The naked truth about shooting raw (very long post)

Started Nov 9, 2005 | Discussions thread
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Barry Pearson
Barry Pearson Veteran Member • Posts: 7,656
DNG will encourage, not stifle, innovation

Mig wrote:
[snip]

I do not favor OpenRAW - as you spelled out to me before, each
maker designs things different. An open source will take this
design out and the result is progress will stop. I would rather
spend the money on the best than have a TV stuck in technology from
the 1940s. OpenRaw is fine for a static environment, but digital
at this stage is too dynamic to stick to one system. Let the
industry evolve to its fullest before putting something so
stiffling and crippling on advancement as a standard. As you
stated the D1X is a different animal, as is the Foveon and Fuji
system. CMOS and CCD differ - CFA's can an may change. Maybe less
green or, as Sony has done, another color. How does OpenRaw handle
this? Any deviation needs to be w/n parameters or it will not
work. Progress is thwarted.

[snip]

First, OpenRAW is primarily an initiative to persuade camera manufacturers to publicly document their raw formats. Although they later added a desire for a universal raw format, that has never been a major theme. (I believe that was their only significant mistake).

Second, DNG has more flexibility than you assume. I won't repeat what Ross Burke has said in his response, but I'll add a few things. Remember two things:

1. DNG already caters for Bayer CFAs, Sony 4-colour arrays, Fujifilm SR offset sensors, and Foveon sensors.

2. And DNG contains enough information in the publicly-specified fields to do a high quality raw conversion, because they are the fields that ACR itself uses.

Raw image data changes surprisingly slowly. Thomas Knoll has said that if DNG had existed for years, the last time it would have needed to change because of new sensor technology was for the Fujifilm SR sensor, well over a year and a half ago. Camera makers may add extra metadata for various purposes, but the image data and image metadata changes rarely.

DNG can handle bit-depths to 32, up to (I think) 7 colours in an array, non-square pixels, a variety of offset configurations (or none), etc. These are represented by individual parameters. New parameters can be added as needed - DNG has a version scheme to let the DNG specification, and DNG readers, and DNG writers, to evolve at their own paces.

Lack of general support of a common raw format is stifling innovation, and photographers and users of photographs are paying the price.

Consider a hypothetical example. Support that you want to use a GPS logger to record where you are at any time. Then you want to load your raws into a folder, download the GPS log, and run a software product that reads the date and time from the EXIFs, and writes back the relevant GPS metadata. Perhaps even get the description of that location from a database, or an online service. ("This photograph was taken in front of the White House").

There is a product (GPS-Photo Link) that does something like the first part of that for JPEGs. A problem is that updating a file typically needs more knowledge of the file format than simply reading it. Updating raw files in this way is tricky for a small company. (Even Adobe doesn't attempt it except for DNG). Could GPS-Photo Link be constantly upgraded for each new camera? Or should it support a common raw format? And if it does, it had better be a common raw format that can then be read by raw converters and asset management systems and other niche products too.

When DNG becomes the de facto standard for raw formats, it will be exploited for all sorts of things that will benefit the rest of us.

 Barry Pearson's gear list:Barry Pearson's gear list
Panasonic LX100 Pentax K-3 II Pentax K-1 Pentax smc DA* 55mm F1.4 SDM Pentax smc DA 10-17mm F3.5-4.5 ED (IF) Fisheye +20 more
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