I'm shooting HD

I keep hearing this at weekly and even twice, thrice a week now. "I'm shooting my next film on HD". "How much difference would it make if I shot on HD?". "I've read that HD cannot be made to look like film" Or, "I've read that HD looks as good as film".

I'm not about to answer or refute any of these. What I'd like to put forth simply is that HD is not a single monolithic format like 35mm film is. So if you used the phrase "...shooting on HD..." in a sentence, you could be shooting on...
HDCam, HDCamSR, HDV, DVCProHD, Varicam, CineAlta, P2, XDCam, XDCamHD now.

Further in many of these you could be shooting as...
720p24, 720p25, 720p60, 1080p24, 1080p25, 1080p30, 1080i50, 1080i59.94 etc etc.

So what's your flavour of HD?

A quick run-down on what the figures mean.
Normal or SD TV meaning what you shoot on DV, DigiBeta, play back on DVD, watch TV on, etc in India is...
Frame size 720x576 at 25 fps. So this will be called 576i50.

In HD the numbers are
720p24 meaning frame size 1280x720 pixels at 24 fps progressive (no fields)
720p25 meaning frame size 1280x720 pixels at 25 fps progressive (no fields)
1080i50 meaning frame size 1920x1080 pixels at 25 fps interlaced
1080p24 meaning frame size 1920x1080 pixels at 24 fps progressive (no fields)
1080p25 meaning frame size 1920x1080 pixels at 25 fps progressive (no fields)
 
These are the numbers we would normally encounter in India.
If what you shoot will be used for TV, then do 'i'. For film outputs or mixing with film do 'p'

Outside India there would be other formats like 720p30, 1080i60, etc.

What about shooting formats?

If you're in India, in Mumbai, here's the deal.

If the camera is large and Panasonic and takes prime lenses you most likely are using a Varicam. So you're shooting on small DVCProHD tapes at 720p something. Frame size is 1280x720 pixels and compression is 12:1. In each frame 8% data is kept, 92% thrown away.
If you shoot on a small hand-held Sony camcorder you're shooting HDV. Frame size is 1920x1080 and compression is MPEG-2 50:1 Yes that's 50:1. In each frame 2% data is kept, 98% thrown away. Camera would be HVR-Z1
If you shoot on a small hand-held Panasonic camcorder and on small flash cards not tape, you're shooting P2. Frame size is 1920x1080 or 1280x720 pixels and compression is 12:1. In each frame 8% data is kept, 92% thrown away. Camera would be HVX 200.
If the camera is large and Sony and takes prime lenses you most likely are using a CineAlta. So you're shooting on DigiBeta sized HDCam or HDCamSR tapes at 1080p something. Frame size is 1920x1080 pixels and compression is 5:1 or 3:1. In each frame 20% to 33% data is kept, 80% to 66% thrown away.

If the camera is large and Sony and shoots on disks you most likely are using a XDCamHD. So you're shooting on Blu-Ray disks 1080p something. Frame size is 1920x1080 pixels and compression is Mpeg-2 at about 20:1 to 30:1 depending on format. So, in each frame 5% data is kept, 95% thrown away.

As you can see there's no real uncompressed HD format. All use some or other kind of compression. But they are all very good compressors. Really can't see defects unless you see the image up close.

Cost. Just find out what tape costs. And then what it costs to hire the camera. Now do the math. Is film costlier by a huge margin? You'll be surprised by the figures.

And does it/can it look like film? Very subjective. Very. My take on this is "Why bother?" Just go ahead and shoot for some other reason. And check if the image you've shot goes with the story. If it does, then like I said "Why bother?"