Tips on aspect ratios – HD vs SD

It is inevitable that there will always be new electronics and new technology which means more format options and confusion for many consumers. While High Definition has been around for decades it is only now starting to become the prevailing production mode. As consumers scramble to figure out what kind of monitor they should purchase and clients can’t figure out how they should have their production shot, it is important to clarify the terms in question.

Wide-screen vs. “Standard”

It is now common knowledge that major retailers are only selling wide-screen TV’s/monitors now. The “standard” monitors have a 4 by 3 aspect ratio, giving the picture an almost square shape only slightly wider than tall. Wide-screens have a 16 by 9 aspect ratio, the width and shape of most movie screens. “Letter Box” is a term referring to a 16:9 picture inset inside a 4:3 screen.

Since all new TV’s are going to be wide-screen, we believe it makes sense to shoot new productions in wide-screen. Some clients have hesitated doing this for different reasons. Some are comfortable with the 4:3 aspect ratio and fear other people won’t have wide-screen TV’s and they do not like the look of letterboxing. This opinion is dying as fast as the sales of 4:3 TV’s. Every public place with a screen is 16:9 these days and people are already so used to letterboxing on 4:3 screens that you see a letterbox-type frame around ads of all shapes and sizes now, making the ad look more “movie-esque” and at the same time providing convenient space above and below the picture for graphics.

Squeezed vs. Stretched

Sometimes you may see video on a wide screen that looks stretched – everyone looks fat – not how most people want to be photographed. This occurs when something shot in 4:3 is shown on a wide-screen – a very important reason to film in 16:9. This way, the picture will look good on wide-screen monitors and if it is shown on a 4:3 TV, it will be letterboxed, not “squeezed.” The only time you may see a squeezed picture is when you film in wide-screen and then display that image directly on a 4:3 monitor. Anything that has been edited properly will automatically format in a letterbox on a 4:3 monitor and not look “squeezed.” While we may all be on diets, a squeezed picture is not flattering either!

Letterboxing vs. Cropping

If you film a production in wide-screen you can edit it so that it will be shown in letterbox on a 4:3 screen as noted earlier. Or you can also crop the image so that it fills a 4:3 frame. When filming something that might be shown in 4:3, it is important to frame the essential action within the 4:3 frame. Most cameras have frame markers in the viewfinder, but it may be necessary to put some thin pieces of tape on a monitor the client is looking at to signify the 4:3 cut-off.

What are the options for a production that is utilizing existing 4:3 footage? Of course there are decades of valuable footage already shot in 4:3 and the options are not to throw that footage away or to stretch it. You can design a letterbox frame for this footage using either a graphic border or extending the background image digitally. You can also layer footage into smaller frames in a montage effect. When combining existing 4:3 footage with new wide-screen footage, we have often used the new wide-screen shots as a background image with the 4:3 shots inset. We used this to great effect on the City of Arlington video. We had a lot of existing standard definition 4:3 shots donated to us that we integrated with our new wide-screen HD footage.

High Definition vs. Standard Definition

Wide-screen does NOT automatically mean HD. High Definition relates to the greater number of lines of resolution of the image and not necessarily the shape. Standard Defintion can be filmed in either 4:3 or 16:9 and High Definition can be displayed wide or it can be cropped or letterboxed. When filming television ads, we film in High Definition regardless, to give the highest image quality. Then we often edit a High Definition master and standard definition master for stations that can broadcast both. Not every TV station currently has the capability to broadcast ads in HD, but more and more do. The HD versions are broadcast to people that have HD service and the SD version goes out to everyone else.

1080 vs. 720 HD

High Definition can have either 1080 or 720 lines of resolution. Our HVX-200 cameras can shoot either 1080 or 720, yet many of the most popular HD cameras such as the VariCam can only shoot 720. Down converted to standard definition, 1080 and 720 will look the same — the only way you can see a difference is if you compare 720 and 1080 HD on a 1080 screen that is over 50 inches.

p vs. i

Many people wonder what the “p” means in 1080p or 720p. “P” stands for progressive scan vs. “i” or interlaced. In progressive scan, all the even and odd lines of resolution in a frame are scanned sequentially and at the same time to give the footage a smoother image with more detail, sometimes described as “film look.” With interlaced, first the odd lines of resolution are scanned, followed by the even lines in twice the amount of time as progressive. This looks fine a cathode ray type of monitor, but on a computer monitor or digital screen, there sometimes appears to be a “flicker effect.” There are much more detailed, precise definitions available but the intent here is to be concise and not too confusing.

Digital vs. Analog

Progressive scan, wide screen and High Definition are all only available with with a digital signal. In February 2009, all tv signals will be digital and it will be necessary to either have a digital TV or to have an analog to digital converter (the government will be providing coupons for those unable to afford them). Digital signals do not have ghosting and do not become weaker or stronger depending on the circumstances – you either have an image or you do not. There is also a greater consistency of color and many other features such as surround sound, multiple language audio and text services in addition to much higher picture quality in the same or less bandwidth as analog.

Now that you have decided you want a new digital, wide screen tv (preferably HD) what kind should you get? There are brand names and sizes to consider and here consumers will go with what brands they are familiar with and sizes that work for their space and budget limitations. They will also choose between 720 vs. 1080, but keep in mind that the differences betwen 720 and 1080 are not discernable on screens under 50 inches.

DLP, Plasma and LCD

DLP is the rear-screen projection TV using “the thousands of tiny mirrors” we hear about in the Texas Instruments commercials. While the picture is great, these systems come in very large screens, large in depth and also very heavy, so they are not at all portable and you need more space than with a flat screen. Also, if you are not at eye level with the screen, it can look dark. Plasmas and LCD’s are flat screens, so they are light and can literally mount on your wall like a picture. The drawback to plasma screens is that they are made of glass and thus are highly reflective. In a room with lots of windows or lamps at the same angle as the screen, there are tons of reflections. LCD’s don’t have this problem, but like DLP’s they also must be viewed at the proper angle for optimal results. Prices between the three formats range widely based on brand, size, retailer, and day of the week.

What else do you need to see HD besides buying an HD TV? An HD TV does not automatically show you images in HD. In fact, you will notice that analog TV signals look much worse on an HD TV than an analog TV. Digital signals will look very nice, but you will need to make sure your cable, satellite or fiber provider has you equipped with HD service to see programs in full HD. Right now only certain networks and cable broadcast in HD; soon more and more will. Some of the HD broadcasts will come bundled into your plan and other premium HD networks may cost extra. To view DVD’s in HD you will need an HD TV, and HD DVD and an HD DVD player. While there was a strong fight between competing HD DVD formats it appears that Blu-Ray has won that fight, so that is one less decision you have to agonize over. The Internet can already broadcast High Definition and in time should become the predominant HD delivery system.