DNG-JPG-TIFF-PSD

October 10, 2014

DNG-JPG-TIFF-PSD

Surge of Silence

Digital photos have been created, modified, transformed, copied and archived in so many file formats.  Each file format has a definite advantage compared to others and it's hard to choose which ones to use.  This is neither the RAW vs DNG and RAW vs JPG debate.  This is just a simple guidance on the file formats and it's brief advantage over the other.

I will outline what file formats I use so this can give you some ideas.  In my workflow, I use 4 file formats, namely:

• DNG 
• JPG
• TIFF
• PSD

All four (4) formats are completely different from each other.  Each serves me a purpose.  I could not favour one to let go of the others.  

Golden Decree

DNG (Digital Negative)

My files are initially NEF, a proprietary image format from Nikon.  But if I import all these to Lightroom, I convert them to DNG.  Thus, DNG plays a big part of my workflow as it's where I view, manipulate, render, export my photos.  

Back in the early days, I didn't use DNG and just import NEF directly.  But after knowing the advantages of DNG, I was convinced.  I manage my photos in Lightroom and I chose the DNG format because of the following:

• Support and Continuity - Adobe promised that DNG itself will be supported until the end of time.  Thus you won't worry even if Canon or Nikon stopped supporting the RAW files of your old cameras.  
• Open Source - to standardise anything, it should be open source.  Ideally, any digital photography software will be able to read DNG.  
• Single File with Metadata - as we all know, RAW files are the digital negatives.  It can never be altered in anyway.  This is very good security.  But useful information (settings, location, metadata, keywords) are prevented to be written on the file as well.  Lightroom's work around is to create a text file(same filename) that goes along with the RAW files.  The text file, called XML (Extensible Metadata Platform), contains all additional information not captured by RAW files.  Since it's a separate text file, it's prone to getting lost or corrupted.  DNG houses both RAW and text files so all information are just in one file.  It's like a zip file.
• Smaller file size - amazingly, DNG files are a bit smaller than their RAW counterparts. 
• Archiving - DNG is also a lossless file thus it's best to use this for archive.

There maybe other advantage of DNG but I did not know them or might not make any difference in my workflow.  Definitely the above points are what I see and use.

Ray of Triangulation

JPG (Joint Photographic Expert Group)

JPEG or Joint Photographic Expert Group is a common file format being read by many digital photographic software.  This is widely used.  It's very easy to share photos in JPG format.  I point out below why I use JPG:

• Speed - if you need speed, high quality JPGs would be ideal.  If you need more speed, you can dial down the quality to an acceptable level.  As a landscape photographer, I don't use this.  The only instance I used JPG when shooting is if I'm trying to capture fireworks.  But for my normal shooting, I use RAW (NEF). 
• Quick View - some software can't read RAW files.  Thus you can't view a file.  I use the JPG equivalent of my DNG files to view it's DNG counterpart.  Please read my article about importing photos without Lightroom as I use JPG extensively here to view my DNG files.
• Internet - from the 4 formats I use, JPG ensures me that anyone browsing the net can view my photos 
• Sharing - in most occasions, sharing or giving a copy of your photo should be in jpg format.

I use JPG for speed, ease of use and universality.  JPG ensures that your photos can be viewed by any type of media in any shape or form.  If you can't view a JPG, then there must be something wrong somewhere in your end.

Finite Protection

TIFF (Tagged Image File Format)

If you read Wiki, TIFF is created by a company known as Aldus.  When Adobe came into power, Adobe bought Aldus.  Thus retaining all the rights to this file format.  TIFF is also an open source file.  Thus many software can read and import TIFF (unlike PSD).

Once I finalised all my edits, I flatten the image and declare it as final.  Once final, I only view them or export a JPG copy.  I rarely edit final photos.  TIFF is a lossless file format. If you want to archive a finalised photo, just use TIFF.  

TIFF can also hold many information in place including layers.  But if you're using Photoshop, it's still best to use PSD as it is Photoshop's native software.  

Sky Fury

PSD (Photoshop Document)

Adobe's standard editing software, Photoshop, uses PSD as it's own native file format.  Just like DNG that stores multiple information, PSD can store all information made during editing.  This includes layers, alpha channels, masks, transparencies, text etc.  

Yes, I occasionally save PSD files.  The reason why I keep PSD is because they save all my edits.  If I edit a photo and is well satisfied of what I did, I'll save it to PSD.  If in the near future I forgot how I did this edit, I can just go back to this file, open it in Photoshop and refresh my memory on all the steps.  This is easier for me to 'archive all my editing steps' rather than keep a separate notebook. (I always lost my notebook).

Turimetta Sunrise

Final Thoughts

I can summarise everything below:

• DNG - file management
• JPG - share photos (export)
• TIFF - archive, processed photos
• PSD - remember my editing steps

Those are the only file formats I use so far.  Others may use alternatives or additional formats.  What matters most is you know the advantages and maximise the advantages in your own workflow.  

If you have other formats that you normally use in your workflow, please let me know from your comments below.  I may have missed them.  Thank you.

Edge of Solace

Location: Turimetta Beach, Warriewood NSW 2102, Australia