[Jonathan Cross Participant Posts: 51]

Computers & Displays

on: February 8, 2024 at 7:18 am

Forgive me if this is the wrong section for this!

I was idly wondering about file formats, what ones software and hardware recognise and handle now and may do in the future.  I seem to remember as the digital era started image files tended to be JPEG or TIFF.  Then proprietary RAW came along.  These three seem to have stayed, but along the way DNG arrived, and now HEIF/HEIC is appearing and Apple Pro RAW as well.  I also read queries about the best file format for archiving. I am not really interested in video, and formats for that medium are a minefield to me.

I am reminded of a meeting I attended run by the UK Government’s Department of Education along time ago.  They were interested in national assessment standards and whether they were consistent over time.  The Department archived paper student work that had been assessed, but were running out of space.  Digital archiving seemed a way forward.  The meeting went well until the format for the archived files was discussed.  There was great uncertainty about whether the formats available at the time and the hardware and software to handle them would be available in 20, 30, or 50 years for comparison purposes.  The spectre of VHS and Betamax came to mind.  The meeting fizzled out on this pint, and I moved on and lost track of what happenned.

My digital photographic experience started in 2003 with a Canon 10D.  Fortunately, LR and PS still recognise the Canon RAW format from that time, but how much longer?  I also see colour prints from the 70’s fading, as a consequence of the process used then.  We look back fondly at photos taken 100 years ago.  Will our descendants be able to do so in 100 years time?

Speculation invited!

Jonathan

 

 

[Kevin Raber Silver Member Posts: 1311]

Re: File formats

Reply #1 on: February 8, 2024 at 10:24 am

You ask a good question. In the photography industry, they’re probably three formats of people work with the most specifically photography related. You got the RAW file which is usually supplied by the camera manufacturer, and most raw file converters are able to open those. Some of these RAW files have calibration files built into them, and other little sauces and the information for how to read, those is usually shared with companies like Adobe, Capture One, etc. Then you have a DNG file which is basically stands for digital negative. This was created by Thomas Knoll to be able to archive images 30-40 years in the future when raw processors might not read the original raw files any longer. Then you have Tiff files which are known to be probably the better file to use because it doesn’t do compression and it can be 16 bit and include large color spaces. JPEG files or files essentially or the same as a Tiff except they compress them taking out all the unnecessary information. These are a lot  easier to move over the Internet, share, store and do things with. However, so they say and I have seen experiments with these that every time you open and close a JPEG file it deteriorates a little bit. Most likely you’re not gonna see it unless you do it 1000 times. Those needing one time images and need to get them somewhere fast use JPEG (press, weddings, sports etc.). No need for big tiff files with the way they are used. Also, many camera save files as jpegs.  They essentially process a raw file that comes off the sensor and then compress it and save it.  Many people like this because they are pretty good and you don’t need to get into the RAW Processor.  Pros and serious photographers will shoot RAW, process the file and then save it as a RAW.

Files you might be concerned with are PSD files, which are essentially layered files in Photoshop. The PNG files which are another form of files that are used as a crossover between Photography and Graphics. There’s a lot of good information on the Internet. You can go and look these up but for the most part if photographers we’re gonna be working with Tiff, JPEG’s and raws. The new ATC format comes from Apple and used primarily by Apple, but gives you the ability to compress images with more details than what you get in JPEG, and without the loss of opening and closing so I’m told. Most processors like Lightroom are able to open all these files easily, and work a separate note, a lot of people will say take your files and convert them toDNG and that’s not wrong but it’s not right (IMHO) Keep your RAW file as long as you can as long as there are processors that open them because there are things in the raw file that you may want, for example, some manufacturers pixel map the sensor in your camera individually. The DNG file won’t pick that map up.

Some photographers say convert your files to DNG right away.  Please don’t do that.  DNG is an archival file that you can convert to 20 years from now if needed.

I would do a deep search using Google and you’ll learn a lot about these file formats. Just my $.10

Kevin Raber
Owner and Publisher of photoPXL

[Andrew Rodney Participant Posts: 416]

Re: File formats

Reply #2 on: February 8, 2024 at 1:05 pm

Like TIFF, DNG is an openly documented file format owned by Adobe. It is a step-brother of TIFF*. Anyone who desires can find the SDK to understand the format, and anyone can create software to access this data at no cost. NOT the case with PSD* or proprietary raws.

For photographers or anyone worried about long-term access to digital images, it’s pretty simple:

Proprietary = BAD. Openly documented = Good.

* Virtually everything a PSD provides for a Photoshop, LR user a TIFF provides as well. No need for PSDs.

Author “Color Management for Photographers" & "Photoshop CC Color Management" (pluralsight.com)”

[Jeff Schewe Gold Member Posts: 136]

Re: File formats

Reply #3 on: February 8, 2024 at 8:17 pm

Read through this:

Sustainability of Digital Formats: Planning for Library of Congress Collections

[Jonathan Cross Participant Posts: 51]

Re: File formats

Reply #4 on: February 9, 2024 at 6:00 am

Thanks Jeff.  Buried in The Libary of  Congress documents is

https://www.loc.gov/preservation/resources/rfs/RFS%202023-2024.pdf

which seems to suggest for 2023-2024 quite a wide range of formats on page 13.  Preferred are TIFF, JPEG, PNG and BMP.  There is also a list of acceptable  formats including DNG and Camera RAWs.

It is all quite reassuring.

Jonathan

 

 

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