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Author Topic: expose to the right?  (Read 38842 times)
AndreNapier
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« Reply #140 on: November 13, 2007, 01:16:40 PM »
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PhotoShop also allows one to apply mathematically perfect grain. Can not argue mathematics but
 IT AIN'T PRETTY!!!!!!

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AndreNapier
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« Reply #141 on: November 13, 2007, 02:33:15 PM »
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With your above statement, about the Canon/P45 and how you prefer to only use your eyes, I'm certainly happy you're not an airline pilot.
[a href=\"index.php?act=findpost&pid=152486\"][{POST_SNAPBACK}][/a]

Andrew,
Very good that you brought this example.
Instrument flying is close to my heart. All pilots use blindfold navigation for their comfort and when visual control is not possible ( example - night flying )
However with all that technology no pilot ever attempted auto pilot landing or start. This same applies to all critical flying situation where human judgment exceeds all mathematical combination.
Matter of fact whenever situation allows visual control most pilots still prefer to trust their eyes and intuition. I do not think that this situation is any different for well trained photographers and pictures that have many critical variation in order to capture the soul. ( By the way I am not religious at all. Quite contrary I have to see it to believe. )

{" Young lady comes home a catches her husband with another women. The other women runs away.
Young lady cries and screams - how could you do it to me.
Husband calmly replies - do what?
Lady - well cheat on me.
Husband replies again - I never even thought about cheating on you.
Lady - what are you saying, I have seen it with my own eyes!
Husband - well, you have to decide if you are going to trust your husband or  you are going to trust your own eyes.}

By the way the most advance computers far more mathematically advance than photoshop software still have a heck of a time to beat the stupid eye-brain combination of master player in the most mathematically advance game - CHESS.

Andre
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TechTalk
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« Reply #142 on: November 13, 2007, 03:23:22 PM »
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Andrew,
Very good that you brought this example.
Instrument flying is close to my heart. All pilots use blindfold navigation for their comfort and when visual control is not possible ( example - night flying )
However with all that technology no pilot ever attempted auto pilot landing or start. This same applies to all critical flying situation where human judgment exceeds all mathematical combination.
Matter of fact whenever situation allows visual control most pilots still prefer to trust their eyes and intuition. I do not think that this situation is any different for well trained photographers and pictures that have many critical variation in order to capture the soul. ( By the way I am not religious at all. Quite contrary I have to see it to believe. )

{" Young lady comes home a catches her husband with another women. The other women runs away.
Young lady cries and screams - how could you do it to me.
Husband calmly replies - do what?
Lady - well cheat on me.
Husband replies again - I never even thought about cheating on you.
Lady - what are you saying, I have seen it with my own eyes!
Husband - well, you have to decide if you are going to trust your husband or  you are going to trust your own eyes.}

By the way the most advance computers far more mathematically advance than photoshop software still have a heck of a time to beat the stupid eye-brain combination of master player in the most mathematically advance game - CHESS.

Andre
[a href=\"index.php?act=findpost&pid=152508\"][{POST_SNAPBACK}][/a]
Trust your eyes if you like, but they can and will deceive you. The laws of physics will remain constant.

Do you trust your eyes to tell you that square "A" and "B" are exactly the same shade of gray? They are.

[attachment=3817:attachment]
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jonstewart
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« Reply #143 on: November 13, 2007, 03:46:32 PM »
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My personal experience with the Canon 5D versus Phase P45 shooting architecture:

With the 5D I have to make sure not to get underexposed images (I will rather blow some highlights) since the shadows looks very bad. With the P45 I tend to expose a little to the left since I can recover all shadow details without any noise at all.

This is based on real life photography - not reading color theory. Just like I don’t read MTF carts when choosing a lens, I simply try different models and look for the sharpest lens using my eyes.

Mr. Dog I think you are the religious one - not wanting to accept real life photographers experiences with MFD - you just keep hanging on to your theory based on Canon files, and simply cant get into your head that MFD is another ball game.
Torben
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Thank you Torben, you have explained more cogently what I feel to be true in my limited experience of MFDB's (and I too have the 5D)
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Jon Stewart

If only life were so simple...
AndreNapier
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« Reply #144 on: November 13, 2007, 04:43:45 PM »
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Trust your eyes if you like, but they can and will deceive you. The laws of physics will remain constant.

Do you trust your eyes to tell you that square "A" and "B" are exactly the same shade of gray? They are.

[attachment=3817:attachment]
[a href=\"index.php?act=findpost&pid=152520\"][{POST_SNAPBACK}][/a]

Very good one. This is an amazing staff. Never seen anything like it. You converted me completely.
Matter of fact I will no longer calibrate my computer screen just by my eyes. Actually I may end up like Claude Oscar Monet who after his cataracts surgery wanted to repaint all his works.
God so much work in front of me to catch up with the time I have inadvertently lost.
Andre
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AndreNapier
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« Reply #145 on: November 13, 2007, 04:57:14 PM »
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Did I say GOD?
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samuel_js
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« Reply #146 on: November 13, 2007, 05:08:43 PM »
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Trust your eyes if you like, but they can and will deceive you. The laws of physics will remain constant.

Do you trust your eyes to tell you that square "A" and "B" are exactly the same shade of gray? They are.

[attachment=3817:attachment]
[a href=\"index.php?act=findpost&pid=152520\"][{POST_SNAPBACK}][/a]

Go to your magazine's editor or a client with that arguments and the will give you..... "that look"...
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AndreNapier
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« Reply #147 on: November 13, 2007, 05:35:32 PM »
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an
« Last Edit: June 17, 2008, 12:41:10 AM by AndreNapier » Logged
david o
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« Reply #148 on: November 13, 2007, 05:49:05 PM »
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Trust your eyes if you like, but they can and will deceive you. The laws of physics will remain constant.

Do you trust your eyes to tell you that square "A" and "B" are exactly the same shade of gray? They are.

[attachment=3817:attachment]
[a href=\"index.php?act=findpost&pid=152520\"][{POST_SNAPBACK}][/a]

may be but so far the only species I know that are looking/buying images are human... so if tomorrow my computer can say something and buy photographs I'll take care of that.
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bjanes
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« Reply #149 on: November 13, 2007, 05:52:35 PM »
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It has nothing to do with Canon files. Linear encoded data is linear encoded data.

The math is undeniable. End of story.
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There are some differences between a Canon with a 12 bit ADC and the medium format backs with 16 bit ADCs. For example, the Kodak 39 MB KAF 39000 chip used in some of these high end backs has a full well capacity of about 60K electrons. At base ISO, the unity gain would be 1 electron/ 16 bit data number.

Unity gain for the Canon 5D with a 12 bit ADC is at ISO 1600. When one is exposing according to light meter readings with the meter set at 1600 ISO, one must increase the ISO on the camera setting to 1600 so that the electronic gain will increase enough to enable the ADC to capture all the information in the image. The 5D has a full well of 80,000 electrons, so the gain at base ISO is 19 electrons/12 bit data number. The granularity of the measurement at base ISO is 19 electrons and this would lead to significant imprecision at ISO 1600 where fewer electrons are collected. At ISO 1600 the 5D would collect 80000/16 = 5,000 electrons in the highlights and half as many in each darker f/stop as one goes towards the shadows.

With the 16 bit MFDB, one could leave the ISO setting of the camera at base ISO and increase the exposure in the raw converter and still get all the information. This is explained by [a href=\"http://www.clarkvision.com/imagedetail/digital.sensor.performance.summary/]Roger Clark[/url] on his web site.

However, signal to noise ration in digital cameras is limited primarily by photon counting statistics. If you double the number of photons collected, the S:N will increase by the square root of 2, 1.414. This applies to Canon and Nikon 35 mm style cameras, MFDBs, and the Hubble space telescope. This is the main rationale behind ETTR. Perhaps you boys with MFDBs are satisfied with your S:N, but you could do better with ETTR. That is a fact of physics and mathematics.

Another consideration is that noise with a 39 MB file will be much finer grained than with a 12 MB file when the images are printed at the same size, even though the noise expressed as a standard deviation of the pixel value might be the same.
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digitaldog
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« Reply #150 on: November 13, 2007, 06:03:43 PM »
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There are some differences between a Canon with a 12 bit ADC and the medium format backs with 16 bit ADCs.

I don't think anyone has disputed this.
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Andrew Rodney
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Ray
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« Reply #151 on: November 13, 2007, 11:04:18 PM »
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Trust your eyes if you like, but they can and will deceive you. The laws of physics will remain constant.

Do you trust your eyes to tell you that square "A" and "B" are exactly the same shade of gray? They are.

[attachment=3817:attachment]
[a href=\"index.php?act=findpost&pid=152520\"][{POST_SNAPBACK}][/a]

Interesting, isn't it! This is symbolic of the sort of thing over which major wars have been fought, one side claiming they are white and that the other side is black and vice versa, when in fact, according to a more objective standard, they are both similar shades of gray. Gives pause for thought, don't it?

I checked the values in Photoshop, just in case wou were kidding me  , and it's true, both squares A and B are exactly the same shade of gray, 120,120,120.
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Ray
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« Reply #152 on: November 13, 2007, 11:34:07 PM »
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Andrew,
Look, I am already improving. I fixed my overexposed white dress by cloning it from picture B
to picture A. Is it my eyes or the A looks more beige. They are the same color, I swear.
Andre[attachment=3832:attachment][attachment=3832:attachment][attachment=3833:at
tachment]
[a href=\"index.php?act=findpost&pid=152566\"][{POST_SNAPBACK}][/a]

Both dresses look approximately the same shade of white to me, Andre. Only the background and the model's skin tones have changed. But I concede the point that what appeared to me as overexposed dresses may not actually be overexposed.

I sometimes forget that the appearance of things on my Adobe Gamma calibrated laptop is not accurate. I've since discovered by attempting to print images from my laptop that all values of grey between about 230,230,230 and 255,255,255 look the same.
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seberri
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« Reply #153 on: November 23, 2007, 05:24:59 AM »
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where  did   HE  get this informations ?  :  

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Because CCD and CMOS chips are linear devices. And, of course, each F/Stop records half of the light of the previous one, and therefore half the remaining data space available. This little table tells the tale.


Within the first F/Stop, which contains the Brightest Tones
2048 levels available
Within the second F/Stop, which contains Bright Tones
1024 levels available
Within the third F/Stop, which contains the Mid-Tones
512 levels available
Within the fourth F/Stop, which contains Dark Tones
256 levels available
Within the fifth F/Stop, which contains the Darkest Tones
128 levels available

I  find allways on internet this 5 (or 11 zones) from  Bright tones to Dark tones
but nobody says from where they know it ?

from Canon ?  NIkon ? KodaK ?

any idea or link  ?

thank you
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Ray
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« Reply #154 on: November 23, 2007, 08:25:06 AM »
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where  did  HE   get this informations ?  : 
I  find allways on internet this 5 (or 11 zones) from  Bright tones to Dark tones
but nobody says from where they know it ?

from Canon ?  NIkon ? KodaK ?

any idea or link  ?

thank you
[a href=\"index.php?act=findpost&pid=155171\"][{POST_SNAPBACK}][/a]

Thomas Knoll I believe. It's always been the basic rationale for ETTR on this forum since the phrase was first coined.
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Henry Goh
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« Reply #155 on: November 23, 2007, 08:45:53 AM »
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If you are asking about Zones, then it was Ansel Adams.
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digitaldog
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« Reply #156 on: November 23, 2007, 09:25:41 AM »
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Thomas Knoll I believe. It's always been the basic rationale for ETTR on this forum since the phrase was first coined.
[a href=\"index.php?act=findpost&pid=155192\"][{POST_SNAPBACK}][/a]

I also think he (and or Michael) used this set of values to make the math easier for us to understand. I don't think he's saying this 6-stop, 12 bit file is based on any exact real world capture device but rather a theoretical one such you can see how the 4096 steps divide up per stop.
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Andrew Rodney
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thsinar
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« Reply #157 on: November 23, 2007, 10:46:06 AM »
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at the same level of "Perceiving/Seeing/Interpretating" things, go to:

http://www.bbc.co.uk/science/humanbody/bod...enge/senses.swf

Good luck for the test!

Thierry

Quote
Very good one. This is an amazing staff. Never seen anything like it. You converted me completely.
Matter of fact I will no longer calibrate my computer screen just by my eyes. Actually I may end up like Claude Oscar Monet who after his cataracts surgery wanted to repaint all his works.
God so much work in front of me to catch up with the time I have inadvertently lost.
Andre
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Thierry Hagenauer
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AndreNapier
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« Reply #158 on: November 23, 2007, 01:42:13 PM »
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at the same level of "Perceiving/Seeing/Interpretating" things, go to:

http://www.bbc.co.uk/science/humanbody/bod...enge/senses.swf

Good luck for the test!

Thierry
[a href=\"index.php?act=findpost&pid=155222\"][{POST_SNAPBACK}][/a]

15/20. Granted I new all the anatomy question from school.
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seberri
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« Reply #159 on: November 24, 2007, 02:06:38 PM »
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Thomas Knoll ?

thank you


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I also think he (and or Michael) used this set of values to make the math easier for us to understand. I don't think he's saying this 6-stop, 12 bit file is based on any exact real world capture device but rather a theoretical one such you can see how the 4096 steps divide up per stop

my question was more about  each F/Stop records half of the light of the previous one, and therefore half the remaining data space available
« Last Edit: November 24, 2007, 02:10:20 PM by seberri » Logged
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