Problem with Celestron Astromaster 130

[jijokarthikeyan]

I have a problem with my astromaster 130.I have connected my cam to the scope using 2xbarlow [removed word] t adapter.I took the images of the moon,but at the time of processing realised that images are not that much clear.Then I removed the barlow part.The moon appeared to be blured and out of focus.I am not getting the clear pic of moon.

I s there any solution for this?

Regards

jijo

[Kirscovitch]

Sounds like you weren't focused. If you focused with the cam and and the barlow and then removed the barlow, you will have to refocus.

[Cornelius Varley]

The usual problem with Newtonian telescopes such as yours and prime focus imaging is that you cannot reach focus. This is due to having insufficient inwards focuser travel to reach the point of focus. The normal solution is to use a Barlow lens which has the effect of moving the point of focus further out. More drastic solutions to the problem include moving the primary mirror a little up the tube to shorten the distance between the primary and secondary mirrors or modifying the body of the the focuser to allow more inwards focuser travel, I don't recommend this option because it might invalidate your guarantee.

[ronin]

I assume that you are using a webcam??

You have removed the lens from the webcam, the lens has to come off, the filter can remain in.

The simple answer is that the moon was never focused on the webcam at the start.

Next I read that the scope is for astro and terrestrial use, meaning there is an erecting prism in the optical path. I would remove this from the system if possible as they are not top quality and may be giving a poor image.

The scope may be well out of collimation, for a simple quick check get/make a collimation cap.

The barlow could be poor and producing a bad image.

Has the focuser slipped during use?

If you have a DSLR on the scope then this is a possibility as they are heavy.

What were you displaying the image on - laptop? at the start. If you focused the image for your eye then dropped in a barlow and camers the positions they shoule be at will be completely different so it would be out of focus.

[jijokarthikeyan]

I have used my canon 60d for taking the pics of moon.

I tried removing the barlow lens from t adapter,but i was not getting the proper focus of the moon.Moon appears as a big dot.Is it due to the limitations of the focuser?

Regards

Jijo

[Cornelius Varley]

It is due more to the limitations of the telescope than the focuser. Some newtonian telescopes have insufficient inwards focuser travel for prime focus imaging with a dslr (they were designed for visual use with an eyepiece) , the point of focus being too close to the secondary mirror. This can be resolved by the use of a barlow lens which will move the point of focus away from the secondary mirror. See also post #3 regarding alternative solutions and also this video