I was reading another thread (http://www.dvinfo.net/conf/showthread.php?t=118075) and really got to thinking about this... I hear a lot of people saying that you should only use a broadcast monitors for color grading. I'd like to hear from the collective group on what would be a good criteria as to when will LCD monitors be ready for color correction work???

To my way of thinking... if an LCD can meet the requirements of the specified gamut you're working to (primaries, white point, grey scale, etc) why would it not be acceptable for grading??? If it's more than just faithfully reproducing the color space, then what is it???

So I guess what I would like to know is what measurable parameters, when met, would be sufficient to say that an LCD is acceptable???

Mark

In my opinion, the Sony BVM-L (ballpark of $30k with input cards I believe) looks pretty good. Sharper than CRT, blacks not quite as good on dark scenes. But most people can't tell it apart from the Sony BVM CRT (depends on distance though).

I'd also look at the eCinemasys monitors... they look like a better buy than the Sony monitors.

LCD display technology is getting better very fast... it's only now that it looks like they are good enough.

2- LCDs have historically had some limitations like:
- Blacks not that good (they still aren't that good)
- Colors are off
- Limited viewing angle
- Response time and motion portrayal not that great
- Need to de-interlace the image
- The image may not be that uniform
- Bit depth

Many of those points aren't issues now.

3- I'd still get a broadcast monitor over a computer monitor. Computer monitors can be affected by video overlays, probably won't handle interlacing right, etc.

Thanks for the input Glenn.

I always like to be able to use the best tools I can get or afford, but I don’t think most people have anywhere close to 30k to drop on a monitor. How about something more realistic???

The list you provide are fair complaints against LCDs, but I would like to come up with quantifiable parameters that are measurable so as to be able to say “yep, this is a reasonable solution that’s also affordable”.

Let’s take them one at a time:

- Blacks not that good (they still aren't that good): I would agree… it’s a trade off. I’m thinking that this would translate to contrast ratio. Assuming that the manufacture’s number is inflated, what would be a good “true” contrast radio that could be measured???

- Colors are off: Obviously this would translate to calibrating the display to the required spec (ie: Rec709 for HD), most of the newer displays provide the controls to make most of the necessary adjustments. Also, I assume you can calculate a dE that tells you how close you are to being dead on. But what would be a good spec that says you’re close enough??? Also, how accurate of equipment do you need for the process??? Would a i1 type device be accurate enough or do you have to step it up a notch or two???

- Limited viewing angle: Granted, this can affect color on the off axis, but I would accept this as a trade off. Those who make a living at this probable can’t.

- Response time and motion portrayal not that great: Ok… how fast do you need??? Some of the newer panels are in the 2-4 ms range.

- Need to de-interlace the image: This might be a gotcha, I would think most of the newer displays with HDMI inputs should be able to handle this as this is more of a TV connection vs a PC connection, but I really don’t know.

- The image may not be that uniform: I think this will always be a problem with cheap displays. I’m not proposing bottom fishing here, so I move up the food chain a bit.

- Bit depth: How many bits are enough??? 8 is a gimme, I think 10 would be do-able via aja box or equivalent. I’m not familiar enough with the digital interfaces (HDMI or DVI) to know if they would support 10 bits on the LCD, I’m thinking not. If you have to convert to analog to get this then it seems to me to defeat the purpose.

- Computer monitors can be affected by video overlays: Do you mean overscan??? If so, I’ve seen several that have a 1:1 pixel mode, assuming it works, this should be ok.

Mark

Mark,

I understand that you're looking for quantifiable answers. And I'd LOVE to give them to you. Just like I'd LOVE to find a camera that takes great pictures under all lighting conditions with just a single AUTO button.

But the reality is that right now, things can only be simplified so much - particularly in a world where you're trying to make nice pictures under so many, MANY variable conditions. Take the recorded signals, and pass them along over so many MORE variable conditions, and then view them on even MORE variable conditions.

The whole point of the professional CRT monitor what that is was FAR from being a regular TV. The system of color bars, blue gun, pluge, etc, was to make it possible to have some consistency from place to place, shoot to shoot.

And like it or not, NOTHING like that exists today in the world of LCD screens. The analog tools I mentioned above just don't cut it for LCD monitoring. Not when viewing angle and other factors have such a drastic effect on how images are displayed.

Two notes might help you understand why.

I've used DV Monitor from Red Lightening Software on about six different LCD screens over the past year or two. Typically LCD computer screens. It's a very nice tool for monitoring and recording DV in the field and I enjoy using it. But the one area where it (and EVERY other computer based monitoring system I've used fails miserably and that's COLOR adjustment and monitoring.) That's not the software's fault. It's the nature of LCD screens! Red Lightening built in a way lovely way adjust the display's brightness and contrast as you would with bars and pluge on a CRT.

The FIRST time I used it, I'd set the screen to be PERFECT. Then noticed that if I moved my head as little as 2 inches in any direction, the "perfect" reading would suddenly NOT be perfect. The angle of illumination coming from the computer screen would change drastically with viewing angle.

So doing monitor screen "setup" on a laptop was an exercise in futility.

Now I'm talking about relatively expensive editing laptops in the $2000 to $5000 range and I'd expect the screen technology in them to be as good as anything available at modest cost in a field LCD.

Next is an anecdotal test you can do for yourself.

Go to a sports bar in the next week.

Find a nice expensive commercial big screen TV. Preferably HD and preferably one that looks like it's new, and set up properly.

Find a sports channel showing any of the NCAA games.

Find a "highlights" show. And watch the edited work with an eye to skin tones and color reproduction.

After the shoot yesterday that I mentioned in the post in the old thread I was buying my crew a late supper. Nearby such a highlights show was playing in the bar and the crew and I started playing a game I'll dub "call out the lousy color."

We watched from our table as a cavalcade of highlights shots ran across the screen while we pointed out "too GREEN", "too RED", "decent" "too dark" "too Red" etc.

All of those shots were taken by professional crews with great gear.

I won't hazard a guess whether the problem was actual bad shooting, or poor camera shading, problems in different satellite feeds or whether that stuff looked fine on a decent monitor but the big BAR LCD TVs somehow translated subtle signal differences into seriously different pictures.

In 10 minutes, our little group of 3 video professionals, could barely find two March Madness shots in a row where the color looked accurate (or even similar!) at least from the angle of view we had.

THAT SHOULD NOT HAPPEN.

But it does. And it happens more on LCDs and Plasmas then on CRTs in my experience.

So I don't trust them. Period.

I hope some day I can, because like everyone else, I HATE dragging around CRT field monitors.

But it's the ONLY way I know right now to get it consistently RIGHT in field shooting.

Ces't la vie.

Bill, then can you throw out a few recommendations for CRT's, prefferably at different price points, that you feel can cut the mustard--and HD footage :).

THANKS MUCH!

You guys all come from NTSC land where colour (color) is a myth available for any techie to play with, as it seems to be a total phantom.

The "Never The Same Colour" tag was well earnt, and very well deserved.

HD has killed that cold. NTSC is dead. Yippee.

If you are shooting HD now, wherever, colour (color) correction is practically a thing of the past and only required on gross screw ups.

My experience (which could be totally atypical, admittedly) is that if properly CB'ed on shoot, it doesn't need any CB after, and is good to go.

If, of course, you're still shooting for NTSC, jolly good luck to you - the flourecsent greens were always my favourite scream in Canada.

How you guys put up with that rubbish for so long has me utterly amazed, but that's another story.

Just my 2 cents worth, but if you need to correct HD footage, er, why?


CS

/\ /\ April Fools?

Bill,

I enjoy your comments; they remind me that there is a much bigger sandbox out there than the one I play in.

Yes, I’ve noticed the difference in color in sports clips… I always figured that these differences were introduced at the source, it's just too great a difference to be the set. And to think that each of these clips were probably shot by professional crews with as much passion for their craft as you, and most likely graded on CRT broadcast monitors to the best of there abilities. Odds are, nothing I ever shoot will end up on the nightly news and if it ever did it would look more like the Zapruder film than anything you would see on Sports Center. But just as there is a whole world of video outside of my sandbox, there is also a world outside of yours. What I’m trying to achieve is the best I can for the very limited resources I have. By your standard, how are any us weekend shooters to do that without explaining to our kids why it was more important than their college fund???

There’s got to be a reasonable compromise here. I’m not suggesting that pros like you ever use them… you have better options. But us little guys need a better solution than what we’ve had in the past. The improvements in LCDs make it an attractive choice, but I think all will admit not a perfect one. As long as I know and understand what those limitations are I can accept them, work around them, or try to make a better choice.

Mark

If you are shooting HD now, wherever, colour (color) correction is practically a thing of the past and only required on gross screw ups.

My experience (which could be totally atypical, admittedly) is that if properly CB'ed on shoot, it doesn't need any CB after, and is good to go.
1- Sometimes color correction also refers to color enhancement, where you might want to artistically tweak your colors (e.g. film look is one example).

2- Even ignoring color enhancement, most shoots will have a few shots where exposure or white balance is not perfect.

3- There's no reason why HD would change any of this.

NTSC is "never the same color" mostly because of wide differences in consumer TVs. NTSC as a way of transmitting color can cause color inaccuracies since the receiver has to be calibrated, so digital transmission has an advantage there. But in one area HD has less color accuracy because of the whole 601 versus 709 luma coefficients mess.
In any case, consumer TVs will continue to be quite different from one another so we'll still never have the same color.

There’s got to be a reasonable compromise here.
For SD, you can get a CRT broadcast monitor starting at around $600. That is definitely the way to go IMO.

For HD, you could:
--Wait for monitors to get better (they are getting better at a very fast pace).
--There are some 1920*1080 LCD broadcast monitors from JVC and eCinemasys for about $4,000. It's difficult to get HD CRTs anymore and they're probably not worth getting (none of them do full HD resolution).
--The cheapest options would be just a computer LCD. You kind of get what you pay for. I'd probably just get a Dell LCD (they are good value when Dell is running a good promotion on them; check hot deals sites).

"But in one area HD has less color accuracy because of the whole 601 versus 709 luma coefficients mess."

Glenn... I know there are differences but I've not heard that there is less "color accuracy"... please explain.

Mark

For the Mac/FCP users there is the Matrox MXO that turns a 24" Apple Cinema Display into a pretty good SMPTE reference monitor.

If there was somethinig for Windows I'd be on it in a heartbeat.

George/

Thanks George. I've seen a little bit about the MXO, but after reading these reviews I think I need to look at it some more. Nice solution. They constantly make mention of it being designed for an Apple display, I wonder if it would work with any other??? Perhaps but suboptimal.

What I'm reading up on right now is the different LCD panel technologies (ISP, PVA, etc), I've not yet seen which type of panel that the ACD use, anyone know???

Mark

I believe its a PVA display. Most of them are. However LCD technology also uses a backlight (behind the panel) which is important for gamut. The backlight is the reason LCD's are generally 'greenish'. New backlight technology has improved on this. Some of the newer DELL displays use this.

The reviewer actually uses a DELL monitor at first, but gets less-than-optimal but "nice" results.

As with the current drivers you can adjust the output, it could work better with other displays that are on par with the Apple Cinema Display. However it has been specifically desiged to work with the ACD and that has no on-monitor controls that can mess up the color (it only has brightness adjustment).

Non ACD monitors usually have a slew of settings that prevent this from being a good solution (when "set wrong").

George/

"But in one area HD has less color accuracy because of the whole 601 versus 709 luma coefficients mess."

Glenn... I know there are differences but I've not heard that there is less "color accuracy"... please explain.
HD should be encoded using the Rec. 709 luma coefficients, but some consumer TVs decode HD as if it were encoded with Rec. 601 luma coefficients. They aren't engineered correctly, which leads to major color inaccuracy.

Anyways, this is sort of off topic.

One of the other problems I've discovered while researching computer LCD's for use in color correction is that using the VGA or DVI input limits the tweaking that can be done to calibrate. Most computer monitors only allow brightness, contrast and color temerature adjustments. To get as accurate as possible you really need to tweak hue and saturation as well just like a broadcast monitor. However, I know that some video cards will allow these adjustments. The most inexpensive solution right now may be to go with a high quality 1080p consumer LCD. I've noticed that the image quality has been increasing.

read thru this link. it has valuable info re: LCD displays:

http://en.wikipedia.org/wiki/SPVA#PVA

To get as accurate as possible you really need to tweak hue and saturation as well just like a broadcast monitor.
LCDs shouldn't need this if connected digitally.

You would need this if monitoring via composite analog.

In practice, probably just get something like eCinemasys' FX24 monitor (ballpark of $4k). 1920x1080, viewing angle looks good. I didn't carefully look at the colors (e.g. to see if they are close to what a CRT would show), but it doesn't strike me as being particularly off like some other LCDs (and aged CRTs). Blacks still have that glow-in-the-dark look like (nearly?) all LCDs. I'd hazard to guess that you could use that monitor to pass broadcast QC (other things are more important).

I don't know the cheaper solutions too well so I won't comment on things like computer LCDs versus Decklink, Matrox MXO, etc.

first you have to set your target. If your target is to display your work on the average consumer LCD flat screen, a good 600$ computer LCD panel, properly calibrated should fit the need.
After all why should you spend 4000$ on a monitor to display something nobody will ?
If your target is the film reel on big screens that is another story.
the only thing that differentiate an expensive professional LCD screen from a cheaper consumer is the electronic inside. The LCD panel by itself is probably from the same origin (Samsung, LG).
since the settings you can change into a cheap lcd are usually limited to contrast and luminosity, you need to use the overlay settings into the PC offering a lot more features. That is why using a computer is generally a good thing for such purpose.

Giroud... I respectfully disagree.

A broadcast monitor will have things like a proper deinterlacer (which computer monitors won't do), 3d LUT calibration or better (I've not seen a $600 computer LCD that does this for video), etc. etc.
A computer LCD is also prone to errors from color space conversions, video overlays, etc.
A broadcast monitor (the higher end ones anyways) can take SDI in and therefore not be affected by video overlays and things like that.

Thanks all for the good suggestions. I'm still undecided as to what to do, I like the look of the Dell 2408 which supports HDMI input and controls that look more like a TV than PC monitor... it definitely fits my meager budget. I also like the Apply Cinema with the matrox box, but it's still nagging at me that you should be able to do this without the matrox mxo if the dispay has the right controls as all it's really doing is adding the controls. And at about $1800 for both, its more than I'm wanting to spend at the moment.

I've read all I can on the various LCD panel types and it looks like a toss up for IPS and S-PVA, and both types can be found in monitors from $500-$2k. I'd really like to know which panel is used in the LCD studio monitors from JVC, Sony, NEC or Cine-tal.

LCDs shouldn't need this if connected digitally.

You would need this if monitoring via composite analog.

Theoretically I suppose this would be correct. I assume this is why computer monitors only offer brightness and contrast controls. However, in practice the addition of hue and saturation controls would allow the panel to become alot more accurate when calibrating to a colorbar pattern. I think it is the subtle differences in the way each LCD displays color that needs to addressed. My point is that having more control in the panel would allow for this. That is why I think LCD TV's have an advantage over LCD computer monitors. They allow for all aspects of color to be changed no matter what input.

The better monitors are calibrated with look up tables... they offer more control than simple hue/saturation controls. Those controls can't correct for the primaries being off, the transfer function of the monitor being off, etc.

2- In practice, I've not seen a computer LCD (or LCD TV) with color reproduction close to that of a Sony BVM broadcast monitor. If you know of one... then that would be very interesting. The consumer manufacturers could make a display like that... but they don't.

again , i agree with all of us. A 4000$ professional monitor offers better settings/feature than a 600$ computer monitor.
But , again what is the purpose to spend all that money to get the perfect picture if you know that the movie will be anyway played on low cost lcd TV that are most of the time incorrectly set up.
Take any cheap S-PVA LCD screen, carefully calibrate as much as you can and you will get 80% of what a 4000$ screen is able to give.
And what you get will be anyway 2x better than any consumer's screen you can find on the market.
currently there are few technology for LCD. S-IPS (the best for color, but too slow for good video), S-PVA (a bit faster, and almost as good as S-IPS for color), MVA and TN (the most common on the cheap side, but unable to display all colors, so this not the one you are looking for).
today, most of 24" inch monitor are offering components, HDMI inputs, few settings for calibration. And if you use them on a PC, the software of the graphic card probably gives you a lot of features.
The problem with DELL and others, is sometimes they start to lauch a screen with a very good panel (from LG or Samsung) and fews month after, they switch to less good panels (those with small defect you can't usually see, like backlight uniformity ) or with cheaper manufacturer. That's probably the price for not going "professional grade", quality can greatly vary.
But how many of us are editing video on a computer, and how many of us have only made the slightest effort to calibrate it once ,instead just unpack and switching it on ?
http://www.lagom.nl/lcd-test/

I've simply not seen the colors on a consumer computer monitor to be close to that of a broadcast grade CRT... so I think that is definitely a big difference between a consumer computer monitor and a broadcast monitor.

FWIW - I have a broadcast CRT for SD and use a reasonably good big screen LCDTV for HD (not that I do that much HD). When I do HD, I check the downconverted SD from my Avid on the broadcast monitor and I check everything on a cheap TEAC TV set (for comparison it's handy to see what it might look like on my audience's set.) The colours (particularly the blacks) on the TEAC are more accurate than the LCD, if that gives you a clue (the LCD is now three years old so it's not as good as my Sony full HD set that I have at home, but it's close). Contrast ratio and blacks are the major stumbling blocks on LCD's and they are getting better as technologies improve.

I think Glen has a good point - for critical CC work you can't beat a broadcast CRT. You simply have to decide how critical colour correction is for your workflow - a lot of my work ends up on corporate DVD or lo band satellite broadcast. For that purpose near enough is definitely good enough. However if I was going to a widespread film release, I'd use a telecine based CC and pay the dollars - but they'd have their own CRT monitoring.

I've simply not seen the colors on a consumer computer monitor to be close to that of a broadcast grade CRT... so I think that is definitely a big difference between a consumer computer monitor and a broadcast monitor.

There are some mid-grade choices such as the NEC Spectraview series. On the photography site smartshooter.com, there is a monitor shootout that places a few monitors in the acceptible category. I wonder how they do for video as they are chosen for color but not reponse times. I have the NEC 2190UXi for digital photography work. It's an S-IPS panels which is supposedly too slow for video, but I'm not held up for the amateur-grade video work I do.

The better monitors are calibrated with look up tables... they offer more control than simple hue/saturation controls. Those controls can't correct for the primaries being off, the transfer function of the monitor being off, etc.

2- In practice, I've not seen a computer LCD (or LCD TV) with color reproduction close to that of a Sony BVM broadcast monitor. If you know of one... then that would be very interesting. The consumer manufacturers could make a display like that... but they don't.Glenn, can you explain a little more about what a broadcast monitor does as it realtes to making a DI for a filmout? I realize that there are interlacing and IRE 709 color level issues related to broadcast. Should the same broadcast monitor for doing CCing to a make a DI for a filmout? I plan on getting the software only version of Avid's DS and would like to use it to do as much finishing myself as I can.

Thanks much for your insights.

I use the JVC TM-H150 CRT for SD correction. However, I highly considered purchasing a Sony LMD model before going with the JVC, which ultimately won on price. I would not hesitate to use the Sony however for the same purposes. The BVM line is obviously the reference standard but probably out of the budget for most. The PVM line seems like a great alternative.

SD Model:
http://www.bhphotovideo.com/c/product/363944-REG/Sony_LMD1410_LMD_1410_14_Inch_Professional_Series.html

HD Model:
http://www.bhphotovideo.com/c/product/494605-REG/Sony_LMD2030W_LMD_2030W_LUMA_Series_20_.html

After a couple of more days researching and reading, I’ve finally got a concept to run by everyone.

The LaCie 324 looks to be a good compromise between price and performance… at least in my price range. It has a HDMI input that I’ll drive via an Intensity card, the ability to separately adjust hue for primaries and secondaries, true 1920x1080 framing (letterboxed, no scaling), the ability to handle 1080p (future proof, I’d only be using 1080i for now) and they advertise 92% NTSC color gamut. What it doesn’t have is separate saturation control for primaries and secondaries, and the ability to view what overscan vs underscan would look like. LaCie has a good rep for displays that faithfully reproduce color with even backlighting and no banding, but has a bad rep for service (roll the dice). I had originally considered the latest Dell, but decided not to go there due to lack of controls for CC, and issues with banding. The 324 is fairly new and I have only been able to find one review of it so far and that was more for photo than video.

I can generate gray scale and color test patterns in FCP for calibration and use HCFR with an i1 probe like any other monitor as the Intensity won’t support an ICC profile and I’d rather have it be wysiwyg anyway, similar to a true broadcast monitor.

I have no illusions that this will perform anywhere near what a good broadcast monitor would, but it should get me as close as I can for the money.

Comments please.

if it is really for CC, i think S-IPS are good even if too slow, since most of time, CC is done on paused video.
The you will see some ghosting when playing fast paced action video, but if you stay focused on color rendition, this shouldn't be too disturbing.
Remember that LCD evaluation are usually done by people testing games, with fast or ultra fast action. That is rarely the case in real life video, except perhaps kung-fu or sci-fi movies.

If it's what you can afford, then it's what you can afford. Do it and don't look back. When you have enough work coming in, you should be able to dump it and go with something more dependable.

Until then just keep 2 thoughts in mind.

Until you know what it's doing in terms of framing (no underscan) try not to capture audio using a boom mounted mic - because you won't be able to monitor whether it's in frame if you don't have an accurate frame line at the monitor.

And be VERY, very careful about mixed lighting situations. Train yourself to notice exterior windows, fluorescent lights, practicals, and anything else that might deviate from the primary light source in your scenes, because your LCD monitor will most likely HIDE the differences between non-standard color temperature lighting - and the person or product that looks warm and attractive on your LCD may well look greenish, or redish or just WRONG ish when you get back to the studio.

Those are the PRIMARY things that proper monitoring helps you avoid.

But if you can't afford to do it now, so be it. Just understand this reality and know you'll need to THINK your way around those issues if you can't actually see them on location.

Good luck.

Bill,

Good advice... Thanks! Those are things I hadn't thought of.

Panasonic 17" Lcd
Matrox mxo
spyder
those are the top 3 choices inthat order or all of the above