Help required! Newbie! Can't get focus on Celestron 5SE
Hi everyone!
I have recently bought my first telescope however struck a hitch already. I'm learning to use a Celestron Nexstar 5SE and Bought a Star Diagonal for it- GSO to fit visual back; 1 1/4 inch. Hoping I'm providing right info here. I have a 25mm eyepiece in and found an obstruction to focus. I tried Barlow and 6mm too, found similar problem. I just tried all I had. Couldn't focus on moon. Lots of tries- a haze or fuzz seemed to be in the way, even though I had her lined up sweet. Haven't tried since. I'm sure I'm just new at it and it's something simple I'm missing!
Took out diagonal, just used eyepiece during day and managed to focus on a tree some distance away. Haven't tried this at night yet without star diagonal in place.
Any suggestions would be greatly appreciated!
Nikki,
That’s very puzzling. I have a C5 and can focus both using an eyepiece in a star diagonal and with just the eyepiece. Furthermore, I have used a number of star diagonals with this scope and they have all worked.
Have U tried taking the star diagonal out from the scope and looking through it without an eyepiece? If everything can be seen clearly, then there should be no problem with the star diagonal.
New telescopes can be a little frustrating and unfamiliar, I sympathise. If you are viewing the Moon at low altitude then it can appear a little soft or hazy, even shimmering like a desert mirage.
These types of telescopes (Schmidt–Cassegrain or SCT) are known for their ability to focus over a wide range as the main mirror moves when you turn the focus knob, so usually you can focus on nearby terrestrial objects as well as celestial objects such as the Moon and stars.
Try again when the Moon is at an altitude of over 30 degrees and look at the craters on the terminator (the dividing line between light/dark) let us know how you get on.
Due to turbulence in the atmosphere during the day, it's not uncommon for an image to be somewhat blurry over 40X.
A 25mm eyepiece yields 50X in that scope, so, for daytime use, you only have a 50/50 chance of getting a decently sharp image with it.
Higher powers? or Barlow? Forget it. You will see fuzz, basically.
At night, when the atmospheric turbulence settles down, you'll get reasonable sharp images up to about 125X and, occasionally, above that.
That means if the eyepiece focal length is shorter than 10mm, you'll need calm, steady, skies.
It also, as was mentioned, depends where in the sky you view. When you look straight up, you look through about 10 miles (16km) of air. At 30 degrees above the horizon, it's twice that (20miles/32km). At the horizon? 100 miles(160km) of air. Needless to say, all the extra air adds extra turbulence, dust, smog, haze, water vapor, etc.
So try to look at things as high in the sky as you can. Instead of looking at an object when it's just above the eastern horizon, wait 3-4 hours and view it higher in the sky. The image will be sharper and your scope will be cooled down, too. This type of scope cools for a couple hours as it's outside and yields better images when cooled to ambient temperature.
One last thing: dew can lightly coat the front corrector plate and end your observing quickly. When using the scope at night, use a plastic or metal dewshield to extend the tube forward past the corrector plate by about 15-18cm. [I used firm foam to make one] It will help prevent dew for a few hours and give you a chance to view more objects.
Nikki,
That’s very puzzling. I have a C5 and can focus both using an eyepiece in a star diagonal and with just the eyepiece. Furthermore, I have used a number of star diagonals with this scope and they have all worked.
Have U tried taking the star diagonal out from the scope and looking through it without an eyepiece? If everything can be seen clearly, then there should be no problem with the star diagonal.
