Reddit reviews Celestron 1.25" Universal Barlow and T-Adapter

Thank you, I will look into AutoStakkert.

I built my own cradle (I realise I've made the pivot point too far back, will be fixed later) for the scope as it didn't come with any accessories and the next mod is a linear actuator or a stepper motor so hopefully I can set it up to track slowly enough, maybe with the assistance of an arduino.

This is the barlow I have, its not Celestron branded however looks super similar. When you say nosepiece do you mean the end closest to the camera or furthest?

I'm looking at getting a barlow lens to do some planetary imaging. I currently have a D3300, which I hook up to the scope with a 1.25" T-adapter and a T-ring. If I want to include a barlow in this setup, do I have to get an item that is a T-adapter and barlow, such as the Celestron barlow here, or can I get any barlow and insert it between the telescope and the T-adapter?
Also, is there a big quality difference between cheap barlows? I'm looking to spend <$50. I've heard that the Celestron one I linked is alright, as well as some GSO and Astro-tech barlows, but I'm wondering how much better they are compared to a cheap alternative like this.
One more problem- I have two telescopes, one is an old Meade alt-az goto that works fine with the current D3300 setup, and the other is an old 8" Bushnell dob. With the T-adapter and T-ring on the dob, the sensor on the camera is too far back to focus, even with the focus scrolled all the way in. How would I go about fixing this? Will a barlow make this problem worse, or fix it?
Thanks to anyone who takes the time to read through all this!

I have this Barlow which, combined with this t-ring adapter allows me to shoot with my Nikon at prime focus with an additional 2x magnification.

I think the way the magnification is going to work is you take the focal length of the telescope divided by the size of your camera's sensor, which is the magnification you'd get with just the camera and the telescope. So with that 500mm focal length scope and your camera's 35mm sensor (although I think the sensors aren't exactly 35mm) then you'd end up with 500/35 which is a 14x magnification. So with the 2x Barlow I linked you'd get 28x, although you'll also have to compensate with the slightly dimmer magnified image.

Here are a couple pics. These are screenshots because I was having trouble uploading CR2 files. I'm using a Celestron C8 with the Canon 450D. I'm using a T ring adapter with this barlow but I take out lens so I don't get the 2x magnification. I was using BackyardEOS and was doing at both ISO 800 and ISO 1600. I was also varying the exposure time between 30 seconds and 1 minute (I even tried a few at 10 seconds). DeepSkyStacker kept telling me I only had 1 frame to stack, even when the threshold was set as low as possible.

The barlow is built into the adapter

I love my C90. It has really clear glass for the money. I'd recommend getting a 2x Barlow to double the power. If you don't plan to ever hook a DSLR to it, this is a good one:

http://www.amazon.com/gp/aw/d/B00008Y0TM/

If you want the flexibility of hooking up a DSLR to the Barlow, I have this one:

http://www.amazon.com/gp/aw/d/B00009X3UV/

You'll also need a hefty tripod. I have this one, but I also use my C90 for astrophotography and track planets with it:

http://www.amazon.com/Celestron-93607-Heavy-Duty-Altazimuth-Tripod/dp/B0007UQNY0

EDIT: Forgot to mention Celestron has a lifetime warranty (not like Vortex, but still good). I had trouble with the little finder scope. They helped me troubleshoot it and then sent me a new one without asking for anything but the address.

I use one of these

https://www.amazon.com/Celestron-Adapter-Barlow-Universal-T-Ring/dp/B00009X3UV


And

https://www.amazon.com/Astromania-Metal-T-ring-Adapter-Cameras/dp/B0140U9KLK/ref=mp_s_a_1_4?ie=UTF8&qid=1541163075&sr=8-4&pi=AC_SX236_SY340_QL65&keywords=canon+t+ring&dpPl=1&dpID=410nlYU2LYL&ref=plSrch