Altitude Measurement for Dob

[Sconesbie]

Ok, I have tried finding the answer here on the forum but haven't really got anything that I am comfortable with.

I have a 10" collapsible dob and want to have some settings for the altitude component. I already have the azimuth circle on the base and that seems to work well. I've printed the template on another thread I found here.

Research tells me that the altitude settings are from 45 degrees (horizon) to 90 degrees (zenith). If I use Sky Safari I am hoping the co-ordinates on that are based on my location.

So that said, anything with a altitude measurement lower than 45 degrees isn't viewable?

Well, I think I have answered my own question as I write this but want to be doubly sure this is correct before I go sticking things on my scope and make adjustments to it.


Regards
Scott

[gaseous]

Hi Scott,

I 'm happy to be corrected by more knowledgeable members, but I thought 0° is the horizon and 90° is your zenith for altitude settings, so from one horizon to the opposite horizon would be 180°, both in altitude and azimuth.

[Sconesbie]

Well, I stand corrected. More research tells me that I had a typo in my question and it is in fact 0 - 90. How could I make such a rookie error. My son could have told me that.

[Sconesbie]

Thank you Patrick.

[gaseous]

No worries - it'd be an empty forum indeed if it excluded all those who've ever made rookie errors! Good luck.

[OzEclipse]

Scott

Sky Safari can display real time altitude and azimuth of an object for your location.

It will only do it if the current location setting is correct. You can manually set your position coordinates or it can take them automatically from the GPS on your tablet or device.

In Sky Safari, the altitude and azimuth of the centre of the display is displayed in blue in the top left corner below the current location. So your object needs to be centered.

1. Select an object by tapping on it so it is highlighted by cross hairs.
2. Then tap the "centre" icon.

The objects ALT and AZ are then displayed and updated in real time in the top corner.

You can also display it by tapping the object to select it then tapping the info icon. The real time ALTAZ will be displayed in the info window.

You can print out a protractor to surround the ALT bearing. The base needs to be level for this to work.

Another possible solution to your altitude setting is to mount a digital clinometer to the tube or altitude bearing. This is independent of the leveling of the Cheap ones are accurate to about 1/5 of a degree, well within the field of a wide angle eyepiece and cost between $30-$60. Not that the tube and optical axis are not exactly parallel unless the optics are well mounted.
https://www.ebay.com.au/p/?iid=322401732384&&&chn=ps

Joe

[Sconesbie]

Thanks for all the comments.

I bought one of these. I haven't used it yet but hoping it does what it's (sort of) intended for.


Regards
Scott

[garin]

I used something similar on my Dob, works well. I did have to change the magnets to some rare earth ones to stop it sliding down the ube when I was near zenith.