Mental blockage !!!!!!!!

Question

Hi everyone
I have spent some time now playing with & trying to get to grips with LR but there are some things that I just cannot nail down & fully understand although I have made some progress thanks to you guys on these forums, Scot Kelbys book & the LL videos. I always seem to skirt around the bits I don't fully understand, and I admit that even if I can use something I do like to understand how it ticks. For now lets just think of the develop module which is the one I use most & forget the pro's or cons of DNG format & DAM.
To me LR is a tool that produces an instruction script for each image you adjust and either saves these instructions in an XMP sidecar file or within a DNG, I accept this and the instructions make sense.
But whats the pro's & cons of importing my NEF's into LR as NEF's, converting them to DNG & then import them into LR or convert to DNG imediately after importing into LR as NEF's ???????????????
I don't think I am going to embed the original NEF into the DNG so either the LR or standalone convertor is Ok .
If LR treats all file formats the same for editing purposes and makes no changes to the original then do I have the same amount of data in a DNG as in the original NEF, I suppose what I am asking is what happens during the conversions. NEF converted to TIF & printed, or NEF to DNG to TIF & printed. You can see my confussion, the final results must depend upon both the Adobe RAW conversion plus also the DNG conversion, but then if the RAW convertor is good does it mater if the output file is TIF or DNG ?

Answer 1

>A DNG can be returned to the original state of the RAW, in terms of appearance of the image, whether you tweak a RAW then convert to DNG or convert to DNG then tweak.
Does it matter that this statement is FALSE? Much to my amazement I'm surprised it hasn't been corrected by some of the more senior people in this forum. IMO, a better metaphor might be:
DNG is first and foremost a container. Period. It's like digital tupperware -- only with well organized slots and locking compartments. What you store inside is secondary. A DNG can store raw data, metadata, bitmapped data, and/or other file types (like the camera makers raw file). In fact it's unlimited as to what it can contain because it's extensible. The flip to that benefit is that it may also be limited to what can be retrieved. Caveat Emptor.
So what's inside? A DNG can contain the raw data -- or a partial set , and/or either a reversible, or irreversible transformed data set. That is left entirely up to the DNG creator application -- which may differ by way of vendor. Access to information inside this digital tupperware also depends on what the DNG reader is designed or licensed to unlock and read. So while it's true all your original data can be stored inside a DNG, it isn't necessarily so.
Currently, DNGs work pretty well across the Adobe suite of applications because it's obviously in Adobe's interests to promote as much compatability as possible. I suspect this will always be the case when using Adobe's premium tools.
But let's run through this with an example (i.e. NEF). With some DNG writers (currently not LR) one has the option of embedding the original NEF inside the DNG -- in which case you are guarenteed a copy of:
1. all the original image data
2. all the original metadata
3. the original roadmap as to where it was all filed away.
Without the original, you get a transformation of the original data. In general, this is a good thing because it standardizes where the most common information used to render a raw file is stored. Any DNG reader would have the capability to retrieve that common data without knowing anything about the camera.
However, the danger of TRANSFORMING something is that it can be lossy. It might not take you exactly or even remotely back to where you were. It depends on the transformation. For instance, DxO cooks your raw data with corrections before it stores it inside a DNG. Even when transforming raw files data is changed. You can verify this by comparing the color temperatures written inside an NEF --as opened within NX --vs. the color temperatures calculated when written to DNG. They are not identical. That's not a criticism, as TK has gone to great lengths explaining why that is so, but it's a fact. I have additional concerns as to whether all the original public and private metadata is identically transferred when raw files are transformed inside a DNG. In some cases the original data is not kept which is why some people recommend archiving the original. Only you know whether this is going to impact you. Or maybe you don't know and want to take additional precautions.
>A RAW is a DNG is a RAW -- that's just what I needed to understand!
That makes about as much sense as a HAMBURGER is a WATERMELON is a CHEESEBURGER. See above. :~)
A DNG is just a container. Digital tupperware. It has secret compartments, locked compartments, may contain raw data, or semi to fully cooked data. The integrity of the raw conversion and retrieval of data is entirely dependent on the application.
You may not always safely step backward to the original raw state -- unless you keep a copy of the original.
Why is this important? If you need to ask, you're workflow is probably not critical enough that it matters. Some of the careless assertions being made seem to verify this. YMMV. :-)