NikonGear'23
Gear Talk => Camera Talk => Topic started by: bobfriedman on December 23, 2017, 15:25:23
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An initial comparison.. processed identically in DarkTable, some level/contrast enhancement, demosiac turned off, matrix exposure, identical lighting D55
Nikon D800M ,Zeiss Apo Sonnar T* f/2 135mm
1s f/5.6 at 135.0mm iso100
(http://www.pbase.com/bobfriedman/image/166750830/original.jpg)
Nikon D800 Stock ,Zeiss Apo Sonnar T* f/2 135mm
0.62s f/5.6 at 135.0mm iso160
(http://www.pbase.com/bobfriedman/image/166750834/original.jpg)
100% crop center
Nikon D800M ,Zeiss Apo Sonnar T* f/2 135mm
1s f/5.6 at 135.0mm iso100
(http://www.pbase.com/bobfriedman/image/166750845/original.jpg)
Nikon D800 Stock ,Zeiss Apo Sonnar T* f/2 135mm
0.62s f/5.6 at 135.0mm iso160
(http://www.pbase.com/bobfriedman/image/166750843/original.jpg)
D800 Stock Color Image
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Thanks Bob. I want to see the bottle with label again, shot the same as before with stock and M, but just without the vibration which messed up that test.
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Thanks Bob. I want to see the bottle with label again, shot the same as before with stock and M, but just without the vibration which messed up that test.
it wasn't vibration.. the focal plane shifted..
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it wasn't vibration.. the focal plane shifted..
The focal plane shifted? Can you mount the camera securely to a 1 cubic yard block of granite?
At some degree of magnification an image simply must exhibit vibration. If you hear a camera it's because the camera moved and caused the air to vibrate. At some point a flaw in an image will be so minute it will be impossible see in any practical sense. “now we know that we shall never know.” or something close to that. A nuclear physicist regarding the change in the behavior of particles when observing them.
Back to our reality...
Bob,
Can you re-shoot the bottle lables again and post them?
Dave Hartman
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the problem was that there are grooves in my tile floor where the grout lines are and one of the tropod legs was precariously perched on an edge.. it shifted when i shot the stock D800 image and hence moved the focal plane enough to show up in 100% crop of the neck but with the image still appearing reasonable sharp overall... so guess what guys.. the stock D800 will be sharp. as you can see from the colorchecker cards. maybe not quite as sharp as the monochrome converted sensor but sharp.
the stock D800 bottle neck i posted was just not in focus.
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Bob, I am confused. It wasn't in focus, or the tripod 'shifted'? Also, 'shifted' is what I meant by vibration, which we discussed.
Anyway, I want to see a bottle label comparison again now with a non 'shifty' shot.
Right?
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Bob, I observe very fine grid patterns on the patches of color checker (100% crop?) shot with the stock D800. Are they caused by the demosaic turned off?
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Personally, I can't see any grid pattern in the color shot, but I certainly do with the other shots.
I would like to see the same comparison again that was done before in the other topic, with the D800 and D800M, with the label,
with/without the demosaic turned off/on if you want, but I would like one to be like the comparison before.
I want to judge that first.
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Personally, I can't see any grid pattern in the color shot, but I certainly do with the other shots.
I would like to see the same comparison again that was done before in the other topic, with the D800 and D800M, with the label,
with/without the demosaic turned off/on if you want, but I would like one to be like the comparison before.
I want to judge that first.
Kuri, I was referring to the second last B&W image where you should be able to see the grid pattern clearly.
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Akira, Oh yes, I agree, the black and white shots show the pattern.
But why even start a new topic.
Show me the label. :-)
Who wants to look at a color checker in black and white?
Show me the label again.
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But the same crop by D800M doesn't show the grid. That's why I suspected that the demosaic turned off.
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Bob, I observe very fine grid patterns on the patches of color checker (100% crop?) shot with the stock D800. Are they caused by the demosaic turned off?
yes.. demosaic turned off.. the reason you see this is that those colors with greater grid pattern have a purer red or blue channel.. since there is 25% red, 25% blue and 50% green, the colors with more green components will have more contributing pixels.. consequently more resolution 36mpx = 9mpx red + 9mpx blue + 18mpx green
the monochrome conversion sensor has the full 36mpx resolution
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yes.. demosaic turned off.. the reason you see this is that those colors with greater grid pattern have a purer red or blue channel.. since there is 25% red, 25% blue and 50% green, the colors with more green components will have more contributing pixels.. consequently more resolution 36mpx = 9mpx red + 9mpx blue + 18mpx green
the monochrome conversion sensor has the full 36mpx resolution
But resolution is determined by luminance, even in colour images, because "the human brain enables rather coarse color information to be added to fine spatial information and integrates the two almost seamlessly". (http://micro.magnet.fsu.edu/primer/digitalimaging/cmosimagesensors.html). It can do that because the channels are not pure, however pure the colours on the card are, because there is a lot of spectral overlap in the filter transmission. The result is that most of the spatial data from any colour is in all the channels when you have a Bayer array (ie, the MaxMax site's [https://maxmax.com/b&w_conversion.htm] statement that "suppose the target is illuminated with a blue light? You would only get 1/4 of the pixels possibly seeing the blue light" is badly wrong). The blue filter has the least overlap, so spatial resolution is lower for monochrome blue areas - so in your images the texture in the Colorchecker squares should be least evident in squares 3, 13, and above all 8, and it isn't.
One thing that bothers me is that the lightness of the patches of the Colorchecker are as they should be in the native images but they are not in the Bayer-less images. For example, square 2 should be the same as square 21 and in the native images it is, but in the Bayer-less images it isn't; another example is 17 and 18, which should be the same.
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yes.. demosaic turned off..
What is purpose of turning of the demosaic? i.e. what are you trying to show?
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What is purpose of turning of the demosaic? i.e. what are you trying to show?
i would search for monochrome cameras on the web.. e.g. below
http://www.red.com/learn/red-101/color-monochrome-camera-sensors
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i would search for monochrome cameras on the web.. e.g. below
http://www.red.com/learn/red-101/color-monochrome-camera-sensors
Still confused, I understand how they work, what I am trying to understand is what your trying to show? Are you trying to show what it looks like with out the picture being demosaiced and if so for what purpose, or something else? Sorry it is not at all obvious what your trying to show. The heading suggested it was a comparison between the D800M and the standard one.
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300% crop - unfortunately i get aliasing on the checkerboard pattern but you can see how much sharper the D800 monochrome conversion is.
Stock
(http://www.pbase.com/bobfriedman/image/166759205/original.jpg)
Monochrome Conversion
(http://www.pbase.com/bobfriedman/image/166759206/original.jpg)
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Without the color filter array how much faster is the camera? 1 stop? Half a stop?
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Without the color filter array how much faster is the camera? 1 stop? Half a stop?
i am getting 2/3 of a stop..
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i am getting 2/3 of a stop..
Also in UV Bob?
Looking forward to seeing some UV results... ;)
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Also in UV Bob?
Looking forward to seeing some UV results... ;)
yep... in UV i get more.. pretty soon i will have a D800 UV-VIS-IR for comparison but for now i have some examples below.. i can take handheld UV shots outside... am expecting a Convoy S2+ 365nm Nichia UV Waterproof LED Flashlight soon to do so more testing indoors.
Using the D800 monochrome sensor conversion (no CFA or microlenses) with an accompanying BG-38 internal filter replacement while i was out photographing snowy owls, i decided to try the D800M out with an el-nkkor and the Baader on one of my friends..
Nikon D800M ,Nikon EL-Nikkor 105mm f/5.6, ultraviolet
1/40s f/5.6 iso2500
(http://www.pbase.com/bobfriedman/image/166765992/original.jpg)
Nikon D800M ,Nikon El-Nikkor 105mm f/5.6 ,ultraviolet
1/400s f/5.6 iso1000
(http://www.pbase.com/bobfriedman/image/166764462/original.jpg)
another shot showing exposure times..
Nikon D800M ,Nikon El-Nikkor 105mm f/5.6, ultraviolet
1/50s f/11 at 105.0mm iso1600
(http://www.pbase.com/image/166797509/original.jpg)
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This tread clearly shows how you get better accutance with a monochrome sensor. But to me other advantages is not so obvious? Leica i said to produce a picture with better tone values and beautiful greytones in their monochrome sensor, but from the pictures I have seen the accutance seem to be the largest benefit just as with the monochrome D800. I have a fullspectrum D600 and an ordinary D800. My largest prints are typically 50 cm x 75cm (the best gallery size imo) and both cameras fullfill this giving me enough accutance even cropped in B&W conversions. A bayer sensor gives you the advantage of skipping filters. To me it seems different software can make more differences than just a monochrome sensor, so I have stuck to lightroom/photoshop for my B&W conversions because I have learned the software... But since I never have used a monochrome sensor, I might be wrong? Any comments about what to gain except for accutance trying out a monochrome D800 in my photography?
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Any comments about what to gain except for accutance trying out a monochrome D800 in my photography?
As noted above, an extra 2/3 to full stop of sensitivity. This makes low light photography without a tripod easier. Seems good for street shooting or interior work.
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Bob, those UV results are rather spectacular, given the short exposure times!!
So from that, such a camera would work well as a scientific instrument to do documentations,
from an artistic standpoint, I prefer to have some false UV colors ;-)
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Bob, those UV results are rather spectacular, given the short exposure times!!
without the CFA and microlenses you realize a significant increase in speed.. so much so i could easily do walk around UV movies (video) with the D800M
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someone named Robert Suffak robert.suffak@bluewin.com contacted me at my web site after reading this post and i tried to reply to him at that email address with no luck.. all came back.
he wanted to know who did the conversion ... i responded maxmax.com