PHOTOSHOP for ASTRONOMY
From Raw to Rave!
Half the work in creating great astronomical photographs is in the processing. Adobe Photoshop is the most important tool we have to process images from DSLR and mirrorless cameras, to bring out the maximum detail with the minimum of noise.
My other workshops deal first and foremost with how to take great images in the field. This half-day workshop picks up where those workshops leave off.
From that starting point, we explore the next stage: processing those images in step-by-step detail using Photoshop, and its companion programs Adobe Camera Raw (ACR) and Adobe Bridge.
COURSE CONTENT (Varies with the length of the workshop)
What's the Workshop About?
The Photoshop for Astronomy Workshop explains professional "non-destructive" techniques for processing:
• Still image nightscapes and star trail composites
• Time-lapse movies of the night sky
• Tracked deep-sky images using stacking methods
...all shot with a DSLR or mirrorless camera.
What This Workshop is NOT About
• My workshop focuses on Photoshop’s functions most useful for processing astrophotos.
• This is not about restoring old family photos, creating graphics, or processing your vacation snapshots!
• This workshop does not cover techniques for processing solar, lunar and planetary images, and movies taken with specialized “planetcams.”
• Nor does it cover how to process images from CCD/CMOS cameras (monochrome or one-shot colour) using specialized software such as Maxim, PixInsight or ImagesPlus.
• However, many of the Photoshop steps I'll outline are applicable to the later stages of processing images taken with astro-cameras that were "calibrated" with specialized programs.
Who Is the Workshop For?
• Serious beginners starting out in astrophotography who want to learn the essential techniques for using Photoshop to make their DSLR images look great.
• Experienced astrophotographers who want to learn more advanced Photoshop tips and techniques, to make the most of Photoshop’s powerful features.
• Nightscape and deep-sky photographers – I cover processing techniques for both fields, working with DSLR/mirrorless images.
What You Should Know — The Workshop Assumes…
…You know how to use any software to open and save files, as well as navigate menus and dialog boxes. This is not a seminar on “how to use a computer.”
…You have at least some familiarity with Photoshop already, and have used it for some of your day and night photos.
…You use your DSLR or mirrorless camera to shoot Raw files, not JPGs. My entire “workflow” is based on processing Raw images from a DSLR/mirrorless camera.
…You know how to use your camera to shoot sharp, well-exposed images, whether it be simple camera-on-tripod nightscapes or guided deep-sky portraits with telescopes.
In this workshop I will not be advising on how to take images.
What’s In the Workshop?
• While I’ll briefly describe Adobe Lightroom and Photoshop Elements, outlining their strengths and weaknesses, the workshop focuses on using Adobe Photoshop.
• Essential functions shown will apply to CS4 and later. However, you will need CS6 and higher to use the majority of Photoshop’s features and functions demonstrated.
• All the demonstrations will be with the latest version of Photoshop CC.
• Throughout, the emphasis is on non-destructive processing. You should never flatten, rasterize, erase, delete or merge! You should never have to say “I wish I hadn’t done that earlier on!”
• When used right, Photoshop allows you to change any adjustment, mask or filter at any time, even weeks later. I'll show you how.
Using live demos of Photoshop CC, you'll learn how to…
• Set Preferences and Workspaces in Bridge, ACR, and Photoshop
• Set Tool Presets in Photoshop
• Use the keyboard shortcuts everyone should know in Photoshop
Import and Develop Raws
• Import images with Adobe Bridge, and use its functions to sort, organize, select and keyword images
• Use Bridge to call up Photoshop scripts such as Batch, HDR and Photomerge
• Develop Raw images in Adobe Camera Raw (ACR), the most important yet often ignored step in processing astronomical images from DSLR cameras
• Use ACR to extract the most detail out of 16-bit Raw images, including functions such as Color Balance, Lens Correction, Noise Reduction, and Adjustment Brushes
• Use ACR to re-balance off-colour images from filter-modified cameras
• Use the histogram display to judge exposure and colour balance
Work With Smart Objects
• Open Raw files in Photoshop as “smart objects” for non-destructive processing
• Apply smart filters: Reduce Noise, Smart Sharpen, and Shadows & Highlights
• Reduce noise and banding with third-party plug-in filters
• Apply Clone, Heal, and Dodge & Burn tools to smart objects using special non-destructive layers
• Use Content Aware tools to magically remove unwanted elements in an image
Work With Adjustment Layers
• Apply adjustment layers: Curves, Levels, Brightness & Contrast, Selective Color
• Use the wonderful Targeted Adjustment Tool to shape a contrast-enhancing curve
• Manage, group and blend layers
• Apply dark frames and flat field frames in Photoshop
Work With Masks
• Create and apply masks to work on selected areas of an image
• Use selection tools such as Quick Select and Color Range for fast selection of the ground, the sky, or even just the stars
• Add to or subtract from a selection
• Use Select and Mask controls for easy masking of complex shapes such as trees
• Create and apply Luminosity masks for selecting complex tonal areas
• Use Photoshop's little-known shortcut for creating a star mask with one click
• Paint on a mask to further refine a selection
• Create a gradient mask for removing sky gradients
• Adjust Mask Properties, for non-destructive feathering and opacity adjustments
• Clip a mask to an underlying layer
• Mask a group, to mask an already masked layer
• Use Photoshop's little-known Statistics command to stack, register and blend images for noise smoothing in deep-sky images (no need to use other programs)
• Select a Stack Mode for best results
• Use manual stacking and alignment methods for special cases, such as merging tracked and untracked images of nightscapes
• Apply layer “Blend Modes” such as Lighten, Overlay, and Luminosity
• Stack and blend short- and long-exposure images of nebulas and galaxies
Apply Final Touches
• Apply the “Stamp Layers” command and High Pass filter for non-destructive and selective sharpening
• Apply star shrinking effects
• Crop non-destructively (never delete pixels!)
• Add metadata to images for captions and keywords that ride with the image
• Save images in the best formats, file sizes & colour spaces for distribution
• Use Adobe Lightroom for cataloguing, watermarking, and exporting images
If Time Allows...
Create HDR, Panoramas and Star Trail Stacks
• Create high dynamic range (HDR) composites of high-contrast scenes
• Use ACR to tone-map 32-bit HDR images (the best HDR method!)
• Stitch panoramas of Milky Way landscapes and mosaics of deep-sky fields using Photoshop and third-party programs such as PTGui
• Create star trail stacks using Photoshop, Advanced Stacker Actions, and StarStaX
Process and Assemble Time-Lapses
• Process hundreds of frames in one easy step
• Batch export hundreds of frames using Image Processor
• Assemble those frames into a movie using Photoshop or third-party programs
• Apply gradually changing settings to a folder of images with LRTimeLapse software
• Deflicker and process "holy grail" time-lapses in LRTimeLapse
All workshop participants receive a handout PDF via download of all the workshop slides and screen shots of the step-by-step processing techniques demonstrated live in the presentation.
Final content depends on length of the workshop and intended audience.