Lets try this:

Put the Pictor on the telescope, put your finger on the center of the back of the Pictor.
Push the N button to move the scope north (with the other hand of course :-)))), the line
your finger traces on the back of the Pictor is the line that points at the north celestial
pole. Estimate the angle between this and a line passing through the center of the back and
the button.

This does not work when you use a diagonal.

Ralph

M. Gartland wrote:

> Now I am really confused......Putting aside the lens/eyepiece image reversal issue for
> now.....and again assuming a straight thru refractor on an Eq. mount, then:
>
> What I think you are saying is that the Pictor orientation has to be calibrated as a
> visually estimated angle measured from the camera button orientation to a direction
> along a plane in a (curved) line directly from the center of the camera to Polaris (or 0
> degree North), even though that direction is 180 degrees opposite of the (North)
> direction as far as the (Business) end of the telescope is concerned. If this is true,
> then it is not a very good way of doing it. First of all, at certain telescope pointing
> angles it is difficult to site up the camera orientation and estimate this angle.
> Second, it is based on a visual approximation and not an angle that can be measured in
> any way.
>
> The algorithim for setting the pictor orientation angle should be referenced against the
> telescope (business end slewing) direction of NSEW. not the actual direction (as the
> crow flys). The orientation procedure for the pictor when standalone guiding is a good
> example, it says to: "have the pictor (writing) oriented parallel to the (EW) RA slewing
> plane as viewed thru an eyepiece". Thats real simple, just press the (EW) keys while
> viewing thru a (reticle) eyepiece, watch which way the star moves and then insert and
> orient the pictor accordingly. By doing it this way, a diagonal is already taken into
> consideration. If you wanted to allow someone to change this and set an angle as
> compared to (N), that would be good, in case someone has to orient the pictor in a
> certain way for (wire) clearance. My assumption has always been that the pictor just
> wants to know that if a star moves up in the field, that it is either north or south,
> and if it moves left, is it either east or west.
>
> If you can confirm that my spin on this is correct, then I think I understand it.
>
> m.
>
> Ralph P. Pass III wrote:
>
> > Yes, as I understand what you have written, this is reversed. I also read your
> > discription as having the scope pointing on the east side of the meridian in the
> > northern hemisphere. The reason that I think this is reversed is because the
> > eyepiece inverts the image. As such, the appearance of 'South' in the eyepiece is
> > in the direction of the North Celestial Pole. As you move the telescope to point
> > further north the eyepiece end will move south. So to have an offset angle of zero,
> > you should put the button on the Pictor away from the direction of travel of the
> > eyepiece end as you increase the declination angle of the telescope.
> >
> > Verify by a test! Should not take but a couple of minutes.
> >
> > Does this help???
> >
> > Ralph
> >
> > M. Gartland wrote:
> >
> > > It's probably me, but I still can't see it. I 'd be more than happy to write a
> > > clarifying procedure, but I need to understand it first.
> > >
> > > Let me propose a simple scenario that could clarify it all..........
> > >
> > > 1 - Suppose I have my (EQ mount) refractor telescope set up, polar aligned and
> > > tracking on another star (not polaris). Also, suppose I am using a reticle
> > > (crosshair) eyepiece and no diagonal. I then push the (N) key on the handbox and
> > > observe the star move across the eyepiece field directly to the left. Then, I
> > > remove the eyepeice and install the 216xt with the button facing (I think)
> > > directly right (180 degress opposite of the way the star moved because the star
> > > in the eyepiece moves opposite of the actual telescope slewing direction). I
> > > then dial in an angle in Pview (FOV calculator) of 0 degrees for pictor
> > > orientation because the Pictor "UP" is now aligned directly in the "North"
> > > direction. This setup would now be good for any object on this side of the
> > > meridian.
> > >
> > > 2 - However, if I now slew to an object or star on the "other" side of the
> > > meridian, I would have to change the pictor orientation in Pview (FOV
> > > calculator) screen from 0 degrees to 180 degrees because the orientation of the
> > > EQ mount to North for slewing purposes is opposite as from before.
> > >
> > > Can you follow and confirm the above? The only area I think I am really guessing
> > > on is in aligning the button to the "Right" as opposed to "Left" in number (1),
> > > I may have that backwards.
> > >
> > > Thanks for helping!
> > > m.
> > >
> > > Ralph P. Pass III wrote:
> > >
> > > > Yes, the buttom above the word Meade indicates the marker position. For a
> > > > Fork mount the orientation angle is independent of where you are pointing
> > > > the telescope. For an equatorial mount it is independent if you stay on the
> > > > same side of the mount. It changes by 180 degrees if you go the other side.
> > > >
> > > > I am not familiar with the 'focus lock' or where it is. However, for one
> > > > side of the meridian this is correct and for the other it is 180 degrees off
> > > > (see the prior paragraph).
> > > >
> > > > I am afraid I am not familiar enough with the LXD mount to answer other
> > > > questions. The intend of this angle is to provide the software with an
> > > > indication of the direction of North on the chip. You do not need to be
> > > > perfect, but the closer the better.
> > > >
> > > > If you can imagine a line from the center of the back of the pictor pointing
> > > > at the north star. You then estimate the angle between that line and a line
> > > > from the center of the back of the Pictor through the button on the back.
> > > >
> > > > While it may sound complicated (and perhaps the words can be improved with a
> > > > diagram), simply trying to autocenter star and noting if the object gets
> > > > closer as you change the angle will help get you setup.
> > > >
> > > > If you get it understood, perhaps you could provide a writeup that could be
> > > > used to clarify the words in the readme file? I would suggest sharing it
> > > > here on MAPUG.
> > > >
> > > > By the way, you can change the estimate angle at any time and the change is
> > > > used for the next centering or mosaicing command.
> > > >
> > > > Ralph Pass
> > > >
> > > > M. Gartland wrote:
> > > >
> > > > > Help!
> > > > >
> > > > > Can someone please help me in clarifying the alignment for the 216xt
> > > > > when guiding? The new 6.4 final version has you put in an angle for
> > > > > computer guiding but it is very poorly written. Here are some
> > > > > questions....It says that the writing on the camera represents the
> > > > > orientation, is the button considered up (0 degrees)? If the button is
> > > > > up, what angle am I measuring to? My scope is on a LXD Eq. mount, does
> > > > > it matter what my scope is pointing at?
> > > > >
> > > > > Are we really talking about how my OTA is mounted in the cradle? In
> > > > > other words......if my cradle is the orientation, then north would be
> > > > > "straight up" in the cradle, and..if the OTA is mounted with the focus
> > > > > lock as "straight up" in the cradle, and....the 216XT is mounted with
> > > > > the button in line with the focus lock ,....then.....the angle to be
> > > > > entered in pictor view in the field on view menu screen for pictor
> > > > > orientation would be "0 degrees". If the button is to the "left" or at
> > > > > the 9 o'clock position in relation to the OTA focus lock, then the angle
> > > > > would be 90 degrees, if right, then 270 degrees, etc. etc.?
> > > > > Am I correct with this? Way off base? Please put all of this into
> > > > > english for me?
> > > > >
> > > > > Confused....
> > > > > m.

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