About this product
Part Number: M54 OAG
The Askar M54 OAG is a nicely made wide aperture Off Axis Guider that will not vignette even when used with full-format cameras.
Features a large 10mm x 10mm Prism that delivers a wide and bright field so easier to find suitable guide stars.
Includes threaded M42, M48, and M54 adapters to easily interface with a wide range of cameras and three threaded 18mm extender rings to help you achieve standard 55mm back focus when using cameras with a sensor recess distance of 17.5mm (most ZWO and Starlight Xpress Cameras).
Also includes M42 and M48 adapters and an M54 gasket for use on the telescope side.
The top of the OAG has a 1.25” adapter and M42x0.75 threads for attaching most guide cameras and a scaled helical focuser with 10mm of travel to help you achieve focus with the guide cam.
The Askar M54 OAG has an optical thickness of only 19.5mm so is ideal for situations where back focus is limited.
- Askar M54 off-axis guider supports imaging with up to full-frame astronomy cameras
- Includes M42, M48, and M54 adapters and extension rings to attach to a wide range of cameras
- Interfaces with guide camera with included 1.25” adapter or standard M42 thread
- Large 10mm x 10mm prism makes it easier to select guide stars
- Made from black-anodised CNC-machined aluminium
|Average Rating (1 Review): |I love this OAG! Very well made and a pleasure to use.
05 June 2022 | Alan
I needed a better Off-Axis Guider for my Celestron C9.25 at its native focal length of 2350mm than the ZWO 8x8 one I had before; it just wasn't finding stars. So on the recommendation of the FLO guys I went for the Askar. To be honest I was won over as soon as I watched their charming video on the product page! They obviously take pride in their product. What I found to be unusual when the OAG arrived - above and beyond most astro accessories - was the provision of a range of all the likely adapters you may need, lovingly slotted into the foam cut-outs. You would probably pay at least £10-30 each per adapter if you were to buy them separately! The packaging is very luxurious and somewhat at odds with what can be a fairly mundane item.
Anyway onto the OAG itself. Although its just the same basic design and mode of operation of any other OAG, somehow the Askar just does it better. When adjusting the prism's distance into the light-path for example, the ZWO adjustment always feels fiddly and imprecise. The same Askar adjustment is quicker and smoother- the parts just seem to be machined better, with tighter tolerances.
In action, it's the focus control that offered the biggest improvement for me, over the ZWO. It is very smooth, with precise markings on the barrel so you can find the same focus point again. There is also a decent amount of travel and solid defined end-stops, rather than the ZWO's focus which manages to be both stiff and loose at the same time across its short focusing distance, with only a stiffening of travel to indicate the end of the focus range rather than well-defined end stops.
Finally imaging; well the Askar works as advertised- its larger prism sucks in more light (technical term there) and even during (current at time of writing) June's low-contrast, never totally dark skies, seems to find at least one star more often than not and fairly well defined stars at that. I'm only using a ZWO mm mini guide camera, so once I upgrade the camera to something more sensitive I reckon I'll never not have guide stars in the field of view, most likely several in fact.
So there we have it- a resounding 'buy, buy, buy!' from me if you rely on an OAG for accurate guiding. There are OAG's with bigger prisms on the market, but I reckon they would start to make shadows on the main light-path more likely.
The Akar's 10x10 is for me is the sweet-spot of OAG prism size and just a great product overall.
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