Guide

AstroShader allows you to:

• "Live-stack" multiple exposures from your iPhone

• Save multiple exposures to you photos library - like an intervalometer

• Edit photos with tools specific for astrophotography

🔧 You need to manually adjust all camera settings; focus, exposure time, ISO, number of exposures, and so on.

🧪 Top tip: Test with 1-10 exposures, before firing off 1000 exposures.

⚙️ Open the camera settings with the cog on the bottom right.

🖌️ Open an image in the editor with the image button on the bottom right.

Focus:

• Use the slider or + / - buttons to adjust focus.

• Set the exposure time to ~0.1s and focus on a bright star.

Number of exposures:

• How many exposures to live-stack.

• If saving each exposure this is the number that will be saved to Photos (see "Save individual exposures").

Exposure time:

• Exposure time for each image.

• This can be extended beyond the iOS limit of 0.3/1.0s but the results may differ from the preview so please test.

ISO:

• Camera ISO with an extended range.

Camera type:

• Choose which iPhone camera to use.

• The wide-angle camera generally has the best sensor.

Camera timer:

• Countdown timer before capture - to allow any vibrations to stop before image capture.

Rotate camera 180:

• To correct for the optics - along with horizontal flip.

Horizontal flip:

• To correct for the optics - along with rotate camera 180.

Save individual exposures:

• This setting saves each exposure to your phone.

• If choosing RAW and an exposure time beyond the native limit (usually 1.0s) this will save each un-edited RAW. e.g. Choosing 500 exposures at 3.0s will result in 1500 RAW files.

Set reposition interval:

• This can be useful for untracked users to re-centre the target as it drifts out of the frame.

• Activating this setting will mean after the chosen number of exposures a repositioning stop is added to the capture flow.

Manual white balance:

• Activate this setting to set the white balance manually.

Pixel binning:

• This setting uses a 4x4 downsampling to the image.

• This can be useful for dimmer targets.

Alignment function:

• This setting controls the trade-off between alignment accuracy and processing time.

• Use medium or strong if you images are not aligning well.

Color / Brightness:

• Brightens images smoothly.

Color / Background extraction:

• Removes the dominant background color from an image.

• Note: This is designed to work with deep sky images and may produce irregular results when used with day time images.

Color / Stretch:

• This performs an adaptive contrast enhancement.

Color / Saturation:

• Adjust color saturation.

Color / Blackpoint:

• Performs a blackpoint adjustment with a smoothing function.

Color / Temperature:

• Adjust image temperature (blue vs yellow).

Color / Tint:

• Adjust the image tint (green vs magenta).

Detail:

• This tool enhances details of different sizes.

• Uses the larger sizes for nebulae that might cover a high portion of the image. Then smaller sizes for planetary or lunar surface details.

• Uses the sliders together for a smoother transition usually results in a better image.

Curves:

• This sliders are histogram curves adjustments.

• The handles correspond to points along the histogram; 0.0, 0.25, 0.5, 0.75, 1.0.

Sharpen:

• This tools allows you to set up to 3 unsharp masks on the image.

• The steppers control the radius and the slider controls the amount of sharpening.

Save:

• Save in a variety of image formats: PNG, HEIF, JPEG, TIFF.

• If you are saving an image capture use PNG or TIFF for the highest quality. Both are 16bit and lossless.

Reset:

• Reset the image to it's original state.

Close:

• Close the current image and return to the home screen.

• Note: Image are not automatically saved after edits.