mode for video and Enhanced mode of PC feeds. I've dug around a little more on the net and found some info on the spears and munsil website. They don't give a real good straight forward answer...

I guess what I'm asking is, is this an exercise in futility?onder:

Just curious... what would you do?


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## Joel Barsotti (Nov 26, 2011)

27dnast said:


> Ah... okay. Thanks for your response.
> 
> Just so I understand: I shouldn't use the SuperWhite mode... the better option is Enhanced (considering that I recalibrate to adjust the brightness and contrast)?
> 
> ...


Some of this depends a little bit on your screen size and how much light you're getting out of your projector.

Using standard mode will clip at 235. This isn't the end of the world and will allow you to maximize light output at a slight loss of visual fidelity (only for YCC values that convert to values greater than 235).

If I were to calibrate to see >235, I'd use enhanced and crank the brightness back down so to get the black level correct. This would enable you to see levels above 235, but would likely reduce the light output of the 235 level.

So there is your trade off. Most people using projectors try to maximize light output at the expense of the few pixels that exceed 235. Being that I don't live with a projector on a day to day basis my opinion on the trade off isn't particularly applicable.


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## Todd Anderson (Jul 24, 2009)

Cool. My projector is in a completely dark, light controlled room. 14' throw distance onto a 96" 2.40:1 screen.

Sounds like I should try tinkering around with the enhanced mode?!


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## Todd Anderson (Jul 24, 2009)

Alright, so I ran through the calibration disc with HDMI Enhanced "on".

Interesting result... in general, the picture looks basically the same as my first calibration with HDMI set to standard (meaning, the Spears and Munsil disc shows I have clipping).

I did notice, however, the calibration setting with Enhanced ON results in images that have a little bit more of a red push --- faces are a tad rosier... etc. I actually think that I like the image presented by my calibration with HDMI set to standard. I'm sure there is probably a way to take some of the redness out... but, for the life of me, I can't figure out how to go about doing that. ;-)


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## mechman (Feb 8, 2007)

Did you try adjusting color and tint with the filter provided?


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## Todd Anderson (Jul 24, 2009)

Yes, I went through that whole process... following the detailed articles on the spears and munsil website. Because the Enhanced setting is so washed out, the contrast and brightness settings came out much different than when I used the calibration disc for the standard or super white settings.

The color and tint were also different. Honestly, using the blue filter isn't exactly easy. It's fairly subjective... seems like there are several values for color, for example, that are impossible to distinguish through the blue filter. I'm sure someone with the right equipment could get all three HDMI settings to look similar color-wise.

All that being said, I just can't see a difference between paused images in the Standard mode (where the PJ clips) and the Enhanced mode (where the PJ doesn't clip).

Perhaps the subtleties are so subtle they don't matter?


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