186
Replies
I promised not to reply but you have used such a great example, (why didn't I think of that?), that I just could not pass it out. First of all your Statement: "That is not true from a computer science standpoint and also not true from a logical standpoint. There is no reason a "generic file format "cannot contain all info that is in a "specific format."" - is totally wrong - why can't they contain all data? - because it would be not efficient ass generic formats would have to have all possible data points of all possible formats it supports (which would make the generic format inefficient, "bloated" and not so generic since every time new supported format was added new formats data points (the ones who you can't map at that time) would have to be added) - Generic formats just do not do that. Now to the example you used - PSD (as specific) and TIFF (as generic) - first of all - TIFF DOES NOT contain 100% of PSD data - just its rasterized image data - all layer, masking, effects, smart object, vector etc data IS LOST - now imagine RAW NEF being a PSD type format. - look at the example below (NOTE: this is a drastically simplified example which is designed to only act as an example and is NOT how the real generic/specific mapping actually work): Imagine a Specific format containing data points A, B, C, D - generic format had data points: 1, 2, 3, 4, 5, 6. Simple mapping of the specific format would be 1=A, 2=B, 3=C, 4=D, 5=NULL, 6=NULL - all works fine - generic has 100 % of the specific data. But what if (we will disregard simple example as A,B,C,D,E,F,G,H - where H could not be mapped and would have to be stored as a dynamic field) the specific data has something like : A, A1 (layer data), A2, A2.1(masking data), B,C, D,D1? during conversion process (lets look at A) A data point gets captured (or sometime recalculated) and all sub-sets get discarded - just import image to PS, create some layers, masks etc and export it to TIFF - then open that TIFF in PS - do you have any of the layer data? No, it is gone - forever. If you want to now change something what use to be an easy fix in the original PSD (you want to add to a layer mask lets say) becomes an impossible task. Now imagine a D-lighting, NR, WB being treated as layers in NEF (or most likely nodes) and LOST once you convert to DNG. Makes me wonder if that's why "lifting" that example will always be better in Capture NX-D as during import of the NEF LR may just "flatten" all the layer/node data - I hope you can at least admit that TIFF DOES NOT hold entire PSD data set... 
as in my previous post - I did not use a PS for a while so the layer output to TIFF is new to me (my first version of PS was 3.05 (which was one of the first PS versions which run on Win NT) - as long as I could remember tiff did not support layer data - shows you how behind the times I have been) - - Yes - Tiff format has come a long way since then - but really - we are talking about TIFF and PSD which have been married for a long time - my generic to specific format example still applies (since I doubt that TIFF would support D-lighting etc nodes of NEF) (btw - just so we understand each other - I always though that tiff was THE BEST image file format) - If I have time I will disassemble New NEF and TIFF formats just to take a peak what is inside - disassembly is easy - analysis not so ( I do have full time gig you know - and try to play with my photography and have 1000 other hobbies - ADD is a b..ch or a blessing - depends how you look at it)
There is an option to save RAW data into DNG (which makes the file DNG + RAW in size) - There must be a data loss in the DNG conversion or there would not be an option to actually embed the RAW into DNG - you have explained the linear-DND quite well - thanks . I like PS - when I was still doing graphics and Animation, PS was my main tool (for graphics and to do some final texture edits for animation/modeling, as I said, first time I used PS was when first PC version come out - version 3.something?)- ligtroom was great too (when it first come out my jaw dropped how easy it was to change the light on the underexposed picture - something my old D70 did a lot - and it did it not consistently so +ev did not work great) - I still love the workflow capabilities, but quite honestly, the sharpness difference was quite big - and I don't think that it is due to the RAW to DNG conversion as I did see comparable import captures from Nikon D800 in Capture Pro and LR - similar to what I've seen with my files. I also noticed that any adjustments in LR result in more noise (but I bet this is because the DNG file does not have complete per pixel data)
>The raw data is still in the DNG. What a DNG adds is the camera profile and other metadata so an older Camera Raw engine can interpret the raw data.
Exactly. The standard dng conversion gives an exact copy of the raw data in the original raw. There is no loss. All raw file formats, including dng are based on the tiff standard. These files contain the sensor data simply as 12, 14, or 16 bit (some leaf medium format backs can do 16-bit capture) linear greyscale intensity data that still has to be demosaiced to get a rgb triplet at every pixel location. There is nothing secret or weird about this. Tiff and its many variants can easily support this. The ONLY reason why dng converter allows you to embed the original raw is as a backup because camera software such as Nikon's capture and Canon's DPP do not read dng even though they would get the EXACT same conversion out of the dng file as they can get out of the original raw. There is no other reason. The dng file contains all the proprietary metadata that was in the original NEF, including the hints to do Active D-lighting and everything else. There is no technical reason for Nikon to not support dng. There are only marketing reasons. Those marketing reasons could be good or bad for Nikon depending on your outlook on things but the fact is that they are not technical.
Here is a small part of the output from exiftool on a nef and a dng file created from the same nef file. This is looking at a small part of the Nikon Proprietary metadata which is much larger than this. As you can see, everything is there, even the unknown proprietary tags. Dng converter copies everything over lock stock and barrel.
this is metadata - not the data - hehe - like ssprengel said - we do not know if the actual data (not the metadata) contains CIS based pixel data or linear data (compounded, merged, rasterized however you want to call it) - Once again - if everything is based on tiff then why even bother with DNG - just convert to tiff - or better - why don't camera manufacturers just capture to tiff? (since it will contain ANY data) I love when idiots are trying to talk about things they have no clue about (but they did read few forums) - edit - copying metadata does not ensure copying of the actual raw data - - hmm so Adobe is pushing for the "generic format" which is proprietary to Adobe - nice concept - instead of Adobe writing ability to read native RAW files convince everyone that camera manufacturers should eat up that cost and embrace as a standard a format which is native ONLY TO ADOBE products. So in short - Adobe will not have to spend more money to use native RAW files (camera manufacturers will). Adobe will become a standard in photo imaging (since DNG format is NOT supported by other photo imaging suits such as DxO or Capture One - sweet deal for Adobe) - Am I missing something here? Looks like bunch of wins for adobe and none for users, camera manufacturers and most definitely none for the competitors - but Adobe banks that they can convince the plebs that this is the way to go and tries to use public to try to force everyone to do what is good for Adobe and nobody else!
did you try to open dng file in Dx0? (I stand corrected on Capture One) Even OpenRaw does not support DNG - I am not confusing tiff format with anything - tiff is tiff. No, not everyone reads DNG - DNG is a Adobe standard format just like pdf is - many apps can read pdf format but it still is an Adobe standard which benefits Adobe. After digging a bit to the actual DNG file it seams to be a dump container with a 100% metadata capture (using Adobe own XMP - what a shocker) (from NEF) - however, there seam to be loss of a raw format specific data (not sure exactly what but there is a data loss) (it may be just a format specific markers used by proprietary software but there was a data loss - not sure if that can cause lower performance of LR when compared to Capture NX-D or Capture One - thanks for the sleepless night yesterday - was surprised to see ) I will make a test today importing a D750 RAW converted to DNG into Capture one and comparing it to the Capture NX-D - Once the Raw support for the D750 is added to Capture One I will re-compare - so far LR performance has been a disappointment and the reason I was barking at the DNG was because I was hoping it was the format and the data loss in the conversion but I think it may be just imprecise way LR is interpreting that data - this is still to be seen. I do realize that this is an Adobe forum and for most part (most part) I was always an adobe advocate, but that does not mean that I will kiss Adobe's behind - and what exactly did you mean by this: "No compounding, merging, or rasterizing happens. It is still simply raw sensor data. All it does when you enable ADL is lower the ISO" if it is a per pixel mosaic data than a data recorded in the pixel is one thing and the D-Ligting is an additional processing information with a potential overlay filter data - if you capture just meta than it would do just what you said "lower the ISO" or in reality adjust the ISO level which can result in the higher noise. So if the DNG contains just a raw data and meta but no proprietary overlays than that can explain why LR handles lighting/exposure changes in war inferior way than the Capture NX-D which reads all proprietary data which contains any proprietary filter data - do whatever - as ssprengel said - I am not adding anything to this discussion - furthermore I am sure I am being annoying to the Adobe supporters and diehard users, so I will just remove myself rom this discussion - I hope that Canon, Sony and Nikon will not give in to the Adobe DNG bid but I also do hope that they will finally start doing what OpenRaw is hoping for - thoroughly document their raw formats... so by all means reply to this, but I am done - will block notifications in my google account as spam - cya - at the end all I did was reply to "Customers should just boycott camera manufacturers who do not conform to a unified format, such as DNG" - a statement which I could not disagree more with (and I'm sure Adobe loves)... cya
AdChoices