There is a lot of discussion about High Definition (HD) video these days and this information can be as confusing to the professional as it can be to the consumer.  If you are interested in choosing an HD package it is necessary to have a basic understanding about HD formats prior to choosing a videographer.

Introduction

What do 1080i, 1080p, 720p, 24p, 60i, 60p, and 30p have in common?  The answer is that they are all part of different HD standards.  Like most other products in life, all HD is not created equal.  In addition to the multitude of finishing formats available there are even more origination formats!  While the final format of your wedding video is important, any videographer shooting on any number of different origination mediums is capable of generating any of the most popular HD formats.  In the paragraphs that follow I will attempt to shed some light on the issues surrounding HD footage acquisition, editing, and finishing without a lot of tech-speak or boring descriptions.  Who knows if I will be successful.

Finishing Formats

Now, I know I said that the origination format was just as important as the finishing format, but lets start at the end.  Assuming the goal is for you to walk away from your videographer with a Blue-ray Disc containing your HD video production it is important to understand a little about valid Blue-ray formats.  Above you'll notice that I listed several number and letter combinations.  If you were to walk into a big box retailer selling HD televisions, you would no doubt see one of the following:

• 720p
• 1080i
• 1080p

The number here (720 or 1080) indicates how many lines of resolution, vertically, the set is capable of displaying.  For a television set 1080 is obviously better than 720 because the resolution is significantly higher (this is not the case in footage acquisition as we will see later).  As far as the 'p' vs 'i' goes...well, that is a little more technical conversation.  the 'p' stands for progressive and the 'i' stands for interlaced.  If you've ever wondered why films (movies, i.e. Terminator, etc.) look different than the evening news or reality shows (i.e. Frontline, American Idol) then you've partially, without knowing it, wondered what the difference between progressive and interlaced is.  While the line between the two has gotten muddier in recent years with the advent of more advanced cameras, the interlaced technology goes back to the earliest days of television in which the receptors in the screen could not "reset" quickly enough to display the next frame of the video.  The way engineers got around this issue was by drawing every other line of the image at once (the odd lines) and then going back and drawing the remaining lines (the even lines).  Thus the video image was not made up of individual frames but was rather a collection of alternating lines.  This resulted in what subconsciously became known by television viewers as "the T.V. Look".  Interlaced footage has a distinct look as opposed to progressive footage, which is what film capture entails;  film is a collection of still pictures, independently captured with no relation to the frame before it or behind it.  Each frame in progressive scan video operates on the same theory.

With the advent of HD progressive scan images are generally thought to be more appealing to the eye although during fast motion events, such as car races or sporting matches, progressive scan video has a byproduct called 'strobing'.  This effect can be noticed in the background of the image where the contents of the scene are changing rapidly.  This effect is distracting for many people.  Interlaced footage, however, has problems of its own.  While not as noticeable, interlaced footage shot in the same fast motion environment will cause the background of the scene to separate and loose a tremendous amount of detail.

Most professionals working in the video industry, especially those coming from a creative or film background, have been longing for the progressive scan qualities of HD (and of higher end SD cameras such as those used by Orchid Studio).  In fact, everything Orchid Studio shoots, unless specifically requested by the client, is done in progressive mode.  We have used progressive scan cameras since 2004 even in our SD weddings.

Are you still with me?  I hope so.  You may be asleep but we have a ways to go yet.  Above in my introduction you also noticed smaller numbers; 24, 30, and 60.  Obviously these aren't the number of lines of resolution, that would be a very poor image indeed.  If this number has a 'p' behind it then it indicates how many frames per second there are in the video images.  Generally, for things like weddings and graduations, 30 frames is preferable to most viewers over 24 frames per second.  This is due to the fact that 24 frames per second is generally associated with a film look and, when "normal everyday people" see themselves shot like this they generally find it somewhat distracting.  30p is a good intermediate between 24p and 60i.  If you are asking what 60i is then you're in luck because I haven't forgotten that I haven't explained it yet.  Remember when I said that television images used to be interlaced; even lines 'drawn' on the screen then 'odd' lines drawn, and on, and on?  This video look actually doesn't speak the "frame" language; interlaced video uses "fields" instead because technically there are no frames, only fields and it takes 2 fields to make a frame (even though technically that can't be called a frame). So 60i is similar to 30p but has the look of traditional video as opposed to a slightly cinematic look.  Don't be fooled by the higher number here, in the vast majority of cases 30p will offer a superior image (not to mention will be much easier to edit and apply effects to by the editor).

Acquisition Formats

Now that that is out of the way, and hopefully you have in your mind that a 1080 30p final project is ideal, I want to tell you that all of what I just told you is contingent on a decent acquisition format.  There are a number of ways to capture HD footage available to the videographer.  What most event videographers have been using up to this point is a format called HDV.  HDV is an enhanced consumer grade (prosumer) HD format that introduces a considerable amount of compression artifacts.  HDV is a tape based format (and actually records on the same mini-dv tape as home video cameras).  Once back in the editing studio, the editor is required to capture all of the footage shot into the editing system.  Aside from being a non-professional video format that, because of the Long GOP formatting, requires additional editing system power to actually edit, the editor must spend this time digitizing footage.  For example, if your editing package includes 15 hours of editing and there are 7 hours of video footage, then it will take 7 hours to digitize this footage and thus your editing time is effectively cut almost in half.

The next step toward the professional world are what are known as H.264 codecs.  These formats offer an intermediary between professional formats, such as DVCPRO-HD.  They offer very good image quality for such a high compression rate however they suffer from some of the same issues that HDV does.  While most cameras shooting in a variation of the H.264 standard are tapeless (meaning no digitization of footage after shooting), they generally record onto a media such as SD cards or other low bitrate media. There are several reasons for this.  First of all, this type of media is cheap and readily available.  Secondly, the high compression rate, which makes editing the video footage more painstaking, also allows the videographer to get a fairly high quality result with a relatively minimal investment.  In other words, one can get into the HD game for cheap.  H.264, while a great finishing format (and in fact is the format of blue-ray discs), suffers from similar compression issues as HDV does.

Often times people think 'digital' and assume that everything digital is lossless from generation to generation.  Nothing could be further from the truth!  Once  compression algorithms (and therefore compression artifacts) are introduced to video they cannot be removed!  When compressed footage is edited, the compression artifacts introduced in the original acquisition are still there.  When that footage is then rendered, as is required to be complete and burned to a media (i.e. blue-ray disc), the compression artifacts of the finishing medium will then be added on top of the original compression artifacts, thereby accentuating the effects of this original compression.  In order for compression to work to our advantage, the compression rate of the acquisition format must be lower than that of the finishing format.  This is not the case with HDV, H.264, or AVCHD (another popular compression technique).  It is the case, however, with DVCPRO-HD and XDCAM.  You will find one of these two formats in nearly all of the television stations and broadcast companies in the country.  They have adopted these professional level formats because they edit easier, have a better picture quality, and offer a level of overall production quality that is unmatched by the prosumer formatted cameras.  Orchid Studio is also dedicated to a professional level of video production and, as such, has adopted the Panasonic DVCPRO-HD workflow with the tapeless P2 card system.

The biggest drawback to these high end formats, however, is the cost; and this is why many videographers have chosen less professional systems.  Because DVCPRO-HD has a higher bitrate it cannot be acquired onto consumer level memory cards; they are just not fast enough to sustain a transfer rate conducive to recording DVCPRO-HD footage.  Instead, our higher end cameras use what are known as P2 cards to record video.  The cost of these, as you can see if you followed the link, is significantly higher than that of standard run-of-the-mill memory cards.  The storage requirements are also much higher in these formats.  One 64 GB P2 card (over $2000) can record just over one hour of footage!  A standard 2 camera wedding, for example, will take nearly 500 GB of hard drive space to store! Add this to the higher initial investment of cameras and memory cards and you have a cost structure and overhead base that is not nearly as lucrative for most videographers.  At Orchid Studio we pride ourselves on providing professional production service at competitive prices. We do this by, quite honestly, cutting into our margin.

Cameras: What you need to know

Now that we (hopefully) understand something about how video footage is captured, it is important to understand how cameras see the world.  If you can still remember when I said that 1080 lines were not necessarily better than 720 lines in terms of image capture then you are probably doing better than most.  Here is where I'll get into that and more.

As with to many things in life video production also has trade offs.  Videographers who invest in lower end HDV systems can easily advertise they shoot in 1080p, even though they technically don't.  The reason they technically don't has to do with physics and the CCD (or CMOS) size.  90% of videographers shooting weddings are shooting on cameras with 1/3 inch CCD sensors.  The cost increase between 1/3" and 1/2" CCD cameras can be cost prohibitive, even to the most well meaning video company.  Many people shooting on 1/2" sensor cameras will tell you that they're camera, because the sensor is bigger, does a better job at capturing footage in low light situations.  While traditionally true, recent advances in this area make newer 1/3" sensor cameras just as good as 1/2" sensor cameras in low light situations.  Where 1/2" sensor cameras do perform better than 1/3" sensor cameras is in resolution.  Physically it is impossible to fit 1080 lines of pixels on a 1/3" CCD.  You can fit 1080 lines on a CMOS chip but CMOS chips this size suffer from many image quality and technical issues that don't effect the CCD.  Additionally, there is currently only one 1/3" camera on the market that uses 3 CMOS chips to capture images; the rest only use a single CMOS chip.  Conversely, almost all of the 1/3" CCD cameras on the market today that would be used for event videography are using 3 CCD chips.

Because most cameras on the market today use 1/3" CCDs as the image sensor, and since it is impossible to fit 1080 lines of resolution on this sensor, how, then, is the camera capturing a 1080 line image?  The answer is through a technique called pixel shifting.  Pixel shifting is a type of in-camera increase of resolution (known as upresing) in which some pixels are duplicated or used as the basis for a calculation for the camera to form new pixels where there were none before based on the pixels around it.

The Bottom Line

There are many factors that influence the quality of HD video.  You can use a 1/3" CMOS camera with a native resollution of 1920x1080 ("full" HD) and, when using a highly compressed and low bandwidth format such as HDV, end up with an image quality that is inferior to one shot on on a camera using 3x CCDs and employing pixel shifting and recording to a high bandwidth, low compression format such as DVCPRO-HD.