Dynamic Range Digital Camera - A Survey
A study of the dynamics of several selected digital SLR cameras including the Nikon D100, Nikon D2x and Canon D20.
Presentation
Many sensors of digital cameras have a depth of 12 bits per color. Depthdefines-bit dynamic range camera. However, it is difficult tofind any recommendation by any of the cameras that manufacturers weshould use all 12 bits to work with 16 bits instead of 8 bitfiles. In addition, many of the characteristics of the image processing software (like Photoshop) do not support 16-bit mode, because they can beused only in 8 bit mode. Perhaps, after using 8-bits, four bits of information that causes to be thrown away, ranging thedynamic camera is small and the data will be lost.
Toovercome this problem, many photographers process their work in 12 bitRaw, converting 16-bit TIFF, when the end result is beprinted. This method of working is detrimental to the workflow itprecludes the use of many features.Assupport the most useful Photoshop 16-bit mode is mixed by manufacturers saythe least, there is a suspicion that the 4-bit to lose whenworking in 8-bit mode, do not contain consistent data, containonly noise. It is also possible that the noise of 4 bits that are partially swampedby higher order bits of the four contain datawhilst consistently lower order bits contain noise.Method
Thefollowing method was used to determine, lost 4 bitscontain no coherent information. The method involves theImage marker. This provides an easier method of entering the addresses correspondingdata 8-bit and 16 bit files, such as data calculation ofinterest byhand addresses.As 4 bits most likely to contain data consistent camera'slowest sensitivity, the sensitivity was originally set to ISO 100 Theeffects increase the sensitivity of ISO 400, ISO 800 and ISO 3200 wastried tests.1 later. Imagewas very vague and stored in a raw file. Strongly focused on the ability to use topic toavoid any texture interferes withthe results. All camera parameters, including noise reduction, wereturned away. Camera sensitivity is set to at least 100 ISO
2 The Raw File was saved as a 16-bit tif using Nikon Capture.3. A small section at random (approx. 5%) of the image was chosen usingPhotoshop is the Marquee tool. The image was cropped thusproducing an image of a manageable size.
A fourth sample of the harvest was completed, using Photoshop ColourPicker and fill tool with a characteristic bit pattern (R = Hex, G = B = hexAAand hex) to serve as a marker.
5. The image was recorded at 16-bit and 8 bit mode files.7 separated. Hexedit (an excellent freeware editor) was used to display binarycontents have two files. Markersection information as soon as the Hexa labeling was identified and compared.
Results and conclusions
Thetable Below are a representative sample of small Animage the results obtained using a Nikon D2X ISO 100 All values ??are inhexadecimal. Row 1 shows the RGB channel. Row 2 ContainsData tif files saved by 8-bit mode. Row 3 containscorresponding information line 2, the tif file mode bit savedin 16. Line 4 contains the low byte of 16-bit data.Colour channel (red, green, blue) R1G1B1R2G2B2R3G3B3R48 B8BE90B8BF90B9C08FB916 little bit, byte ms
B8BE91B9BF90B9C090B916 bits, bytes ls DDC1B92B81B9A10F0B15Theresults bytes too low in the fourth row of the table indi Cate att There is no correlation for each color channel, or in binary models valuesor. Taking the performance of red channels, for example, DD = R1, R2 = 2B, R3 and R4 = A1 = 15 This seems to be random data thataffects every four bits. This difference in some of the values ??that indicate the noise affects att the least significant bit of the byte of higher order.
Other results are obtained for the D2X at ISOs 400, 800 and3200. They show the higher order byte of 16 bit word formatbecoming gradually overwhelmed by the noise that the increase in ISO.
Similar results were obtained for Nikon D100.Implication
Theimplication of these findings is that the Nikon D2X and D100, which works with 16-bit mode or RAW to maximize the dynamic range is ineffective because no comprehensive data is lost when using the bitmode 8.
Pictures/SnapShot :
Presentation
Many sensors of digital cameras have a depth of 12 bits per color. Depthdefines-bit dynamic range camera. However, it is difficult tofind any recommendation by any of the cameras that manufacturers weshould use all 12 bits to work with 16 bits instead of 8 bitfiles. In addition, many of the characteristics of the image processing software (like Photoshop) do not support 16-bit mode, because they can beused only in 8 bit mode. Perhaps, after using 8-bits, four bits of information that causes to be thrown away, ranging thedynamic camera is small and the data will be lost.
Toovercome this problem, many photographers process their work in 12 bitRaw, converting 16-bit TIFF, when the end result is beprinted. This method of working is detrimental to the workflow itprecludes the use of many features.Assupport the most useful Photoshop 16-bit mode is mixed by manufacturers saythe least, there is a suspicion that the 4-bit to lose whenworking in 8-bit mode, do not contain consistent data, containonly noise. It is also possible that the noise of 4 bits that are partially swampedby higher order bits of the four contain datawhilst consistently lower order bits contain noise.Method
Thefollowing method was used to determine, lost 4 bitscontain no coherent information. The method involves theImage marker. This provides an easier method of entering the addresses correspondingdata 8-bit and 16 bit files, such as data calculation ofinterest byhand addresses.As 4 bits most likely to contain data consistent camera'slowest sensitivity, the sensitivity was originally set to ISO 100 Theeffects increase the sensitivity of ISO 400, ISO 800 and ISO 3200 wastried tests.1 later. Imagewas very vague and stored in a raw file. Strongly focused on the ability to use topic toavoid any texture interferes withthe results. All camera parameters, including noise reduction, wereturned away. Camera sensitivity is set to at least 100 ISO
2 The Raw File was saved as a 16-bit tif using Nikon Capture.3. A small section at random (approx. 5%) of the image was chosen usingPhotoshop is the Marquee tool. The image was cropped thusproducing an image of a manageable size.
A fourth sample of the harvest was completed, using Photoshop ColourPicker and fill tool with a characteristic bit pattern (R = Hex, G = B = hexAAand hex) to serve as a marker.
5. The image was recorded at 16-bit and 8 bit mode files.7 separated. Hexedit (an excellent freeware editor) was used to display binarycontents have two files. Markersection information as soon as the Hexa labeling was identified and compared.
Results and conclusions
Thetable Below are a representative sample of small Animage the results obtained using a Nikon D2X ISO 100 All values ??are inhexadecimal. Row 1 shows the RGB channel. Row 2 ContainsData tif files saved by 8-bit mode. Row 3 containscorresponding information line 2, the tif file mode bit savedin 16. Line 4 contains the low byte of 16-bit data.Colour channel (red, green, blue) R1G1B1R2G2B2R3G3B3R48 B8BE90B8BF90B9C08FB916 little bit, byte ms
B8BE91B9BF90B9C090B916 bits, bytes ls DDC1B92B81B9A10F0B15Theresults bytes too low in the fourth row of the table indi Cate att There is no correlation for each color channel, or in binary models valuesor. Taking the performance of red channels, for example, DD = R1, R2 = 2B, R3 and R4 = A1 = 15 This seems to be random data thataffects every four bits. This difference in some of the values ??that indicate the noise affects att the least significant bit of the byte of higher order.
Other results are obtained for the D2X at ISOs 400, 800 and3200. They show the higher order byte of 16 bit word formatbecoming gradually overwhelmed by the noise that the increase in ISO.
Similar results were obtained for Nikon D100.Implication
Theimplication of these findings is that the Nikon D2X and D100, which works with 16-bit mode or RAW to maximize the dynamic range is ineffective because no comprehensive data is lost when using the bitmode 8.
Pictures/SnapShot :
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