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Canon EOS Crop Sensor for HD
APS-C sensor cameras including the 80D, 70D, 7D Mk. II, 7D, EOS M and Rebel models for HD video recording.


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Old October 27th, 2009, 10:58 PM   #16
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Agreed, Daniel. Every time I picked up the 5D Mk2 to shoot video, I had to be paranoid about avoiding shingled roofs, close vertical-lined fences, vehicle front grills, people wearing striped shirts etc. Often the moire and other artifacts showed up on the computer screens even without down-converting or scaling. I sometimes think these large-sensor DSLRs are made to shoot specifically background blurring scenes.
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Old October 27th, 2009, 11:59 PM   #17
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Originally Posted by Jonathan E. Shaw View Post
in the real world experience of these cameras (which I know is highly subjective) the image quality (resolution, color depth, sharpness, etc.) is incomparable. The HV20 looks like consumer HD, nice enough if that's your thing, and the 5D Mark II (sorry, no 7d yet for me) is a world better. Breathtakingly better.
I know exactly what you mean, and that is what people respond to. But the question was regarding actual resolved resolution. And I stand by my answer.

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Also, can you explain how resolution (both of which are 1080p) is better one on than the other?
1080p specifies the recording format. It doesn't specify how much detail is in that shot.

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You obviously aren't talking about raw lines of resolution, right?
That's exactly what I am talking about, yes. What I am not talking about, is the recording format. 1080/24p (and 720/60p, etc) are recording formats. They are not "resolutions". They do not specify how much detail is perceivable, they only reference that it's a video recording format with 1080 lines, etc.

You could dub VHS over to 1080p, and have a 1080p recording with VHS resolution. Saying that something records 1080p doesn't imply that you will actually see 1080 discernible lines of detail!

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Because in your above post it kind of sounds like Canon is practicing false advertising claiming that the 5d and 7d shoot full 1080p video, if you are saying it resolves only 500 lines.
I'm not saying anything of the sort about false advertising or anything like that!

What I'm saying is that it resolves about 500 lines, maybe 550, which is what it does. Put it on a chart and take a look, you'll see. There is no actual detail beyond about 500, maybe 550 lines, when in 1080 mode. Which, by the way, is about the same as an HVX200, which has been an extremely popular HD camera for nearly four years. The amount of resolved detail is only one aspect of picture quality, and is, in fact, arguably one of the least-important factors.

The HDSLRs let an absolutely massive amount of aliasing through, which goes to help their perception of "sharper" images, but it is not actually resolvable detail. It's false detail, and it's an inaccurate representation of what was actually imaged. In many cases it looks great (because, when shooting a face, who cares whether the hairs being rendered are exactly in the right position or not? Who cares if a freckle isn't rendered in the exact spot it is in reality?) In some cases, it backfires and causes objectionable artifacting. But aliasing is not resolved detail.

Back to your question about "500 lines not being 1080" -- you can't find a camera out there, short of maybe an F950 or HPX3700, that can resolve a full 1080 lines. The HV20, etc., that class can handle about 700 or so. An HMC40 can handle over 800. An EX1 or HPX300 can easily resolve 800, and I don't know how much more because the chart I tested them on only went up to 800! And those cameras do so without aliasing.

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All that to say, if we charted these cameras up, one might have statistically better video resolution
By a huge margin, yes.

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but I'll tell you right now which one "looks" better. And I'd be shocked if 100% of people you showed side by side footage to of each camera didn't agree with me.
Agreed. But charts don't lie, and the problems that you'll see on a chart may very well show up in real world footage. Aliasing causes artifacts like moire, jaggy lines, and -- on the Canons, at least -- color pollution. Look at the chart for a 5D or 7D some time, you'll see some things that are simply not typical of a conventional video camera. Those type of things manifest themselves in rainbow-color moire, weird moving patterns in tiled roofs, chain-link fences, certain patterned fabrics, window blinds, fences, brick walls, anything with a repeating pattern of detail is a potential failure point.

Where the DSLRs excel is in natural shooting -- faces, natural landscapes, etc. Nature doesn't have patterns of repeating detail, like vinyl siding on a house or a pattern of windows on a building or perfectly straight lines. But manmade, that's a different story. Look at this photo and see what happens and the unpredictable nature of it -- same camera, same shot, but when you're at just the wrong distance, moire and colored jaggies spring out:


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I'd be thrilled to show something shot really well on a 5d to a client, not so much on the HV20, even if it were the same project, shot the same way.
Depending on what you shot, I'd agree. But there are some things that you could be disappointed to have to show to a client, such as... oh, a bridal veil at just the right distance that turns into a massive purple/orange blob... or an architectural shot where the windows are a shimmering purple and the roof has a wavy bizarre pattern on it (a few roof examples in this video, shot on my 7D):
video
SOMETIMES those things will look fine. But when you're at the right combination of focus and magnification, these false patterns emerge and can ruin the shots.

Point is, aliasing is a two-edged sword. It can make images look far sharper than they have any right to, and it can pollute the images with false detail and false patterns that can be very distracting.

But back to the original question of resolved detail -- shoot a newspaper at various distances with the HV20 and with the 5D or 7D or GH1 or whatever. You'll find that you can easily read and discern the text on the HV20 at significantly smaller type sizes than the DSLRs can resolve. That's because the raw resolving power just isn't there, and aliasing can't fix that.

"sharpness" doesn't equal resolution. The HDSLRs don't have all that much actual resolution. They do offer the perception of sharpness (and artifacts can come with that) but as for pure resolution, they just don't have that much.
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Old October 28th, 2009, 12:18 AM   #18
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Quote:
Originally Posted by Barry Green View Post
Where the DSLRs excel is in natural shooting -- faces, natural landscapes, etc. Nature doesn't have patterns of repeating detail, like vinyl siding on a house or a pattern of windows on a building or perfectly straight lines.
Barry knows this already, but for what it's worth, some people are strongly allergic to aliasing even in natural shooting.

For example, the following natural image has strong aliasing:



And here it is the same image with much less aliasing:



To me, the aliased image looks fake, disjointed, and "digital", whereas the anti-aliased image looks realistic, natural, and "filmic". For me, natural images with aliasing is like looking at the natural world through a screen door. A lot of other people, though, prefer the look of the aliased image.
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Old October 28th, 2009, 12:41 AM   #19
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To me the 7d looks great in low light and night scenes because of all the surrounding illumination it picks up on the subject matter. However, during the daytime the 7d looks nothing special compared to other cameras and its low resovling power starts to show.
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Old October 28th, 2009, 06:54 AM   #20
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Good info and comments.
If we could summarize a too large topic, the main point should be that this DSLR technology for narrative work must be used with a lot of care concerning it`s technical limitations.
Real world experiences like Steve Mims should also be considered.
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Old October 28th, 2009, 08:43 AM   #21
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Originally Posted by Daniel Browning View Post
Take a nice, natural, unprocessed raw clip from the RED ONE. Apply normal sharpening to one and ridiculously over-the-top sharpening to the other. Guess which one 100% of people will pick "looks" better? The oversharpened one.

Now apply normal saturation to one version of the raw file, but oversaturate the other raw conversion until the grass is bright neon. People will pick the neon grass every time.

Leave a nice, small amount of noise in one version, providing subtle texture throughout. Apply heavy-handed plastic-like noise reduction to the other. 99% of people pick the plastic.

Convert one to use a full 9 stops of dynamic range with detail in the blacks and whites. In the other version clip the whites and crush the blacks for extremely high contrast. People pick the high contrast image every time.

Convert one to show the maximum possible detail at 1920x1080 with no aliasing artifacts. Make another version that has barely 720x480 worth of resolution, but is riddled with aliasing artifacts. Most viewers will pick the junky aliased image.

Render the audio to use a 40 dB of dynamic range and compare it with one that is compressed to within an inch of its life. Listeners pick the "louder" compressed version.
If this truly is the case, then what's the argument here?
Who cares if the 7D doesn't have the resolution of the EX1 if there isn't a demand for it?
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Old October 28th, 2009, 09:22 AM   #22
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It would be a case of picking the camera for the job or perhaps even the shot in hand. If the DSLR has the look required and meets the needs of the story (subject to satisfying any commissioning broadcasters technical requirements etc) that could be the camera to go for. Or, perhaps use it as the B camera for the shots that its strengths are a requirement.
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Old October 28th, 2009, 10:56 AM   #23
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Why is everyone getting their knickers in a knot, the 5D and 7D really are fantastic stills cameras :-) If I was honest though I am using a 7D as a B-Camera on a documentary shoot in a couple of weeks not for the look as much as it's small form and low light capabilities.
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Old October 28th, 2009, 11:47 AM   #24
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Originally Posted by John C. Plunkett View Post
If this truly is the case, then what's the argument here?
Who cares if the 7D doesn't have the resolution of the EX1 if there isn't a demand for it?
That's only one possible response: if people want junk, give them junk. If they want to eat a bag-full of high fructose corn syrup for dinner, give it to 'em.

Another possibility is that they only *think* they want junk. On a different level, maybe even subconsciously, they actually like and appreciate the quality image more. They might *say* they want to eat a bag full of candy, but if you give them a 5-star dinner by a world-class chef instead, at the end of it they will actually have liked the dinner better than if they had eaten candy.
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Old October 28th, 2009, 12:12 PM   #25
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Originally Posted by Barry Green View Post
"sharpness" doesn't equal resolution. The HDSLRs don't have all that much actual resolution. They do offer the perception of sharpness (and artifacts can come with that) but as for pure resolution, they just don't have that much.
Isn't the reason for the lack of resolution and the aliasing artifacts with HDSLRs due to how the information is read off of the chip and "binned" and compressed? It isn't due to a specific limitation of the CMOS chip and the optics, which should theoretically be capable of spectacular resolution. Ultimately isn't the cure to this problem new software (and I don't mean a firmware update) for reading and "binning" the pixels off of the CMOS chip and compressing the data stream?

If that is so, then the current generation of HDSLRs can be looked at as an early stage of the evolution of such devices for video use. They can produce spectacular results in some circumstances, but they have serious limitations. It seems that these limitations could be addressed in future products.

Whether the companies will do this is up to debate. Perhaps at the price point of current HDSLRs, manufacturers will saddle the cameras with these limitations, and will come out with higher end (more $$$) camcorders using the current chips and lenses of HDSLRs, but improved software, to differentiate the market.
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Old October 28th, 2009, 12:32 PM   #26
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David,

The problem is that at the current technology level, sensors that are the best for stills are not capable of the fast frame rates required by motion.

To get around that, less than the full info. is used from the sensor when a camera like the 5D is in video mode, which allows for faster reads.

But it's not just software, there are real design challenges.
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Old October 28th, 2009, 12:55 PM   #27
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Originally Posted by David Sholle View Post
Isn't the reason for the lack of resolution and the aliasing artifacts with HDSLRs due to how the information is read off of the chip and "binned" and compressed?
Yes, exactly.

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It isn't due to a specific limitation of the CMOS chip and the optics, which should theoretically be capable of spectacular resolution.
They are capable of spectacular resolution. I shot a side-by-side of the 7D in movie mode, vs. the 7D shooting the same scene in motor-drive stills mode (6fps) and then resized the stills in PhotoShop to 1920x1080. It was shockingly better.

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Ultimately isn't the cure to this problem new software (and I don't mean a firmware update) for reading and "binning" the pixels off of the CMOS chip and compressing the data stream?
Yes but no. The whole reason they have to do the pixel binning/line skipping thing is because the sensors cannot be read fast enough to deliver motion at full resolution. These are still-camera chips, with maximum read speeds of maybe 8fps. To get them to 24fps (or even 60fps!) they can't read the whole chip, hence they have to bin pixels and/or skip lines, and it is those processes that cause the aliasing and color mushing to occur.

Plus there's the whole other topic of the anti-alias filter, which you simply cannot do for both modes. Either it's tuned for stills, or for video, but not both. And in the HDSLRs, it's tuned for stills, designed to let a 14-to-18 megapixel image through. And that is what lets all this aliasing through in the video modes.

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If that is so, then the current generation of HDSLRs can be looked at as an early stage of the evolution of such devices for video use. They can produce spectacular results in some circumstances, but they have serious limitations. It seems that these limitations could be addressed in future products.
Agreed 1,000%.

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Whether the companies will do this is up to debate. Perhaps at the price point of current HDSLRs, manufacturers will saddle the cameras with these limitations, and will come out with higher end (more $$$) camcorders using the current chips and lenses of HDSLRs, but improved software, to differentiate the market.
Not with the current chips -- that's a hardware limitation. One company is addressing the chip read speed and will introduce an HDSLR that will have no such compromises; they should announce that the day after tomorrow.

But let's be clear on something: the companies aren't "saddling" anything with limitations! They're offering low-cost products. It is no more fair to say that they're "saddling" the current cameras with limitations, than it would be to say that a laptop manufacturer is "saddling" their netbooks with Atom chips. It's all about price point. Pay $6,000 and you can have a Core i7 chip. Pay $299, and you get the Atom. That's how it works. Better chips cost more. And these cameras' chips are still-camera chips, not designed for video at all. In terms of video performance, these cameras have given us the Atom chip right now (limited to 8fps read speed). If/when they produce the 60fps or even 120fps barnstormer we all want, I guarantee you it won't cost $1699, any more than a screaming Mac Pro Octo-Core is going to cost $599. You got $599, you get a Mac Mini, that's how it works. You want an Octo-Core Mac Pro, you find $5999 in your wallet for that. The cameras will be the same way.
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Old October 28th, 2009, 12:58 PM   #28
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Daniel,

The aliased image is also slightly warmer, which will cause more people to pick it.

I brought both grabs into Avid and CC'd just the non-aliased one to make it warmer.

I think it looks more appealing.


"AliasingNoCC4" is the aliased file, untouched, just imported into and exported from Avid.

"NoAliasingCCd4" is the non-aliased color corrected in Avid to make it warmer.
Attached Thumbnails
"Real" 1080 24p resolution-aliasingnocc4.tif   "Real" 1080 24p resolution-noaliasccd4.tif  

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Old October 28th, 2009, 01:02 PM   #29
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Barry, Daniel : How About Adapters

Very interesting discussion. I attempted to shoot a close up of a computer screen with the 5D for a narrative film, and the moire was horrible. I got the HV20 out, and it avoided the problem for the most part. Kind of proved Barry's and Daniel's points to me.

That being said, I would rather shoot the 5D (especially when it gets 24p added) over the HVX200 which had been the standard bearer for "Rebel" digital film makers. That camera was poor in lower light situations, and grained up pretty quickly, even in open daylight shade, when using a 35mm adapter. And from Barry Greens assessment, it sounds like the 5D resolves as good as HVX200, and I am guessing that he is referring to that camera before you drop an adapter on it.

And let's face it. Barry and Daniel can tell us we are getting better resolution in the HV20 and its progeny (and I agree as I have one) and in other HD Cameras, but when you slap an adapter on those cameras to get to the depth of field characteristics we are looking for ( and that is, afterall the only reason we shoot this camera over regular video cameras), does the Canon come out on top, even resolution wise ? I would be curious about comments and anyone's testing there.

I for one am thankful, as an enthusiast who shoots no budget films, that I have access to full frame sensor cameras to work. I am also inspired by the professionals who are doing some amazing work out there and selling it, using this camera. And, afterall, the goal we all have is a watchable film.

In that respect, I have to challenge the comparison Dan raises between a bag of candy and a five star meal at a pretentious restaurant..... that may be his preference, but I would wager a lot more out there would opt for a pizza or burger....because of the waste of money associated with the overkill at that five star restaurant. The same would apply to choice of cameras, depending on your need.
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Old October 28th, 2009, 01:44 PM   #30
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That's only one possible response: if people want junk, give them junk. If they want to eat a bag-full of high fructose corn syrup for dinner, give it to 'em.

Another possibility is that they only *think* they want junk. On a different level, maybe even subconsciously, they actually like and appreciate the quality image more. They might *say* they want to eat a bag full of candy, but if you give them a 5-star dinner by a world-class chef instead, at the end of it they will actually have liked the dinner better than if they had eaten candy.
Not meaning to inflame any situation, but I think everyone here has a pretty good idea of who their client base are or at least the scope of their projects overall. I know for my purposes the footage I can achieve with the 7D is going to work just fine for my clients as well as for the viewing public. Having achieved this at a third of the cost of the EX1, my bosses are also pleased.
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