Files in DWARF mini can not only help you relive various moments of your observations but obtaining single-frame images for advanced post-processing is a significant milestone in your journey to becoming a mature astronomer! Without further ado, let's get started!

1. How to Get Access to Files in DWARF mini

1.1 Connecting DWARF mini to a Computer

Use a USB A-C or C-C cable to connect DWARF mini to your computer, and the computer will recognize DWARF mini as a USB storage device, allowing you to copy or edit files stored in DWARF mini. This method is compatible with both Windows and macOS.

*Notes:

1. After connecting to the computer, newly captured content will not refresh unless you re-connect the DWARF mini. If needed, you can browse newly captured files wirelessly during this period. [How to view DWARF mini files wirelessly on a computer]

2. External storage devices, such as portable hard drives, are not supported to be recognized by DWARF mini.

3. Some mobile devices that support USB OTG (such as certain Android phones, tablets or iPads) can recognize DWARF mini. By using a C-C cable, you can browse and transfer data between them.

1.2 USB OTG Connection (with mobile or tablet devices)

This is a very useful option when you’re on the go and don’t have access to a computer, or when you simply need to free up space on your DWARF device.

Using a USB-C to USB-C data cable (or USB-C to Lightning for some older Apple devices), you can connect your phone or tablet directly to the DWARF Mini. When connected, the DWARF will appear as external storage, allowing you to browse, copy, or delete files and folders directly from your mobile device.

This works on both Apple and Android devices and is ideal for quick backups in the field. Below are two examples showing successful USB OTG connections on both Apple and Android devices.

Example: Apple Device (iPhone Files access - DWARF storage is labeled "untitled")

Example: Android Device (Samsung File Access - DWARF is labeled "USB Storage 1")

1.3 Important note (don’t skip this)

If you back up or copy files using USB OTG, always delete the session afterward from within the DWARFLAB app using the Album → Delete option.
This ensures all associated session folders and metadata are properly removed and prevents orphaned files from lingering on the device.2. Introduction to Files in DWARF mini

Open the "DWARF mini" Disk, you will see Astronomy, Burst, Normal Photos, Videos, and some basic data folders.

2.1 Astronomy

Here, there are 5 types of folders: CALI_FRAME, DWARF_DARK, DWARF_RAW, Solving_Failed, StarTrails and Restacked.

2.1.1 CALI_FRAME

The prebuilt (factory equipped) dark, bias, and flat files are stored in this folder.

Within the Bias, Dark, and Flat directories, you’ll see two subfolders: cam_0 and cam_1.
cam_0 contains calibration frames captured by the telephoto camera
cam_1 contains calibration frames captured by the wide-angle camera
This separation is intentional. Each camera has different optics and sensor characteristics, so their calibration data must remain separate for proper image correction.

2.1.1.1 Dark Frames

Naming format based on data interpretation of telephoto dark field, as follows:

Take dark_exp_30.000000_gain_70_bin_1_10C_stack_2.fits as an example:
exp_30.000000 → exposure time of 30 seconds
gain_70 → gain value set to 70
bin_1 → binning mode
For the telephoto camera:
bin_1 = 2K resolution
10C → dark frame temperature of 10 °C
stack_2 → dark frame created manually (and can occur during session capture)

Note: Any additional dark frames you capture with the same settings will be stacked into this file and stored in this directory for use during image stacking.
Bottom line: the filename fully describes the capture conditions, and matching those parameters is critical for proper calibration.

2.1.1.2 Flat Frames

The data of telephoto flat field is as follows:

gain_2 → gain value is set to 2
bin_1 → binning setting
For the telephoto camera:
bin_1 = 2K resolution
ir_1 → filter parameter
ir_1 = Astro filter
ir_2 = Duo-Band filter

2.1.1.3 Bias Frames

The name of the bias field is telephoto and wide angle bias_gain_2_bin_1

Where gain_2 means the gain is 2

bin_1 Is the binning setting. For the telephoto configuration, 1 represents a 2k image.

2.1.2 DWARF_DARK

Your self-captured individual dark frames are here. However, the dark frames stacked using them for later shooting can still be found in the Cali_Frame section as mentioned earlier.

2.1.3 DWARF_RAW

Each astrophotography shooting session generates a dedicated folder that stores the captured light frames (raw files).

2.1.3.1 DWARF_RAW folder naming

Light frame folders follow this format:

DWARF_RAW_TARGET_EXP_value_GAIN_value_TIME

Where TIME is recorded with millisecond precision.

Example
DWARF_RAW_TELE_M 31_EXP_30_GAIN_70_2025-10-24-22-41-19-941
This indicates:
TARGET → M 31
EXP_30 → 30-second exposure
GAIN_70 → gain set to 70
2025-10-24-22-41-19-941 → October 24, 2025 at 10:41:19 PM, 941 ms

Accessing the light frames allows you to perform post-processing on your own or, when you're not satisfied with the stacked images, you can bundle this folder and send it to us for review!

2.1.3.2 DWARF_RAW File Naming

Each folder contains individual raw files. The name of the respective single-frames inside this folder is:

Each capture session includes metadata and output files containing the following information:
Target name
Exposure and gain values
Filter used
Timestamp
Format: YYYY/MM/DD/HH/MM/SS/FFF
Includes year, month, day, hour, minute, second, and millisecond
Sensor temperature (°C / °F)
Rejected frames (frames excluded during stacking)
In addition to the raw data, each session produces:
8-bit stretched JPG (stacked)
This is the downloadable version on mobile devices
16-bit non-linear PNG (stretched and stacked)
16-bit linear FITS file (single and stacked)
(Or TIFF, if selected in the app settings)
Thumbnail files
All folders also include files with the _thumbnail suffix.

2.1.3.3 Shotsinfo (JSON File)

A JSON file associated with astro images on the DWARF smart telescope is a metadata file containing technical data about an imaging session. It does not contain the image data itself, but rather the parameters of how the image was captured.

Key Information in shotsInfo.json File:
Coordinates: Right Ascension (RA) and Declination (DEC) of the target.
Camera Settings: Binning (e.g., 1*1, 2*2) and IR filter status.
Exposure Details: Exposure time per frame (e.g., 15 seconds) and gain settings.
Format of primary file: FITS or TIFF
Temperature: Sensor temperature, which is useful for calibration.
Stacking Stats: Number of frames taken vs. number of frames successfully stacked.
Target: The name of the celestial object being imaged.
Purpose of the JSON File
Debugging Stacking Issues: If photos fail to stack, this file helps determine if frames were overexposed or poorly focused.
Post-Processing Data: It provides essential information for processing FITS images in software like PixInsight or Siril.
Session Tracking: It accompanies individual sub-frames in a directory to provide a summary of the session.

Example of shotsInfo.json Content:

2.1.4 Solving_Failed

When the classic "Calibration Failed" occurs, this folder is automatically created.

The naming convention for the Calibration Failed folder is DWARF_CALIBRATION_TIME_(precise to millisecond).

Each folder includes all attempts made during this calibration failure.

Example: folder containing "failed" images for review

When calibration failure happens, don't be upset or frustrated. First check if there are clear and properly focused stars in the images here. The image format is JPG, making it easy for you to review on your own. Alternatively, you can package it and send it to our experts to receive professional advice!

2.1.5 RESTACKED

This section contains stacked images generated using the Mega Stack feature.

Each stacking session creates a new folder, and includes these formats: PNG, FITS JPG and thumbnails.Each stacking session creates a new folder, and includes these formats: PNG, FITS JPG and thumbnails.

2.2 Burst

This folder contains your burst photos, perfect for capturing fast-moving subjects or creating a series of images to be compiled into animations or high-dynamic range (HDR) photos.

In burst mode, you can use both the telephoto and wide-angle lenses to capture shots. With the previous explanations, the naming convention here becomes self-explanatory: DWARF_WIDE_TIME and DWARF_TELE_TIME. I'll save my tongue.

2.3 Normal Photos

The naming convention for this folder is completely consistent.

For your convenience, we have placed all the unnecessary thumbnails in one folder.

2.4 Videos

Just like in your App album, the contents of the Videos folders are divided into two categories: videos shot in Video Mode and Time-Lapse Mode, each named with DWARF_TELE_TIME and DWARF_TELE_TL_TIME, respectively.

3. Manually Manage your Files (Deletion and Format)

You can connect the DWARF mini to your computer to manage files, or directly delete the desired content from the App album.

3.1 How to DELETE files:

Select the files or folders you want to remove. Right-click and choose Delete, or drag them to the Trash/Recycle Bin, just like on a regular PC or Mac.
Empty the Trash/Recycle Bin to permanently delete the files. (This step is especially important on macOS.)
Reboot DWARF Mini (power off, then power on), reconnect to your PC or Mac, and verify that the available storage has updated.

Deletion Notes
iOS devices: Deleting a file is usually a two-step process:
Delete the file from its folder.
Remove it from the “Recently Deleted” folder to permanently free storage.
macOS devices: Make sure to empty the Trash to complete the deletion process.
After following these steps, DWARF Mini's available storage should increase. If your storage does not update or you run into issues, contact DWARFLAB for assistance.

3.2 How to FORMAT the DWARF mini internal storage:

Important: Formatting will erase all data on your DWARF device. Make sure to back up any files before proceeding.

Connect DWARF Mini to your computer using a USB-C to USB-C or USB-A to USB-C cable.
Power on DWARF Mini. It should appear as a drive/disk on your computer.
Format the drive:
1. Windows: Right-click the DWARF Mini drive and select Format. (Do not choose “Quick Format”)
2. macOS: Select the DWARF Mini drive and choose Erase Disk
Select exFAT as the file system.
Verify storage: After formatting, check the folder structure and available storage. You should see approximately 53 GB available. (Remaining space is reserved for the device’s OS and system functions.)
Reconnect DWARF Mini to the DWARFLAB App and start a session. Retake any necessary calibration files (dark frames)
Optionally, reconnect DWARF Mini to your computer later to verify that folders have been created and your session data is saved.

Formatting Notes:
Formatting the DWARF Mini will delete all folders, but they will be automatically generated during the next shooting session.
Do not worry about losing the factory created calibration frames when formatting the internal storage. The factory calibration frames in Cali_Frame (stacked Flat, Bias, Dark Frames) will be automatically regenerated when the device restarts astro shooting.
If you are ONLY removing old session folders for the purposes of retaining storage space, it is highly suggested you do not delete Astronomy > DWARF_DARK folders. This will save time on having to re-do your processes for your self-created DARK calibration frames if you need them to process your images later on your own.

Alright, the above covers all the information about the internal storage files. If you find it helpful, don't forget to give it a thumbs up and schedule some time for post-processing!

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Get to Know the Files Stored in DWARF mini