HDV is a compression system designed to record high definition digital video and audio onto standard MiniDV tapes. A 720p variant (HDV 1) was employed by JVC with the HD101 camcorder. The most common type of HDV was 1080i (HDV type 2) favoured by Sony. Most notably the best selling HVR-Z1. Later in the life of the format Canon introduced HDV1080p with the XL H1. Sony followed with the HVR-S270/Z1.
The 1080i variant of HDV causes some confusion because the recorded footage is 1440 x 1080i rather than 1920 x 1080i. It’s important to separate the data recorded to either digital video tape or to a hard drive/memory card by an HDV camera from what the camera is capable of.
An HDV type 2 camcorder is 1920 x 1080i square pixel capable and can output a full, uncompressed 1920 x 1080i signal via analogue component.
When compressing footage to tape, memory card or HDD, or sending it’s signal via iLINK (IEEE1394/FireWire) an HDV type 2 camcorder in 1080i mode downscales 1920 x 1080i footage to 1440x1080i with a pixel aspect ratio of 1.33:1. .
The reason the footage is downscaled slightly is to reduce the datarate to the 25mbit/s and therefore employ cheap MiniDV tapes.
If you play back an HDV 1440x1080i recording it will automatically be upscaled and displayed as 1920x1080i.
Getting full 1920 x 1080i output from a 1080i HDV camcorder
1080i workflows using HD-SDI are still commonly used in broadcast and corporate production. In particular the early models of Blackmagic Design ATEM mixers such as the Television Studio will only take either 720p or 1080 interlaced signals via SDI or HDMI.
Some HDV camcorders had HD-SDI or HDMI outputs. These outputs will be full 1920 x 1080i provided the output options are set correctly in the menu.
If you want to use an older 1080i HDV camera like a Sony Z1 or FX1 then you will need to convert the analogue output to HD-SDI. To do that properly you need to make sure the camera is sending a 1080i signal via analogue.
HDV cameras and players have comprehensive menu systems. The analogue output (YUV) is always uncompressed but it can be set to either SD or HD so you need to check that there are no downscaling options enabled in the menu. Set downconversion to OFF or NONE for Component Analogue output. You may also need to turn off any iLink/Firewire downconversion options. This should result in a full 1920 x 1080i output from the YUV component connections on the camera.
Later progressive scan capable HDV camcorders may also have an option to output 1080p via component as 1080i – again check the menu options.
Quick summary of HDV1080i
HDV1080i camcorders are full HD 1920 x 1080i capable and can send 1920 x 1080i uncompressed via analogue component or HD-SDI/HDMI if available.
HDV1080i camcorders can only record compressed 1440x1080i to tape/disc/card even when they are outputting 1920 x 1080i via analogue or HD-SDI/HDMI.
HDV1080i camcorders without HD-SDI or HDMI will need a adapter to convert the component output to digital and set the camera menu correctly.