Some notes on how to use the SBIG STV

Some notes (work in progress) on how to use the SBIG STV

Setup
Focusing
Imaging
- Deep Sky
- Planetary
Guiding
Other
Miscellaneous

STV Setup Sequence

Connect all of the connectors you're going to need to use (power, DB25 and BNC connectors from the STV head, serial cable if you're connecting a laptop, RCA jack if you're connecting to a VCR or monitor, autoguider cable if you're going to be guiding with the STV)
Turn the STV on. The STV's video screen and alphanumeric display will both light up and the alphanumeric display will show the STV's current firmware revision number (the latest is 1.06G, make sure to have the latest) and a second line saying "Initializing...". After a second or so the alphanumeric display it will change to indicate the STV's filter position, the current head temperature, the current current load as a percentage, and a request for you to "Please set Date/Time". The STV's video screen will show an SBIG logo.
If you're going to be imaging, or simply want to use the STV to keep track of the time while you're using it to guide, you will want to set the date and time. Otherwise, you can skip this part. If I'm just going to guide, for example, I do not usually set the time. The first thing to do is press the Value button to start setting the date and time. After doing this, the Parameter button or knob can be used to select "Month", "Day", "Year", "Hour", "Minute", "Second", and "SYNC TIME", in that order. The Value button and knob are used to change the actual value for the month, day, year, etc. When all the date and time values are correct, set the Parameter to "SYNC TIME" (usiNG either the button or the knob) and then press the Value button to "Do It!" (i.e., set the date and time you've specified). This final action cannot be done using the Value knob, it has to be done with the button. Once you hit the Value button to "SYNC TIME", the STV will display "Date/Time Set".
If you ever want to set the time after you've already been using the STV for a while, simply hit the Setup button (or first the Interrupt button and then the Setup button if you are in the middle of something), rotate the Parameter button until "Date/Time" appear on the display, and then press the Value button to get to the point where you can follow the directions above. An alternative method of setting the date and time, once you've specified the correct values, is to hit the Setup button, but in this case the STV will simply go back to its default screen and not display the "Date/Time set" message. You will see that the STV's image display (if you have the STV Deluxe) will display the newly entered date and time at the bottom of the screen.
Other items that you will most likely want to set (or at least check) the first time you use the STV are

If you're imaging the moon or sun, you will probably want to put the lunar filter in place. Hit the Setup button and then use the Parameter button or knob until you see "Filter No" in the display. Use the Value button or knob to change the "No" value to a "Yes".
If you are going to be using the STV for autoguiding, you should set the STV's values for you guiding scope's focal length, aperture, and design type. This is important because the STV uses these numbers to calculate how much time to exercise your mount's RA and DEC motors when it is determining how sensitive your mount is to guiding corrections (this process is called calibration). You will see that you can manually override the STV's calculated values, but you will likely find it convenient for the STV to calculate good values right off the bat.

First you will want to make sure you know which units, inches or centimeters, the STV thinks your focal length and aperture are going to be in. Enter the STV SETUP list of options (pressing the Interrupt button followed by the Setup button will always get you there) and then use the Parameter knob or button to get to the "Units" parameter. Then use the Value button or knob to specify whichever units you prefer.
Now that you've set the units, use the Parameter knob or button to change to "Focal Len." (focal length) and use the Value knob or button to your guide scope's focal length (in the units you specified above, inches or centimeters). Note that the metric units are centimeters, not millimeters.

Note that if you find that the STV computes the wrong calibration values for your particular telescope mount, change the value of the focal length parameter until the STV DOES compute values that work for you. In general, reduce the focal length of the guide scope to increase the amount of calibration time (per axis) and lengthen the focal length to decrease the amount of calibration time.

Use the Parameter knob or button again to change the Parameter to "Aperture Diam." (aperture diameter) and then use the Value knob or button to your guide scope's aperture diameter. Note that if using metric units, to enter centimeters and not millimeters.
Now use the Parameter knob or button to change the Parameter to "Telescope" and set the value to "Reflector" if you have anything but a purely refractor design for your guide scope. If you are guiding through a Schmidt-Cassegrain or Maksutov-Cassegrain, SBIG recommends using the "Reflector" value.

Finally, make sure the date and time are displayed on the STV Deluxe's screen (and on it's video output). Enter the STV SETUP options list (again, the Interrupt button followed by the Setup button will always get your there), and use the Parameter button or knob to go to the very last option, "Video", and then press the Value button to go to the VIDEO SETUP options list. Use the Parameter knob or button to change to the "Date/Time" option and then set the value to "On" or "Off", according to your preference. To get out of the VIDEO SETUP options list, you will have to press either the Setup or Interrupt buttons (it is OK to hit the Interrupt button here - the values you specified will be retained.)
You may want to turn on the STV's audible beep, which it uses in a number of situations, including whenever you press a button and when it finds a new and better image in Best-Sharp and Best-Peak imaging modes.
I usually never turn the Grid on, nor the Night Vision, but you can set these in the STV SETUP options list to your own liking.

At this point it is a good thing to check the current load. The STV determines a CCD temperature set point on its own, based on the ambient temperature, that usually results in a 70-75% current load. This current load is not always maintained, however. After you have done all your other setup, check the current load at the default STV screen (you can always get to this by hitting the Interrupt button) and look at the value in the center of the bottom row of the alphanumeric display. Make sure it isn't too high (a current load of 90-100%, indicating that the temperature setting is too cold) nor too low (current load of 60% or lower, indicating that the temperature setting is too warm). To set the temperature, press the Setup button, use the Parameter knob or button until you see "CCD Temp" on the lower row of the alphanumeric display, and then use the Value knob to raise or lower the setting from its current value. When you have selected a new value, press the Setup button again and then watch the current load, waiting for it to approach a steady value. If the new current load is too high or too low, you will need to change the temperature set point again and repeat until the current load is about 75-80%.
Note: Keep an eye on the STV's current load, as every once in a while I've found it to suddenly be near 100%. While I have not figured out why this happens, it is NOT due to a sudden warming of the ambient temperature (such that the STV is trying to maintain a temperature that is no longer attainable). It might be that the head itself warms up after an initial cooling period and can no longer sustain the initial temperature setpoint. The suggested current load is around 75%, so simply reduce the temperature setpoint in the Setup menu to something that results in a steady state current load of around 75%.

Focusing is easy with the STV. It has to be the easiest CCD to manually focus, since real-time focusing on even moderately bright stars is possible. The basic steps of getting the STV to focus are to hit the Focus button, change parameters to the values you want, and then hit the Focus button again.
For rough focusing, follow the following steps:
1. You will want to very closely align your finderscope with your telescope before attaching the STV or make sure your GOTO system is working quite accurately.
2. Point your telescope at a moderately bright star close to what you want to image.
3. Once the STV is turned on and you have done all the setup that you want, press the Focus button once. The STV display that you are now in the "FOCUS SETUP" menu. You can now change some focus parameters before actually starting to focus or simply press the Focus button again to begin focusing. You can change all of the important parameters while actually focusing the camera so there is no harm done to skip the rest of the FOCUS SETUP menu and just hit the Focus button again. Read below on what the important options are and then decide whether you prefer to specify them at the FOCUS SETUP point or while focusing.
4. You will most likely be best off starting focus using the STV's widest field of view and sensitivity. Putting the STV in "wide" imaging mode sets up the STV to use the maximum amount of its imaging chip and displays dim objects the brightest. To do this while focusing, press the Parameter button repeatedly until "Wide" shows up on the left side of the bottom line of the STV display. The Parameter knob will not allow you to do this.
5. Next, press the Value button until "Partial" appears on the right side of the bottom line of the STV's display. You will not be able to use the Value knob for this. Setting the framing mode to "Partial" updates the screen as quickly as possible (although I personally do not notice an update rate increase between "Partial" and "Full" framing while in "Wide" imaging mode).
6. Rotate either the Parameter or Value knobs clockwise (they work exactly the same at this point) to increase the exposure time until a big bright curved band or a bright donut appears on the monitor somewhere (this would be the out-of-focus star). If you are way out of focus, the exposure time will need to be pretty high to begin with, maybe to the maximum of 2.2 seconds (do not worry about the exact exposure time). If you are lucky, stars might already be close to focus and you'll see them as bright multi-pixel spots. Do not confuse single bright pixels as stars - these are only "hot" pixels in the chip that are being displayed. If you want, you can reduce the exposure time by rotating the Parameter or Values knobs counterclockwise.
7. If you do not see either a bright wide curved band, a donut, or the star, you do not have the star close enough to the field of view and will need to move the telescope until you do see something.
8. Do rough focusing in both directions to see which direction you need to change focus in and focus in that direction until the band becomes a donut and the donut becomes a bright spot. If you started with just a wide band, the star is probably just out of the field of view of the STV and you will most likely need to move the telescope to center the star once you see where it is located.
9. Once you have a star (or stars) as a bright spot, center one of the nearly-focused stars and switch to zoom imaging mode by pressing the Parameter button until "Zoom" is displayed on the left side of the bottom line of the STV display. This sets the STV to use the central half of it's chip in the most accurate (for focusing) but least sensitive mode.
10. Adjust the exposure time until your focus star is not completely "whited out" by rotating either the Parameter or Values knobs counterclockwise.
11. Change focus until the star is looks the smallest. Switching to "Partial" framing mode by pressing the Value button will speed up the update rate if it is too slow for you.
12. You are now roughly focused!
Critical focusing with the STV can be done using any of a number of methods, the simplest being the following:
1. Put the STV in "Zoom" focusing mode with a 0.50 second exposure and 4X, 8X, or 16X gain. To do this, enter focus mode (just hit the Focus button twice) and press the Parameter button until "Zoom" is displayed on the left side of the STV's second display line and then rotate either of the knobs until you see ".50s, 4x", .50s, 8x", or .50s,16x" in the center of the bottom display line. The first number is the exposure time and the number before the "x" on the right is the gain. You need to use an exposure faster than 0.50 seconds at a sensitivity of more than 4X to use the STV's peak brightness indicator like we want to below. You can certainly set the focus exposure time and gain to lower values and will need to do so for planetary focusing but you will lose the ability to use the peak value number to help with reaching critical focus.
2. Move the telescope to a star that is dim enough that the STV's peak value reading is well below 1024, it's maximum value. The peak value is displayed in the center of the top display line just to the right of "Pk=". You will have to experiment with stars to find the right brightness of star that satisfies this condition, but you'll figure which ones work pretty quickly. You may want to use the "Wide" focusing mode to first center such a star first if you find that necessary to get it into the narrower field of view of the "Zoom" focusing mode.
3. Change focus slowly while watching the peak value indicator. The peak value will vary a bit due to seeing conditions even when not touching the focus and can fluctuate wildly in poor seeing, so try to determine an "average" peak. If the average peak value is decreasing, you are moving focus in the wrong direction.
4. Keep changing focus until you reach what you think is the peak brightness, remember what the peak value is, and then GO PAST that point. If you don't go past the actual best focus point, you can never know that you've actually reached best focus.
5. When you've certainly gone past best focus, return slowly to the focus point that gives you a value close to or better than what you thought was best focus.
Additional focusing help can be found by using a Hartmann mask or a diffraction mask. With a Hartmann mask, instead of seeing donuts when you have an out of focus star, you get two or three stars that get closer together and finally merge as you get closer to focus (and move farther apart when moving away from focus). With a diffraction mask, diffraction spikes become visible and then brightest and sharpest at best focus. In either case, maximizing the peak value indicated by the STV will indicate the point of critical focus for either focusing aide.

Imaging with the STV is easier than focusing. So, if you've gotten the STV well focused, you're well on your way. The basic steps of imaging are to hit the "Image" button, change parameters to the values you want, and then hit the "Image" button again.

Note that the STV has numerous ways of taking an image.

You can have the take a single image and then stop, which in STV parlance is "Snap" mode.
You can have the STV keep taking (but not saving) individual images, which is called "Continuous" mode.
You can have the STV keep taking (and saving) individual images, which is called "Auto Grab" mode.
You can have the STV take multiple images and add one on top of the other to build a better and better image, which is called "Track and Accum" mode (for Track and Accumulate).
You can have the STV continously take images and keep the best one of the bunch based on sharpness or brightness, which is called "Best Sharp" and "Best Peak", respectively.

First, note that image sizes are not quite what they're claimed to be by SBIG literature. A bit different from the SBIG documented dimensions is the "wide" mode images, which are 216x164 after 3x3 binning, apparently from an original 648x492 pixel array (compared to an SBIG documented array of 656x480). The STV's "zoom" mode images (i.e., the central 320x200 part of the chip unbinned) are 320x200. The "normal" mode images (i.e., the central 640x480 of the chip binned 2x2) are also 320x200.

Finding objects - Finding objects with the STV is relatively easy. Quite dim objects are visible in a 2.2 second "Wide mode" image. On a couple of other occasions, when the object I was imaging was too dim or diffuse, simply putting the STV into 5 second continuous and "Wide" imaging mode revealed traces of what I was looking for. If you have a GOTO telescope or carefully align your viewfinder with your telescope, you will eventually be able to place an object somewhere on the STV chip almost every time and then can easily center it.
Saving images - In some imaging modes, the STV automatically saves images to its internal memory. However, for most of the imaging modes an image is not automatically saved and you'll have to do this yourself. To do this:
1. Press the "File Ops" button.
2. Use the Parameter button or knob to change the STV display until it reads "Save" on the left hand side and then press the Value button once.
3. In the image window, the STV now displays a rectangle highlighting one of seven image positions that you can save the image you just took. The STV can store 14 images total, so there are two "pages" of 7 image positions. Rotating either of the knobs will move the highlighting rectangle through the 14 different positions. You can choose to save the image in an "empty" position where no image has yet been saved, or you can save the image over top of a prior image. Once you've selected the position, press the Value button and in a couple seconds the new image will appear in that position.
Deep Sky imaging:
- The two most useful imaging modes for "deep sky objects" (star clusters, nebula, galaxies, etc.) are "Track and Accum" and "Auto Grab".
  - To take images in "Track and Accum" mode:
    - "Track and Accum" imaging mode does not automatically save images, so you will probably want to save the image to the STV's internal memory as described above.
  - "Auto Grab" mode, where the STV keeps taking images and saves them off individually to the STV's internal memory, requires that you perform image stacking yourself later on, but lets you filter out poor individual images, for example ones that might have a satellite going through it or where wind or kicking the tripod jiggled the telescope. This also lets you do things like averaging multiple dark exposures, taking one or more flat frames and averaging them, and then applying the averaged dark and flat frame images to your individual "object" images, resulting in much better overall image quality..
  - To take images in "Auto Grab" mode:
    - Before starting imaging, it is probably a good idea to copy the images that are already in the STV onto a laptop and then clear the STV's image memory. "Auto Grab" mode saves images in the STV's memory starting with the first empty positon (of 14 possible) so starting without any images in memory lets you take 14 images without interruption.
    - Set all of the parameters except "Mode" as in the description for "Track and Accum" mode above.
    - Set the "Mode" value to "Auto Grab".
    - Use the Parameter button or knob until you see "Auto Grab Interval" on the left side of the STV display window. Use the Value knob to set the amount of time you want between the end of one image and the beginning of the next.
    - Once you have all of your imaging parameters set up, press the "Image" button again and the STV will start taking images, perhaps starting with a dark frame. After it takes an image, you will see the STV switch it's image display to that of its internal memory storage as it saves the image and then it will return to the imaging screen to take the next image. You can stop the image taking at any time by using the "Interrupt" button, otherwise the STV will continue to take images until it fills up its internal memory.
  - Taking deep sky images in any of the other imaging modes is very similar to the above two modes.
    - If you want to take a single image and then stop, set the mode to "Snap". After the image is taken, you will have to save the image yourself otherwise it will be lost when you start taking another image.
    - If you want the STV to keep taking (but not saving) individual images, set the mode to "Continuous". This will not save any of the images, but you can stop the image taking at any time by using the "Interrupt" button and save the most recently taken image.
    - For deep sky objects, the "Best Sharp" and "Best Peak" imaging modes are probably not very useful as you end up with only a single image. While this "Best Sharp"ed or "Best Peak"ed image will possibly be a very good single image, a single image will have quite a bit of thermal and readout noise unless it is quite long. It is probably more constructive to use either "Track and Accum" or "Auto Grab" to gather many images that end up getting added or averaged together. However, for planetary imaging , "Best Sharp" and "Best Peak" are VERY useful.
Planetary imaging:
- The secret of planetary imaging is to take a lot of images and select the very best ones for subsequent averaging or adding. Planetary imaging is usually performed at as high a focal length as is practical in order to gain a large image scale (a rule of thumb is to image at about 0.50 arcseconds/pixel). The tradeoff of this is that seeing ruins the detail of many images, rendering them useless. It is therefore usually not constructive to use "Track and Accum" mode to automatically stack planetary images. Instead, use "Auto Grab" mode to take many images that you can later save to a laptop and then sort through them later, or use "Best Sharp" or "Best Peak" to have the STV evaluate a large number of individual images and then save "best of" images for subsequent stacking. With the former, you get to choose what's best, with the latter, the STV chooses what's best.
- To image in "Auto Grab" mode:
  - Press the "Image" button
  - "Exposure" should be displayed on the left side of the STV information window, and a time setting on the right hand side. Adjust the image exposure time to what you'd like by rotating the Value knob (clockwise increases the time, counterclockwise decreases the time). You can increase the exposure time using the Value button, but you cannot decrease the exposure time that way. For planetary imaging, exposures will run between 0.01 seconds and 0.50 seconds, depending on aperture and effective focal length. Try to select an exposure length that will get the brightest portions of the planet to around 900-1000 (i.e., close to saturation but not saturated).
  - Press the Parameter button or rotate the knob one position until you seen "Gain" on the left side of the STV display window. Set or keep the Gain value to 1X.
  - Press the Parameter button or rotate the knob one position until you see "Zoom" on the left side of the STV display window. Use the Value button or knob to set the imaging mode to "Zoom" in order to get the highest resolution.
  - Press the Parameter button or rotate the knob one position until you see "Dark Subtract" on the left side of the STV display window. Using the Value knob, you should probably select "Reuse" (new to STV firmware version 1.06G), as this will take a dark frame if an appropriate one does not exist or will use the last dark frame taken if imaging settings (e.g., zoom level or exposure time) have not been changed. This will save some time compared to using the "Yes" value, which will always take a brand new dark frame before starting to perform imaging.
  - Press the Parameter button or rotate the knob one position until you see "Mode" on the left side of the STV display window. Use either the Value button or knob to change the value display on the right side of the STV display window to "Auto Grab".
  - Once you have all of your imaging parameters set up, press the "Image" button again and the STV will start taking images, perhaps starting with a dark frame.
  - "Auto Grab" imaging mode will stop when the STV's internal memory is full. You can always press the "Interrupt" button to stop taking images.
- To image in "Best Sharp" or "Best Peak" mode:
  - Press the "Image" button
  - "Exposure" should be displayed on the left side of the STV information window, and a time setting on the right hand side. Adjust the image exposure time to what you'd like by rotating the Value knob (clockwise increases the time, counterclockwise decreases the time). You can increase the exposure time using the Value button, but you cannot decrease the exposure time that way. For planetary imaging, exposures will run between 0.01 seconds and 0.50 seconds, depending on aperture and effective focal length. Try to select an exposure length that will get the brightest portions of the planet to around 900-1000 (i.e., close to saturation but not saturated).
  - Press the Parameter button or rotate the knob one position until you seen "Gain" on the left side of the STV display window. Set or keep the Gain value to 1X.
  - Press the Parameter button or rotate the knob one position until you see "Zoom" on the left side of the STV display window. Use the Value button or knob to set the imaging mode to "Zoom" in order to get the highest resolution.
  - Press the Parameter button or rotate the knob one position until you see "Dark Subtract" on the left side of the STV display window. Using the Value knob, you should probably select "Reuse" (new to STV firmware version 1.06G), as this will take a dark frame if an appropriate one does not exist or will use the last dark frame taken if imaging settings (e.g., zoom level or exposure time) have not been changed. This will save some time compared to using the "Yes" value, which will always take a brand new dark frame before starting to perform imaging.
  - Press the Parameter button or rotate the knob one position until you see "Mode" on the left side of the STV display window. Use either the Value button or knob to change the value display on the right side of the STV display window to "Best Sharp" or "Best Peak".
  - Once you have all of your imaging parameters set up, press the "Image" button again and the STV will start taking images, perhaps starting with a dark frame.
  - "Auto Grab" imaging mode will stop when the STV's internal memory is full. You can always press the "Interrupt" button to stop taking images.
  - When you press the "Image" button the second time to initiate the actual imaging, the STV will behave quite a bit differently than in other imaging modes. The main display window will be split in half, with the left half being the most recent image and the right half showing the best image so far (either the sharpest or brightest yet, respectively).
  - The bottom row in the STV information window will show two "FOM" values, which stands for "Figure of Merit", and represents how good the images are. The left FOM value shows how good the most recent image was evaluated, and the right FOM values show the best since imaging was started. When the most recent FOM value is better than the best so far, the right-hand image and right-hand FOM values are updated.
  - The "Best Sharp" and "Best Peak" modes will run forever unless you stop it. Once you have what you think is a very good image, either press the "Interrupt" button or, as will probably be more useful since you'll probably want to save the image anyway, just press the "File Ops" button and proceed to save the image to STV internal memory.
  - You can quickly start "Best Sharp" and "Best Peak" imaging again simply by pressing the "Image" button twice in a row and all of your previous settings will be reused. Wait again until you get another excellent image and then save this one to STV memory as well. The more images you save, the more images you can stack later on and the better final planet image you will get as a result.
  - You will likely want to fill up the STV's internal memory at least once, if not multiple times. Once you've filled up the internal memory, save the stored images to a computer.
Guiding
- Using the eFinder
  - To focus the eFinder, you can use the general instructions above on how to focus the STV. Focusing is relatively painful, however, because the focusing mechanism is very crude. You have to loosen one or both of the thumbscrews enough to be able to move the focal reducer lens in or out of the extension tube. Determining the focal point of average best peak brightness of a star in "Zoom" focusing mode will give you a focused eFinder.
  - Before you can use the STV to guide your telescope mount, you need to have the STV figure out how sensitive your mount is to guiding corrections. This is called calibration.
    - Note that the STV camera's head does not have to be aligned in any particular manner relative to the telescope's RA and Dec axis (i.e., "up" on the STV chip does not have to be North). If the STV's head is rotated relative to these axis, the STV will be able to figure out what this rotation is and compensate for it.
    - Press the "Calibrate" button once. "CALIBRATE SETUP" will be displayed on the top line of the STV display. After this, you will need to specify the following:
      - "Mode": This is either "Auto" or "Manual". Setting it at "Auto" will cause the STV to calculate an exposure length and movement times (based on the "Setup" settings you have given for the telescope aperture and focal length) and then take images and move the telescope to see how much the stars in the images move after each telescope move. The STV first takes a reference image, then moves the scope in one direction (+RA usually), takes another image and sees how far the +RA motion moved the stars, then moves the scope in another direction (-RA usually), takes another image and sees how far the -RA motion moved the stars, and continues with +Dec and -Dec motors. After it has done this successfully, the STV will display a diagram showing the relative motion in each of the four guiding directions (four arrows making a plus sign "+"). It is OK if the lengths of the four arrows are not exactly equal, but they should be pretty close to each other. Also, the four arrows might not be exactly 90 degrees from each other, but slight variations here are also OK. The "Auto" mode may or may not work correctly for your setup. If they do not work for you, then you can either adjust the telescope settings so that "Auto" does work, or you can select the "Manual" calibration mode and follow the instructions below.
        
        Failure modes:
        
        "Error: No Move!" will be displayed if the STV does not detect any motion in the star field after trying to move the telescope. Try selecting a longer calibration time and, if that fails, a faster guiding rate on your telescope mount (if it supports that).
        "Angles?" appears when two or more of the RA/DEC directions are too close to each other. The STV expects RA and DEC axis to be close to 90 degrees apart and will show this error if some of the angles are too far off of this value. You may have a very unbalanced telescope or something like cables that are pulling on the telescope that is affecting the movment of the telescope.
        "Speeds?" appears when two movement directions differ by quite a bit. For some reason one axis or movement direction is much slower or faster than one or more other directions. This may also arise from an unbalanced telescope or something like cables or other binding of the telescope.
      - In "Manual" calibration mode, you have control over many parameters, including the amount of time each axis of the telescope is moved as well as how long images between movements are. The most important parameters are:
        
        "Exposure": This sets how long of an image is taken at the very start and after each telescope move. Longer values yield more stars that can be used to determine telescope motion. Too short of an exposure may result in stars being too faint to determine scope motion and calibration will fail. For the eFinder, I find that a 2 or 3 second exposure pretty much guarantees successful calibration.
        "Cal. Time": This stands for calibration time. This sets how many seconds of time the telescope is moved between images. The longer the calibration time, the more precisely the STV can calculate the relative sensitivity of your telescope's motor drives to guiding corrections. Too short of a time and you will not get an accurate calibration or possibly even a "no move" failure. Too long of a calibration time is a waste of time. I use 10 to 20 seconds, but you should play with this value to best suit your setup.
        Other settings that you might want to play with are:
        
        "View Results" can always be selected (and then activated with the "Value" button) and the STV will display the results of the last calibration run (a set of four arrows corresponding to the movement direction and relative amount of movement for each of the four guiding directions).
  - Finding a good guide star: Using a simple Meade piggyback adapter to hold the eFinder on top of the telescope. I find that a very bright guide star works the best, the brighter the better on my rig. If I don't end up with an optimal guidestar in the field of view (something that could happen even given the 2.7 degree field of view), I simply pivot the whole eFinder assembly to find a better star field. I don't pivot the assembly too far, probably less than 5 degrees, and this seems to work just fine even without re-calibrating the setup.
  - In order to autoguide a device that needs normally closed contacts, like my LX10's hand controller port, you need to use something like an SBIG Relay Adapter Box. You also need to change two jumpers on jumper block B4 within the STV. The STV manual has a diagram and clear directions on how to do this on page 45.
  - I have found that images turn out best when the RA is running just a little bit slow on the LX10. That is, I adjust the tracking rate so that the LX10 predominantly needs positive RA corrections by the STV.
Other
Miscellaneous Tips
- Upgrade to the latest version (Version 1.06G dated September, 2002) of the STV firmware. This has several nice new features, including increased control over a number of the STV's functions.
- Solar imaging
  - You will need a light shield to see the screen.
  - Use of the built-in "lunar" filter is very useful for reducing overexposure problems.