Tagged with bits - Personal View Talks https://www.personal-view.com/talks/discussions/tagged/bits/feed.rss Sat, 04 May 24 22:54:11 +0000 Tagged with bits - Personal View Talks en-CA 5D Mark III / Shooting 14 bits Raw Video https://www.personal-view.com/talks/discussion/7833/5d-mark-iii-shooting-14-bits-raw-video Tue, 20 Aug 2013 06:21:28 +0000 ghostlayer 7833@/talks/discussions I Finally surrender to the enemy : 5D Mark III + Raw by Magic Lantern the 14 bits dynamic is crazy. Here's my first test :
(I still have my GH2...)

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Understanding Dynamic Range, type of sensors and film. https://www.personal-view.com/talks/discussion/4504/understanding-dynamic-range-type-of-sensors-and-film. Sat, 08 Sep 2012 02:58:51 +0000 endotoxic 4504@/talks/discussions Hello!!

Lots of people here undestands, dont undestand, and soso undestand what dynamic range is. Some people compare it to latitude, which in a simple way is much the same thing but on an analog sustrate.

COLOR HAS NOTHING TO DO WITH DYNAMIC RANGE.

Both sensors (bayer or foveon) and films stocks (diferent emulsions) captures light, in a time and a speed. Both use this to gather all the information available to them in that specific time.

""Dynamic Range of a Sensor: is defined by the largest possible signal divided by the smallest possible signal it can generate. The largest possible signal is directly proportional to the full well capacity of the pixel. The lowest signal is the noise level when the sensor is not exposed to any light, also called the "noise floor" This is interpreted by bits in a digital level.""

In the photosites of the sensor. When the photosites are well lit, they full themselfs with light particles. Then we can know how much light has enter each photosite and have a comparison between the low lit ( not so fully loaded ) and high lit scene ( fully loaded photosite). have the average and get results. So as bee told before Dynamic range is defined by the largest possible signal divided by the smallest possible signal it can generate.

""Even if one's digital camera could capture a vast dynamic range, the precision at which light measurements are translated into digital values may limit usable dynamic range. The workhorse which translates these continuous measurements into discrete numerical values is called the analog to digital (A/D) converter. The accuracy of an A/D converter can be described in terms of bits of precision, similar to bit depth in digital images, although care should be taken that these concepts are not used interchangeably. The A/D converter is what creates values for the digital camera's RAW file format""

"sensor has millions of pixels collecting photons during the exposure of the sensor. You could compare this process to millions of tiny buckets collecting rain water. The brighter the captured area, the more photons are collected. After the exposure, the level of each bucket is assigned a discrete value as is explained in the analog to digital conversion topic. Empty and full buckets are assigned values of "0" and "255" respectively, and represent pure black and pure white, as perceived by the sensor. The conceptual sensor below has only 16 pixels. Those pixels which capture the bright parts of the scene get filled up very quickly"

we can easily understand this, but inside the sensor there are more dificult parameters that must be calculated.

This differs alot from what actual film is made of, and the prosess that has to be done to make the film capture light. foveon sensor is more like Film, it has diferent levels of colors, chemicaly aligned in layers using diferent sutrates and quemicals for each color. So film does not "hold light inside" it uses it for a quemical reaction, so color can be generated using this method. Foveon sensors are quiet the same, the are made from layers of silicon with diferen materials, so the wavelenght of the light can traspass easily each layer. Also foveon sensors use pixel by pixel information, thats why foveon sensors with less pixels have better image quality than good old bayern pattern sensors (GHx, Canon, RED, Nikon Pentax)

But here is the question ive been hunting me some hours ago. I didnt knew that Dynamic range is limited by the bits the sensor can output. As @berniez put at the GH3 rumors topic. Vitaliy answer was quiet good but i didnt manage to undestand it at its full.

IF THIS IS TRUE CAN SOME ONE EXPLAIN MORE DETAIL ABOUT IT, COS I DONT HAVE THE KNOWLEDGE.

Here the eplanation but .... can someone explain it in more detail please.

""As an example, 10-bits of tonal precision translates into a possible brightness range of 0-1023 (since 210 = 1024 levels). Assuming that each A/D converter number is proportional to actual image brightness (meaning twice the pixel value represents twice the brightness), 10-bits of precision can only encode a contrast ratio of 1024:1.

Most digital cameras use a 10 to 14-bit A/D converter, and so their theoretical maximum dynamic range is 10-14 stops. However, this high bit depth only helps minimize image posterization since total dynamic range is usually limited by noise levels. Similar to how a high bit depth image does not necessarily mean that image contains more colors, if a digital camera has a high precision A/D converter it does not necessarily mean it can record a greater dynamic range. In practice, the dynamic range of a digital camera does not even approach the A/D converter's theoretical maximum; 5-9 stops is generally all one can expect from the camera.""

Info:

http://learn.hamamatsu.com/articles/dynamicrange.html

http://www.kenrockwell.com/tech/dynamic-range.htm

http://www.cambridgeincolour.com/tutorials/dynamic-range.htm

http://www.dpreview.com/learn/?/Glossary/Digital_Imaging/dynamic_range_01.htm

Please feel free to post any info concerning this topic. Thank you very much for reading, and please correct me if im wrong since im still in learning stage.

Cheers.

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