Convert Minolta RAW to Adobe Digital Negative file

[MrIconoclast]

I have a Minolta A2, which I bought almost 2 years ago after looking at similar cameras and reading MR's review.  

I usually shoot RAW files with it (gloat, gloat, gloat!!).  I noticed that if I convert a Minolta RAW file to a Adobe digital negative file, I can save at least 3 megs of space per image.  And I have a file format that probably has a better chance of being supported 10 years from now than the Minolta A2 format.  ( I am not sure if Sony has taken a position on supporting the older Minolta file formats.)

My question is this.  What if anything do I lose in terms of image quality and flexibility by using the DNG format to save my work?  

Thanks.

[jani]

My question is this.  What if anything do I lose in terms of image quality and flexibility by using the DNG format to save my work?

Anything that the DNG format doesn't contain, which is contained within the original raw files. If there is proprietary information in the raw format that the DNG format doesn't support, then that will be lost. Important? Hard to say, and I can't give specific comment on the A2's raw format.

The prudent solution seems to be:

1) Keep the raw files.
2) Convert them all to DNG, so that you have both.

For now, however, it appears that keeping support for older raw formats is so simple and cheap, that cameras like the EOS D30 and the A2 will remain supported.

There are no guarantees, however, just like there are no guarantees that future software will continue supporting DNG.

But the more people who use DNG, the greater the chance of it working "forever".

[michael]

You have the option within DNG of also retaining the entire original raw file. This makes it unnecessary to save both.

Michael

[Jonathan Wienke]

My question is this.  What if anything do I lose in terms of image quality and flexibility by using the DNG format to save my work?

The compatibility and archival issues have been addressed pretty well, so I won't rehash them. But the short answer to your actual question is "nothing". DNG is the same RAW image data as the manufacturer's proprietary format, just in a publicly defined, standardized format instead of the manufacturer's secret sauce. It also uses a more efficient lossless compression algorithm than most of the manufacturer's formats, which is why DNGs are smaller than the manufacturer's RAW files. If you convert a DNG and the RAW it came from with the same settings, you will get the exact same image out of ACR from both, and from any other RAW converter that handles DNG correctly. The only things you may lose are some of the metadata tags like flash mode or lens focus distance, which generally aren't a big deal. Processing options and flexibility are identical between DNGs and the original RAWs. While I was deployed in Ramadi, Iraq, I had to make do with an Olympus SP-350 digicam and my laptop instead of my DSLRs and desktop network with a terabyte of server space, so I converted all the RAWs on my laptop to DNG and saved about 15GB of disk space. I finished my deployment with about 10GB of disk space on my laptop, and sacrificed nothing in regards to image quality or processing options.

[b2martin]

Another advantage of DNG is all ACR settings are saved in the DNG file rather than an external XMP file.  I convert all my NEF files to DNG before I start processing.