Name: Used Celestron Off-axis Guider undefined
Brand: Celestron
SKU: US1654263
Price: 289.00 USD
Availability: Discontinued
Rating: 4.4 (8 reviews)

Celestron Off-axis Guider

Celestron

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Adorama

Used

Optics & Binoculars

Telescopes & Astronomy

Astrophotography

Celestron Astrophotography

Celestron Off-axis Guider 

Open Box: Used Celestron Off-axis Guider undefined

The Off-Axis Guider is an essential astroimaging accessory for long focal length telescopes that require the most accurate guiding possible. The Celestron Off-Axis Guider uses a prism to intercept a small portion of the telescope's focal plane (outside the field of view of the main imaging camera) to locate a guide star. Any movement seen by the guide star will be the exact same movement seen by the imaging camera. Guiding this way will correct for tracking errors, as well as opto-mechanical errors or flexure. The result: better astroimages with pinpoint round stars.  Off-Axis Guiders have been around for a long time, but typically pose three main challenges:  1. Finding a guide star from the far edges of the telescope's focal plane can be difficult, considering the small field of view and sometimes less-than-ideal illumination.  2. Getting both imaging camera and autoguider to reach focus with one another is time consuming and sometimes requires experimentation.  3. Additional spacers and adapters are usually required for your particular camera, telescope, and autoguider, which adds to cost and complexity.  Celestron's Off-Axis Guider addresses these challenges by: &#149; Providing a large 12.5mm prism that can be adjusted to move closer to the center of the telescope's focal plane, depending on the size of the imaging camera. This results in brighter guide stars, with the help of the large prism to fully illuminate the autoguider sensor. &#149; Featuring a high-quality, fixed-orientation Helical focuser. This provides extremely smooth and accurate focus of the autoguider without changing (or twisting) the autoguider camera orientation. &#149; Including all the needed spacers and adapters are included for most common imaging configurations, including DSLR cameras, Nightscape CCD cameras, and more. The following adapters are included: SCT/EdgeHD, female M48, female M42 (T-thread), male M48, male M42 (T-thread), 3 T-thread spacers  Additonal Specifications  &#149; Helical Focuser Travel: 8mm &#149; Telescope Connection: M42 T-thread, M48, and SCT/EdgeHD &#149; Autoguider Connection: M42 T-thread, and standard 1.25" adapter &#149; Camera Connection: M42 T-thread, and M48

Used Celestron Off-axis Guider undefined

Love it, well made, works great. Large prism and inside diameter. Easily rotates with adjustment screws on each side. Excellent adjustments for guide camera focus (Locking screws plus Helical adjustment).

Great OAG

Celestron Off Axis Guider (OAG) is an excellent product. Includes all needed spacer and pices to assemble out of the box. The prism is huge and able to find stars in a light polluted sky. The only reason I give it four stars is that  it is heavy and should include the 48mm visual back.

Celestron OAG

This OAG allows a wider viewing window for my guide camera to pick up guide stars, thereby allowing me to rack stars more accurately.

Celestron Off Axis Guider

Nice (relatively) wide field prism, nice for use with a SC Telescope like the EdgeHD series and a larger sensor guiding camera to get more stars.  The standard adapters it comes with are designed to take up all the space between the telescope and the camera, I still haven't figured out a way to have both this and my 0.7x reducer on at he same time.  One downside, if there's a bright star nearby you'll get circular reflections in the image -- usually just faint streaks to an arc.  PHD2 seems to always choose these to guide on.  It doesn't happen to me on all targets, but when it does you need to manually choose a guide star.  See attached images.

Nice wide FoV for a prism, but optical design could use improvements.

Just what I needed.  Built solid, plenty of adjustment.  The non rotating helical guider focuser is a real plus.  It has a good selection of adapters included that fit well and the included spacers came in real handy.  First time use was quite easy.  Of it took a little time to get both cameras focused but it was not a difficult process.  Great off axis guider.

Get pinpoint stars with this OAG

The large amount of adapters and extensions included in this kit are a great help when working out your back focus in an imaging train. The entire unit is extremely heavy duty, as most Celestron OEM parts are. That can be good or bad depending on your intent. Fully assembled it is quite wide for an OAG, and weighs a fair bit. You may have trouble if you use a motorized focuser in the range of auto guide cam rotation. All in all it’s an excellent quality OAG with a large and easy to adjust prism.

Excellent quality, a little heavy

Easy to set up. The only minor change I would suggest is to use stronger thumb screws.  These seem easy to break if you tighten them too much. Otherwise a good product. I am still waiting on a few good nights to use this product.

Easy to set up

I'm impressed with the flexibility of this device. Easy to rotate the guidescope or the dslr camera individually. I did need to add a short extender to allow for focus of my lodestar x2 so that dslr and guide camera would focus together. I'm attached to a celestron c8.   OAG is on the heavy side but a solidly built device with many accessories to accommodate different scopes etc

Used Celestron Off-axis Guider

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Celestron Off-axis Guider