DPI is irrelevant, use specific pixel size

As with SD DPI setting in HD makes no difference whatsoever. It’s the pixel size that counts. All graphics must be prepared based on the HD standard.

Required Sizes:

1080 requires 1920×1080 pixel dimensions

720 requires 1280×720 pixel dimensions

If you intend to make “motion control” moves on your still images you will require files larger than the sizes described above. The actual size will depend on how close you want to zoom into the picture.

A simple rule of thumb is to imagine an invisible 16:9 frame around the area that you will be zooming into. The pixel count within this frame should be close to the required size appropriate for your standard.

Decide on aspect ratio, timecode.

Downconversion is a process of transferring a high definition master onto a standard definition videotape.

There are several considerations when downconverting your HD masters. First of all, you may downconvert your camera tapes prior to offline. In addition to this you will likely downconvert your finished master to standard definition.

This can be achieved through SD output of the VTR itself or through a third party converter. Standalone converters typically provide better picture quality but cost more. Ask plenty of questions before committing to either method.

In some cases you’ll need to specify whether you require DF or NDF timecode.

Aspect ratio of the SD downconversion also needs to be specified.

Since HD screen is wider than SD screen you need to specify how to deal with this. The options are:

Letterbox

Top and bottom black matte is added and the image is not cropped. This effectively turns a 4:3 monitor into a 16:9 monitor but the top and bottom of the screen are not utilized.

Anamorphic

Original widescreen image is squeezed to fit a 4:3 frame. Video must be unsqueezed by the monitor or another device before it reaches viewers. This method is commonly used for DVDs.

Center Crop

A 4:3 area from the center of the original widescreen image is extracted while the sides are cropped off. This method may compromise titles and important action that takes place close to the edge of the frame. This is the quick and dirty way of providing a full frame 4:3 SD downconversion.

Pan and Scan

Similar to Center Crop a 4:3 area is extracted from the original widescreen video. The crop is not locked in the center of the screen. The operator has the ability to move the area left and right so no important action is excluded from the frame. This type of downconversion is the best option for 4:3 full frame deliveries but it is time consuming and can be costly.

Always NDF with 23.98p source.

Downconverting a 23.98p tapes requires a decision on timecode (TC).

TC from such HD tape can not be regenerated on SD tape formats because one runs at roughly 24fps and the other at 30fps. In this case TC will get converted and you will have a choice of going either DF or NDF. Ask for NDF and “A” frame at 01:00:00:00 or you may be in for many sleepless nights.

An exception to this would be the case of downconverting a finished master. The SD downconverted master can be created with either DF or NDF timecode.

When shooting 1080 59.94i the TC on the downconversions should always be regenerated from the camera master.

Downconverting from 720 59.94p is similar to 1080 59.94i. The original camera TC should be regenerated on the SD tape.

For additional discussion click here.

No. Only one HD session and one SD downconversion.

You can always derive your SD NTSC and PAL masters from the finished HD master. A cost of downconversion to SD will be more affordable than a cost of another SD online edit session.

There may be rare cases where for technical or other reasons it pays to do a separate SD session. For example, if you’re able to output broadcast quality picture right from your SD offline NLE and you’re confident that your version is the same as the HD version you may save yourself a buck. This would apply only to the simplest of projects that do not use effects, color correction, titles, etc.

In some cases you can, and in some cases you can not.

Many producers have access to library material or in-house stock shots that can be repurposed for new shows. Most of legacy material is in standard definition and this poses a question whether such material is suitable for use in a high definition show.

In most cases you can upconvert and use SD stock shots. They will appear significantly softer than native HD material but this negative impact can be drastically reduced through judicious editing.

It is difficult to use SD clips shot on video in 1080 23.98p shows. Unless the stock footage originated as a 24p material such as film, it is difficult to avoid motion artifacts when changing the frame rate from 29.97 to 23.98.

Lastly, your network may have the final word if upconversions from SD are acceptable.