Memory in a Flash

Flash memory is very useful stuff. It holds the pictures, songs and videos in your camera or portable device. It stores your files on your thumb drive. The best part is, it’s non-volatile, which means it doesn’t need a constant flow of electricity like the RAM in your computer. There are dozens of varieties of flash memory, and I’m not going to describe each of them here, I’m just going to focus on the three most popular.

SD

SD memory, created by memory manufacturer SanDisk, is probably the most common form of flash memory available. The initials stand for Secure Digital, not SanDisk, though. It’s inexpensive, it’s widely available, and it comes in several sizes, including mini and micro, which are more compact forms that fit well into smaller devices like cell phones, which are constantly looking for ways to reduce size.

The original specification for SD cards only worked up to sizes of 2GB. A whole new specification called SDHC, the HC standing for High Capacity expands the amount of memory that SD cards can hold beyond 2GB. Devices created before the new specification was finalized will not be able to use the newer cards. So, be sure your device has SDHC stamped on it, not just SD before you buy a card bigger than 2GB, or you may be disappointed. However, the specification has been in place for several years, so devices that won’t handle the new stuff are getting more and more rare.

Compact Flash

Compact Flash is generally limited to high-end Digital SLR cameras. You don’t find it elsewhere very often. Compact Flash is much larger and heavier in physical size, but it has a significant advantage over SD in speed and capacity, which is why it is popular among high-end camera manufacturers. Just like SD is coming out with new specifications to allow for more memory and speed, CF is also developing new specifications which will allow for better performance. So, it’s important to know what revision number (1.0, 2.0, etc) your camera will handle so you don’t wind up buying a card that won’t work with your camera.

Memory Stick

Sony really likes to be original. They usually wind up doing their own thing and no one else joins in. Memory Stick is a format that only works with Sony devices. It’s the only other format that has any real traction in the marketplace, but no one else seems to be interested in using it. It has gone through several revisions from MS to MS Pro, which offer higher capacity, better speed and smaller size, just like SD and CF.

Shopping around

Finding the right memory for your camera isn’t that hard unless you’re buying memory for old equipment. If your camera is more than 2 years old and you’re buying the largest capacity card you can find, it’s generally a good idea to pull out the manual for your device and compare the specifications it will take with what you’re buying. Either that, or make sure you understand the store’s return policy.

MiniDV

MiniDV, or Miniature Digital Video, was a breakthrough for home video enthusiasts. The format used analog tapes, but encoded a digital signal. This is like the old style modems that sent a digital signal over telephone lines. When it first connected, you heard that series of squeals and beeps that was the sound of digital information being communicated in an audible format. These cameras are all able to transfer video to a computer through a Firewire cable. This technology ushered in the era of desktop video publishing. Software to edit video has become a standard feature for operating systems, and many excellent software video editing packages are available at a reasonable cost.

MiniDV is on the way out as a standard format, and the cameras are starting to get rare in stores. But, no other format has emerged which completely surpasses MiniDV in every respect. Every other format that has come out since MiniDV is also digital, but instead of storing a digital signal on an analog medium, the new formats store a digital signal on a digital medium, like a Hard Drive or Flash Memory. This makes a difference, because analog tapes have way more room for information than a Hard Drive or Flash Memory. That means that MiniDV required very little compression to make things fit. It’s able to store video information that hasn’t been shrunk down to a lower quality. Newer formats, because they have less space to work with, need to compress video down to fit onto a digital medium.

Compressed video isn’t a problem if all you want to do is play the video back. But, if you want to edit the video, then that compression means that you have less raw material to work with. When you apply effects and transitions, a compressed signal is not going to produce as nice a picture as raw video. For most people who just want to capture video of the kids as home movies, this isn’t a serious issue, but if you want to make a short film, you might want to pay attention to how much compression your video camera is putting on the video you capture, and what options the camera has to reduce that level of compression if you want video that is higher quality.

MiniDV tapes can stretch or become caught in the camera mechanism, but on the whole it is still a good option for Standard Definition, because it stores uncompressed video on an inexpensive medium, and the cameras are getting dirt cheap…if you can still find them.

Mini DVD

Mini DVD, which annoyingly has almost the same name as MiniDV, is an all-digital format. DVDs are highly compressed, and the minature discs don’t hold a lot of video. This format is most suitable for those who do not wish to edit video at all. If you primarily want to record and be able to watch the video on your DVD player without having to bother with editing it on a computer, then this might be a good option for you.

The primary drawback of this format is that discs need to be ‘finalized’ before they can be played on a regular DVD player. The process of finalizing a Mini-DVD can take up to twice as long as the recording time. This means that if you shoot an hour of video, it could take the camera as long as two hours after you finish shooting to prepare the DVD for a DVD player. Different cameras do better or worse at cutting this time down, but be aware this can be an issue and read some reviews on the camera before taking the plunge. This format is also on the way out, and while the discs are cheap right now, the cameras are getting rare, and are only available in Standard Definition models.

Hard Drive

Hard Drive video cameras are currently the popular choice. A 30-40 GB Hard Drive will store several hours worth of recording, and offloading it is quick and easy. MiniDV transfers video information in real time. This means that if you want to transfer an hour of video to a computer, it takes an hour to copy it over. Mini DVD takes a long time to finalize a disc. The advantage of a Hard Drive camera is that it stores computer files on a Hard Drive, just like the files you would store on your computer, so when it comes time to transfer from camera to computer, it only takes a few minutes to move those files, just like you were transfering a file from one computer to another. Quick and easy.

The inherent drawback of a Hard Drive camera is that the Hard Drive is sealed inside the camera and you can’t swap it out for another when it gets full. If you’re out shooting for a day or two then returning to your computer, it’s no problem, just offload the files. But, what happens when you go on a two-week vacation? Unless you have a laptop, you might run out of space pretty quick.

The answer is flash memory. When 2GB memory cards were the only reasonably-priced option, buying a dozen of those and swapping them out regularly would be a terrible hassle. But, now that 8 or 16 GB cards are getting into a decent price range, buying several of those cards gives you the flexibility to significantly increase the amount of recording time available on a Hard Drive video camera.

The good thing about Hard Drive cameras is that many of them are available in High Definition formats. This means that they can record in 720 or 1080 resolution. The tricky thing is that the abbreviation for Hard Disk Drive is HDD, and the abbreviation for High Definition is HD. So, there are a lot of letters stamped on the side of one of these units and you need to look closely to see whether it’s a HDD unit, yet only Standard Definition, or both HDD and HD. In order to be able to shoot in HD, a lot of these cameras will significantly compress the image they shoot and often will only offer 1080i resolution (interlaced) which alternates lines of video, not progressive, which displays each line each time. See earlier posts for a further explanation of the difference.

Flash Memory

The next step is to entirely skip the Hard Drive, and only use flash memory. As memory becomes less expensive, this becomes a more attractive option. Without a Hard Drive, the bulk of the unit can be significantly reduced and the power required takes less of a toll on the battery. These cameras can often take High Definition still images, and the line between where Flash Memory camcorders ends and regular Digital Cameras begin blurs a little. This is especially true since some regular Digital Cameras are now offering High Definition video as an option.

If I’m just taking a short video that I want to upload to Facebook or YouTube, then I just use a point-and-shoot Digital Camera. It is able to record at Standard Definition, the video responds reasonably well when I put it into a desktop video editor, and the result is more than enough resolution to look good online. If your job is posting to the Internet, you’ll want a real video camera, but if you’re just having fun, a regular digital camera is really all you need. Some Digital Cameras even come with a ‘YouTube’ mode, which records in the format YouTube uses, to make it easier to upload your videos.

Digital SLRs

Some Digital SLR (Single Lens Reflex) Cameras have begun to offer video. This is a huge development, because the ability to change lenses and control focus directly is really what separates consumer video cameras from professional equipment, and the price difference is HUGE between the two. Now that DSLR makers have started to add in video, they have been able to offer a product that gives amazing control over video shots for thousands of dollars less than professional equipment.

Early DSLR models that offer video do so with some limitations. The units that have just come out tend to overheat if used too long. The auto-focus these cameras use is often designed around taking still pictures and hasn’t yet been optimized to be effective when shooting video, so manual focus tends to be a better option. That manual focus is possible with these cameras is a real positive, but there are times when you just want the camera to do its thing. DSLR Video is still a very new thing, and some of the limitations that currently exist will soon be overcome, but this is a very exciting development and will soon become the must-have tool for those who are serious about shooting amateur video.

Standard Definition

A Movie DVD contains compressed video at what we refer to as Standard Definition, 480 lines of resolution. DVDs introduced progressive video, which was an improvement over older interlaced signals. Instead of alternating odd and even lines, progressive video presents every line every time. This results in a smoother picture than older television systems were capable of producing.

High Definition

Television has now moved beyond the limits of standard definition. 720p and 1080p dramatically increase the number of pixels displayed on a screen. Screens can display better images, but the medium that distributes the stuff you want to watch lags behind. DVDs are stuck at Standard Definition.

This isn’t the first time that there has been a lag between the ability of a TV to display a better picture and the lack of a medium to store video. VHS (Video Home System), the most popular form of VCR (Video Cassette Recorder)  could only display 240 lines of resolution. I was recently attending a seminar delivered over the course of several weeks, and each week we watched a DVD. There was a problem with the group who had lent the DVDs, and they needed them back. The organizer managed to borrow an alternate copy, but it was a set of VHS tapes. I was amazed at what a difference it made to go back to the old format. Faces were fuzzy and indistinct. I never had a problem with VHS 15 years ago, but once you get accustomed to something better you realize the difference and going back is painful.

The Contenders Vie for the Crown

DVD has not yet been succeeded by another format. HD-DVD and Blu-ray were two new formats that were meant to replace the DVD. One is now defunct, and the other is struggling to gain traction. There is speculation it will never become popular enough to truly replace DVDs. One reason why Blu-ray struggles is that DVDs are really, really inexpensive. This is partly because those who sell DVDs see the end of the line and are rushing to make all the money they can before the gravy train ends. This doesn’t make a whole lot of sense because they’re the same people who want to Blu-ray to take off. Making DVDs dirt cheap changes people’s expectations of what a movie should cost, so the movie industry is shooting itself in the foot.

Fortunately, the people behind Blu-ray have announced plans to lower costs for the new format in the near future to kick-start the transition. Let’s hope that happens.

The Conversion Experience

Upconverting DVD players are the other reason Blu-ray hasn’t taken off. Older DVD players didn’t always look all that great on the new high-resolution screens. This is because the screens are so precise. To illustrate, let’s assume that you have a bar with 4 lights on it. The lights flash according to a pattern. If you want to display that same pattern on a bar that has 8 lights, it’s easy because you just double the pattern, and wherever light number 1 was flashing, both 1 and 2 now flash. Wherever light number 2 was flashing, both 3 and 4 flash, and so on. The pattern translates easily, because it’s just double. But, what if there are only 6 lights? Now, you can’t just double the pattern, you need to make choices about which lights will flash when to best represent the original pattern, but you’ll never get a pattern that identically represents the original pattern because the math doesn’t divide evenly.

One of the great ironies of Digital television is that it is so precise, it shows up flaws. Older, analog TVs could fudge an image and come out looking OK. It is important that that you feed a Digital TV a properly formatted signal so that it displays correctly. The better the TV the better a good signal will look and the worse a bad signal will look. It cuts both ways.

An upconverter improves the way your existing DVD collection looks on your big screen TV. An upconverter doesn’t improve the resolution, it still works from 480 lines of resolution because that’s all that’s available on a DVD, but it takes the original image and stretches it smoothly over the larger space, fudging the numbers to keep things looking smooth, despite the fact that the numbers don’t translate evenly.

To understand the difference, imagine a balloon with words written on it. Before the balloon is blown up, the words are small and clear and you can read them. An old DVD player playing on a big screen TV is kind of like stretching the balloon with your hands to try and make it bigger. The image will be uneven. An upscaler or upconverter stretches the image smoothly, like blowing up the balloon. The even pressure causes each part of the image to be smoothly stretched as the balloon increases in size. It’s still the same image, starting small and stretched big. Nothing new has been added. High definition is like printing in a large font on a piece of paper. There’s no need to stretch the paper image, it’s already as large as the words on the balloon when the balloon is blown up, and it’s going to be a clearer and sharper than the stretched balloon. Even if the balloon has been stetched smoothly by blowing it up, there’s only so much ink to spread out, and it won’t be as crisp and clear as the printed page, but will still be better than stretching by hand.

In addition to smoothly stretching the image, an upconverter can output video via an HDMI cable, which is a digital cable. Older DVD Players are only able to output analog video. This means that the digital signal from the DVD gets converted to analog for the cable, then when it reaches a digital television, it gets converted back into digital. The conversion process to and from analog reduces the quality of the video signal. By using a digital cable, an upconverting DVD player maintains the digital quality of the picture from start to finish, resulting in a better picture, as long as your TV can accept HDMI.

So, an upconverting DVD player provides a smoother, clearer image on a big screen TV by stretching the image smoothly and delivering it to the TV in a digital format.