|
General Considerations
|
|
|
Shooting envioronment
|
|
|
Twilight periods
- Civil twilight - Often called "Blue Hour", this is the period after sunset when only the brightest stars are visible.
- Nautical twilight - More stars are becoming visible. The Milky Way is not visible. This is a good time to take exposures for the land if you intend on blending sky and land exposures.
- Astro twilight - Many more stars including the Milky Way are visible. The skies are as dark as they will get at the end of astro twilight.
Moon
- Moonless nights provide the brightest stars.
- Look for the period 3-5 days before and after a new moon for moonless nights.
- Some moon light (less than 10% illumination) can add interest by providing light on landscape features.
- Use a planning app such as TPE, PhotoPills, or PlanIt to determine the moon phase, position, illumination, set, and rise.
Clear skies
- Cloudless skies are best but some clouds can add interest.
- Air quality (haze or smoke) can affect your images.
- Use ClearDarkSky.com, iCSC, or Clear Outside for sky forecasts.
Light pollution
- Only the brightest stars and planets will be visible within light polluted areas (the Milky Way will be very dim).
- Even when shooting from unpolluted areas, the glow from distant urban areas can render stars on the horizon less visible.
- There are many resources online and mobile apps that show maps of light pollution (see "Planning your shoots" below). Pick a location with little or no light pollution.
- Broadband light pollution filters can help in light polluted areas. Be aware that you will loose some color in the sky with these filters.
|
|
|
Planning
|
|
|
Mobile apps
- TPE, PhotoPills and PlanIt - Feature rich apps used to determine the position and timing of the Milky Way and the Galactic Core (GC) from a given location. These apps can also be used to plan the sun, moon and much more.
- iCSC and Clear Skies - These apps provide 72 hour sky visibility forecasts (cloud cover, transparency, seeing, darkness, etc.) from many locations in North America.
- Sky Guide, Star Walk (and others) - These apps show you the Milky Way and constellations from your present location. This is useful for locating the Milky Way in the field prior to seeing it.
- Dark Sky Guide - An app sjowing light pollution maps.
- Dark Skies - An app that allows you to determine the longest shutter speed based camera body and focal length.
Scouting
Scout your area during the day so you can clearly see potential distractions (power lines, structures, etc.) and determine any access issues. Be respectful of private property (ask permission before entering private land).
|
|
|
Exposure
|
|
|
- Use manual mode - Cameras will not meter properly in the dark so you will need to use manual mode and set your shutter speed, aperture and ISO manually.
- Shutter speed - The earth is constantly rotating. To prevent the stars from becoming small streaks making them appear blurry, you will need to limit your shutter speed. The maximum recommended shutter speed depends on focal length of your lens (e.g., maximum shutter speed for a 15mm lens is 30 seconds and 15 seconds for a 35mm lens).
- Aperture - As stated above, you are limited by shutter speed. To keep the ISO as low as possible you will need to use a very wide aperture (use f/2.8 or faster lenses).
- ISO - Since shutter speed and aperture have limits, your only remaining choice to obtain a proper exposure is ISO. Use the lowest ISO possible to get a proper exposure (you will be in the 4000 to 6400 ISO range depending on the aperture used).
- DO NOT judge exposure using the LCD playback. The LCD is too bright and images can appear properly exposed when in fact they are most likely under-exposed. Therefore, always use the histogram to judge exposure. You want the bulk of the pixels in the left 1/3rd of the histogram.
|
|
|
Focus
|
|
|
Auto focus will not work properly. Set your lens/camera to manual focus and focus at infinity.
"Infinity" DOES NOT mean turning the focus ring all the way to its limit. Some lenses have an index mark on the focus scale or an infinity symbol. Align the index mark with the mark on the lens body or the center of the infinity symbol.
- TIP #1 - If you're in the field when it's still light enough, auto focus on something in the far distance. Then set your lens to manual focus and leave it there.
- TIP #2 - If your lens does not have an infinity index mark, turn the focus ring past infinity and back it up a little bit. This will give you a good starting point. Take test shots and adjust accordingly.
- TIP #3 - If you're using a mirrorless camera, view the playback through the view finder to check focus/sharpness.
- TIP #4 - Mirrorless cameras (and even some DSLRs) have focus peaking (edges in focus are highlighted in red or another color). Some of these cameras will focus peak in the dark showing the stars in focus. Set your focus peaking level to high, the color to red and give this a try.
- TIP #5 - Use a Bahtinov mask to set focus at infinity. These masks place a pattern around bright stars. When the pattern is centered on the stars, infinity focus is achieved. Make sure to remove the mask before shooting.
- TIP #6 - Once focus is set, carefully place gaffer's tape on the focus ring to lock it in place (make sure your lens is set to manual focus).
Regardless of how you focus, ALWAYS CHECK FOCUS - Take a test shot and magnify the playback image over the stars to judge sharpness and focus. On mirrorless cameras, look through the view finder during playback to judge focus. Adjust focus if necessary and take another test shot.
|
|
|
Composition
|
|
|
Composition is challenging in the dark. Your view finder and live view will not work well (if at all). Aim the camera like a gun, take a test shot and recompose based on the playback of your test shot. If there is something in the foreground (like a building or tree), shine a light on it to help base your composition on.
|
|
|
My General Post Processing Workflow
|
|
|
Stacking for noise reduction in the field
- Make sure exposure, focus and composition are good to go.
- Set the in-camera intervalometer to take 20 consecutive shots at an interval 2 seconds greater than the shutter speed. If you don't have an intervalometer, use a remote shutter release and take the shots one after the other wating only a few seconds in-between shots.
- Shoot the stacking sequence.
- Wait a couple of minutes and take another stacking sequence.
Prepare stack sequence images in Lightroom
- Select the first image in the stack sequence.
- Hold the Shift key down and select the last image in the sequence (this selects all images in-between).
- In the Delevop module, set the Sync option to Auto-Sync (any develop settings will be automatically applied to all selected images).
- Apply some basic tonal edits in the Basic panel (avoid using Clarity, Dehaze and Saturation).
- Leave the default sharpening settings.
- Reduce noise reduction to zero or leave at default settings.
- Apply lens corrections as long as the result is to your liking.
- Remove Chromatic Aberrations.
- If there are color fringes around the stars, remove them with the Defringing eyedropper tool.
- Export all stacked images as TIFF files (I export them to a pre-defined folder).
Stack the images
- I work on a Mac so my only choiuce for stacting is Starry Landscape Stacker for stacking. If you're on a Windows computer, use Sequator (Starry Landscape Stacker is not available for Windows) - the steps will be different than shown here but somewhat similar.
- Open the TIFF files in Starry Landscape Stacker.
- Input the focal length if asked.
- Follow the workflow in Starry Landscape Stacker.
- Save the stacked image (I save to the same folder as the original images in Lightroom).
Lightroom to Photoshop
- In Lightroom, go to the folder where the original images are located and the stacked image is saved (it will not show up in Lightroom just yet).
- Right click on the folder and select Synchronize Folder.
- The stacked image is now in Lightroom.
- Send the stacked image to Photoshop as a Smart Object.
Photoshop
- Create a copy of the smart object layer in Photoshop using Layer > Smart Objects > New Smart Object via Copy.
- Rename the top layer "Sky" and the bottom layer "Land".
- Create a sky selection.
- Apply the sky selection to the Sky layer as a mask.
- Use Camera Raw through the Smart Object to edit the Sky layer (do not pay attention to how these edits affect the land in Camera Raw).
- Use Camera Raw through the Smart Object to edit the Land layer (do not pay attention to how these edits affect the sky in Camera Raw).
- Repeat the edits to the sky and land in Camera Raw if needed.
- Use luminosity masks to dodge the Milky Way.
- Use luminosity masks to burn the dark areas of the sky.
|
|
|
My Gear
|
|
|
Camera bodies
|
- Canon 6D MkII (astro modified - full spectrum)
- Filters used with the Canon 6D MkII: Hot mirror (blocks all UV and infrared light allowing normal color to be captured). H-Alpha (blocks UV and some infrared capturing many reds in nebulas and galaxies)
- Sony a7IV
- Sony a7RV
|
|
|
Lenses (all Canon EF mount)
|
- 15mm IRIX f/2.5 Firefly
- 20mm Sigma f/1.4 ART
- 28mm Sigma f/1.4 ART
- 35mm Rokinon f/1.4
- 50mm Rokinon f/1.4
- Sigma MC-11 Sony FE to Canon EF lens adapter
|
|
|
Tripods and heads
|
- Manfrotto 055 CX-PRO3 tripod
- Really Right Stuff BH-40 ballhead with quick release clamp
- Really Right Stuff L-Brackets on all cameras
- Manfrotto 055 tripod
- Really Right Stuff BH-40 ballhead with quick release clamp
|
|
|
Sky Tracker
|
- iOptron SkyGuider Pro
- Feisol CB-40D ball head
- Upgraded Willimas Optics base for SkyGuider
|
|
|
Miscellaneous
|
- Wired intervalometer/shutter release (for Sony and Canon cameras)
- Lens heater
- Broadband light pollution filter
- Bahtinov focus mask
|
|