Quote:
Originally Posted by koputai
Essentially I need to know at what the height above ground should be
for the centreline of the OTA at the top of the pier. Does this height
vary between scope types, ie would pier height be different for Newt
vs Refractor vs SCT/RC ?
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Depends on the type of mount and also type and length of the scope plus it's dominant use. Diferent mounts are different heights.
Also, bear in mind that the same pier will probably have to serve your needs for some considerable time to come and this may well involve changing both your mount, your scope and your usage oatterns. You'll pprobably scale your equipment upwards as you get more and more into it and that will probably involve getting bigger not smaller. So future use is a factor also.
A long refractor and a newtonian used visually would require to be at different heights dependoing on how you want to use them - visual or imaging or a bit of both. Picture yourself in the middle of the night trying to look through an eyepiece and imagine the position you'd have to be in to do it comfortably for any length of time. Newtonians can put you in some odd positions and one too close to the ground will have you on your knees with your head cranked backwards and that can very quickly be a turn-off.
On the other hand, scopes being used for imaging are a bit different - apart from using the finder scope occasionally, your dominant concern is balancing the payload and making sure nothing fouls the mount as the scope slews and tracks.
You've referred to an ED80 and an 8" newtonian. Assuming the newtonian will be used both visually and for imaging, a compromise height seems to be a good idea so you don't have to spend time perched on a stool or on your knees to look through the newtonian eyepiece, I'd suggest a basic pier at about 800 mm high (floor level to the base of the mount).
Peter
