Need some help with orientaion & moving my SCT

[SXBB]

Hi Stargazers,

I'm confused about how to best orient my DSLR at prime focus on my Atlas Pro mounted LX200 OTA.  I'm using it with EQMod and when using the N-S-E-W on screen buttons it seems that movement of objects is different based on where they are located in the sky?  How do you orient your camera at the beginning of the night and do you rotate it when you get your target sighted?  I'd like to do mosaics and I'm thinking that if the camera view isn't square with the way that the mount is rotated then the mosaic will need much more overlap?  What's the most logical way to setup so that I'll know which way the view will move when I push any of the directional buttons?  Somtimes it's diagonal or horizontal or vertical.  I believe it's flipped vertically but not horizontally?  Any insight is greatly appreciated!

 

[michael.h.f.wilkinson]

It almost sounds like the mount isn't polar aligned properly. If a mount is polar aligned, the NSEW buttons should show the same motions of the stars regardless of where the scope is pointing

[SXBB]

At times it is not...  I've been doing a rough alignment with the mount's polar scope and then doing everything from PHD2 Drifting to Alignmaster and having mixed results.  I started out by following Dion's setup videos for his EQ6 and aligning my polar scope but I verified it's alignment the other night and found that the polar scope had come out of alignment.  It's aligned now and next chance I get to do a polar aligment , hopefully I'll have a better result.  Another thing about the polar scope is that it uses the new version of the Orion reticle which does not have a circle in which to center Polaris.  I find it difficult to judge exactly what is the 12 o'clock/3 o'clock etc position when I'm down on the ground craning my neck.  I don't have a web cam to adapt to the task like Dion does but that is on my list.  Since the polar scope is rotated at an arbitrary position and there is no line up circle or stationary hash marks I choose a spot and pretend the circle is there such as the 12 o'clock position and rotate the RA and adjust the Altitude until Polaris is in that position but I can't precisely position that spot myself when I rotate in RA to match what the position of Polaris should be at my time/date/location.  I'm going to try using the EQAscom PA routine to help eliminate the guess work in that part of polar aligning.  I'm also looking at trying the Polarfocus app at scopefocus.info but need to sort the offset that I'll be entering so that it's correct.  If I enter -2 instead of 2 it'll mess upp my alignment even worse.  If I do that I wonder if there is an easy way to backstep and chenge the offset entered from - to + or do I have to start the PA all over again?

This has definitely gone beyond the scope (no pun intended) of my original question but it's all interconnected in the most complicated way...

Thanks

[SXBB]

I guess I'm asking how the orientation or more specifically the rotation of the DSLR should affect the movement of objects in my view.  Rotating the camera 180 degrees will change the direction of a star's drift as seen on my computer that is running Back Yard Nikon correct?  So Is there a "Correct" orientation rotation wise to get the NSEW buttons to be correct?  Is it just that the camera should be rotated upsidedown because it flips the image vertically?  Do you orient the camera to the horizon as you start the night or do you rotate it each time you center a new object?

Thanks

[Davey-T]

Has it got an "auto rotate off" setting in the menus ? the Canon has and I set it to off to stop the images being rotated.

Dave

[SXBB]

I don't see a autorotate setting in Backyard Nikon. After comparing my images to others of the same objects online, I t appears that Astrotortilla says my images are flipped when they are not. They are rotated but I can fix that.

[MarsG76]

The reason your stars do not move in the same direction is because it depends on what part of the sky your OTA is targetted at. For example when OTA is pointing toward South-West part of the sky, moving the scope in RA or DEC the stars will move in the opposite direction compared to if the scope is pointing toward North-East part of the sky when pressing the same RA or DEC direction buttons. Same would go for the other parts of the sky, except RA will seem reversed when comparing South-East and South-West parts of the sky... or when comparing North-East and North-West part of the sky.

Same will go for camera body orientation, it will seemingly look like its at a different orientation when comparing the horizon. Of course the orientation will not change at all if you're only moving the mount in RA, such as tracking, but once you do a meridian flip then the orientation of the camera will seem to "rotate" 180 degrees.

I hope you can visualize what I'm trying to say.

I'd say plan your mozaic and rotate the DSLR to the orientation you require once you frame your object. Refocus and start the marathon mozaic data gathering.

[SXBB]

Hi Mars,

I just found your reply when I looked in my profile.  I don't believe I was notified by email.  Great information!  This is exactly what I've been wondering about.

Thanks So Much!

Bruce