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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Canon 7D Zone Plate Shots

morgan_moore said:
While I dont dispute that 7d is way worse than Red I am a little suspicious of relying on zone plates to prove that..
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That suspicion will disappear once you've had a few crucial shots ruined by aliasing.

A lot of people make the mistake of not listening to Graeme and Jim. I've made that mistake myself. They say, "Yeah, but luckily I'm not shooting test charts in my commercial." Well, it's all fun and games until your clients see moiré horror shows in the dailies.... :hand:

The zone plates are basically warnings, kind of like when a rattler snake shakes its tail.

BTW, did I miss the action at DPreview? Links?
 
Indeed, that why Ive got a sony EX1 near me at times - it a safe but boring bet for delivering 'HD' on a budget - you wouldnt catch me shooting that roof on a canon

Graham

Anything to say about my potty data rate theories ?

S
 
Tom L said:
That suspicion will disappear once you've had a few crucial shots ruined by aliasing.

A lot of people make the mistake of not listening to Graeme and Jim. Myself included. They say, "Yeah, but luckily I'm not shooting test charts in my commercial." Well, it's all fun and games until your clients see moiré horror shows in the dailies.... :hand:

The zone plates are basically warnings, kind of like when a rattler snake shakes its tail.

BTW, did I miss the action at DPreview? Links?
Click to expand...

Aliasing also reduces the perceptual depth of field dramatically, making it much harder to pull focus on moving images. A side effect of that is it also tends to exaggerate age on talent (a common complaint at another camera company that had a very mild aliasing filter).
 
For people who are experienced, objective tests like these are great pieces of information to add to their arsenal. I, for one, appreciate knowing these technical limits of the camera.

The real problem is that for people who are starting off and lurking through these forums, seeing tests like these with no discussion to the real world values and implications can seem like the end all be all of how good a camera is. I know that I certainly almost got caught in that when I was starting off (HVX vx. EX1).
 
If you shoot those zone charts with the still mode of the 7D, 5D, 1D4, they will look damn good. It's not the chip that is the problem here, it's getting the data out fast enough.

Canon has been working on their CMOS for years (10ish) and they have incredible range and quality. Especially in low light now.

Look at the 1D4 - you can shoot 14bit, 10fps (28 frames Raw, 121 Jpg) uncompressed raw files with a mechanical shutter moving up and down at full resolution (4896x3264).

http://vodpod.com/watch/2397737-canon-1d-mark-iv-frame-rate-on-vimeo

When they added live view they realized they could get almost free HD video out of their bodies and didn't really put any dedicated hardware to it. So who know what will come in the next couple of years but it seems to me that they have many parts of the puzzle in place they just need to get the codec and read out perfected.

What they truly lack is the RED mentality. Doubt they will ever have it and that might be what gives RED the leg up in this market. I'm excited to see the Scarlet but I need S35 min, so lets see what it will cost me and what else is out there when Scarlet is finally available for purchase and we can buy what works best for what we shoot and what it will cost.

Competition is good, even for RED. It's all exciting stuff.
 
Graeme Nattress said:
http://www.cinematography.net/natress-red-res.html

is what I shot on RED One, and posted on CML. It actually shows detail out to 4k with minimal aliasing, which is nice, but past around 3.2k, the MTF of the detail is very low. This is practically optimum performance - high resolution combined with very low aliasing.

Graeme
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Have you tried the Zone Plate with the 7D/5DII with a Caprock 2.0 anti moire filter in place. I've seen footage with this filter and it seems to mitigate this problem with little if any loss in sharpness. If so, this all seems like a mute point.
 
I don't have access to either the 7D or the filter. An anti-moire filter can only work by blurring the image, because, well... that's how they work. They're a low-pass filter.

The problem is though, that the horizontal resolution especially is already so severely compromised, and that the aliasing is not as bad horizontally as vertically, that you'd not want to blur that any further. Vertically, you'd need incredibly strong blur to do anything at all with the aliasing. So ideally any such low pass filter should be much stronger vertically than horizontally and absolutely aligned to the sensor.

What you'd have to do is shoot proper charts to determine the effect of such a filter to see if indeed it does help sufficiently without vastly reducing resolution.

Graeme
 
Line skipping in RED ONE... don't shoot me!

Line skipping in RED ONE... don't shoot me!

Lauri Kettunen said:
...
In the same spirit, one may say the line skipping is (imagewise) a poor choice but as well from Canon managers' point of view this may be (costwise) a miracle and the engineers behind it are considered as genius. ...
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Why not adding line skipping in RED One for 2k/3k slow motion instead of only censor cropping?

It would have the great advantage of using the same optic caracteristics (dof/angle of view) and would not alter (?to be confirmed...? by RED scientists!!!) resolution compared to cropping.

Canon way of doing 30p on their sensor could also be usefull for RED slowmotion... (?)

I remember there was an endless discussion about line skipping for 1080 output and RED dicided they will not go this way. But would slow motion give the same resolution problems?

Any ideas? Graeme?

Pat
 
Patrick Tresch said:
Why not adding line skipping in RED One for 2k/3k slow motion instead of only censor cropping?

It would have the great advantage of using the same optic caracteristics (dof/angle of view) and would not alter (?to be confirmed...? by RED scientists!!!) resolution compared to cropping.

Canon way of doing 30p on their sensor could also be usefull for RED slowmotion... (?)

Any ideas? Graeme?

Pat
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I fear Graeme just spilled his beloved whiskey... :nono:

Even though I can see the use for this...
:emote_couch:

But, I think it would not have gained the R1's market penetration to take these kind of shortcuts, even though I guess they've tried it at some stage.
 
Patrick Tresch said:
Why not adding line skipping in RED One for 2k/3k slow motion instead of only censor cropping?
Click to expand...

Pat, LOL, cause RED is a professional camera. But, if line skipping is the trick to make a $1.500 DSLR with a usable HD video mode for some or perhaps many needs, that's not that bad idea from the Canon engineers. Especially so, if the additional cost is low. But RED is a different story. As Jim has said several times, RED is all about professional cameras.
 
Lauri Kettunen said:
Pat, LOL, cause RED is a professional camera. But, if line skipping is the trick to make a $1.500 DSLR with a usable HD video mode for some or perhaps many needs, that's not that bad idea from the Canon engineers. Especially so, if the additional cost is low. But RED is a different story. As Jim has said several times, RED is all about professional cameras.
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I'm afraid you din't get the point.

Pat
 
Too early in the day for whisky. I would have spluttered my tea all over my monitor if I'd been drinking at the exact moment when I read that.

Graeme
 
Thanks, Graeme. If I were planning to shoot a feature with a DSLR, I'd certainly think twice about it. I'd also like to comment on the very simple testing methodology used here. I get so much more out of a simple technical test like this versus the shoot-out style that everyone likes so much.

The results in this case are impirical, repeatable and objective. Shoot -out style comparisons are inherently subjective, non-impirical, often unrepeatable. I'm always skeptical of multiple-camera comparisons using different cameras but with the "same" lighting set-up for both, without regard for either camera's strengths or weaknesses.

The test in this thread gives me a benchmark for what I could expect a camera's performance to be. Setting up a scene with actors or a still-life and lighting it-- then shooting that scene with multiple cameras-- I'm unconvinced that such comparisons are relevant. You either fully take into account the DP's skill and experience or you eliminate it altogether (as Jarred and Graeme have done in this case).

DP's are expected to make technically proficient, aesthetically pleasing (or displeasing) imagery regardless of what camera they are using. They are expected to take into consideration a specific camera's strengths and weaknesses and deliver the best possible result. A shoot-out style test throws this principle out the window in favor of a forced-failure exercise. Forced-failure testing is important, but should never be the sole benchmark any piece of equipment's viability.

Even in the case of the DSLR's tested here - they are advanced instruments for professional image-making and they have their niche in the filmmaking world. I'd like to see more testing of this nature and less drama over these shoot-out comparisons that tend to reveal nothing more that the aesthetic proficiency of the people shooting them.
 
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