5D Aliasing

Dave ©

Dave ©

Well-known member
I shot some footage of my daughter over the weekend and was a little disappointed when I got home and started editing the footage to see this:



Aliasing is quite apparent looking at the walls of the drain pipe. However, when you download the file and watch it closer to full size, the video looks OK (it's not great footage -- focus, etc -- but the aliasing doesn't seem as bad).

Would you consider this normal? Is there any way to reduce the aliasing for web viewing (ie. via Vimeo)?

Here is a link to the video on vimeo: http://www.vimeo.com/10389404
 
I've been wondering the same thing. At full-screen size, the original file looks fine as far as the lines on the pipe go. I tried resizing & recompressing in Compressor with Frame Controls and Statistical Prediction enabled (higher quality resizing algorithm) and still got nasty aliasing on the output. One quick and dirty way of doing it would be to add a slight blur to take the edge off the high-detail areas, but that's pretty unsatisfying. It seems a better method of downscaling is needed.
 
I dont think that theres anything wrong here, show this vid to random person a ask whats wrong with it ,he will probably wont guess that some aliasing appears on black/white borders.
DSLRs have aliasing we all know that and we cant do ANYTHING about this reallly besides making our footage worse in quality ,when seeing threads like this im wondering if this became obsesssion for some folks ,aliasing is not that big deal for most people watching you know?
People dont really care about this ,people who always want more more more moremore care about that,if its not acceptable - sell your cam,its simple.
But first ask random peoples whats wrong with vid but dont tell them anything about aliasing and moire.
Ive seen aliasing many times on my TV on movies ,do you think i got scared and turned it off or something ?It didnt stopped me from watching.
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theres more aliasing on vimeo because resize algorithm is similar to line skipping in dslrs.
 
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bwwd said:
I dont think that theres anything wrong here, show this vid to random person a ask whats wrong with it ,he will probably wont guess that some aliasing appears on black/white borders...aliasing is not that big deal for most people watching you know?
Click to expand...

I hear ya and am almost always right there with you regarding the extreme focus on technical quality vs. aesthetic quality. To be honest, I had to look up "aliasing" on wikipedia 'cause I'd heard the term but didn't know exactly what it was. I say that to emphasize that I don't get too caught up with the technical side. Usually, if it looks good to me and sounds good to me, I'm happy. But for some reason, this just really jumped out at me as looking kinda bad (which is why I started searching around to see if I did something wrong).

I asked my wife if she saw anything wrong with the footage and said, "No."

Thanks for the input. I appreciate it!
 
If the original file looks ok and the compressed one has artifacts, then this is compression issues. This is quite usual when files are scaled down.
 
Fix this in post, easy
Track the camera shake, and just put a still frame (maybe with some photoshop touchups if you want) on there and your done.
Your lucky, no hard masking because she doesnt cover the bad spots on the right side.
 
This shot is kind of a worst case scenario for aliasing/moire, as well. It looks kind of like a circular resolution chart :)
 
kevinottawa said:
Fix this in post, easy
Track the camera shake, and just put a still frame (maybe with some photoshop touchups if you want) on there and your done.
Your lucky, no hard masking because she doesnt cover the bad spots on the right side.
Click to expand...

Great idea. I'm going to try this when I have time this weekend. I'll put up another video with the "after" shot if I get anything successful.

Thanks.
 
It seems that shallow DOF is the main situation you want to use the vDSLRs in.

Where this effect is a huge problem is if you are interviewing somebody with stripes on their shirt etc... Then it becomes something people will notice.

Maybe someday we will once again use tools that do not have these CMOS/line skipping and other limitations. I know people say others don't notice, but how much are we going to horsetrade as professionals with our image quality? With the skewing, the flash exposure and now the line skipping, what is next?

This list of what we should not do with the cameras seems to be growing.
 
Please , 2-3 years ago you wouldnt even DREAM about filmic depth of field for this price,sell your DSLR if something is so wrong with it.RED doesnt have problems with aliasing, you want to know the price ?
We are where we are and there is no cure to aliasing really without sacrificing quality and blurring it out,accept it or sell it.
 
Precisely my point.

You (and everybody else) seem to be willing to trade image integrity for being able to get something cheap, high resolution and now. This trend all started with the up-res chips of the HVX cameras.

Sure the image quality is nice and the shallow DOF is at never before at this price levels, but I see this "good enough" mentality being the prevailing mode of thought. "Clients will never notice it". "its just a little noisy in the shadows" "You only see it if you really look for it"

If we marginalize professional standards, who will want to pay for a professional?

I won't sell my DLSR because I use for still work.

RED is a video camera. So its design eliminates this.

I hear you, it is what it is.
 
Which is why people going out and selling their proper video cameras for an HDSLR is not very smart. What if you're in a situation you cannot change where the camera cannot handle the detail it is being presented? Your client wants an interview with a person who is wearing an outfit that is causing noticeable aliasing...are you going to ask them to go home and change?
 
Bassman2003 said:
Where this effect is a huge problem is if you are interviewing somebody with stripes on their shirt etc... Then it becomes something people will notice.
Click to expand...

For sure.

Bassman2003 said:
...how much are we going to horsetrade as professionals with our image quality?
Click to expand...

Well, I'm not a professional...yet...but thanks for the compliment. I don't really think I'm horsetrading anything. I happen to have a camera that shoots video that I'm more than pleased with 99% of the time. This just happens to be one piece of video that I am not 100% pleased with.

But this horsetrading you speak of sounds interesting. Tell me more!
 
Bassman2003 said:
RED is a video camera. So its design eliminates this.
Click to expand...

Why is the RED thrown into almost every single one of these threads? If I wanted to buy a RED, I would. My questions are about the 5D. If I have questions about the RED, I will go to REDuser and ask them.
 
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