View Full Version here: : Diagonals

26-06-2007, 02:34 PM
Hi Guys, I should probably know this, but would like to ask, just in case.

When one looks through a diagonal with a refractor telescope, are all views up, down, east and west correct.

So if one needed to correct a little to the west, would he/she turn the adjustment so the mount moves west.

Thank You.


26-06-2007, 07:53 PM
A refractor with diagonal shows north and south correct but east and west are reversed. This means to move west you nudge the telescope east. If you're trying to starhop using charts this can cause a bit of a headache as you have to mentally mirror image the chart.

A further complication is that standard maps of the moon and planets are usually drawn from a Northern Hemisphere point of view, in the Southern Hemisphere the Moon for example will appear upside down to the naked eye but upside down and mirror imaged east/west in the refractor.

I've scanned some of the maps of the moon I use in and use photoshop to apply the correct transformations so as to match what I see in the eyepiece before printing them out. I was thinking of doing the same for my star charts but its a big project.

26-06-2007, 08:39 PM
Thanks Stephen, much appreciated.