Lidl LXD75 telescope help thread 2007

Hi,

Just starting a new thread so that anyone who has purchased on of the LIDL Meade LXD75 telescopes can ask for help or advise. Hopefully most of the posts will be about what to see and not how to get a faulty motor replaced!

The thread from last year is still availble , but having a new telescope owner read through 11 pages of a discussion might be just a tad overwhelming at first!

Clear Skies,
~Albert

is this not a LXD75 Al?

is this not a LXD75 Al?

It is now. Thanks Dave!

Are there any recommendations for high magnification eyepieces?

I have the Meade 4000 set of plossls - I also have a 3x Barlow (Meade as well). I tend to find that the eye relief on the 6 and 9mm plossls is quite poor and I get better results using the 26,20 and 15mm pieces with the 3x giving roughly 9,7 and 5mm or 80, 100 and 150x mag - that works well for me.

At the otehr end I love the view through the 32mm - also have the 40mm but I don't believe it gives any more of a view - just smaller, and the only problem I have with it is that the central obstruction isn't quite defocussed enough so that one is always aware of it.

Are there any recommendations for high magnification eyepieces?

Just remember the rules of thumb:

Using the objective diameter and focal lengths in mm -

Maximum practical magnification: M=2*OD=2*152=304x
- gives an eyepiece focal length of FL/M=762mm/304x=2.5mm
This limit is applied to all Newtonians and other scopes of average quality. With good quality catadioptric telescopes magnifications as high as OD*2.4 can be usable (or so the manufacturers claim) and high end refractors may be able to use magnifications as high as OD*2.5.

Lowest practical magnification: M=OD/7=152/7=21.7x
- gives 762mm/21.7x=35.1mm
In longer focal length eyepieces you may see the obstruction in a Newtonian or Catadioptric telescope. Lower magnifications may be pleasing with refractors but binoculars would yield a better view.

The maximum pupil diameter that the average human eye can expand to is approximately 6mm. The Low Power Law proposes that this gives us the minimum useful magnification: M=OD/6=152/6=25.333x
- gives 762mm/25.333x=~30mm

The minimum pupil diameter that the average human eye can contract to is 0.63mm. The High Power Law proposes that the highest magnification that can fill this pupil diameter is given by M= OD/0.63=OD*1.58= 152/1.58=96.2x
- gives 762/96.2=7.92mm

All of which tells me that you should be able to use eyepieces with focal lengths between 2.5mm and 35mm with the LXD75 N6-AT but that the eyepieces you will find most comfortable to use will likely be between 8mm and 30mm.