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Author Topic: Dynamic Range - Digital sensors  (Read 4818 times)

Meh

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Re: Dynamic Range - Digital sensors
« Reply #15 on: November 08, 2011, 07:32:27 PM »
@archangelrichard... What?

Digital sensors have only 4-stops of DR:  Wrong, why do you think that exactly?

Each 14-bit conversion has color and brightness:  Wrong, each photosite is only measured for luminance levels, color is interpolated after the fact by looking at the luminance of adjacent RGB pixels.

Sensors are strictly on or off:  Wrong, each photosite builds up a voltage as photons are absorbed and converted into electrons.  The voltage is measured and encoded by the Analog-to-Digital converter into a Data Number (DN) that represents the luminance level of the photosite.

Accuracy of the 14 bits:  What do you mean?



« Last Edit: November 08, 2011, 07:47:14 PM by Meh »

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Re: Dynamic Range - Digital sensors
« Reply #15 on: November 08, 2011, 07:32:27 PM »

Mt Spokane Photography

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Re: Dynamic Range - Digital sensors
« Reply #16 on: November 08, 2011, 11:25:47 PM »
I recently scanned many hundreds of old negatives from my parents estate taken mostly from the early1940's thru the 1950's.  There were a few overexposed and under exposed images that were often recovered nicely, it was amazing how much latitude for over or under exposure there was.  They were not taken with a expensive camera, just a ordinary Kodak camera of the times, but they were great.

When I got to the 35mm images of the 1960's and later, they were usually color, and far inferior to the older medium format images, noticibly inferior to todays DSLR images.  In the 1960's, I have lots of images I took with better quality cameras, a Yashica TLR, Argus C3, Canon FT,  mostly using Kodachrome II or a few with print film, and while these are fairly good, they still do not match those old 1940's B&W negatives from 120 film.

Still, overall, a ordinary point and shoot camera would blow away the IQ of those old images if I were to enlarge them to even 8 X 10.  We definitely have been spoiled by the capabilities of the new technology for ordinary home photos.

koolman

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Re: Dynamic Range - Digital sensors
« Reply #17 on: November 09, 2011, 03:33:57 AM »
From all I am reading here (thank you all for your comments) it seems that digital photography is quite far behind film as far as DR abilities. Is this true of the high end bodies as well? Say a Nikon D3x or as such ?
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JackSw1ss

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Re: Dynamic Range - Digital sensors
« Reply #18 on: November 09, 2011, 04:39:39 AM »

Your eyes only do 13 f-stops


that sir, is totally wrong.
If you want I can explain, though it's a long explanation and very tough and time consuming.
It might be around 15 stops, but not if you consider lateral inhibition...that's one big "invention" of the eyes.
All is controlled by amacrine and horizontal cells in the eyes. In short: these are cells that run on the "lateral way", through the retina (and not retina --> optical nerve --> brain) and make connections between rod/cones and other "patches" of cones (usually are cones but there are connections also with rods) in the prossimity (and not) in order to tell something about this (think about if they were talking):
 "you cones in point A are "seeing" X, exposed by X light....ok, but cones in B sees a different area Y exposed differently by Y light".
this is principle of adaptation (dunno if is the right term sorry) suitable also for the sense of smell. Eyes is even more complex but the main principle is that.
Think about it, when not on extreme conditions (for example the situation I'm right now) I have a big table halogen lamp but my room now is in almost total dark, I've in front a windows which is dark (no light) but the screen of the mac is thoroughly illuminated as well as the book I've in front of me. Though all around me would be completely dark. Now, if I look at the screen all around (the parts I'm not focusing...sorrounding area) is perfectly exposed, lamp is properly exposed as well as I see in the dark, almost perfectly (i'm still focusing on the screen). If I move my eyes into the darkness and try to "see", without actually focusing the screen, I still see it well exposed (maybe a tad bit more exposed) as well as the lam and the book.
That sir is lateral inhibition...if our eyes would have had "fixed" 15 DR you couldn't have such incredible adaptation.
Think about seeing stars, too....in these kind of situations DR of eyes is meant to be (not theorical by any studies) of maybe 10 times more (remember it's logaritmic the scale...)

there are not many but quite a few studies on this regards....unfortunately there's not much on the internet...I fortunately have it on my books so, I can haaaz the info eheh.
Eye is a very interesting subject and his values are far away than "fixed" values or principles...it's a very variable and adaptable organ (and we didn't even put into the equation the brain LOL)

anyway I could go on and on for hours but it becomes tough to read (patience) and too long and boring for many.


film has been measured at 10 - 11 f stops (film is analog, it can have measures like 88.73; digital can not)

digital is usually estimated at 4 f-stops


first part is very true but your statement of digital is totally wrong mate.
Not because I say it....just check  the video linked on the page 1...and also the clarkvision link. these are the years where digital is overtaking film (fortunatly or unfortunately it's up to us)
the 4 stops DR might have been true about 6 or 7 years ago, but not anymore...facts, not my opinions.


Again, film does not have this issue; it can register a near infinite number of possible colors (your eyes often can not detect them) In fact, film's issue is LOSING Dynamic Range - it loses through the f-stop of the lens, the age of the film; etc. so it loses a total of 2 - 3 stops from what our eyes can see; Digital starts from the ground up with the basic sensor seeing only off and on

There is a "law of diminishing returns" going on here, as people no longer view images on reflective screen (slides, movies) or paper (prints) we are in an age where the limiting factor is screen accuracy and tolerance for detail - what is your screen;s real resolution and it's color response at that resolution and why should camera makers make images that have detail differences you can't see? Your eyes arfe estimated to make out only 10 million colors, so why try to process many more than that?)


I dunno if I understand it all correctly but I think I agree with you.
I mean what I understood and what i know is that, yes, film might also be 12 DR or 10...but in the end when you made slides they are maaax 4 DR...when you make prints they are about 5 or 6 DR and that's a fact.
BUT as for digital goes actually it's pretty much the same...meaning that if you print a dig picture again, you'll probably go down of about 5 or 6 stops of DR in the paper from the camera and already in the screen the DR has fallen...
if this is circa what you meant I completely agree with you.
« Last Edit: November 09, 2011, 04:44:21 AM by JackSw1ss »

JackSw1ss

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Re: Dynamic Range - Digital sensors
« Reply #19 on: November 09, 2011, 04:53:21 AM »
From all I am reading here (thank you all for your comments) it seems that digital photography is quite far behind film as far as DR abilities. Is this true of the high end bodies as well? Say a Nikon D3x or as such ?
mmm no, it's superior if we consider the max value as sheet facts.
Film it's superior if you consider the abilities of some films that can capture a wider range.
But, to sum up:
some kind of films (not all), like some BW negatives (not every one and surely not the color ones!) are able to capture max 12 DR...motion picture films are even better (and they're also color ones), like kodak 5219 which goes up to max 15 DR (and that's why some directors still opts for films and not dig).
BUT....BUT, in regards to motion pictures, there are (and are coming into the market, see C300) amazing cameras nowadays, like the Arri ALEXA (geez look at the gamma and range...) but even the Phantom and well, we all now the Red, that are fast reducing the gap....see the video pag 1. So life of motion films, I believe, will be short.

As far as photography goes, as stated previously, yes, some films might be able to have a DR of 12 max (usually is around 7-9) but in the end either you make a slide or a print you'll end up losing a lot of DR, dropping to about 3 to 5 DR. See the E6 process for slides i.e. which downs you to 3.5 DR (my friend and a member here stated it)

Digital?I dunno the sheet facts but it's logically obvious that if you print, no matter what quality, it will get as well lower DR. if a 5DII is able to capture circa 11DR, then if you print what you get?around 4 or 5 DR less?maybe...or maybe we are still kind eheh and it loses even more.
On the screen?maybe the loss it's lower but it will have it as well.

« Last Edit: November 09, 2011, 05:06:46 AM by JackSw1ss »

awinphoto

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Re: Dynamic Range - Digital sensors
« Reply #20 on: November 09, 2011, 08:43:20 AM »
For what it's worth, DXo Mark, who rates the sensors rated the 5d mark 2 with a dr rating of 11.9 ev. I know they can be questionable by many photographers but take that for what it's worth.

Canon 5d III, Canon 24-105L, Canon 17-40L, Canon 70-200 F4L, Canon 100L 2.8, Canon 85 1.8, 430EX 2's and a lot of bumps along the road to get to where I am.

awinphoto

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Re: Dynamic Range - Digital sensors
« Reply #21 on: November 09, 2011, 09:20:43 AM »
DPR rated the 5d 2 with a DR of 8.6ish with as-is settings but with highlight priority bought you another stop in the highlights. Others said the 5d2, such as art adams, that the same camera has 11+ ev. Fact is there is no real benchmark everyone can accept without running our own tests so arguments such as this is really futile.
Canon 5d III, Canon 24-105L, Canon 17-40L, Canon 70-200 F4L, Canon 100L 2.8, Canon 85 1.8, 430EX 2's and a lot of bumps along the road to get to where I am.

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Re: Dynamic Range - Digital sensors
« Reply #21 on: November 09, 2011, 09:20:43 AM »