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General HD (720 / 1080) Acquisition
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Old January 18th, 2005, 07:48 AM   #61
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<<<-- Originally posted by Juan M. M. Fiebelkorn: Any decent modern SRL lens (call it Canon, Nikkor,Zeiss,Leica or even Pentax :) ) easily exceed an "aerial resolution" of 100lp/mm.
Limitations are not in fact related to the lenses themselves but to contructive characteristics of camera body, shutter mechanism, ambiental/weather conditions and negative itself.
(think about that an ultra prime lens is supposed to resolve beyond 600lp/mm "aerial" and you will never get much more of around 80 lp/mm on 35mm movie film negative no matter what you try to do) -->>>

Can you tell what you mean by "aerial resolution"?
If we take the best canon lense for slr: EF 200/1,8L USM
http://www.photodo.com/prod/lens/det...8LUSM-56.shtml
It has mtf of 0.71 with 40lp/mm.
So I can't believe that it resolves anything above 100lp/mm.
Zeiss digiprimes have 90% mtf at 56lp/mm. From that I believe that they still resolve something in 100lp/mm, but not much after that.
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Old January 18th, 2005, 02:24 PM   #62
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"aerial" is the resolving power the lens give for an image before hitting the negative, I mean it is the "actual" resolving power of the lens not affected by any mechanics or negative.
Zeiis uses it all the time.Make a deep search at their page and you will find it.
BTW.I tested A Pentax 50mm F 1.7 long time ago and with a low ASA intermediate stock it resolved around 90 Lp/mm at F 4.0.
(using open shutter and a flash light.
When we did the same using the mech shutter it went down to around 49 lp/mm)
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Old January 18th, 2005, 02:30 PM   #63
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<<<-- Originally posted by Juan M. M. Fiebelkorn : "aerial" is the resolving power the lens give for an image before hitting the negative, I mean it is the "actual" resolving power of the lens not affected by any mechanics or negative. Zeiis uses it all the time. -->>>

There's no sense talking about lp/mm figures without MTF.
Do you honestly believe that Zeiss would advertize their Digiprimes with 56lp/mm if it would be hundreds with some mtf?
Or do you think that your Pentax is so much better?
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Old January 19th, 2005, 07:29 PM   #64
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Ok.I'm not trying to argue.
I'm just saying the normal SRL Lenses you use are enough for motion picture and for HDTV.
You say they aren't.
Here the conversation ends.
I won't change my point of view because it came from my own tests.And you won't change your point of view cause probably you have your own different experience, so there is no point to keep posting about this here.
Bye :)
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Old January 20th, 2005, 03:42 PM   #65
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I'm not saying that they are not "enough".
I'm just saying that it might not be optimal format.
With 4/3" would be easier to focus and lenses would be smaller and lighter weighted.
And compering the zooms that are available, it seems that you could get bigger apertures with 4/3" than with 24x36 size, so that compensates lesser sensivity of smaller chip.
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Old February 17th, 2005, 02:56 PM   #66
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<<<-- Originally posted by Chris Hurd : ...any of the current Canon Optura series camcorders (which have an RGB filter) will match the look of the older three-chip Canon XL1 and GL1 camcorders under the proper lighting conditions... -->>>

Chris,

Which Optura do you consider current? I recently did a comparison between an Optura-10 and my GL2 hoping to use the smaller camera on some riskier shots. I was pretty disapointed. Once it was in the NLE, the shots looked like the difference of film and video. Granted, the GL2 settings were tweaked, but I wouldn't say the cams were even close. In fact, color was the big penalty, the reds on the Optura were dull and the greens were grey.

You must be talking about the newer Optura-40 or somthing I haven't seen, no?
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Old February 17th, 2005, 08:51 PM   #67
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The Optura 10 uses a CMY filter, the new Optura's use RGB. Check this chart:

http://www.dvinfo.net/canonoptura/articles/compare.php
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Old February 18th, 2005, 01:12 AM   #68
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The interesting thing about digital SLR's is that when the lighting gets bad we use a flash to give what is needed for that single ccd. If we could always shoot video with a huge light a single ccd video camera will look good. Try using your digital SLR in bad lighting with no flash and it will look pretty bad.
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Old February 19th, 2005, 06:57 AM   #69
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Thomas,
sensivity is just about pixel sizes.
If resolution is constant, then is't just about chip area.
Eg. 2/3" 1-chip has area of 4x1/3" so it is more sensitive than 1/3" 3-chip camera.
There isn't any magic in 3ccd's.
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Old February 21st, 2005, 10:19 AM   #70
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Doesn't 3 chips give you more detail in your picture than a 1CCD?

Sorry if it's a stupid question.
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Old February 21st, 2005, 02:11 PM   #71
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3 CCDs in a beam splitter arrangement will give you more resolution that 1 of the same CCDs with a Bayer mask because there is no interpolation. And then the pixel offsetting trick yields a bit more still. But then remember that the green channel provides most of the picture information, that in a Bayer chip half the pixels are green sensitive, and that in DV 3/4 of the color information is tossed out and you can see that the engineers have a very interesting trade space in which to evolve their designs.

And it certainly is not a stupid question.
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Old February 21st, 2005, 04:42 PM   #72
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Old February 21st, 2005, 08:55 PM   #73
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> I have some canon ef lenses, so using them with
> moving image sounds tempting, but I believe focus
> pulling in documentary style shooting with 36mm
> wide imager might be too hard.

No. Well... yes, it would be hard if you used the larger apertures. But having a large sensor and lenses, you have more light to work with so if you were to film documentary style, you would expose at the slowest possible shutter speed and keep the lens at the smallest aperture. Thus, larger optics don't keep you from having wide DOF, rather they give you the option to control DOF.

Anyway, we are way off-topic. My proposal to camera makers is, make a camera with a single large sensor, and if you can't make a low cost 35mm sensor, go as large as possible but small enough to keep the camera below US$5k and have it include a built in ground glass or similar intermediate surface, and a 35mm photo mount which accepts servo-focus lenses.
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Old February 28th, 2005, 10:09 PM   #74
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I like this little topic

Who does make the ccd's? the majority?

Matsushita or Sony?

The reason most cams are 1/6th of an inch are they are made in a crap full and outsourced (like intel or amd chips)

We will be seeing more small ccd's its just the market, if they start making one 2/3 ccd's performance and low light go up but the ratio of production drops(for every slab less peices come out good) same thing with micro chips(the intel P4 prescott produces more heat and is slower than northwood, but its made on a 90nm fab(northwood 130nm) %30-40 more profit after production starts rolling)

1/6'th ccds are mass produced, gotta applaud Pana giving us 3ccd in the $600 relm (electronics and maybe everything is all about production and profit)
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Old March 1st, 2005, 04:05 AM   #75
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The other thing about still cameras is they have a lot more flexibility in shutter speed -- you can, in some circumstances, reasonably take the camera to shutter speeds exceeding a second. You can't do that with moving images.
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