Help with telescope

[Florida Bear]

I have a Celestron Starsence Explorer DX 130AZ F5, with 650mm focal length. I can't seem to pull in images as I thought I would. Am I expecting too much? 

Working numbers say anything more than 13mm eyepiece won't focus.

Saturn is smaller than pencil diameter, and the Pons comet is just a small smudge, not very distinct.

Again, am I asking to much for larger, clearer images?

 

[Elp]

Your scope is 130mm aperture, so max mag is around 260x. Therefore an eyepiece of 3mm should be possible as long as seeing is good, very rarely have I been able to use less than a 7mm though with any scope, the seeing just makes very high magnification worse if it's bad.

Visually you'll rarely get the sights you see in images, cameras take in photons over time and are post processed to get them sharp, bright and colourful, visually you can only see what your eyes are capable of at the time and given how dark your skies are as well as the quality of the atmospheric seeing at the time.

[Elp]

Also see this thread:

 

 

[dweller25]

On 22/03/2024 at 16:15, Florida Bear said:

I have a Celestron Starsence Explorer DX 130AZ F5, with 650mm focal length. I can't seem to pull in images as I thought I would. Am I expecting too much? 

Working numbers say anything more than 13mm eyepiece won't focus.

Saturn is smaller than pencil diameter, and the Pons comet is just a small smudge, not very distinct.

Again, am I asking to much for larger, clearer images?

 

Hello @Florida Bear and welcome to SGL.

A 13mm eyepiece gives x50 - thats the focal length of the telescope divided by the focal length of the eyepiece, so 650/13 = 50.

At the moment Saturn is well past closest approach so is very small.

You can certainly use shorter focal length eyepieces in your scope, for the planets I would suggest x185 (a 3.5mm eyepiece) is good.

Or you could buy a x2 barlow lens that doubles the focal length of your telescope to 1300mm and then use a 7mm eyepiece to get x185.

Comets are dull smudges even in bigger scopes.

”stellarium” is a great piece of free astronomy software that you can download to see what is in the night sky.

Hope that helps.

 

 

Edited March 24 by dweller25

[Florida Bear]

I have tried smaller eyepieces, but can't seem to get them to focus, same with Barlow's.

Must be me, and just need to keep experimenting, and patience.

I actually have pondered if something was wrong with my scope.

[dweller25]

Do you need more in focus or out focus with smaller eyepieces ?

If in focus is needed you may be able to remove an extension ring off the focuser.

If out focus is needed you can add an extension ring or just pull the eyepiece out a little bit and then secure it.

Edited March 25 by dweller25

[malc-c]

There is always a trade off... Increase the magnification and the brightness, and thus resolution is reduced.  The way to overcome that is aperture.  Unfortunately unlike a camera's lens we are stuck with whatever the fixed aperture of the telescope being used.  When you see those lovely images of Jupiter, with high detail in the cloud bands and swirls around the red spot are often taken through long focal length telescopes of 12, 14 or more inches in diameter.  The problem comes when people expect to see the same visually and often through a scope of small aperture.

The scope is supplied with  10mm and 25mm eyepieces and no barlow.  This is probably as the 65x magnification is the highest practical magnification for that scope.  Add in a barlow, or eyepieces in single digit magnification and the resulting images are dull and hard to focus as the sweet spot with short focal lengths eyepieces are quite small.   Factor in the turbulent atmosphere, and you may never be able to achieve focus with a 3 or 5mm eyepeice.  

[Naughty Neal]

With higher power EP's try lifting the EP's out of the focuser and see if they gain focus (assuming colimation is good), if they gain focus then one needs a short extension tube to be inserted before the EP.

[bosun21]

It appears that the telescope is sold without any extension pieces so focus should be achievable as it comes. This leads me to think that the collimation of the mirrors must be way off if focus is unachievable. Search on YouTube for collimating a Newtonian as there are a lot of good videos on the subject.

[AstroMuni]

On 25/03/2024 at 00:29, Florida Bear said:

I have tried smaller eyepieces, but can't seem to get them to focus, same with Barlow's.

If you are getting crisp views of features on the moon and stars are pinpoint then I wouldnt worry about collimation.

I had a Celestron 130 and yours looks similar, so dont expect crisp views of planets. The edges will be fuzzy - partly because of the the atmospheric effects and the partly due to steadiness of your scope. The focuser is also not the best so its hard to get exact focus.

 

Edited March 26 by AstroMuni