Creating an Image Sequence with Auto Capture

The “Auto Capture” feature in AltairCapture allows users to capture a sequence of images. You can predefine the name format, file type and get the images saved to a preset directory quickly and easily.

Choose the “Capture> Auto Capture” command in AltairCapture or press the Auto Capture toolbar button. Auto-Capture-ICON This will begin to capture images from the video stream automatically.

When the capture process begins, “Capture> Auto Capture” will change to “Capture> Stop Capture” and the toolbar button will appear active. Choosing the “Capture> Stop Capture” command or pressing the checked toolbar button will stop the auto capture process.

Before using Auto Capture, some parameters need to be defined. This is done in the “Options > Preferences > Auto Capture” properties menu or you can click on the little gear icon on the right of the top menu bar: ICON_PREFERENCES

Auto-Capture-Instruction-Screen-01

Directory: To keep things neat, you can set AltairCapture to automatically save your files in a default target directory and sub directory.

Directory: Enter name of the drive and directory where the new image(s) will be saved.

You can either manually type the file path, or use the Browse button AltairCapture-BROWSE-ICON

to find the directory in which to capture the image files.

Sub Directory: The sub directory can be automatically named with the date of the capture sequence, and various formats are available:

Auto-Capture-Instruction-Screen-03-5-directory-target

Name Format: Year, month, date, hour, minute and second or nnnn (sequence) are used as part of the file name. If more files are saved within a second, a (xx) suffix is attached to the end of Name Format to avoid possible name conflicts. For the nnnn (sequence) Name Format, no suffix is needed.

File Prefix: Enter a file name prefix for Auto Capture when generating file names for a series of images. This prefix will be combined with Name Format to form a final file name according to the naming convention you prefer. You could type file prefixes like Sun, Moon, Jupiter, or Saturn for example:

Auto-Capture-Instruction-Screen-040-file-prefix

File Type: In this box, you can select the format in which you want the image to be saved. BMP, JPG, PNG, TIF, or FITS:

Auto-Capture-Instruction-Screen-043-file-TYPE

Note: When users are capturing RAW images (that’s when the Format under Capture & Resolution is set to “RAW”, the only file type available will be FITS (.fit). This format is Debayered and is a very pure output from the camera which is why it’s the only option available when capturing in RAW mode. FITS file format is normally used for deepsky imaging and stacking of subframes.

Auto-Capture-Instruction-Screen-045-file-format-RAW

File Menu: Many image formats are available in AltairCapture (.bmp, .jpg, . png, .tif or .fit) to save the captured image. For example to choose .jpg format, this option can be pre-set in “Options > Preferences… > File properties“. If the file format has additional options like compression, the Config… button to the top right will be enabled. Note: This menu also controls video files.

Auto-Capture-Instruction-Screen-05-file-format-PREFERENCES

When the “Config…” button is clicked, a dialog will pop up as below, showing the options for the selected format:

Auto-Capture-Instruction-Screen-06-file-format-JPEG-SMOOTHING

The Capture Mode settings define the timing between images. A limit can be imposed on the number of images. This is especially useful for timelapse movie sequences.

Auto-Capture-Instruction-Screen-045-CAPTURE_MODE

Sample: The final file name is shown at the right of the Sample label for reference.

Capture every frame: Checking this will capture every frame in the video sequence.

Time Slot (second): Capture one image at each time interval (0-100s, default is 6).

Total Images: Checking Total Images brings up a field where you can enter the Total number Images to capture in the sequence (1-9999, default is 100). NOTE: If Total Images is unchecked, AltairCapture will continuously capture images until user chooses the Capture > Stop Capture command to stop the Auto Capture process.

After all parameters are set, clicking OK will close the dialog and the parameters will be used as default for the Auto Capture command until changed.

 

Getting Started with AltairCapture

Firstly, when you plug in your Altair Camera you’ll notice the camera model number appear under the “Camera List” menu header on the top left in white text i.e. “GPCAMMT9M034M”. Click on the camera model name, (circled in the image below) and the right-hand preview pane will automatically start the camera running in video mode, displaying an image. If you have the Meteor lens kit attached, you’ll see a wide field image, or just a big blurry field if no lens is attached and your telescope isn’t focused on anything. If the camera isn’t plugged in, “No Device” will appear, instead of the camera name.

Step 2.5 AltairCapture Install START

Underneath the camera name, you’ll see a sidebar with many menu options to control your camera settings. The idea of the sidebar is to allow many options to be available in a small space under an intuitive heading. It can be scrolled up and down. Menus will open when the headers are clicked, revealing their contents. All menus will remain open until you click on the little upwards-pointing arrows in the top right of the menu title bar, upon which the menu will fold up again to save space. The camera sidebar is displayed by default. You can change this in the file menu running lengthways at the top of the interface. In the file menu, click “Options” > “Preferences” > “Misc.” for defaults, including language settings. To reset the menu to defaults on restarting the software, from the top file menu, choose “Window” > “Rest Window Layout”.

The Capture & Resolution menu is next, appearing under the Camera List menu – it can be seen in the image above. It allows you to capture video or a single frame. Clicking the “Record” button starts recording video at the chosen resolution. A preview pane starts displaying the video on the left. Clicking the “Snap” button takes a single “still” frame just like a normal camera, which is immediately displayed in a new tab in the preview area on the right. Each still frame you capture generates a new preview tab. The resulting images can be saved for later processing or processed in AltairCapture. The “Live” field let’s you choose the video resolution to shoot at and is defaulted on full resolution. The “Snap” field allows you to select the capture resolution for still frames.

The Exposure & Gain menu is next in the left-hand sidebar. If it isn’t already open, it will open when you click on it, revealing the exposure settings.

You’ll notice slider controls for choosing exposure settings. You can also click on the numerical value shown above the slider, and entering the value manually using the keyboard, for example you may want to enter a precise number of seconds, minutes, milliseconds. etc. in the field.

Auto Exposure Mode. If you click on the “Auto Exposure” tick-box at the top left of the Exposure & Gain menu, you’ll notice a green box appear on the camera preview pane on the right-hand side. This box can be moved about or resized by dragging the middle area, or resized using the “handles” at the edge. When Auto Exposure mode is active, the camera will try to expose what is inside the green boxed area you have defined. Moving the “Exposure Target” slider will increase or decrease the exposure. Clicking the “Defaults” button will reset the camera to default value again.

Manual Exposure Mode. To enter manual exposure mode, deselect the Auto Exposure tick-box. You now have manual control over the camera exposure time, and gain. If you’re imaging solar system objects like the moon, sun (with filter!) and planets, starting off with around 500 milliseconds with the gain on half setting should show you the object and allow basic focusing. The faster the exposure setting, the easier it is to fine-focus. If you have a mouse with a mouse-wheel you can increase or decrease the magnification of the video preview pane to zoom in on fine details like a star image or lunar crater for fine focusing. This zoom preview doesn’t change the magnification of the final resulting image or video – that’s remains as current. For solar system objects, you may want to increase the exposure speed to as fast a setting as possible by dragging exposure the slider to the left or entering successively shorter exposure durations using the keyboard. It is best to experiment with these settings with the gain set on about 50% to start off with, then see how increasing the gain affects the image quality. As a general rule you should used the shortest exposure duration you can get away with, without sacrificing too much image quality. As the exposure duration becomes shorter, the image will become dimmer. This isn’t necessarily a big deal and the image can be become quite dim. Dim images and video can be radically enhanced in Registax when you get around to processing the .SER or .AVI file. For deepsky exposures this really depends on your telescope F-Ratio, but in most cases 5-30 secs and possibly higher gain would be a good place to start. For autoguiding, between 1-3 seconds is considered enough for most mounts, depending on star availability. 1.5 secs is optimal in most situations. Choose a star which isn’t over-exposed and is reasonably small. For video astronomy – well it’s all about getting the best real-time image in the preview pane for broadcasting and you’ll probably use a combination of exposure, gain and also stretch the histogram in the histogram menu to get the best video feed. There’s a lot of info on the web about optimal exposure settings but this should get you started.

These are the first steps to get you up and running with AltairCapture and your Altair Camera. As always, we encourage users consult with others on the Altair Astro Google Group and report bugs there, where they can be picked up and fixed. There’s no best way to use a camera, but there are many tricks and techniques discovered by users every day! If you have a contribution or spot an error in this tutorial please do get in touch through the Altair Google Technical Support group:

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Get software updates. Discuss tips and techniques to get the most out of your camera. Help others. You do not need a Google ID to use this group, any email address will do. Please give a reason for joining so we can confirm your account.

Clear skies! Altair Astro.