The easiest way to find out what you need to know is to ask someone who knows it. In listing the most commonly asked question we have been asked, we hope that your own questions will be answered. In any case we are always happy to help, so do please telephone us for a chat if your questions are not answered.
HD
Q. When thinking about shooting High Definition, what questions should I consider?
A. What is your market? Home or international? What look do you want, filmic (progressive) or TV (interlace). What is your post production route – HD end to end or down convert to standard definition for lower cost edit (still with significantly better quality compared to Digi Beta SD route). You should also consider field monitoring, down conversion and playing in SD archive material.
Q. What is the quality difference between Broadcast HD and SD?
A. As we have said, HD is four times the quality of SD if you stay in the HD domain through production and post.
Q. Can I shoot HD and still edit in SD?
A. Yes, very easily, and most TV producers will. With the right player you can play out your HD master tapes to SD direct to an SD VTR, Avid or PC / Mac for editing.
Q. Will I lose quality if I shoot HD but edit in SD?
A. Yes, but there will still be a substantial quality improvement over TV shows shot and edited in SD, about 30% actually.
Q. If I down convert to SD for my edit, should I be shooting interlace or progressive?
A. It does not matter. 25P or 50i are both suitable for UK editing. It is the number not the letter that makes the difference.
Q. What HD format should I use if I want to edit in SD?
A. There is no difference between progressive or interlace when it comes to down converting to SD for post.
Formats
Q. What is the difference between 23.98P, 25P and 29.97P?
A. They are all different frame rates in progressive scan mode. You choose the frame rate according to the market you are making the TV show for. 23.98P is more commonly referred to as 24P and, 29.97P as 30P.
Q. What is the difference between 50i and 60i?
A. These are the interlace modes, that broadly speaking will give a TV / video look to the pictures. Europe uses 50i. NTSC countries use 60i (or more correctly 59.94i)
Q. Is there a quality difference between Progressive and Interlace?
A. In short, no. The resolution is the same. The fact is that 24/25P delivers a slightly higher vertical resolution than interlace, but to the human eye this appears to be lost because of the temporal difference between progressive and interlace. Some would say that with the right monitor you might see that progressive pictures look better but the general feeling is that there is no noticeable quality difference between Interlace and Progressive as long as it is the same HD origination format e.g. 1920 x 1080, 1280 x 720.
Q. Why should I shoot 50i instead of 25P?
A. You would shoot 50i for European TV production. 25P would be applicable for productions destined for international sale, where a filmic look is desired.
Q. Can I shoot 25P and then convert to 50i
A. Yes you can but the process is expensive and complicated. You need to decide before shooting whether interlace or progressive is appropriate for the show.
Q. OK, can I shoot interlace and convert to progressive scan?
A. Yes. This process is equivalent to field doubling in standard definition. Some vertical resolution will be lost though.
Q. Can I shoot 25P and then convert to 24P
A. Yes, with no loss of picture quality.
Q. Some shows are shot 29.97 frames per second or 29.97P. What is this?
A. This is a drop frame version of 30P; used where the final transmission may be NTSC
Q. What should I use if I am producing a show for a foreign market?
A. This very much depends on the country you are making the programme for and the type of production e.g. commercial, film or TV show and whether or not there will be a requirement for slow motion or shooting fast moving scenes? The US is predominantly progressive scan although some markets will be happy with interlace. We have a number of US clients that only shoot interlace but most shoot progressive. The Japanese are the opposite, with all their channels already HD interlace. We have never had a request to shoot Progressive for our Japanese clients.
Q. What should I use for my production, which will have both fast action scenes and slow motion?
A. Interlace is definitely the way to go. Shooting fast movement in progressive leaves a dragging effect across the picture. Interlace is better for slow motion also. For instance, all sport shot in HD is in interlace mode.
Q. I have experienced image flicker in the past when shooting progressive, whilst panning quickly. What is the cause of this and how can it be remedied?
A. This is inherent in the system when shooting progressive i.e. only 25 pictures per second. Make sure you use the 50 Hertz shutter when shooting.
Lighting
Q. What is the difference when lighting for Chroma Key or Matte?
A. Lighting and attention to detail regarding bounce and spill from a green/blue/red key are the same as with SD production. Make sure when shooting any key work in HD that you are using HD lenses because it resolves image edging better.
Sound
Q. I am getting a back ground hiss through the channel I’m using for my radio mic. What could be causing this?
A. This usually occurs when the phantom power (+48v) on the camera is switched on and conflicts with the battery power of the radio mics themselves. If you set your channel to MIC rather than MIC +46v this should resolve the problem.