hvx 1080 color correction and then into 480 sd

FabioRafael

FabioRafael

Active member
Is it possible that I would end up with a better image quality if I shot the movie in 1080 mode, color correct it ( with a plugin such as magic bullet ) and then convert it into 480? ( comparting to shoot everything in 480 SD and then color correcting it )
 
There's been a lot of discussion on this topic.

I can only imagine the best 480 SD stuff will come from using
the HVX200's DVCPRO50 codec.

Steve
 
I disgress. I would always feel that one should aquire their footage in the highest quailty they possibly can. I would shoot either 720p 24 or 1080p 24 and then post it all in its native format. Then downrezz to SD. It would look better than just shooting in SD. Look at all the movies shot in Film and then get downrezzed to SD. Just my thoughts though.
 
riggieri said:
I disgress. I would always feel that one should aquire their footage in the highest quailty they possibly can. I would shoot either 720p 24 or 1080p 24 and then post it all in its native format. Then downrezz to SD. It would look better than just shooting in SD. Look at all the movies shot in Film and then get downrezzed to SD. Just my thoughts though.
Click to expand...

But in terms of compression DVCPro50 is better than DVCProHD. Plus you don't go down a generation 'cause you don't need to re-encode because you won't have to resize it...

Personally I'd shoot in DVCPro50. On the other hand 720p is going to give you flexibility in terms of "variable" framerates. Either way you're going to get a better image than miniDV.
 
riggieri said:
I disgress. I would always feel that one should aquire their footage in the highest quailty they possibly can. (...) Then downrezz to SD. It would look better than just shooting in SD. Look at all the movies shot in Film and then get downrezzed to SD. Just my thoughts though.
Click to expand...
:thumbup: :thumbsup:


[key (...) =]
riggieri said:
I would shoot either 720p 24 or 1080p 24 and then post it all in its native format.
Click to expand...
So, why 720p 24 (if it will not for slow down purposes) if it is possible 1080/24p?
 
If you're looking for the highest quality, that doesn't always equal the highest resolution.

DV & DVCPro are compressed 5:1
DVCPro50 is compressed 3.3:1
DVCProHD is compressed 7:1

Compression artefacts are going to be more severe - albeit smaller - in DVCProHD than in DVCPro50.

There is no particular advantage in taking a step to HD for SD delivery, unless you plan to offer a HD version at some later date. In fact I suspect your final image is going to be worse if you record to HD then downrez to SD than if you worked in SD natively throughout.

Think about it... The camera "sees" a certain resolution through its optical system. For the sake of arguement lets say the camera can resolve a higher resolution than either SD or HD... You can choose to record that image to HD or SD. If your record SD then you work natively with it until delivery. If record HD then you're not gaining any resolution in the end (your delivery will still be SD) and the camera optics are still the same; the only thing you've added is a recompression stage which loses you a generation of quality.
 
You could consider if you capture at HD initially that you are giving yourself all the options for later..

you can downrez to SD .

but if you shoot SD to begin with and THEN want a HD version later!!!!

would a SD version downrez'd from HD look that much worse , if at all , than initally shooting SD ???
 
just a question, but isnt the DVCPROHD Codec a more advanced codec than the older DVCPRO50? If so it may well yield better results shooting in this res and downconverting.

One thing I have been thinking about is shooting DVCPRO1080 over 720 may not yet yield a better picture quality (depending on lens/ccd size) - but would sure provide more actual chroma samples than a 720P image; therefore you could shoot, key, composite all at 1080 and then downsize.

DVCPRO50 may have more m/bits per pixel, but in pure chroma samples it has far less than in DVCPROHD; so i would bet the latter would be much better for grading/keying - we wont know until we try.
 
Alex Leith said:
If you're looking for the highest quality, that doesn't always equal the highest resolution.

DV & DVCPro are compressed 5:1
DVCPro50 is compressed 3.3:1
DVCProHD is compressed 7:1

Compression artefacts are going to be more severe - albeit smaller - in DVCProHD than in DVCPro50.
Click to expand...
Thank you for your wise answer, as always. And about DVCProHD vs. HDCAM, will it be noticeable differences @big screen even because regarding 100 [DVCProHD] vs. 140 (or 170?) [HDCAM] megabits as bit rate?

<PS>

Concerning a DVCProHD vs. DV (less compression) comparative that it will be similar to HDCAM (not SR) vs. DV?

Or a less compression of a DV codec brings less artifacts comparatively a DVCProHD footage to 35mm film-out?
 
Darkline said:
just a question, but isnt the DVCPROHD Codec a more advanced codec than the older DVCPRO50? If so it may well yield better results shooting in this res and downconverting.

DVCPRO50 may have more m/bits per pixel, but in pure chroma samples it has far less than in DVCPROHD; so i would bet the latter would be much better for grading/keying - we wont know until we try.
Click to expand...

Actually, as I understand it, DVCProHD is more or less like 4 DVCPro codecs ganged together. The actual algorithm is the same.

You're right that you gain in terms of resolution - which may be of benefit for getting very acurate keying for eventual SD output. But you also (potentially) gain more mosquito noise in high contrast areas, and colour blocking.

The question is do you want a sharper but dirtier image... or a softer but cleaner image...?
 
Emanuel said:
Thank you for your wise answer, as always. And about DVCProHD vs. HDCAM, will it be noticeable differences @big screen even because regarding 100 [DVCProHD] vs. 140 (or 170?) [HDCAM] megabits as bit rate?

<PS>

Concerning a DVCProHD vs. DV (less compression) comparative that it will be similar to HDCAM (not SR) vs. DV?

Or a less compression of a DV codec brings less artifacts comparatively a DVCProHD footage to 35mm film-out?
Click to expand...

I think undoubtedly HDCAM is higher quality than DVCProHD... But I think the difference would be imperceptible for 99.9% of people - especially if your footage is well exposed, well graded and cleanly posted.

Personally I'd always go for DVCProHD, because it's so much easer to work with. Panasonic have done a great job of creating very accessible workflows for HD Post-Production with DVCProHD. Plus, I personally stopped being a Sony fan ever since they sold our station Betacam SX, which was very expensive and completely rubbish!

As to DVCPro50 vs DVCProHD for film-out - personally I think that the higher resolution of DVCProHD would be of benefit for film out... However, I know that there have been some very nice film-outs from material shot with the (gorgeous) SDX900 (DVCPro50). But I don't actually have first-hand experience of that myself, so this is just speculation.
 
Alex Leith said:
You're right that you gain in terms of resolution - which may be of benefit for getting very acurate keying for eventual SD output. But you also (potentially) gain more mosquito noise in high contrast areas, and colour blocking.

The question is do you want a sharper but dirtier image... or a softer but cleaner image...?
Click to expand...


Yes you are right - but until we see the image I don't think we'll know for sure how much mosquito noise would be introduced. As far as keying goes I would have thought having more chroma samples would be better than having a cleaner/lower res image.

One of the great things is that even at DVCPRO50 the image is samples as 1080 and then downsized. This alone should guarentee a REALLY nice SD image anyway. So who knows if it will be nicer than DVCPROHD downconverted.

Im in PAL land so I wont get hands on until March - i expect lots of tests and results to come swarming in on these topics over the new month or two.

If this is something you are really interested in - you'll find this page VERY useful.
Its a comparison of codecs, and how they look encoding, and reecnoding the same image. To me DVCPROHD seems like a better choice than DVCPRO50 - but it's all subjective.

Go to http://www.onerivermedia.com/codecs/

then click on the 4:2:2 compressed codec page. Here you'll see comparisons with 720p 1080i and DV50.
 
Darkline said:
Yes you are right - but until we see the image I don't think we'll know for sure how much mosquito noise would be introduced.
Click to expand...

I agree.

Darkline said:
If this is something you are really interested in - you'll find this page VERY useful.
Its a comparison of codecs, and how they look encoding, and reecnoding the same image.

Go to http://www.onerivermedia.com/codecs/
Click to expand...

Wow! Thanks for that. That's a very interesting website. :thumbsup:
 
No problem :-)

I did a quick test. Tho I dont know how 'real world' this is. I took the DVCPROHD 1080i encoded image and downsidez it to SD. Then compared this to the DVCPRO50 encoded image.

It seems to me that the DVCPROHD image is a lot cleaner - however this is not an ideal test as the HD image also needs encoding to DVCPRO50 for final output.

Nice to see another Brit on here Alex!
 
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