Pro Res Lt = Good enough? ( Canon Dslr footage )

V

vision_filmz

Carbonite Member
Running out of hard space and decided to edit a new project in Pro Res Lt vs Hq which I always use. As of now I really see no difference, can someone help me out here and let me know if this is ok or should I be using Hq?


Thank you
 
I would venture that pro res LT is the most popular choice for those converting HDSLR footage in FCP 7.

If you look at the data rates, the conversion is virtually indistinguishable from the original and it does save disk space.
 
I use LT exclusively now for DSLR footage and no issues at all. it keeps the transcoded file sizes reasonable. Other than output for TV, the big screen, or heavy grading manipulation, I see no reason to burden a workflow and storage with HQ.
 
LT supports specs higher than what DSLR's produce. HQ is a waste of disk space and CPU horsepower for DSLR, AVCHD, and HDV footage. And if you're using Canon DSLR's, use their EOS Movie plugin for FCP's Log & Transfer to convert the footage. Retains metadata that's useful, as fast as any other method.
 
*scratches head


So Hq does nothing to the footage? On apple's website is sats Lt is for news broadcast and Hq for higher end media ( which I would like to think short films are )

Thanks for the replies
 
They're talking about the format you shoot in. No, transcoding to a codec that supports higher specs does NOT in anyway improve your footage. ProRes (all flavors) is lossless. HQ is a waste of time for any DSLR, AVCHD, and HDV footage. When Apple says higher end media, they mean "film" either celluloid or RED or Vipeer, etc, that actually has MUCH higher specs than what you're using.
 
Dont feel like an idiot! I always use HQ whether its a small film or trailer. When using 5D, 7D, and/or RED i would still recommend using HQ if you have the space. LT might look just as good on your computer but you never know when someone might say that they want to submit it to a fest and its going to be on a huge 100 ft screen and then it might be noticable.

My friend who is a professional DP notices a difference as the screen size goes up in size for the display of the project.

I usually Just ask ahead of time where/what the project is going to and for and then decide if its worth using LT or HQ.
 
To be very clear, there is absolutely no need for HQ when using DSLR's for any purpose. LT surpasses the H.264 bit rate, color sampling, etc. There is absolutely nothing to be gained using HQ with DSLR footage, ever. Even for a film fest, HQ adds no advantages to DSLR footage.

I'd also never group RED footage in the same category as DSLR footage, two completely different levels of compression. HQ and 4x4 are for use with RED, but do nothing by waste disk space with DSLR's super compressed H.264 footage.

When going up in screen size, I've never seen any difference. The digital pixels are the digital pixels that make up the frame. The projector can make a difference, though. We use a 200+ inch screen every month at our FCP users group meetings, we've show lots of stuff on it, compared, and don't see the difference.

You can use HQ, but technically, you're not gaining anything. You can't add quality to what the DSLR's H.264 records. That data is set, it can not be added to.
 
Hopw about panasonic 50mbps?

Hopw about panasonic 50mbps?

Interesting thread, was wondering if LQ is still suficiant for panagonic 50mbps or should standard 422 (or highter) be used)?

Ben
 
Is the same true for all AVCHD footage, as that out of the C100? I have been transcoding to HQ and yes it's quite the disk space hog. I'd love to use just LT with it.
 
DSLR is similar to AVCHD, think both use H.264. It depends on bitrate (which can be as low as 17 for AVCHD). I believe canon uses around 45mbps so if your AVCHD is not higher than this LQ should be fine. Do some tests and have a look (make sure you use stuff in low light and stuff with fast movement). One thing to bear in mind is that high bit-rate video is generally only necessary when you are going to really push the grade/do secondary colour correction so if you dont need to do any extreme or selective grading/colour correction it is not really nessesery.
 
there's a lot more than the bit rate going on, AVCHD / H264 is a both a spatial and a temporal compression, uses a full "ident" frame then 4 frames that only record the difference between the I frame and the frame in question.. so only 1 frame out of 5 is a real frame, the rest are invented by software

ProRez of any flavour uses a spatial compression but zero temporal compression, so to maintain the full I frame compression of AVCHD / h.264 ProRez Lt or DNxHD 36 are just not enough and you are capping image quality by using other one of them, even if their bit rate is higher as each frame of the h.264 decoder is presented as an "I frame" to the next process down the line

To maintain a visually lossless re-compression of AVCHD / h.264 you need ProRezHq or DNx115 at a minimum

Really the question is how visible is the loss taken by using a further de-compression and re-compression pass? As one poster mentioned it really depends upon the deliverable's target… you should be fine for web deliveries, but for anything going to broadcast or festivals the better / safer answer is not to add a layer of compression by using Lt or Dnx36, and use a intermediate codec that maintains everything the camera sends out, or just run uncompressed.. that's what i do when i have DSLR or similar footage to work with

I'm starting to grade a feature shot on 7D shortly, and i am working directly from the camera originals and in a uncompressed environment using Nucoda FIlmMaster

I can easily see the difference between the camera originals and a ProRez Lt proxie on the 16' screen in the grading theatre… the show was cut with Lt proxies, and it's imedatly apparent when i put up the screening copy output from PP edit system to check lip-sync against the camera orignals

But for the 99.9% of folks who us these cameras seem to mainly deliver to the web, that quality hit will never be seen by them or their clients… but using a Lt/Dnx36 proxie as a master is really not a best practice, or the best way to maintain the image quality… again it's more down to the question - should that really be a concern in any one particular case? Only the producer can make that call...

d
 
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Dermot said:
To maintain a visually lossless re-compression of AVCHD / h.264 you need ProRezHq or DNx115 at a minimum
Click to expand...

You had be ging there, was almost going to comment that I did not think prores or DNxHD were lossless but I know what you mean.

as a matter of interest are you saying that you can see the difference with 422 or 422 HQ also?

Ben
 
Someone ran a test on the Ninja with each prores flavor vs AVCHD from the c100.

AVCHD fell between 422 and 422 HQ. With fast motion it fell apart. I wouldn't say LT is necessarily good enough.
 
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