Orion 52080 - Manual (Page 9)

Figure 13. The Combine Images window allows “stacking” of
individual images into one high-quality resultant image.
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4. Focus the camera using the telescope’s focus knob. The focus point for the
SSDSI-II will be approximately 15mm inwards from the eyepiece’s focus
point. If you are having trouble determining best focus, try focusing on a
bright star near the planet. Use the Planet setting in the Screen Stretch
Window. You can also use the histogram functions for most accurate
focus; this will be explained later (see “Focusing”). Click the Stop button in
the Camera Control Window when camera focus is achieved.
5. Now, in the box beneath the Mode box, choose Autosave. Set the number
of images you would like the camera to take under Autosave (start with 10
or so), select the file folder in which you would like to save the images with
Folder, and enter in a Base filename for the captured images. Typically the
name of the object being imaged, such as “Mars1”, will be entered here.
If “Mars1” is the Base filename, and you choose to Autosave five images,
then the images will appear in the selected file folder as “Mars1_0001.fit”,
“Mars1_0002.fit”, “Mars1_0003.fit”, “Mars1_0004.fit”, and “Mars1_0005.
fit”.
6. Click Expose, and the camera will commence capturing and saving the
images.
Now that we have multiple images of the planet, we will combine the images
to form one high-quality resultant image. To do this:
7. Select Open from the File menu. Find the folder you indicated with Folder,
open it, and select all images for stacking using the mouse left-click and
the Shift key. All of the individual images selected will open in Maxim DL
Essentials.
Note: In order to combine images, the images must first be opened in Maxim
DL Essentials.
8. Select Combine from the Process menu. In the pop-up window, you will
see all of the images currently open in Maxim DL Essentials. Choose the
individual images you want to stack and press the >> button, or simply
click Add All. Click the OK button when done.
9. The Combine Images window will appear (Figure 13). For Align Mode,
choose Planetary. In the Output box, select Average.
10. Now, you can see how each individual image looks by using the Next
Image and Previous Image buttons. If you see an image that looks poor,
you can reject it from the stack by clicking the Reject Image button.
Note: At least one image must be used as the reference image for the stacked
images to be overlaid upon. The default uses the first image for the reference
image. If you reject the first image or otherwise want to use another image as
the reference, click the Set As Reference button when the desired reference
image is actively displayed. If the image currently chosen as the reference is
rejected from the stack, and another reference image is not selected, you will
not be able to Overlay All Images.
11. Now, click the Overlay All Images button. All of the selected images will
stack on top of each other to form one resultant image. Click OK.
You have now composed your first planetary image. Use Save under the File
menu to save your image at this time. To make it look its best, you will want
to adjust the Screen Stretch Window to Planet. You may also want to do
some image processing, see the section entitled “Image Processing” for more
information.
Imaging Deep Sky Objects
To capture breathtaking images of deep sky objects, such as galaxies, nebu-
lae, and star clusters, much longer exposures are needed. As with planetary
imaging, you will take several individual images and stack them together to
form one high-quality resultant image. But while planetary images are formed
by stacking many exposures of less than 5 seconds, deep space images will
generally be comprised of individual images of a minute or longer!
Because of this, polar alignment and motor drive tracking must be very
accurate. If not, images will be blurred and stars will not appear round. Also,
because camera noise increases greatly over exposure time (due to internal
heat generation), you will need to suppress the inherent camera noise with
the built-in thermoelectric cooler (TEC). Make sure the 3VDC power supply is
plugged into the SSDSI-II.