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Discussion Starter · #1 ·
Last month I got a Sony TRV740 (second best model) Digital 8 Handycam. I would have liked to get DV/mini DV but didnt have the money. I was wondering how does Digital 8 compare to DV/mini DV. And how do Digital 8 and DV/mini DV compare to Hi8. I have an old Panny VHS-C and my Sony Digial 8 completly blows it away. And I noticed a great improvement in PQ when using svideo instead of composite video on my Sony. I have yet to hook it up to my PC via USB or firewire to experiment with digital video editing. While on the subject I also got a Sony CDMavica CD-200 2.1 mega pixel digital still camera. That works great! I love being able to use a 185MB mini CD-RW that costs a buck instead of a 128MB Memory stick that costs ~$90. I orginally wanted to go with the 3.3 mega pixel (CD300) CDMavica but the price difference was too great. I wish there was a 2.7 MP model but Sony only makes the 2 models that I mentioned.
 

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Digital8 is very close to MiniDV in quality. The difference in many cases is minute. Hi8 isn't even close and it a competitor to VHS and SVHS. My personal preference is for MiniDV because Digital8 is a bridge format from Sony. They are wooing users who have alot of video on 8 and Hi8 mm tapes. I don't hence my desire to move to MiniDV strictly. Both are good formats however.
 

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Steve,


Hi8 is an analogue format, not grossly dissimilar to SVHS but with a wider chroma bandwidth. Either of the digital formats will beat its pants off.


Both DV and Digital-8 store a compressed 4:1:1-sampled component video signal at 25Mbps.


Given the similar data rate and sampling regime, I can only assume that there isn't much to pick between them as far as PQ is concerned. Sony might have a lower dropout rate due to the larger form factor (8mm tape instead of 4mm tape).


The compression system used by both formats is 5:1 compression on so-called I-MPEG, which I found described here as follows (it also gives details of the DV transport system):

Quote:
Consumer format, agreed to by 60 companies. I-MPEG is MPEG with minor interfield compression; only I frames are used. Image is 720´ 480 pixels yielding a horizontal resolution of 500 lines at 54dB S/N. The heads spin at 9000 RPM (vs 1800 for analog VTRs), and the tape moves 10mm/sec., twice that of VHS and 8mm. Track width is 10 microns (vs 20 for 8mm and 58 for VHS). Audio is switchable between 16 bit with one pair of tracks or 12 bit with 2 pair of tracks. The 16 bit audio uses 48kHz (24 kHz/channel) sampling, (like DAT) or 44.1kHz, yielding an audio frequency range up to 20kHz. The 12 bit audio uses 32kHz (16 kHz/channel) sampling. During editing a new pair of audio channels is added (not erasing the original pair). Fast tape speed (SP) yields 60 minutes on a mini DV cassette; slow speed (LP) yields 90 minutes.
- David Eddy


[edit: added technical details and reference]
 

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Discussion Starter · #4 ·
Thanks guys, great explanation. Glad I didnt go with hi8. :)
 
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