High-definition video (HD Video) refers to videos of higher quality and resolution than standard-definition video. This involves display resolutions of 1,920 x 1,080 pixels for 1080p HD Video. Video support may vary based on host device, file attributes and other factors.
Full high-definition video (Full HD video) refers to videos of an even higher quality and resolution than HD video. This involves a display resolution of 1,920 x 1,080 pixels for 1080p Full HD Video. Video support may vary based on host device, file attributes and other factors.
4K resolution falls under Ultra High Definition (UHD), a term that encompasses better resolution, color, and frame rates than HD. 4K resolution describes display devices or content having horizontal resolution on the order of 4,000 pixels. More specifically, 4K resolution can be broken down into True 4K and 4K UHD. True 4K (4K x 2K) has a resolution of 4,096 x 2,160 pixels. 4K UHD must have a minimum resolution of 3,840 pixels wide and 2,160 pixels high, making a 4K UHD screen the equivalent of two 1080p screens in height and two in length.
Several 4K resolutions exist in the fields of digital television and digital cinematography. In the movie projection industry, Digital Cinema Initiatives (DCI) is the dominant 4K standard. Video support may vary based on host device, file attributes, and other factors. 4K UHD is more commonly being used in a home context for their TV screens and is also becoming the standard for many premium smartphones and cameras. On the other hand, True 4K is often used by some projectors and many professional cameras. Plus, there are SD cards for 4K video to consider.
With the arrival of 4K, there are four main resolution standards for use in the home: standard definition (480p/540p), high definition (720p), full high definition (1080p) and ultra-high definition (2160p).
There are three kinds of video speed classifications: Speed Class, UHS Speed Class, and Video Speed Class. These indicate the minimum sustained write speed necessary for video recording, so that minimum and constant speed is guaranteed for camcorders and cameras. If the card is not compatible with the quality the video is shot in, there may be issues such as dropped frames, recording error, and added noise. See below for potential Video Speed Class compatibility errors.
Speed Class is designated as Class 2, 4, 6 and 10, and UHS Speed Class is designated UHS Speed Class 1 or UHS Speed Class 3. The latest Video Speed Class was created to enable higher video resolution and recording features such as multiple video streams, 350 degree capture, VR content, or 8K and higher resolution video. Video Speed Class is designated as V10, V30, V60, and V90. Higher Video Speed Class supports higher resolution videos.
Higher class rated cards support high bit-rates of video and higher quality video recording. SanDisk Class 4 memory cards are ideal for HD video capture, and Class 10, UHS Speed Class 1 and UHS Speed Class 3 memory cards support Full HD and 4K Ultra HD video capture. Check your camera/camcorder for the recommended class rating.
For CompactFlash cards, look for Video Performance Guarantee (VPG). VPG-20 means Video Performance Guarantee enabled to ensure video recording at 20MB/s minimum sustained write speed. VPG-65 is Video Performance Guarantee enabled to ensure video recording at 65MB/s minimum sustained write speed. Performance may be lower depending on host device. 1MB=1,000,000 bytes.
1. UHS Speed Class 1 designates the performance option designed to support real-time video recording with a UHS-enabled host device. UHS Speed Class 3 designates the performance option designed to support real-time video recording with a UHS-enabled host device.