my first acceptable HDR

yvesson

209
A540 SX10IS

Re: my first acceptable HDR

« Reply #20 on: 21 / April / 2008, 03:45:48 »

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Hej,
Well usually want I want from a pic is to get as close as possible as what you see with you eyes, that's one reason why I like more not-so-blurry backgrounds from compact cams more than those from SLRs.

But anyway anyone knows a way to compare the "human eye dynamic range" to the one of the sensor/pictures ?

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mrproper

92

Re: my first acceptable HDR

« Reply #21 on: 21 / April / 2008, 06:52:49 »

Quote from: yvesson on 21 / April / 2008, 03:45:48

Hej,
Well usually want I want from a pic is to get as close as possible as what you see with you eyes, that's one reason why I like more not-so-blurry backgrounds from compact cams more than those from SLRs.

But anyway anyone knows a way to compare the "human eye dynamic range" to the one of the sensor/pictures ?

Apparently you can't because the human eye perceives intensity in a logarithmic way, and the sensors are linear. Four times the light, the eye will only see twice as brighter, but the sensor will need four times less exposure.

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jetzt

316
[A710IS,(SD200)]

Re: my first acceptable HDR

« Reply #22 on: 21 / April / 2008, 10:53:20 »

Quote

Apparently you can't because the human eye perceives intensity in a logarithmic way, and the sensors are linear. Four times the light, the eye will only see twice as brighter, but the sensor will need four times less exposure.

So I think that's where you can think about using HDR.

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PS

157
A610 1.00f

Re: my first acceptable HDR

« Reply #23 on: 21 / April / 2008, 11:07:12 »

Quote from: yvesson on 21 / April / 2008, 03:45:48

But anyway anyone knows a way to compare the "human eye dynamic range" to the one of the sensor/pictures ?

Clarkvision Photography -
Resolution of the Human Eye

Quote from: mrproper on 21 / April / 2008, 06:52:49

Apparently you can't because the human eye perceives intensity in a logarithmic way, and the sensors are linear. Four times the light, the eye will only see twice as brighter, but the sensor will need four times less exposure.

That's why you apply gamma correction.

« Last Edit: 21 / April / 2008, 11:12:41 by PS »

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yvesson

209
A540 SX10IS

Re: my first acceptable HDR

« Reply #24 on: 21 / April / 2008, 11:18:01 »

Quote from: PS on 21 / April / 2008, 11:07:12

Quote from: yvesson on 21 / April / 2008, 03:45:48
But anyway anyone knows a way to compare the "human eye dynamic range" to the one of the sensor/pictures ?
Clarkvision Photography -
Resolution of the Human Eye

Hej,
Oh thank you, I had read that some time ago but had forgotten it had an answer about dynamic range as well.

So then guys, what you say to people like me saying about most HDRs "doesn't look natural" ? Is that we're too used about normal pic for years/decades that "natural" means "pics we are used to" ? Is that most HDR makers push the contrasts too much without "respecting" the natural light anyway ? A bit of those, something else (sorry I'm going a bit too far off topic prolly, maybe some mod. split the topic if needed) ?

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mrproper

92

Re: my first acceptable HDR

« Reply #25 on: 21 / April / 2008, 11:39:40 »

Quote from: yvesson on 21 / April / 2008, 11:18:01

Is that most HDR makers push the contrasts too much without "respecting" the natural light anyway ? A bit of those, something else (sorry I'm going a bit too far off topic prolly, maybe some mod. split the topic if needed) ?

One would expect to have a picture or frame or view in the same exposure as all it's parts. Using tone mapping allows for very dark and very light areas to present the same contrast and the same detail.

Also, the halos around contrasted areas, you don't see that everyday... I mean never... in the real life

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Etilord

9

Re: my first acceptable HDR

« Reply #26 on: 13 / December / 2009, 03:34:58 »

Quote from: mrproper on 21 / April / 2008, 06:52:49

Quote from: yvesson on 21 / April / 2008, 03:45:48
Hej,
Well usually want I want from a pic is to get as close as possible as what you see with you eyes, that's one reason why I like more not-so-blurry backgrounds from compact cams more than those from SLRs.

But anyway anyone knows a way to compare the "human eye dynamic range" to the one of the sensor/pictures ?

Apparently you can't because the human eye perceives intensity in a logarithmic way, and the sensors are linear. Four times the light, the eye will only see twice as brighter, but the sensor will need four times less exposure.

What you're saying isn't a bad idea.
How about a logarithmic picture file format. Perhaps better quality can be obtained than jpg in the same file size.

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fbonomi

469
A570IS SD1100/Ixus80

Re: my first acceptable HDR

« Reply #27 on: 13 / December / 2009, 09:15:48 »

Quote from: Etilord on 13 / December / 2009, 03:34:58

What you're saying isn't a bad idea.
How about a logarithmic picture file format. Perhaps better quality can be obtained than jpg in the same file size.

"Quality" being a subjective measurement, this is difficoult to assess.

Anyway, only RAW files are "linear", the conversion from RAW to (any other format) makes the image "logarithmic" (they aren't really logarithmic, but for the sake of simplicity let's assume so)

If you take a JPG file and do some patches of these colours
0,0,0
50,50,50
100,100,100
150,150,150
200,200,200
250,250,250
They will appear uniformly spaced to yuor eye (if everything is well calibrated)

This means a linear sequence of values appears uniform to your logarithmic eye, i.e. a linear sequence reperesents a logaritmhic sequence...

This means that this data is ALREADY logarithmic!

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