Tuesday, June 4, 2013

Monitors, damn monitors.

Shifting gears back to the Nordhavn, a while back I selected the Simrad NSO black box navigation system, but deferred on the selection of monitors.  Little did I realize what a time consuming and frustrating experience would be provided by the seemingly simple exercise of selecting monitors.

First, lets take a look at what I'm trying to accomplish.  I want four monitors, one for each of the two NSO processors, and one for each of the two computers.  And I want them as large as will fit.  Furthermore, I want all the monitors to be identical so I can interchange what's displayed where in case I change my mind about the arrangement of displayed information, and for backup/redundancy in case of failures.  All this rolls up to four 19" non-wide screen monitors.  Sounds simple, right?  If only it were....

The next major decision is whether to use "marine" monitors or standard commercial monitors.  The marine monitors have a few features that tailor them to the application, some of which I care about and some I don't.  The features and their relevance to me are:

  • Waterproof.  These four monitors are going in the pilot house, so there is no need for waterproof monitors.  I don't care at all about this.
  • DC-powered.  This has some attraction since it theoretically reduced power consumption by eliminating the inverter losses to run off AC.  Underway the engine generates plenty of power so this only matters when running the displays at anchor.  DC power brings a slight advantage, but it's not a deal breaker.
  • Designed for panel mounting.  The marine monitors are designed to be panel mounted and come with all the necessary hardware.  This is a slight advantage, but the boat yard is quite good at mounting standard monitors so this doesn't really matter.
  • Lots of different inputs.  Each monitor will be connected to exactly one device via DVI, so I don't care about this feature at all.
  • Dim-to-black control knob.  This offers convenience when dimming the monitors for night operation, and dimming all the way to black is handy.  But a button menu to dim is OK too if it's simple, and theatrical gels can be used over the screens to dim them more if needed.  So the dimmer knob is a slight convenience, but not a deal breaker.
So the marine monitors offer a few advantages, but none of them are deal breakers, so the question becomes "at what cost?"  And that's the real kicker.  The marine monitors cost between 30x and 60x the cost of a commercial monitor.  Yes, that's right.  A commercial monitor costs about $150, where a marine monitor costs anywhere from $4500 to $9000 each.  That $18,000 to $36,000 just for four monitors.  What would you do?  Probably the same thing as me - get the commercial monitors and live with the differences.  Then it's just a matter of picking which brand/model to use.

Backtracking a little, the NSO bundle that I bought included a 17" marine monitor, and using it I came across an interesting issue.  I'll apologize in advance for the deeper than usual tech dive.

All monitors contain a certain number of pixels arranged in a grid.  The computer lights each one up to draw whatever image is required.  Pixels are square so the computer knows how to properly draw circles, squares, etc.  Monitors all have a "native resolution" which is simply the number of pixels horizontally and vertically on the screen.  Normally the computer matches it's output to the monitors dimensions giving the clearest images.  But monitors can also handle smaller input dimensions and upscale the image to fit the screen.  You with me so far?  We are almost there.

When scaling an image, you need to consider it's aspect ratio.  An image that has 4:3 aspect ratio has 4 horizontal pixels for every 3 vertical pixels.  4:3 is the ratio for old-style TV. 16:9 is the ratio for wide screen TV.  All this matters because when you scale a graphics image.  You need to maintain the aspect ratio.  If you don't, the image distorts.  Squares are no longer square, and circles are no longer round.  On your TV you have probably seen "banding" at one time or another.  Those are black bands either above and below, or on either side of the image.  This happens when you scale an image to fit a screen that is a different aspect ration than the image itself.  You have probably also experienced the fat-ass syndrome where people on screen, especially towards the outer edges of the screen, seem to have particularly wide stances.  This happens when you do not preserve the original image's aspect ratio and instead stretch it to fill the screen and it's aspect ratio.  You can sort of get away with this for video, but it's a big no-no for graphics where squares need to be square and circles need to be round.

OK, with that tutorial out of the way, let's go back to the 17" marine monitor that came with the NSO.  The monitor has a resolution of 1280x1024 which is 5:4 aspect ratio.  It turns out, but the way, that 100% of the 17" and 19" non-widescreen monitors on the market are 1280x1024, 5:4 ratio.  The rub here is that the NSO outputs 1024x768 which is 4:3 ratio.  No problem, right?  The monitor should scale the input signal of 1024x768 to fit the monitors 1280x1024 pixel grid.  Maintaining aspect ratio, the image would scale to 1280x960, leaving a top and bottom black band on the screen.

Well, not with this monitor.  Instead it stretches the image to fit the full 1280x1024 screen thereby converting the aspect ratio from 4:3 to 5:4 and turning all the circles into ovals.  WTF?  Instead of range rings you have range ovals.  WTF? After a little back and forth with the manufacturer I concluded there was a reason why this "marine" monitor only cost $2000 where the others cost $4000.  And it turns out this was just the tip of the ice berg.

Having rejected expensive marine monitors because of their ridiculous cost, off I went to research commercial monitors.  I had a number of leads based on monitors used on other boats and web research.  I also had a clear preference for LED monitors.  LED back lighting, as opposed to florescent back lighting, tends to be brighter and lower power.  The first challenge was finding a non-wide screen monitor.  Nearly all monitors are now wide screen.  It appears that the convergence of computers and video has indeed taken place.  But most major vendors still have a 19" non-widescreen monitor.  My first two pics were an LG and a Viewsonic.  I bought both, figuring that I'd just return whichever one lost the comparison.

Long story short, both monitors, along with the original "marine"monitor and two more subsequently purchased ALL distort the NSO video signal when scaling it to display on the monitor.  Now a little more attuned to the issue, I rejected two or three additional manufacturers based on their manuals and/or tech support feedback.  That's seven manufacturers all of whom incorrectly scale input images.  At this point, I give up, and conclude that all the current LED monitors of this class improperly scale images.  So what's next?

A fellow Nordhavn owner much more skilled in google searching that me discovered a device by a company called Gefen that scales VGA input signals to match various DVI output signals.  It looked promising, so I bought one.  The good news is that it does indeed scale the input signal while maintaining aspect ratio.  But the bad news is that the video quality is poor.  Edge definition is fuzzy and the overall appearance lacks sharpness.

It seems I can live with one of two issues; distorted graphics shapes, or overall fuzzy images.  hummm?

And what about those expensive "marine" monitors?  Do they scale images properly?  Reading their manuals, it would appear some have an option to "maintain aspect ratio" so I think the answer is yes, but is it worth 30x the cost?  For me, the answer is No.  I just can't bring myself to pay such a "yacht" price for something, and I have a problem in principal rewarding any company with a purchase who has such business practices.  There are plenty of yachties with deep, wide open wallets, but I choose not to be one of them.  I'm happy to pay for value, but come on, 30x is ridiculous.

Are you dizzy yet?  Well, welcome to my world.  It seems ridiculous that this is so complicated, but it is.  That said, in fairness I have to admit that a big part of this is due to the Simrad NSO which is only able to output 1024x768 which does not match current monitor technology.  Furuno, and perhaps others, output 1280x1024 which happens to match the monitors and hence does not exhibit this problem.

The bottom line is that I have 3 choices:

  1. Live with the distorted graphics from commercial monitors
  2. Use the Gefen scaler to preserve aspect ratio, but at the expense of somewhat fuzzy graphics.
  3. Spend a King's Ransom on a marine monitor which may or may not work.
The plan is to pursue #1 and live with the distortion.  If I can't get used to that, then I can always add the Gefen scalers and do #2.  I figure I'll acclimate to the distortion easier than overall fuzzy images, but time will tell.

The final choice is a Samsung S19C450BR.  Partly because it's one of the monitors that I haven't returned yet, but more because it dims closer to zero than the others.  It also looks like it will be easier to mount than others, and at 16W it's pretty energy efficient.

Link to next article on monitors


  1. WOW! Who would have thought it would get that involved. Good thing is that you have done your homework first, and not after the fact. Can't wait to hear how this turns out. Jim E.

  2. I think the most frustrating part is that there is no good solution. Maybe Simrad will work a miracle and start supporting 1280x1024 to match all the monitors out there.

  3. Wouldn't another option be to revisit Furuno over Simrad? I would imagine it would be painful to back track at this point, but perhaps its worth considering......BTW love the N-build process your letting us follow. I have a GB42 classic and the next boat will be N-47 a few years down the line.....Thank you! Charlie Hodge

  4. Charlie,

    I did consider that, but only briefly. In all other ways I prefer the Simrad system over Furuno. Just as an example, updating the charts on my NN3D system resulted in 8 crashes during the overall process. Very worst case I could use one of the expensive monitors and still be ahead of the game.

  5. Peter: In the end, this comes down to Simrad; they should support the multiple video resolutions. This is basic to all devices in the PC world, and native to nearly any video driver circuit Simrad would use in the NSO (or other black box). In short, it seems that they are suppressing that feature, presumably to protect their own marine monitor sales. I would also add a short word in defense of the marine monitor providers and their pricing. As I work in product management in aviation, and as marine electronics share an important similarity, I can tell you that it is the economies of scale, or lack thereof, that create a large aspect of the pricing disparity between commercial monitors and marine monitors. I'd wager that the volumes are, indeed, at least 30x different; probably much more. The non-recurring engineering (NRE) involved in design, development, testing, tooling, certification, etc. have a much smaller base over which to amortize these costs. Granted, I do agree that there exists situational pricing in marine electronics (market price inflation), but I suspect that their cost-basis is significantly higher then, say, Dell, or Viewsonic. Further, the constant cycle of product revision, and the ever present challenge of component obsolescence necessitating advanced lifetime-buys (e.g., LCD panels have a typical manufacturing lifecycle of 12 months or less), reduces the amortization base even further while simultaneously increasing costs. So, I agree that marine monitor pricing is "market driven" to a higher level, but I don't think it's as simple as a $150 monitor vs. a $4,500 monitor.

    BTW, have you checked out the following:


    Industrial grade monitors may get you the ruggedized design characteristics desirable in the marine environment, but at a much lower price that a marine monitor.

    Anyway, all the best to you, Mate. Keep these build-process emails coming!


  6. Hi Ced,

    You make some good points, and I agree in many ways. There definitely is an argument that says Simrad should support higher resolutions, especially the one that matches all the current market monitors. I'm currently pursuing this with them, but am not optimistic that I'll make any headway. But you never know, I did get them to support C-map, right :-)

    At the same time, I don't think there is any excuse for a computer monitor to scale without preserving aspect ratio. A TV is one thing, but a computer monitor needs to be able to correctly display graphics. All these monitors claim to support all the historic resolutions up to their native 1280x1024. What they don't tell you is that those resolutions will be displayed in a way that somewhat, in some way looks like the original.

    As for costs, volume economics, etc., I partially agree. I would definitely be willing to pay more for a proper panel mount, dim-to-zero, DC powered monitor that scales graphics properly. I'd be willing to pay 10x more for such a specialty monitor, i.e. $1500. I agree this is a much lower volume market and that will both increase costs and require higher margins for the vendors. But all these monitors still benefit significantly from the volume economics of the components that go into the monitors. I expect all the underlying screens are from the same root suppliers as the commercial monitors. And I expect the same is true for all the video chips in the controllers, and perhaps even the whole controller. Yes, they buy fewer of them, but the underlying parts costs and integration levels have been driven down thanks to the volume consumers and that largely flows through to the low volume markets.

    So, if for a low volume variation of a monitor you allow for 2X the cost of goods, and assume an 80% gross margin (i.e. 5x markup) is needed to build a business at low volume, that gets you to a selling price of $1500.

    But I fear that this shared underlying technology is actually the root of the problem. To what ever extent the monitors are using the same controllers, they will also share the same deficiencies. My guess is that the current generation of controllers has punted on implementing proper scaling since in the computer market, as you point out, you simply adjust the computer to match the screen and there is little need to have the screen match the computer.

    Last, thanks for the pointers to the industrial monitors. I've looked into one or two of those, but not all. I'm so burned out on this right now that I can't bear to look at another spec sheet, but maybe in a few days I'll have enough renewed energy to make another pass through.

  7. OK, I took another swing at the industrial monitors. Here's what I found:

    http://www.marinecomp.com/Radiant%2017.htm - Talked to them on the phone and confirmed that the monitor converts (distorts) the aspect ration when scaling.

    http://www.vartechsystems.com/products/ - Looked into them before and couldn't get a coherent answer from them. Sent another follow up inquiry.

    http://www.advantech.com/products/19-Display/sub_1-2MLC1W.aspx - No manuals available online. Typically a quick look at the manual will tell if it works correctly. If there is no menu option to preserve aspect ratio then I know what the results will be.

    http://ab.rockwellautomation.com/Industrial-Monitors/Standard-Industrial-Monitors - Web site doesn't work when trying to access tech info.

    http://www.hopeindustrial.com/panel_mount_monitors.htm - Control buttons are all on the back side of the display. This is common for many industrial monitors intended to be used in Kiosks and other applications where you don't want anyone fussing with settings. Won't work in a marine application where you need to at least be able to adjust brightness from the front panel.

    Speaking of menus for controlling these monitors, I have found a number that list some form of aspect ratio control in their menus, and that's what led me to purchase at least two of the monitors that I've tested. But in each I missed a critical foot note. The aspect ratio control is only enabled for the widescreen variants of the monitor. I find it very puzzling that the widescreen monitors can scale the smaller images correctly, but the 5:4 monitors cannot.

  8. Peter, I'm surprised that the Gefen box had such crappy output as they are supposed to be all about image quality. Did you call their support and/or try another of the same box? Is it possible you got one that was defective?


  9. Hi Adam, I'm not sure what to make of the Gefen. First, let me say that I can be pretty pick about this stuff. For example, I find the image objectionable running a monitor with a video extension cable. It's certainly possible that it was defective, but I think a big chunk of the problem is just the interpolation and dithering involved in rescaling an image. I say this because the one monitor that I have/had that did scale the image (a Samsung wide screen monitor) had a noticeably less sharp image when compared to a 1:1 display of the same image. Another contributing factor is that video and photographs, or more accurately our eyes/brains while viewing them, are very forgiving of image manipulation. Graphics are a whole other story and your eye picks out imperfections much easier. At least that's how I respond to it.

    Anyway, there is another twist to the whole story that rendered moot the Gefen and the whole scaling issue, but out of courtesy to certain third parties I have to wait a bit before telling it. I don't expect it will be more than a few weeks.


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