Modifying a Celestron Nexstar 130

[Amnese (Nathan)]

I recently bought a Celestron Nexstar 130 as my first scope, which I primarily want to use for astrophotography [I'm aware it's not best for this and I should get something better eventually]. The Nexstar 130 has this quirk where prime focus lies below the point where a DSLR sensor can reach, so you need a barlow lens to capture this [I don't know the technical terms for all this].

So, using my DSLR, I've attached a 2x Barlow lens and am using prime focus. I don't like this idea, but it's my short term solution to get started.

I'm limited in the quality of images I'm getting from this, and am tempted to modify the scope to adjust prime focus so that I can return to regular focal length and f-stop.

I've read in some places that the modification means you can't use the scope for visual astronomy, as it pushes prime focus too far forward, beyond the point of the visual lens. I read elsewhere, however, that you can attach an 'extender', and place a visual lens in that [but I can't recall where I read this, nor find any information on what I need exactly].

There's a lot of information on the mod, but not much on this 'extender' idea. Can anyone tell me what I may need to use a modded scope like this for visual astronomy?

Is there anything else I should be wary of in doing this mod [aside from cracking my primary mirror, which is already worrying me]?

To give you a sense of 'where I'm at', here's my latest processing of the Orion Nebula.

https://www.cloudynights.com/uploads...47_2177200.jpg

[raymo]

Hi Nathan, Firstly, it is not a quirk. Until quite recently, most Newtonians
were like yours, not enough back focus for photography. Many buyers got
caught out by this fact. I have posted here many times over the years
suggesting that Newt buyers check with their retailer whether their
purchase was suitable for AP.
Your scope is especially unsuited for AP as it is not equatorially mounted,
and therefore cannot track accurately for more than about 15-20 seconds, as your elongated stars demonstrate.
It is also a longish tube attached to a single arm, which is not a very stable
arrangement for photography, where stability is paramount.
In short, the very mediocre results you will achieve will not justify the
effort involved in moving the primary mirror up further.
raymo