Once upon a time, making underwater videos and photos was considered difficult and expensiveToday, thanks to high definition (HD) and the increasingly smaller size of systems, anyone can approach this world and, with a little effort, obtain excellent results.
While photography is widespread among divers, with one in three now owning a compact camera, underwater video recording remains a relatively rare undertaking. This is due to the fact that making videos is more complex due to movement in the water, the use of lighting, and above all, editing (post-production), which requires good computer skills.
This column was created with the idea of helping those who already make videos or those who are approaching it for the first time, to navigate this world and achieve the best results, without getting too technical, which I wouldn't be able to do, but by providing useful and understandable advice.
A series of articles that, starting from the basics, will analyze: video equipment, underwater suits, lighting systems, new technologies, video shooting and editing techniques.
An enthusiast doesn't necessarily have to turn it into a job, but with a few small tweaks he can significantly improve his shots, giving them a more professional touch.
Of course, to become an underwater videographer you need to start from the basics, so in this series of articles we will touch on the things you absolutely must know, point by point. However, the foundation remains your desire to apply and grow, which I would say is fundamental to achieving a goal.
So, if you thought you'd grab your camera and dive into the water after reading this article, think again. As I wrote before, you have to start from the basics!
Cameras for underwater video
Buying a camera is always a delicate moment. The market offers countless options and different price ranges, starting from less than €300 and easily reaching €8.000. Be careful! The most expensive option isn't always the best solution; everyone has their own budget; it's just a matter of choosing the best compromise within that price range. And don't forget one crucial thing: traveling by plane with large amounts of extra weight has become practically impossible these days!
Recording format:
The new generation cameras all record in HD (high definition) however some of you may still have some models at home that record in SD (standard definition), even the TVs in our homes still transmit in SD unless you have an HD decoder.
Before continuing, however, a clarification is needed, given that we will talk about video encoding below. The video signal is made up of a series of frames (25 is the standard) for each second, which can be stored either in interlaced or progressive mode.
Progressive Scan (p) A single image of the object being filmed is captured or transmitted and reproduced 25 times every second. It is used in all HD TVs, LCDs and computers.
Interlaced Scanning (i) 25 even fields and 25 odd fields are captured or transmitted every second for a total of 50 fields, it is used on standard TVs.
Visually, a still image on our computer would look like this:
High definition is divided into Full HD, HD Ready and HDV. To better understand the real difference between the various formats in terms of resolution, look at the figure below.
At first glance, it may seem boring and confusing with all these acronyms and data. You might be thinking... but I just want to go underwater and take some footage, that's what I thought when I started. Be patient, I'll try to simplify, but knowing the formats is important to be able to choose the right camera!
Format Full HD It is also called 1080i or 1080p. It has a resolution of 1920 x 1080 pixels and can record images at 25 and 50 fps (frames per second) in both interlaced and progressive modes. It has a 16:9 widescreen aspect ratio and can be recorded to memory cards and hard disks. The main compression formats are: DVCPro HD, XDCam, AVCHD, MP4, and MOV HD.
The format HD Ready It is also called 720p and has a resolution of 1280×720 pixels. It can record images at 25 and 50 fps (frames per second) in a progressive manner. It has a 16:9 widescreen aspect ratio and can be recorded on memory cards and hard disks. The main compressions are: DVCPro HD, XDCam, AVCHD, MP4 and MOV HD.
The format HDV It has a resolution of 1440×1080 pixels and can record images at 25 and 50 fps (frames per second) in both interlaced and progressive modes. It has an aspect ratio
(aspect ratio) widescreen 16:9 and can be recorded on miniHDV cassettes, memory cards, and hard disks. MPEG2 compression, the same as DVDs.
The format SD It has a resolution of 720×576 pixels and can record images at 25 fps in interlaced mode. It has both a 4:3 and a widescreen 16:9 aspect ratio and can record to miniDV cassettes. PAL compression is used. If you still shoot videos with SD cameras, it's important to use 16:9; I'll explain why in the video editing chapter.
There is also another piece of information that perhaps not all of you have noticed among the various acronyms that crowd the technical data sheets of video cameras: the colour sampling of the video signal, are three numbers in series like these (4:2:2), the most common are: 4:2:2 – 4:1:1 – 4:2:0.
The highest quality is 4:2:2, which allows for unparalleled color processing in post-production.
Now after all these acronyms you will be asking yourselves, what is better to buy?? I would say that the 1080p 25/50 fps with AVCHD or MOV HD compression is the best choice considering that it is the standard used by Sony, Panasonic for avchd and Canon for HD mov.
Why did I make this choice?
- 1080 because it is always better to have the images in the maximum resolution and then convert them to lower quality formats for TV, web or other.
- Progressive because when processed on a computer it is already optimized and of higher quality than interlaced, otherwise I would have to convert it before starting to work on it.
- AVCHD or MOV HD is your choice, this choice is somewhat based on what kind of computer and editing software we use (we'll cover editing later).
- 4:2:2 sampling because it allows me to do accurate color correction in post-production.
- The type of media you shoot on (memory cards or hard disk) is at your discretion
Now that we've chosen the format, we're only halfway there. To be able to shoot underwater, the most important things are the technical features such as the sensor and the functions and controls: white balance, focus, iris, etc. This will be the topic of the next article... don't miss it!!!
Article published in ScubaZone n. 1
