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Old February 18th, 2004, 11:31 AM   #1
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External LCDs again... (long)

Hi everyone,

This is my first post here after lurking for about a year and a half, and boy is it a long one... :) I figured this would be the right place to come for ideas/thoughts on something I've been contemplating for quite a while, namely camera mounted external LCD monitors! Here goes...

Being an XL1 user who's well fed up with the poor resolution of the viewfinder LCD I've started to look for an external LCD monitor that has high enough resolution to make manual focusing easier during shoots. My research has turned up tons of different small LCDs for video use, from dirt cheap in-car video monitors to extremely pricey pro-video reference LCDs, but they all seem to share an important weakness; resolution.

Every single one I've looked at has a vertical resolution of just 234 pixels! I'm aware that the XL1's CCDs aren't exactly top notch but they should give a vertical resolution of 400 pixels or so (PAL version). Besides, 234 is not a factor of 576, 288 would have been a more logical value and I think PAL would scale better to that?

Also, most monitors have a horizontal resolution of 960 pixels which is also not optimal as in PAL 4:3 the actual video size is 720x576. Aren't the additional 120 pixels on either side "wasted"? Obviously the signal is scaled up to fill the screen but that can hardly improve the sharpness? To represent a significant improvement in detail over the EVF, which has roughly 180,000 pixels, an external LCD ought to have at least 270.000 pixels (+50%) but 720x234 gives a practical resolution of just 170.000 pixels, actually LESS than the EVF! I'm sure the fact that these monitors have 960 pixels horizontally would make the image look nicer but the upscaling from 720 cannot re-create details that aren't there - doesn't this mean it will be just as hard to see whether focus is crisp or not?

Another potential drawback with all these monitors is that they only accept composite video input. While I'm aware that S-Video is hardly a "professional" format it should offer significantly higher resolution/quality than composite as the luminance and chrominance signals haven't been mixed up. Why don't these monitors have S-Video in!?

As I'm a bit of an electronics hobbyist and a computer geek as well I realised there was another potential option and I'd like to pick your brains on this. Recent improvements in the manufacture of LCDs have made it possible to increase resolution by a factor 4 and at the same time increase the transparency of the LCD substrate itself leading to brighter screens with the same amount of backlight. This technology is called "Polysilicon TFT", or "P-Si" for short, and most LCD manufacturers now offer this type of panels. Although they are more expensive than traditional "Amorphus TFT" (or "A-Si") panels the cost is not prohibitive. For example, NEC make a very nice little 6.3" monitor that has an amazing 1024x768 resolution! And it's pretty bright too...

http://www.review-displays.co.uk/Pro...276bc12-02.htm

..couple that with a LVDS controller such as one of these...

http://www.dicon.co.kr/korean/product/controller.asp

...and you'll have a great little monitor that wipes the floor with anything else out there! The NEC panel can be had for around $350 and a suitable controller for about $150. Add box, power supply (or 12v battery pack) and a bit of work and you'll land somewhere around the $600 mark, actually less than what Nebtek charge for their 6.4"! This kit would give you a theoretical resolution of almost 800.000 pixels and a practical of about 400.000 pixels (720x576 PAL) - or two and a half times that of the 960x234 LCDs! And as if that wasn't enough, the software on the controller card would let you set screen height/width, brightness, contrast, independent colour control and colour temperature control all through its on-screen menus. It would also give you a monitor with two switchable video inputs (composite & S-Video) plus a VGA connector which lets you hook it up to a computer.

The only drawback I can see with this is the slightly lower brightness of the NEC panel compared to for instance the Nebtek (250NIT as opposed to 350NIT) but many of the other "semi-pro" monitors I've looked at have a brightness of 250NIT or even less. It will still be considerably brighter than say a laptop screen which can have a typical brightness as low as 150NIT and with a sun hood it should even be ok outdoors. But I'm also currently in discussion with a company that can replace the CCF backlight with a seriously high-power one which could give a brightness of up to 1300NIT - although this would probably double the price and increase the size/weight of the box. But still... $1200 for a 6.3" 1024x768 LCD with S-Video in, advanced screen controls and a brightness of over 1000NIT sounds like a pretty amazing deal to me...

Now over to you dear forum members, what are your thoughts on this? Insane? Pointless? Perhaps even factually incorrect? I humbly submit myself to your critisism...
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Old February 19th, 2004, 03:24 AM   #2
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You aren't telling us what finished products these things end up in.
You aren't telling us how this relates to the "hybrid" screens that we're seeing on cheap camcorders and PALM computers but "not yet" on the little remote LCD's.

If you want focusing resolution, you're going to get a monochrome CRT viewfinder.

When you look at an external LCD, the biggest problem is the bright glare shining into your eyes. You need a hood to get over that.

The NTSC LCD's I've seen are half resolution (360x240).
Scaling looks horrible on an LCD.
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Old February 19th, 2004, 08:45 AM   #3
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Hi Michael,

Thanks for your input! I'm not sure what these screens are used for but I presume they're designed for computer use as the resolution is XGA standard. After looking through hundreds of datasheets I have yet to find a panel that has native PAL resolution...

By "hybrid" screens I assume you mean the small fold-out screens found on many (cheaper) camcorders. These are rarely larger than 3.5-4 inches and the ones I've seen all have pretty crappy resolution, probably 480x234 or there about.

Sure, a monocrome viewfinder would be nice but a) they're more expensive, b) they can't be used to review material and c) they're no good for checking colours whilst shooting... Being on a tight budget I figured I could kill two birds with one stone by getting a good external LCD screen. I know there is no substitute for a real CRT viewfinder or monitor but an LCD with a resolution of 1024x768 should come pretty close, especially if you take into account the excellent overscan and colour tweaking possibilities this screen would offer. I failed to mention that this panel also has a pretty good contrast ratio of 300:1...

The goal of my research is to find an external LCD with optimal price/performance, NOT a viewfinder.

I'm still curious as to where this 960x234 resolution comes from! In my list of 20 or so external LCDs that I've investigated ALL are 960x234 and ALL accept both PAL and NTSC. This seems to be the norm. Sure, there are a few that are 1440x234 as well but am I not right in thinking that the additional horizontal resolution will give little improvement in picture clarity?

You're right about scaling on LCDs, it does look horrible but don't you agree that scaling up to 1024x768 would look far better than the weird up/down scaling that happens on a 960x234 screen? Ideally I'd like to find a panel with 720x576 pixels but they don't seem to exist!

I would also like to know what you think about the brightness rating of 250NITs, would this be enough for daylight use (with a hood)?
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Old February 19th, 2004, 08:47 AM   #4
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I should also mention that since we're talking about analogue video here scaling will ALWAYS occur, no matter what the resolution of the LCD panel.
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Old February 19th, 2004, 03:06 PM   #5
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The "hybrid" I'm talking about is a new technology that produces brighter images in sunlight.
Its in the published spec for the PD-170 and other consumer cams.
I'm not getting interested in a remote LCD until the hybrids show up in the small TV's.
I just need a remote display for a cam up on a crane or on top of the car etc.
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Old February 19th, 2004, 06:23 PM   #6
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Interesting that camcorders now come with this type of screen, your post prompted me to read up a bit on the Sony PD170 spec:

"A new precision Hybrid LCD panel (Transmissive and Reflective, 211,200 dots) has been adopted allowing clear viewing even in bright sunshine."

Although the use of a transreflective screen is good news this panel is actually 960 x 220 pixels, a far cry from 400 lines of vertical resolution. And it has the same odd 960 pixel horizontal resolution as most external screens. Doesn't anyone have any information as to why so many manufacturers have chosen to use 960 pixels horizontally? Btw - most handheld PCs nowdays have similar transreflective screens but these are usually 320x240 or less. I will have a look around and see what else is on offer in terms of hybrid screens (the actual name for this technology is transreflective) but it would be interesting to hear what people think about the quality of the PD170 screen and screens on other cameras using the same technology. Anyone?

I also read in the spec that

"The DSR-PD170P is equipped with an 180,000-dot LCD black-and-white viewfinder, which provides 500 lines of horizontal resolution"

Which equals 500x360. It would be interesting to know if the fact that this LCD is black & white will increase the apparent resolution of the image or if the only benefit of it being black & white is that it is easier to judge exposure? AFAIK when measuring resolution a pixel is a pixel be the screen b/w or colour - but on a colour screen (possibly b/w as well) each pixel consists of three sub-pixels (RGB). It's also intersting that they (perhaps) try to confuse potential customers by talking about "500 lines of horizontal resolution" when you normally refer to resolution in terms of vertical lines. 360 lines of vertical resolution certainly doesn't sound as impressive. But I'm sure it is immeasurably much better than the EVF on my XL1... :(
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Old February 20th, 2004, 12:52 AM   #7
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320=960/3
(3=RGB)
Resolution is 320x240
I think 640x480 is chopped out of 720x480,
then they select every other other horizontal line
(or average lines)

I believe there is no scaling.
I just want one I can see in the sunlight!
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Old February 20th, 2004, 11:01 AM   #8
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Blimey! That makes perfect sense, thanks Michael. But this swings the resoultion issue even further! Now we're not comparing 960x234 but 320x240 with the higher resolution 1024x768 panel... That's a meager 76.800 pixels compared to almost 800.000, more than a factor 10... This makes me think even a 640x480 pixel panel will offer substantially crisper image, or am I missing something here?

For instance there's a 6.4" 640x480 LG/Philips panel (LP064V1-F) with 500NIT brightness. This should be bright enough to be viewed outdoors without a hood and probably would do fine even in direct sunlight with a hood. It's certainly a lot brighter than any of the 960x234 panels I've seen so far.

And isn't it a bit cheeky by manufacturers to refer to these panels as 960x234 when we're really talking about horizontal RGB sub-pixels!?

Aren't there any PD170 users here who can tell us more about the quality of its transreflective screen? Does it really work in direct sunlight?
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Old February 20th, 2004, 11:04 AM   #9
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Also, re. scaling; As the video input is an analogue signal there is no direct correlation between the resolution of the signal and the resolution of the panel. Only if you're using a digital signal with a 1:1 pixel mapping (like DVI-D or LVDS) will you get a sceen that doesn't scale the image.
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Old February 20th, 2004, 11:28 AM   #10
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Ola,

One question I would put to you regarding external LCD displays is, what are you going to do with all that resolution. When we consider the purpose of using an external LCD display, primarily for framing and composition of the image and for checking focus and exposure, in my experience, the current crop of 320x240 displays with composite video input have served more than adequately. There is a Panasonic 7" LCD monitor which is native 16x9 that is probably the best external LCD I've seen outside of the truly professional Transvideo series. The advantage of these lower-res LCD displays is the cost: typically the Panasonic can be found for under $600 USD; other standard 5.5" LCD monitors for less than $400 USD.

If you're willing to pay for higher resolution, S-video inputs and PAL/NTSC switchability, there are such LCD monitors readily available from Transvideo International. Be sure to check out their 6" Modular Monitor System High-res model, which has a matrix of 756 x 556 pixels. Hope this helps,
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Old February 20th, 2004, 05:38 PM   #11
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As long as we're on the subject,
where are we supposed to buy the "green screen" type monitor that I always see mounted on the steadycams in "how we made the blockbuster" docs we get in our movie DVDs.

I was just looking at one on the "Heartbreakers" DVD.

I saw one on the Transvideo site, but can't find where to buy one.
The Steadicam operator was using one in bright light without a hood.
He looks down, so he doesn't have bright light shining directly in his eyes.
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Old February 21st, 2004, 12:18 AM   #12
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I found it,

Glidecam ECLIPSE 5.5 Green Screen CRT (not LCD) Monitor
http://www.glidecam.com/eclipsemonitor.html
5.4 pounds (without batteries)
and only $$2,295 at Adorama
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Old February 21st, 2004, 07:30 AM   #13
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<<<-- Originally posted by Ola Tuvesson : Doesn't anyone have any information as to why so many manufacturers have chosen to use 960 pixels horizontally? -->>>

FWIW, the Sony PDX-10 (and possibly other Sony cameras with the new touch screens) has a 3.5" LCD panel with a stated resoltion of 1120x220.

Has anybody seen the Sony LMD650 6.5" professional LCD monitor? It looks pretty nice with 640x480 resolution, 4:3/16:9 switchable, s-video input and claims high brightness. It lists for $1,500 however...

http://bssc.sel.sony.com/Professiona...20131&id=63283
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Old February 22nd, 2004, 07:48 AM   #14
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The screen on the PDX-10 is probably listed as 1140x220 but as Michael pointed out that would be if you count the horizontal sub-pixels. Actual horizontal resolution is a third, or 380 pixels.

Chris - The idea with a high resolution screen is to have something that is better for focus control than the built in viewfinder on the XL1. I've recently got the Canon 16x manual lens and although I love it I find it pretty hard to get perfect focus without checking on an external monitor. As I explained in my initial post the XL1 EVF LCD has roughly 180.000 pixels and I'm looking for a screen that is a significant improvement over that - or a minimum of 300.000 pixels.

The Transvideo screen is an odd one, never seen a panel with that resolution. I haven't been able to find any price info so I'm sure it's rediculously expensive - besides at only 140NITs brightness it's far too dark for outdoor use.

The Sony looks more promising and is pretty much exactly what I'm looking for. But $1500? No way. That's more than I paid for the manual lens! I'm also suspicious about the lack of brightness data, the only info they give is this:

The high-brightness and high-contrast performance provided by the 6.5-inch LCD panel offers excellent picture quality under high ambient light conditions, including outdoor use.

I suspect a brightness rating of 350 or 400 NITs (it's sold with a sunshade) but if anyone knows more precisely please let us know!

The Panasonic 7" is too big and since it's a 16:9 panel and low resolution it's not even on my list of possible candidates. It still looks to me as if the best option is to self assemble a panel & controller, probably a 640x480 one (you're right, 1024x768 is probably a bit of a waste). These can be had for around $300, plus another $150 for the controller card, and can easily be mounted in an aluminium case costing less than $50. Sure, it's a bit of work but nothing too complicated and pretty rewarding too considering the high price point for the Sony and similar screens.

Speaking of high prices - did you notice what Sony want for the battery charger? I almost fell over backwards laughing; they're asking over $700... for a battery charger!!! LOL

I'm still very interested in the screen on the PD-170, transreflective may well be the way to go. It would be very nice to hear from someone who's actually used one what they think of it.
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Old April 30th, 2004, 04:21 PM   #15
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Sorry for such a late reply Ola... I just found your thread.

I have found that pulling focus or color on anything other than a High definition monitor is asking for trouble. As Chris mentioned earlier, the majority of LCD monitors used in conjunction with the mini-dv market are for framing and composition purposes. Yes it would be fantastic to have a 940x600 image, and as soon as such a panel becomes available you will probably see me jump on the bandwagon. In the meantime, if your planning to construct your own monitor from the ground up, make sure the LCD module your using is an anti-glare/anti-reflective panel or all the money you spend manufacturing it will be for naught.
If you can look at a monitor and see your reflection, I don't care what the resolution or brightness, your "boned". The moment you take the screen outside it will washout completely and in studio lighting you'll end up with an image that reflects so perfectly that you'll be able to shave by it.
I recommend a Primeview panel... they manufacture the best anti-glare/anti-reflective panels on the market. They may not attain the resolution you require but they offer the highest brightness. You will be able to use your monitor outside and in studio conditions a lot easier, without worrying about using a hood.

If you would care to discuss the Pro's and Con's of monitor manufacturing I can put you in touch with one of our technicians. I'm sure he would be glad to point you in the right direction.

Best Regards,
Rob DuBree
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