Leigh Garner - March 2012

An Introduction to Digital Processing

Target Audience• Photographers new to digital processing

• Those unsure about the various software packages available

• Anyone wanting to broaden their knowledge

Disclaimer: These opinions are my own (or those I found on the Internet) and are presented solely in my capacity as a keen amateur photographer.

Agenda• Why processing is important.• File Formats • Why Raw?• Image sizing & the DPI thing• Workflow and Metadata• An Overview of Software

Why Processing is importantPost-processing photos can be a controversial topic

It shouldn’t be – first step: lose the misconception!

• Many of todays Digital processing techniques originate from the Darkroom

• It’s all part of the creative process

• Can help you learn a great deal about how to take photos by looking at those you have taken before

• Even small adjustments can make a big difference

If you’ve been thinking that processing is an extra step you don’t have time for

you’re missing the pointIt’s an extra opportunity to learn more, make better photos and become a better photographer. Neil Creek - professional photographer & author of dPS’s new eBook –  Photo Nuts and Post: a Guide to Post Processing Your Images

Read more: http://www.digital-photography-school.com/how-post-processing-helped-me-become-a-better-photographer

Examples• Small adjustments can make big

improvements• How the creative process can be

continued in post• Photo Manipulation & how the image

capturing is only the start

File formats• JPEG• TIFF• RAW • DNG

JPEG (.jpg)• The most commonly used digital image format• Like an MP3 it’s a ‘Lossy’ format.• Some original image information is discarded and

cannot be restored.• A trade-off between file size and image quality.• What I didn’t know?

• Compresses colour more than detail. Our eyes are more sensitive to detail than to colour.

• Discards the fine detail first because our eyes are more sensitive to coarse detail

JPEG (.jpg)• When editing an image in several sessions, it is

recommended to save the intermediate image in an uncompressed format such as TIFF or PSD.

• If you save an image in JPEG, close it, open it again and save it again with the same quality setting, the file size will not reduce further, but quality will have degraded further. So only compress after all editing is done.http://www.dpreview.com/learn/?/Glossary/Digital_Imaging/JPEG_01.htm

TIFF (.tif)

Universal image format that is compatible with most image editing and viewing programs.• Can be compressed in a ‘lossless’ way (ZIP/ LZW)• Widely used as a final format in the printing and

publishing industry. http://www.dpreview.com/learn/?/Glossary/Digital_Imaging/TIFF_01.htm

• What I didn’t know? • Adobe holds the copyright on the TIFF

specification.

RAW • Raw = unprocessed - contains the original image

information as it comes off the sensor.• Raw = digital negative - same role as negatives in

film photography.• Proprietary formats - dozens if not hundreds of

such formats (NEF, CRW, ARW etc…..)• Many of the formats are similar – but with

proprietary features to each brand.

We come onto Why Raw later……

DNG • Digital Negative (DNG) - Publicly Available

Open raw image format owned by Adobe• Adobe: “DNG helps ensure that photographers will

be able to access their files in the future”• Adobe has submitted DNG to ISO for incorporation

into their revision of ISO 12234-2:2001• ‘Increasingly, professional archivists, working for

respectable organizations, variously suggest or recommend DNG for archival purposes’

DNG • Statistics:- 6th anniversary, September 2010

Camera manufacturers: 14

Camera models: 47

Software products: 240+

Convertible raw image formats: 290+• Except Pentax, no camera manufacturer with a

large market share of dSLRs use DNG in their cameras.

Why Raw?• I’m going to be mostly making the case for….but

there are arguments against:

• Time

• File size

• Proprietary file formats

Why Raw?It’s a personal choice….but I present to you:

The facts

Why Raw?Fact one: What I didn’t know? • At issue is Colour-Depth

• When you take a digital photograph light falls onto the sensor.

• The camera records the level of the light falling onto each of the pixels on the sensor.

• Most modern digital SLR cameras will record in either a 12 or 14 bit format.

Why Raw?• Basically, the higher the bit depth, the more levels

of brightness can be recorded and image quality improves.

• The math (especially for Donald)

• A bit is a binary digit, either a 1 or a 0.• If 12 bits are recorded then your camera is

capable of distinguishing 4,096 (2^12) different brightness levels at each pixel.

• If 14 bits are recorded - can distinguish 16,384 (2^14) different brightness levels.

Why Raw?To put this into perspective • JPEGs are 8 bit files, which means that they

contain only 256 brightness levels at each pixel.

• A considerable reduction compared to the 16,384 that your camera may be recording to begin with.

• If you shoot only JPEG, you automatically throw away at least 4 bits of information that the sensor captured.

Why Raw?Fact one:

Shooting in RAW means that the camera will record a file that contains all the “raw” data from the sensor.

All the glorious 14 bits of colour and brightness

Why Raw?Fact two:• On top of the colour depth issue…..what else do

we know about JPEGs?

• They’re ‘lossy’ ……that is….. Compressed.

• Some original image information is discarded and cannot be restored.

JPEG is a ‘lossy’ format

Why Raw?Fact three:• Many camera settings which were applied to the

Raw data can be changed in processing software.

• For instance White balance, sharpening, levels and colour adjustments can be undone and recalculated based on the raw data.

• Yes you can adjust these in a JPEG…..but they're ‘baked in’.

Why Raw?Fact three :• You are able to extract shadow and highlight detail

which would have been lost in the JPEG.

• You’re NOT giving up part of the creative process to a Japanese software engineer!

The Flexibility of RAW

Why Raw?In summary:

1. All the glorious 14 bits of colour and brightness

2. JPEG is a ‘lossy’ format

3. The Flexibility of RAW

Why Raw?Further reading:

http://leadinglinesphotography.net/tutorials/on-line/understanding-on-line/raw

http://www.dpreview.com/learn/?/Glossary/Digital_Imaging/RAW_01.htm

http://www.slrlounge.com/raw-vs-jpeg-jpg-the-ultimate-visual-guide

What have we learnt so far?

• Shoot Raw when possible

• Save intermediate images in an uncompressed format such as TIFF or PSD

• Only Save to JPEG for output

Image Sizing & the DPI thing..A minefield?

• It’s important to understand the difference between Pixel Dimensions & Document Size.

• A digital photo's resolution is determined by its pixel dimensions.

• Regardless of what Adobe call resolution, if the Pixels don't change, the photo remains the same resolution.

Image Sizing & the DPI thing..

Image Sizing & the DPI thing..

Image Sizing & the DPI thing..Pixel Dimensions = what's physically in the file

Document Size = How it will be printed

DPI – it’s just a number!

• It is a very tiny string in the header of a file.

• It's not actually part of the image.

• It doesn't change the digital photo in any way.

• Some software will use it to set the paper output or display dimensions.

Image Sizing & the DPI thing..Not convinced?

Read: All About Digital Photos - The Myth of DPI

http://www.rideau-info.com/photos/mythdpi.html

For the best results for display in club competitions:

1920 x 1080 will exceed the projector resolution of 1400 x 1050

Workflow & MetadataHow many photos did you take last year?

How many will you have in 5 years?

Are you utilising the advantage of Digital?

– No? Just buy Lightroom!

What is Metadata?

Data that describes data

– what could be more beautiful!

Workflow & Metadata• Get organised….have a structure.

• Do the same thing for every shoot.

• Use Keywords…..

Tip: for folder and filenames:

- Use the format YYYY-MM-DD

- ie. 20120315

- Allows folders/files to be viewed in sort order

Software Overview• By no means a comprehensive list

• But there is more than PhotoShop

• It's very much a personal thing

• Ask yourself:

• How much do I want to spend?

• How much time do I want to INVEST?

• How easy is it to get support?

Software OverviewAdobe Camera Raw (ACR)• Processor for Raw Images• A plugin used by Photoshop, Elements & Bridge.• Adobe Photoshop Lightroom is built upon the

same raw processing technology.• There are alternatives:

• Manufacturers Software• Bibble. LightZone. Capture One. NX2. DXO• And of course Lightroom

Software OverviewAdobe DNG Converter• A free utility that converts Raw files from more

than 350 cameras to the DNG format.• Useful:

• As a single raw processing solution when handling raw files from multiple camera models.

• Or for example using an old version of PS or Elements

Software OverviewPicasa• Free software from Google for Organising Photos

with some editing functions.• Suited to Photographers:

• On a budget & don’t want a steep learning curve• Happy with simple enhancements• Not comfortable with complex software

• Alternative: iPhoto (Mac only)

Software OverviewLightroom• Designed to streamline and accelerate the serious

digital photographer’s workflow.• Suited to Photographers:

• Process Raw files and understand the need for image management.

• Don’t mind a medium learning curve.• Doesn’t exclude those that use Photoshop.

• Alternative: Aperture (Mac only). Bridge?

Software OverviewPhotoshop Elements• Edit & enhance Photos. Use one-stop or manual

adjustments. A good learning process for full PS.• Suited to Photographers:

• Who don't already own Photoshop CS• Don’t mind a medium learning curve• Probably now has 95%+ of PS photography

tools.• Alternative: Paintshop Pro

Software OverviewPhotoshop CS

Software OverviewPhotoshop CS• Digital imaging software with a strong focus on

photography. Tools for superior image selections, realistic painting, and more…

• Suited to Photographers: • Professionals or serious amateurs. • Don’t mind a steep learning curve.• Want to do serious image manipulation.

• Alternative: Gimp - free

Software OverviewOthers• Capture NX2 – For Nikon. Built by Nik software.• Gimp - a freely distributed program for such tasks

as photo retouching, image composition and image authoring.

• Paint.Net – Free. Windows only.• DxO Optics Pro - Adapts very specifically to your

equipment. Each camera-lens combination is the subject of a very precise analysis.

Software OverviewConclusion• Choose a Package that suits you.

• Buy a book.

• Learn it.

Because you're worth it!