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02-18-2018, 11:53 AM   #331
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Three.

02-18-2018, 12:13 PM - 1 Like   #332
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QuoteOriginally posted by Racer X 69 Quote
Three.
I can guess what's coming next, and I agree wholeheartedly :
02-18-2018, 12:19 PM   #333
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QuoteOriginally posted by Ian Stuart Forsyth Quote
You have to remember that iso really is an exposure index, different manufactures will vary slightly from that standard as to how they want the final image to appear.

So when I set my Pentax camera to iso 100 that exposure is 2/3 of a stop larger than the very same iso is set to my Nikon camera. Iso is really an afterthought that is based really on how that camera manufacture is metering for their idea of a correct exposure within the confines of the Iso standard.

I really don’t like to use the term of base iso of a sensor as how low the sensor can be set is more determined by what the camera manufactures want to get out of the sensor short of clipping and how they program it.
Now if we take a look at the D810 and the K1 and look as to how both camera manufactures use that sensor you will see for the same iso the pentax is using a larger exposure.

If we take a look at the d810 and iso 64 when viewing the raw data we are still given the same headroom ( what Nikon like to use is around 1 2/3rd headroom) as iso 100, this to some degree confirms your assumption.
You also have to remember that iso100 to iso 64 is only 2/3rd of a stop

---------- Post added 02-18-2018 at 12:36 AM ----------

To further support your assumption we can look at the Saturation (e-) and the DR of the 2 camera
Sensorgen.info data for Nikon D800
Sensorgen.info data for Nikon D810

D800 Saturation (e-) 48818 DR13.4
D810 Saturation (e-) 78083 DR 13.8

Now if we want to increase the DR from 13.4 to 13.8 we will need to increase the size of the exposure which is just shy of half a stop which is very close to that 2/3rd of a stop we see from 100 to 64
If we also look at the Saturation (e-) value 48818/78083=0.62 stops again very close to that difference in iso 100-64
One of the reason why I don't think we see a full 2/3 of a stop increase to DR with the D810 over the D800 is that at iso 64 the D810 has 5.5 Read Noise (e-) while the D800 at iso 100 has 4.6 Read Noise (e-)

Sorry for using Nikon but that is all the information I have to sensors being used below iso 100
Comparing ISO settings between cameras is only completely valid if one assumes the lens used on each body have the same % light transmission. One way to eliminate the possible lens variable to compare bodies is to not use a lens at all.
02-18-2018, 12:22 PM   #334
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QuoteOriginally posted by BigMackCam Quote
I can guess what's coming next, and I agree wholeheartedly :
Pentax K-1 mark 3 ?


Last edited by BigMackCam; 02-21-2018 at 03:25 PM. Reason: Brand bashing
02-18-2018, 12:35 PM - 1 Like   #335
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QuoteOriginally posted by reh321 Quote
Nikon users nonchalantly talk about theit cameras being able to create several different size of "raw" file; how is this happening without modification?
You've brought Nikon up a few times. I think you're referring to options like "14-bit Uncompressed NEF" down to "12-bit Compressed NEF" and a few variants in-between? Yes, they are modifying the raw file in most of these options. But no, it's not something anyone anywhere has a reason to complain about. Because...it's optional. You get to choose if you want to let the camera drop your raws to 12-bit or apply a lossy or lossless compression to to save space. As far as I know, their 14-bit uncompressed isn't overly manipulated (at least not in the star-eater way).

This is how major in-camera raw manipulations should be handled. User choice. If Pentax had set up their accelerator unit this way, that would be better. At the very least, we could definitely answer what the thing is doing by turning it off and seeing what changes.
02-18-2018, 12:59 PM   #336
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QuoteOriginally posted by BrianR Quote
You've brought Nikon up a few times. I think you're referring to options like "14-bit Uncompressed NEF" down to "12-bit Compressed NEF" and a few variants in-between? Yes, they are modifying the raw file in most of these options. But no, it's not something anyone anywhere has a reason to complain about. Because...it's optional. You get to choose if you want to let the camera drop your raws to 12-bit or apply a lossy or lossless compression to to save space. As far as I know, their 14-bit uncompressed isn't overly manipulated (at least not in the star-eater way).

This is how major in-camera raw manipulations should be handled. User choice. If Pentax had set up their accelerator unit this way, that would be better. At the very least, we could definitely answer what the thing is doing by turning it off and seeing what changes.
No, my understanding is that Nikon cameras have 'L', 'M', 'S' options for NEF, just as they do for JPEG, but that is the least of my comments. I believe there are all kinds of things manufacturers are doing to output from sensor before it becomes a "raw" file - Fuji and Sony are probably most active in this, but I would be very surprised if anyone just transcribes from sensor to "raw" file; I don't see how any of these things reduces number of bits available, color allocation, or any of the other features people are depending on when they 'develop' "raw" file.


Ultimately, I guess we are where we were a few years ago when some people decided not to purchase K-3ii because they didn't want the change in features. If enough people make that decision, then maybe next FF camera, in another three or four years, won't have that feature.
02-18-2018, 01:32 PM   #337
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QuoteOriginally posted by reh321 Quote
No, my understanding is that Nikon cameras have 'L', 'M', 'S' options for NEF, just as they do for JPEG, but that is the least of my comments.
Do you have a link? I can't find anything like that for NEF, they appear to be full resolution only (or cropped to DX). The options of "L", "M", and "S" do apply to TIFF resolutions though, the D800's options are in this link: Nikon | Imaging Products | Still images/Movies common features - Nikon D800/D800E

I don't think Nikon is an example of a manufacturer that runs your raw files through the deep fryer without asking.
02-18-2018, 01:58 PM - 3 Likes   #338
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QuoteOriginally posted by Class A Quote
Note that the K-1 "only" offers ISO 100, unlike the D810, which offers ISO 64 (for simplicity, I'm using the manufacture figures here, not the measured values). It is therefore highly unlikely that the K-1 uses the same sensor as the D810, a "fact" that has often been purported. It is much more likely that the K-1 uses the same sensor (or a variant of it) as the D800.
With a CMOS sensor the saturation capacity is determined by the translation gain and the voltage swing of the source follower. With the D810 Nikon found a way that they could gain a little more exposure wiggle room that allowed them to get away with a larger exposure. If I had to guess they more than likely lowered the variable voltage gain and put up with a little more non-linear output from the source follower.

As much of a Nikon fan boy that I am I no longer believe that they paid more for the sensor in the D810, as more and more sources prove that the D810 is the same as the D800 the reality is that Nikon found a way to get more out of the IMX-094-AQP sensor .

02-18-2018, 02:07 PM - 1 Like   #339
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QuoteOriginally posted by Ian Stuart Forsyth Quote
If I had to guess they more than likely lowered the variable voltage gain and put up with a little more non-linear output from the source follower.
They did what to the what now?
02-18-2018, 02:12 PM - 2 Likes   #340
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QuoteOriginally posted by BigMackCam Quote
They did what to the what now?
I am with you Mike, and I am somewhat nerdy.
02-18-2018, 02:39 PM   #341
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Wake me up when you will start talking about photography again. You guys "cooked" and "baked" the RAW files from different cameras for 2 or 3 pages by now.
02-18-2018, 02:47 PM   #342
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QuoteOriginally posted by BrianR Quote
Do you have a link? I can't find anything like that for NEF, they appear to be full resolution only (or cropped to DX). The options of "L", "M", and "S" do apply to TIFF resolutions though, the D800's options are in this link: Nikon | Imaging Products | Still images/Movies common features - Nikon D800/D800E

I don't think Nikon is an example of a manufacturer that runs your raw files through the deep fryer without asking.
This is not the Nikon Forum run by Adam, so this is the last comment I will make about them. They do have software switches controlling this, but they may manipulate "raw" files, which is all that I said. Ultimately, somebody here needs to be investigating output from Pentax cameras with this accelerator chip, which has been almost totally ignored here for the past year {as demonstrated by the yawn coming from so many here when it showed up in the specs for the K-1ii} and see how various files from the K-1ii compare to similar files from the K-1.


Nikon D810: Digital Photography Review


QuoteQuote:
There's also a new RAW Small Size option, which produces 16MP images with much smaller file sizes
02-18-2018, 02:59 PM - 1 Like   #343
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Thanks to everyone who tries to shed some more light on the technical aspects of raw data capture and manipulation. Even if it still does not reveal what is happening, if there are benefits from AU or not, or only with drawbacks etc.
I guess we will have best chances to come to empirical investigation possibilities with the availability of the rumored K1 II and when it does carry the same sensor with this unit.
Anyway, as a user of the KP I would also not be too sad if it would turn out, that there are no or minor advantages, because what counts in the end is the result and from my experience this imaging tool delivers.

Last edited by MMVIII; 02-18-2018 at 03:08 PM.
02-18-2018, 03:08 PM   #344
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QuoteOriginally posted by BigMackCam Quote
They did what to the what now?
The reality of FWC in a CMOS sensor is that it is determined by the source follower and not the photodiode. I you look at the source follower it collects almost all of the charge, if we take a look at how much of a charge can be collected it is determined by its capacitance and available voltage swing.
02-18-2018, 03:11 PM - 2 Likes   #345
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QuoteOriginally posted by BigMackCam Quote
They did what to the what now?


I'm not sure but it was somewhere in the wiggle room.
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