anotherthing
Can I seriously suggest that you talk to a specialist who is used to setting up and configuring laptops for HD editing. There are a lot of realworld issues to deal with which the marketing folk tend to gloss over. These include minor issues, like which screen size is best for your software and major ones like, which codecs and editing software are going to work best with both your camera and the resolutions that you want to output at. (Even the make of the chip that is being used for the firewire interface is important. Do a search for advice on PPRuNe about incompatible firewire chips.)
Going to specialists will give you access to a quality of advice and experience that you just won't get at other more mainstream laptop suppliers. A proper specialist will have a demo area where you can see their suggested solutions either working properly, working with limitations or even not at all. It will be very valuable and will enable you to talk about the whole of your HD chain from camera to editing to distribution as you have to get the whole chain right. As with most things try several specialists to compare and contrast the advice.)
There was 'fun and games' when working with SD codecs and HD is even more so. Way way more so. For instance a native HDV file in Premiere Pro is about 13GB per hour. However out of the box I don't believe Premiere Pro can work with all the HDV formats, (eg JVC 720p HDV). Premiere codec encoded HDV won't necessarily play in all the other programmes on your computer as its not a general use HDV codec. To get this you will have to transcode it into another HDV codec. (This can take time, and forgive me as I may have got this wrong, but I have heard worst case scenarios of 1 minute of footage taking 1 hour to transcode. (I can't remember which editing software this was in connection with though.) I can well believe it though as four years ago I experienced certain renders out of Final Cut Pro 3 (non HD) taking the same time. I then swapped to Windows editing and the same process, using different software and in better quality, got through one minute of footage in just 50 seconds.)
So to help yourself you may well decide to use something like Cineform Aspect HD (£280ish) as a standalone / plug-in etc. to Premiere Pro. This will put a normal HDV file up to 40Gb per hour, but it will also allow you to work in more resolutions, in a more realtime way and it will handle HDV material from JVC cameras at 720p. However this means an even higher spec computer may be needed to handle the increased files. It really is a minefield of compromises.
You will also need to consider the graphics card in the laptop to ensure that it can play back at least one stream of HD in real-time and also how you are going to back up your finished HDV programme file, (if you decide you need to). Remember standard HDV is 13GB per hour and a single layer DVD disk is 4.x GB and the firewire on your camera is often output only.
As far as actual laptops are concerned, the specialists will often have unbranded laptops on offer that they have specified the components of and which they are familiar with. These machines will usually be the same price as a less well featured brand like HP. On Windows I would be anticipating to start paying from around £1,600 + VAT.
If however there is the possibility that you may move up from Premiere etc. and work on Avid software then you may need a machine that is on Avid's, very short, approved and (Avid) tested list. These are usually HP / Compaq or Dell named and option specified models. Be aware though that due to the high turnover of machines the Avid list can often refer to models that have been discontinued and not show new models that they will subsequently certify.
Finally as I am sure you are aware editing on a laptop is not ideal and if it is possible for you to work on a desktop machine you will get a much more able machine that will allow you to do more work in realtime.
Best of luck.
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