In search of the Holy Grail.?.

TodWulff

(Trying to arrive at the right 'formula' for recommending HD vs. SD.)

Good day all.

Framing dialogue:
Are any of the professionals here aware of any 'formulas' that can be used to objectify if migrating from an SD based system to an HD based system would be of value given content, source, Frame Rate, Scan Mode, screen size, aspect ratio, (lighting?,) and viewing angle/distance?

I manage a team of systems integrators for aircraft - from small Corporate/Business jets to large Air-Transport category aircraft. We have been holding off on going down the path of pushing HD as, until recently, there hasn't been a set of hardware, which we could legally install, that maintained HD interconnect integrity from the source, thru the switching/distribution, and finally to the glass. Until very recently, if we installed HD source equipment, to be presented on HD glass, we would have had to install scan converters, analog NTSC switching/control, etc., except in the very simplest implementations of a 'system'.

That is changing now and determining if there is an empirical method of quantifying HD's value, in the interests of being able to objectively assert that a given scenario is a candidate for an HD system or if we could save the client some substantive monies by recommending that they stick with an SD system (, feeling confident in asserting that there would be no tangible viewing benefit from said upgrade), would be a wicked-good sales tool, and one that I can feel I've maintained my integrity in utilizing.

I am not a 'critical viewer' thus I don't objectively know that I could tell the difference between 720 to 1080, but I do have 20/20 vision, and know when something looks "excellent", "good/adequate", "fair", and "poor" (<<< based on my own personal opinion/experience... )

...

Now I know that there will always be a pilar of subjectivity that will be built upon when dealing with us homosapiens, but I am looking for some guidance that will help me to arrive at a good recommendation for the majority of the viewing audience, the majority of the time.

Any help would be extremely valuable, and greatly appreciated.!. TIA.

-t

Lee Stewart

Hi and welcome to HDF

According to popular belief, the components that make up an image in order of importance are:

1. Contrast Ratio - the difference between the blackest black and the whitest white. If properly done - give the appearance of depth to the image

2. Accuracy of Gray Scale - is black really black and white really white? This is based on a Black Body Curve:



3. Color Saturation - color resolution is the weakest part of both an SD and an HD signal. Color Banding can result if saturation is too high

4. Resolution

Hope this helps.

TodWulff

Hey Lee! Thank you for the warm welcome, the quick response, and the useful information.

(fyi, I did a minor edit that changed the context of my query: from 'HD/SD-based display' to 'HD/SD-based system'... I don't know that said change is material, wrt your reply...)

I understand the content of your guidance, I believe. I understand you to have asserted that the display's quality of the image processing and presentation on the glass (wrt Contrast, Color Accuracy, and Color Saturation) out weighs the value of resolution.

I guess that what I am looking for is a tool that could allow me to make an informed decision/recommendation in any of the following scenarios (please assume that the HD and SD versions of the display have comparable image processing and presentation (again, wrt Contrast, Color Accuracy, and Color Saturation) capabilities:

• Given a wall-mounted 15" 4:3 display, mounted at a height consistent with a seated-adult's Line-Of-Sight, at a distance of 48" from the viewer's face, would the majority of viewers be able to tell the difference between a HD display vs. a SD display?
  
• Given a wall-mounted 32" 16:9 display, mounted at a height consistent with a standing adult's Line-Of-Sight, at a distance of ~96" from seated viewers, would the majority of viewers be able to tell the difference between a HD display vs. a SD display? What if the viewers were seated closer to this display? What if the viewers were seated farther away?
  
• Given a seat-back mounted 8" 16:9 display, mounted in front of the user's face at a distance of ~22", would the majority of viewers be able to tell the difference between a HD display vs. a SD display?
  
• Given an arm-mounted 10" 4:3 display, articulated to a distance of 16" from the viewer's face, would the majority of viewers be able to tell the difference between a HD display vs. a SD display?

There are a limited # of Cabin Entertainment System OEMs that have received FAA authority to manufacture products for installation into aircraft. Some of these OEMs are leading the charge head-long into the HD realm, while others are taking a more deliberate pace.

Now that the HD/Blu-ray DVD situation has firmed up, I find that I am struggling with making recommendations to my client base. Maybe I'll have to get a hand-full of the installs under my belt before I can start to speak to same in an informed fashion.?.

It is tough to weed out the marketing hype from the legit foundational information. I was hoping that there were some existing tools that I could employ the use of helping me to help my customers make an informed and intelligent choice...

What spurred this was during a visit by one of my vendors, a week or two ago, during which I was told that there was 'this website where you could enter the size of the display and the viewing distance, and that it would tell you if HD would be noticeable or not...'. I have searched high and low and have came up empty-handed. My quest continues...

EDIT: For those that are curious, the following is a much abbreviated list of OEMs that produce In-Flight-Entertainment (IFE) equipment (url's domain name follows the hyphen - add the www dot and the dot com...):

• Rosen Aviation - rosenaviation
• Flight Display Systems - flightdisplaysystems
• Thales Group - thalesgroup
• Panasonic Avionics Corp - panasonic (dot aero)
• IMS - imsconsultants
• Row44 - row44
• Lumexis - lumexis
• Mid Continent Controls - midcontinentcontrols
• Audio International - audiointl
• Alto Aviation - altoaviation
• HeadsUp Technologies - heads-up
• LiveTV - livetv (dot net)
• Rockwell Collins - rockwellcollins
• Honeywell - honeywell
• And Many Others...

TodWulff

Here is some info that might prove useful.?.

Lee Stewart

TodWulff

Thanks, Lee. That is extremely helpful.

As a side note, I appreciate the 'technical'/physiological reasoning behind why the #s in the graphs are what they are, as described here:

URL = webvision.med.utah DOT edu/KallSpatial DOT html

-t

Lee Stewart

My pleasure.

I was re-reading your post above the chart I posted.

The key to resolution versus distance = the closer you are, the more noticable HD will be over SD. That is a good rule of thumb to follow. At the same time, I am not sure they even make HD displays that are 10" or smaller (1920x1080).