Framing and Mosaic Wizard
Framing and Mosaic Wizard
Instructions for use:
- Select "Framing and Mosaic Wizard" from the tools menu
- You will be presented with a "longish" dialog with 4 distinct steps.
- In order to fetch your "canvas" (area of the sky to capture), you must be connected to the Internet
- Profile: Using this option will present a list of equipment profiles. Selecting one will overwrite Scale and Camera Dimensions with those in your profile.
- Fetch location from mount: While you can provide data in the form of object name, another image or custom RA and Dec in order to fetch your working canvas, you can also choose to have the RA and DEC locations populated using your telescope's current location (by clicking this option). This will fetch RA and DEC and then populate those boxes on the form. You will still need to click "Fetch" when ready.
The steps below, in general correspond to the black circular numbers found on the mosaic dialog:
- Step 1: Choose the area of the sky that you want to capture. This area should contain more data than you want to actually capture. To get your "mosaic canvas", identify a name (like M42 or NGC6144) and define a field of view in degrees. Clicking fetch will resolve the name into J2000 RA and DEC coordinates and then download the canvas from the DSS. Keep in mind that asking for very large fields might take a bit of time (typically 8 degrees takes about 30 seconds and this will scale almost linearly). Fear not though, once you download an image we will cache it so you can refine your mosaics later without re-downloading. Optionally, you can bypass the name lookup completely, click the "RA/DEC" radio button and enter the J2000 location manually. Note: You can also specify URLs Astrobin or Flickr images that have been solved. Some plates have different background levels than others and you will need to use normal stretching routines to make the image more clearly visible (finding nebulosity, etc)
- You can also use an existing FITS image (taken from SGPro). This will create an image canvas centered on the image you provide. A blue rectangle will be drawn around the area captured in the image your provide. In this way you can extend existing images by drawing frames that overlap your existing frame.
Here the blue rectangle represents the area that your existing image occupies. You can then figure out how you would like to extend it by drawing the normal red rectangles over this area. Here are a couple examples:
Or more complex...
In this case, you would likely delete target 5 after the mosaic sequence was created.
- Step 2: Define your camera data. This is pretty straight forward... define your image scale at 1x1 binning and the number of physical pixels on your CCD. These values are part of equipment profiles and will be automatically populated using that data. Finally define the desired overlap between tiles here. If you are unsure of your scale, a calculator has been provided (click the "*" button next to scale).
The mosaics and framing wizard will allow you to populate the scale and camera pixel values from any equipment profile you have available. To switch profiles (if you want to draw a mosaic with a different set of gear), find the "Profiles" menu at the top of the tool and select the profile you want to use.
- Step 3: Define the area you want to capture. Using the mouse, drag a rectangle over the area you are interested in capturing. The wizard will automatically calculate the number of tiles in your mosaic and number them according to capture order. You can toggle the tile grid on and off using the "Show tiles" checkbox. You may notice that the size of your capture area will expand after it is defined. This is because the wizard will snap to the minimum number of camera tiles required to cover the area of interest. After drawing the capture box, you can then use the mouse to move it around (by dragging). Finally, rotate the canvas to either match your camera angle or to find the angle your camera will need to be at when you start capture. The rotation angle is in indicative of the angle your camera needs to be at to capture your target!
- Note: After drawing the initial rectangle on the canvas, you can adjust the number of horizontal and vertical tiles by hand simply by entering them into the step 4 area. This will automatically adjust the size of the capture area without having to continually redraw in order to achieve the desired size.
- Tip: Camera angle is extremely important when capturing mosaic tiles! If you don't have a mechanical camera rotator, you can use the SGPro manual rotator tool to make sure you are all set before capturing.
- Step 4: Create the sequence. After all of this is defined to your satisfaction, simply click the "Create Sequence" button. You will be presented with a small dialog that asks you for the mosaic name, whether or not you want to append targets or replace targets and finally whether or not you want to save the working canvas with the new mosaic sequence (as a reference... see Sequence Images below).
- Name: This is the base name of the target set that will be created. If you use "M42" and have 4 mosaic tiles, your sequence will contain targets M42-1, M42-2, M42-3 and M42-4.
- Targets: Append to or replace the current target set.
- Auto rotate: Check this box if
- You have a rotator and would like the sequence to automatically rotate to the required angle
- You would like to use the manual rotator (which will verify your camera's angle and provide instructions on how to correct)
- Working Image: Check this if you would like to save an image of your working canvas for later reference
- When you complete step 4, you will have a sequence that contains a target for each mosaic tile. Each mosaic will have the "Center On" checkbox marked and the appropriate centering location populated. None of these targets will have any events populated. The best way to populate events (since most of the panels will have the same or similar event composition) is to create events for the first target and then using the new "Copy event to..." function (right click target), copy the events to all the other targets.
Note: You can easily refine the center position of your mosaic canvas by right clicking on an existing canvas and choosing "Center Here". This will download a new canvas with the specified field of view where you clicked.