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Set it to both settings and see which gives the best picture. In most cases you will not be able to tell any difference.
 

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The Canadian over the air stations are 1080i so I would set it for that on cable as well. I think there are some stations in the US that are 720p. Your TV will figure it out regardless.
 

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Using 1080i, you may see some slight picture degradation due to motion in the tv shots. Fox, ABC/ESPN use 720p because the smoother image is desirable for fast-action sports telecasts.
 

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was going to start a thread about this...

when i got Optik a couple of months ago. When the installer was setting up he set it to 720p and said its better than 1080i when i said my TV's are 1080p.
did not make sense to me but left it at that.

but maybe he is right - is not 1080i 540x540 and in the same cycle 720p would be 720x720 so you have 1440 lines of info to convert to native 1920x1080?
 

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I understand that it is 1080x1920, not 1080x1080. The 720P setting is 720x1440, not 720x720.

The signal available through Telus Optik (and Shaw Direct sat company as well) are 1080i and 720P. The 1080i is interlaced (alternating lines 30 times per second) and the 720 is progressive (all lines 30 times per second). On a standard hi-def TV, 720P might provide for smoother picture for action and sports telecasts. For most broadcasts though, 1080i works just fine. My set has a 120hz refresh rate so I can run mine at 1080i for all types of telecasts without any blurring.

The right answer here is to try both on your set and see which one you prefer. To my eyes, 1080i wins hands down on my set, yours may be the opposite.
 

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Well i did say lines

my panny plasma and sony lcd are 1920x1080.

i said basically what you did. 1080i is interlaced. odd even lines every 30th of a second. so 540x2 for 1080p

in the same 2 30th of a sec cycle to make 1080i the 720p does 720lines x 2
for 1440 lines

i have tried both and really do not see any difference.
 

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Okay, I am beginning to wonder something, SaskTel will be switching to the same software as Optik soon for their IPTV. My TV is branded as being able to show 720p resolution, but I think it can downconvert 1080i into 720p.

Would this affect the choice?
 

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viper, i would stay with 720p. If you went with 1080i it would entail too much conversion for your TV - every 30th of a sec u get 720p where with 1080i you would have to wait out 2 30th of a sec cycles and then convert that 1080i down to 720p
 

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1080i is interlaced. It is scanned from the top to the bottom on the odd lines 1,3,5,7, etc then from the bottom to the top on the even lines. This results in a moving image appearing to shimmer in 1080i. 720p on the other hand scans from the top to the bottom with all 720 lines being PROGRESSIVLY scanned.

To see the difference use you PVR to record a movie that has the credits running on a top to bottom scroll using fine white print on a jet black background, you'll see the 1080i image will cause the credits to shimmer as if your seeing them over a hot road in the summer, while the 720 credits will roll without the shimmer, as they do in a theatre.

If you were using your TV to view pictures from your digital camera then 1080i would look better, but that is because pictures from your digital camera aren't moving so the double scan doesn't affect the picture quality.
 

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1080i HD channels are sharper than 720p channels, on Eastlink I have my Motorola 3400-M DVR set to output native so the video is just passed through to my HDTV. From my perspective 1080i channels are sharper than 720p channels so I like 1080i better .
 

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in the same 2 30th of a sec cycle to make 1080i the 720p does 720lines x 2
for 1440 lines
Please explain this. How does it do 720 twice? It does not make sense.
 

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My understanding is all the HD channels are re-encoded to 720. If that is true that is you best bet.
My Telus installer (yesterday) said the stations are doing 720p. Thats news to me. I challenge someone to name the stations.
 

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I've heard that some stations are broadcasting HD LOCALLY in 1080P, but only LOCALLY. You have to be 'line of sight' to recieve their uncompressed signal. It may be that this is true or it may be that they are just tramsmitting an uncompressed signal (no MPEG2 or MPEG4 etc). I can't be really certain as I have no firsthand experience with this kind of thing, I don't think I want to bother setting up an antenna for Global or CBC to find out, they don't have particularly interesting programming and I don't relish a lightning lure on my roof.

Another great part of Optik, no antenna and built in lightning protection, oh and snow wont build up and block your Opik signal either :).

Once the HD signal is bundled up for transmission over satellite relay to providers such as TELUS or SHAW or Bell Xpressview etc, its reduced to 720P to save bandwidth. 1080P bandwidth is just not doable currently for satellite uplink there isn't the room required.

The providers then decide what type of data compression they will apply to the signal they receive from the networks, in the case of Optik its MPEG4, this further reduces bandwidth, and this is how the signal is delivered to the STB. Non HD signals are transmitted at 480i with MPEG4 compression used in the case of Optik. The STB is capable of changing the resolution of the HD signal to either 1080i or 720P for HD TVs or 480i for non HD TV sets. The SD channels remain 480i as far as I know, the STB doesn't upscale them.
 

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As indicated in the link in post 16, there are no 1080P broadcasts. The only 1080P programming that's currently available in Canada is from BTV via their "on demand" (movie) service, which saves the programme to the HDD of the PVR. (Outside of BDs and Downloads to computer)
 

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720p used to be preferential, but nowadays, it seems like TVs are better at de-interlacing than they used to be. Conventional wisdom used to be to go for 720p over 1080i, but in my experience, 1080i generally looks better on 1080p sets. Telus training, as far as know, is still teaching 720p as the preferable setting.

-Telus tech.
 
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