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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 looks quite Nice

When it comes to stills, I worship what Canon is doing. Their cameras allow me to do things I never dreamed would be possible a couple of years ago. When you can slap a $1,600 lens on a still camera that can match the IQ of a $100K Panavision lens, that's mighty nice.

Video... well, that's another story.
 
I love my Red and I love my Canon primes. Together, its a legit match made in cinematic frosty heaven.
 
Graeme Nattress said:
Can they do better?
Click to expand...

Perhaps they do some things wrong, but they also do some things right. You'll have to pry my Canon 200mm f1.8 lens out of my cold dead hands, best lens I have ever owned, and I have a lot of good ones, even faster lenses, but none with the same creamy purity...

still looking forward to putting it on a RED camera, but it isn't easy or inexpensive, when you consider that the price of the 3rd party mount that currently works with RED now exceeds the cost of the 7D....
 
Ian B. Johnson said:
Blah blah blah, in the end I guess what I'm really hoping for is for RED to respond and blow us all out of the water.
Click to expand...

HeHe - you nailed it. Dammit Graeme, we believe everything you're saying, so can you please just send us an invoice and then send us an epic-x ?!!! :biggrin::smile::party:
 
View finder that lies?

View finder that lies?

Graeme Nattress said:
Or my favourite problem is a optical viewfinder that positively lies about focus. I like to shoot shallow DOF as do so many, especially when I'm taking shots of the kids. But although your lens is wide open while you're viewing (unless you have the DOF preview button pressed), your lens might be F1.2, but the ground glass might have an effective aperture of around F4, making the effective DOF you see around F4, thus making you think you're in focus when you're absolutely not. Couple that with the recent 1D focussing issues and I'm unhappy. I've not spent as much on Canon gear over the years as Jim has, but I've spent enough.

Graeme
Click to expand...
Graeme,
The GG has the effect of ND not the iris.
Otherwise the 35mm adapters would not work...
See I am a careful reader:001_tt2:
 
optical theory of ground glass

optical theory of ground glass

OptiTek said:
Graeme,
The GG has the effect of ND not the iris.
Otherwise the 35mm adapters would not work...
See I am a careful reader:001_tt2:
Click to expand...

I believe Graeme is correct. I think ground glass does have the effect of stopping down, I have observed this in my DSLRs, and the theory makes sense. Think about it: the f/1.4 rays are all the high-angle-of-incidence rays and those do not contribute as much brightness to the image passing through the ground glass as normal incidence, or low-angle rays, because they have a lower probability of getting scattered out of the glass towards your eye, than rays that are already going in that direction (near-normal incidence). You can reduce this effect by making the ground glass a more perfect diffuser, which means more opaque, moving towards opal glass, but with the obvious detrimental side effect of not being as bright a viewfinder. The brighter the viewfinder is, the less scattering it is doing and that means it is capturing less of your high-angle incident light.
 
The 7D adds new frame rate options, but from the videos I've seen, the aliasing and other problems are just as bad as the 5D2. They both have some really nice features:

  • Thin DOF
  • Low light
  • Lens selection
  • Size/weight
  • Price

But they also have many issues that affect image quality:

  • 8-bit
  • jaggies
  • 4:2:0
  • stair-stepping
  • posterization
  • unwanted sparkling
  • macroblocking
  • wavy lines
  • poor resolution
  • bands
  • skew
  • popping
  • ergonomics
  • fringing
  • exposure aids
  • snap-to-grid look
  • patterns
  • mosquito noise
  • contouring
  • strobing
  • discoloration
  • false detail

Of course, there are very few people who notice the problems. And of those, only a very tiny minority think they disqualify the camera on the basis of image quality. One such person is Alan Roberts, who wrote the White Paper disqualifying the 5D2 for the BBC.

My question is: how much worse could Canon make it before more people would start to agree? What would it take? 25 Mbps DV compression? Even more aliasing (if that's possible)? Skew as bad as the D90? Even worse resolution?

I am convinced that neither aliasing nor skew, neither 8-bit nor banding, neither the softness nor the discoloration, nor any false detail, nor anything else in all of the worst artifacts, will be able to separate Canon users from their love of the DSLR video.

Personally, I can barely stand to use my 5D2 for home videos. I do it anyway because I know the rest of my family wont care. Same with the wedding and corporate video projects I've done on the 5D2: they don't mind the many prevalent artifacts.

RED, when are you going to realize that no one cares about image quality? You're wasting your entire effort just to avoid artifacts that no one thinks are objectionable. Most of them actually *like* aliasing! Just give them big sensors and cheap prices. The more artifacts the better. If you move fast, you might be able to add more aliasing than Canon. I suggest skipping 9/10 lines instead of just 2/3: then you will really leap-frog them. Better to have poor image quality and high sales than high image quality and poor sales.
 
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Still...

Still...

jbeale said:
I believe Graeme is correct. I think ground glass does have the effect of stopping down, I have observed this in my DSLRs, and the theory makes sense. Think about it: the f/1.4 rays are all the high-angle-of-incidence rays and those do not contribute as much brightness to the image passing through the ground glass as normal incidence, or low-angle rays, because they have a lower probability of getting scattered out of the glass towards your eye, than rays that are already going in that direction (near-normal incidence). You can reduce this effect by making the ground glass a more perfect diffuser, which means more opaque, moving towards opal glass, but with the obvious detrimental side effect of not being as bright a viewfinder. The brighter the viewfinder is, the less scattering it is doing and that means it is capturing less of your high-angle incident light.
Click to expand...
While you are basically correct the diffusion effect has nothing to do with DOF
and view finder "that lies"-the image is getting darker but the DOF won't change as it is strictly a function of magnification and f-stop -hence my ND effect comment...
 
Daniel Browning said:
RED, when are you going to realize that no one cares about image quality? You're wasting your entire effort just to avoid artifacts that no one thinks are objectionable. Most of them actually *like* aliasing! Just give them big sensors and cheap prices. The more artifacts the better. If you move fast, you might be able to add more aliasing than Canon. I suggest skipping 9/10 lines instead of just 2/3: then you will really leap-frog them. Better to have poor image quality and high sales than high image quality and poor sales.
Click to expand...

:sarcasm: But, you're right, Daniel.
 
OptiTek said:
While you are basically correct the diffusion effect has nothing to do with DOF
and view finder "that lies"-the image is getting darker but the DOF won't change as it is strictly a function of magnification and f-stop -hence my ND effect comment...
Click to expand...

:-) Try it and see for yourself. :-)

Modern ground glass for optical viewfinders are designed for brightness. They're not just a glass that has been ground. They do have an effective optical aperture and do effect DOF. It's their dirty little secret.

http://www.dphotoexpert.com/2007/09/21/live-view-versus-the-cheating-dslr-viewfinder/

has some very good photos showing the effect quite clearly.

Graeme
 
Graeme, that I keep looking his avatar expecting it to move a la Esquire cover. Maybe something to ask Jarred about.

I don't have anything to add to this very interesting conversation. I am trying to keep up without skipping too many lines. :)
 
Graeme Nattress said:
:-) Try it and see for yourself. :-)

Modern ground glass for optical viewfinders are designed for brightness. They're not just a glass that has been ground. They do have an effective optical aperture and do effect DOF. It's their dirty little secret.

Graeme
Click to expand...

Another reason a ground glass mirror reflex finder is an anachronism in the digital age, especially on a camera with video functions.
 
Daniel Browning said:
Of course, there are very few people who notice the problems. And of those, only a very tiny minority think they disqualify the camera on the basis of image quality. One such person is Alan Roberts, who wrote the White Paper disqualifying the 5D2 for the BBC.
Click to expand...

Someone better tell Phillip Bloom to stop doing international spots with it then. :rolleyes5:
 
Internet articles

Internet articles

Graeme Nattress said:
:-) Try it and see for yourself. :-)

Modern ground glass for optical viewfinders are designed for brightness. They're not just a glass that has been ground. They do have an effective optical aperture and do effect DOF. It's their dirty little secret.

http://www.dphotoexpert.com/2007/09/21/live-view-versus-the-cheating-dslr-viewfinder/

has some very good photos showing the effect quite clearly.

Graeme
Click to expand...

With all due respect,
The fact that someone wrote article on internet does not mean it's true.
His observations are correct but the notion incorrect.
In fact I ran into the same issue recently while designing microscope to calibrate the Optimator. I could go on explaining the phenomenon but it's really irrelevant here- I don't think I can convince you.
Oh those camera manufacturer's conspiracy theories....:Angel_anim:
 
If you'd care to educate us on how the ground glass is effecting the DOF that we see, I'd be happy to learn. I'd observed the effect and found it as frustrating as hell when trying to shoot on a fast prime. I'd very much like to know exactly why we see the effect we see. (I was pointing to that article as it has the best pictures illustrating the effect that I know of - I was not pointing to that article as explanation of the effect as really, it doesn't explain it, just illustrate it.)

Graeme
 
in that case...

in that case...

Let me try:
Part 1: ground glass grain
Typical grain size on the ground glass is about 20microns
Typical pixel size- 5 microns
As you can see the ground glass resolution is limited by the grain size
consequently anything up to the 20 microns grain will appear in focus. Since the sensor has higher resolution it will throw things out of focus way beyond the GG capability.
part two: Hybrid imaging:
This is a bit more complicated -not a problem for Graeme:wink5:
In order to make the image in center at least brighter they started to polish the grain a bit so you can see both the screen image and the areal image at the same time.
This is great for on axis or close to it but it causes havoc off axis as the areal image is not visible there any more. Additionally for high magnification macro imaging the depth of field become depth of focus and for a highly adaptive instrument such as human eye makes it easier to adjust and see things more clear-which in this case happens to be a bad thing....
There are other factors as well but hese are the two main causes of the discrepancy between GG and sensor.IMO
BTW I always admired operators that from this tiny, grainy and dark, sometimes distorted image on GG can visualize amazing stories- and I know a few that swear by it...
 
My theory has always been simple for stills cams

-GG is often not correctly aligned with the chip causing misfocus

-the eye struggles to resolve properly on a small area like GG

Eg I used to think that everything was sharp that I shot - badly scanned film and 6mp digicams

When I got a 22mp hassy I realised I was often misfocussing, when I down rezzed those files to 6mp I could no longer resolve on (computer) screen the misfocus

IMO handheld use of DSLRs there is little value in having more than 16mp because movement and misfocus become the limiting factors in terms of ability to resolve not MP

maybe it is more complex

S
 
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