HDTV Forum

If I have an ISF calibration done wouldn't it be best to allow my eyes call the gray and other measurements while the tech does the calibration? Seems to me since I am the end user I would want things the way my novice eyes see them. Is that possible during a calibration or won't they do it thay way?

Mtnmike wrote:If I have an ISF calibration done wouldn't it be best to allow my eyes call the gray and other measurements while the tech does the calibration?

A comment on "gray".

The world of film photography and video production photography centers on a Standard "gray" card that all light meters are calibrated against. A lot of light meters are "average" type and expose to try to recreate this average gray over the frame. You can easily see this effect on pictures shot on snow or the beach where there is a lot of white-the snow comes out gray in your print!. Have too many white clouds in the scene and they come out gray, and the foreground too dark. The problem then is how to properly create a range of brightness between white and black to accurately represent the scenes range of black to white. Color brightness follows this same gray scale. Since the human eye has a wider brightness range than any film or video media or any print paper or TV screen it becomes a compromise which is part of the art of photography.

Turning to TV, the pros spend enormous effort and expense to set the brightness range of the pictures they produce to the proper range for display. It is actually possible to have "blacker than black" or "whiter than white", but if the video is produced outside the "standards" problems occur. There is a FCC requirement that video not be broadcast with bright sections "whiter" than the standard white as damage could occur in the user's display. My video editor has a tool to zebra stripe every white section in each video frame that is "not broadcast safe" for white, and then correct brightness. Many high end video cameras have the same zebra stripe option in the viewfinder to correct the problem at the beginning.


The objective of using proper standards in the User's display is to recreate as closely as possible this Industry standard range of black to white. When it is done you are seeing nearly the same picture the producer of the video intended you to see.

Just as you can't set proper exposure on a film camera by your eye, you can't set up a TV display without some reference standards. The normal user (me included) does not have the equipment or knowledge to do this right.

The eye can be fooled by a colored wall behind a TV display into thinking the display is "off color" and the same is true of room brightness. This is why a dark gray background behind the display is the ideal, but seldom achieved. My wife and I compromised on a very dark green for the wall behind our display matching the green of the decor. In daylight it is dark green, but when the room is dimmed the eye sees it as dark gray since the eye is not as sensitive to color in dim light.

DonShan,

Thanks! I have a new Sony LCD - KDF55WF655 on its way. I have the DVE-DVD. Two questions. How long of a breakin period before I tune with DVE. How long after should I wait to have an ISF calibration done?

Mike

Break in: Preparing the display for calibration
viewtopic.php?t=3796

THANKS!

Hi,

The following suggestion is not meant to insult anyone but I bring it up because of an experience with my own father and his pride.

No one can appreciate the beauty that this world has too offer if they don't see properly. Your vision may very well seem to be fine at HighNoon in a well lit area. I haven't been to a movie theatre in a while but I remember that the last time I was there I noticed many people putting on glasses because thir eyes didn't operate as well in a darkeded room or a dark Highway when driving at night as they used to.

I don't need glasses except to read under normal well lit circumstances but I find my eyes get tired very quickly if I have to drive much more than an hour at night so I don't.

Particularly if you've reached a certain age, please have your eyes checked regularly, (whether you think you need it or not) and tell the eye doctor that you have a Home Theatre and will be watching alot of stuff in a relatively if not totally darkened room.

If your going to have your set professionally calibrated make sure you can appreciate visually the work thats been done.

Peter m.

To me, real calibration comes down to whatever makes the viewer/owner happy,

Hi,
I totally agree about what makes you happy. The only problem with that is, it could be alot of work.

My brother and I have approximately the same tv. Both rptv Tosh (his slightly smaller). I spoke to him a couple of years ago about having a full calibration and having just bought the set, he didn't want or feel the need to spend the money and has long since forgotten about that conversation.

It did however come up a few weeks ago when he took the plunge and got a HDTV decoder from our cable provider.

Since we spend alot of time at each others place, (mine more than his), he asked me quite innocently why whenever he was watching my tv and changed the channels, he never had the urge to play with the brightness and contrast and on his set he finds himself doing that constantly.

I reminded him about the ISF calibration conversation, (particularly for crt based rptv's). He said yeah maybe, but I really don't think its a priority and I don't think he'll have it done. Its his tv, if he's happy thats all that matters.

Peter m.

I just got a older (almost 6 Yrs) Toshiba RPTV calibrated by an ISF calibrater. Details are posted in the "Video Calibration-feedback thread". I had a problem of setting black levels correctly using the user controls due to dirt and aging issues , that was corrected by cleaning the mirror and optics and internal recalibration of the gray scale. I got even more. A "good" monitor became "great"!. It took special instruments and a computer to do it right. My calibration took most of a day to do by an expert( plus a VERY long day for his travel time), because the settings and several convergence setups were checked and done over until everything was RIGHT on. One of the differences between the ISF guy's eyes and mine, is he has seen lots of sets and knows "what is possible and which hex code to enter into the service setup to get it right"

A monitor I feared was wearing out has been reborn!.

Hi Don,

Your post makes me think of those old "FRAM" oil filter ads where a mechanic servicing a neglected car says, "You can pay me now, or pay me later".

People are just starting to wrap their minds around the concept of HDTV and the equipment that will bring it to them. There is so much misinformation out there its freithening.

I was at Best Buy the other day talking to a saleman about something and happened to mention that I"m constantly using my 65" Tosh as a computer monitor at 856 x 480 and the salesman told me that their taught that if a prospect asks them about that on a crt based tv their to tell them that it could cause burnin. I suggested that he keep telling them that because the only thing that will make it safe is the lowering of the brightness and contrast done during an ISF calibration. I also said I'd been doing it for 4yrs without burnin issues.

Anyway I don't let it frustrate me anymore. I used to be evangelical about it but when you see folks eyes glaze over in that "Your boring me look" you stop wasting your time.

Peter m.