ASKAR V mODULAR APO Refractor - Review (3 aug 2023)
INTRODUCTION
This is a succinct review of the new ASKAR V Modular APO Refractor. There are at least three YouTube reviews that I am aware of so I recommend that you compare my findings with those other reviews. The review is not aimed at repeating information you can easily obtain from the vendor’s website, such as weights, dimensions, the focal ratio/focal length in the various configurations etc. This review focuses on my observations when assembling, adapting, and operating the telescope.
BLUF (BOTTOM LINE, UP FRONT):
Performance: The best quality stellar profiles are seen with the supplied Flattener. The scope does have slight chromatic aberration. Bright reflections were seen emanating off Antares which persisted with each optical component and filter used. However, this reflection could of come from the ZWO filter drawer, so this is inconclusive. Overall assessment: Very Good.
Build Quality: Very good.
Adaptability: Excellent.
Portability: Excellent.
Value for Money: Very good.
RECOMMENDED? Yes.
DISCLAIMER: My tests with this telescope utilized a QHY600 OSC camera with 3.76micron pixels unbinned. It is well known that these large sensors with very small pixels can produce sub-optimal results especially where sensor tilt is present. Hence, the use of a smaller sensor and/or one with bigger pixels would most certainly yield better images. The telescope was supplied by SharpStar optics purely for me to provide a review for which I received no renumeration.
Test Environment:
QHY600 One Shot Colour
ZWO EAF
ZWO Filter Slider - IDAS HEUBII filter, Cyclops Optics UV/IR Cut Filter, Optolong Ultimate
Avalon M-Zero Mount
Performance:
For my review I used the telescope with both the 60mm and 80mm objective plus the supplied flattener, reducer or extender adjusted to complement the objective in use.
In my opinion the flattener produced the best images in terms of a flat field and sharp stellar profiles and the reducer the worst (see Disclaimer above). Slight chromatic aberration was seen and a OSC camera certainly shows this when an image is debayered to the individual channels. On this basis, a OSC camera might not be the instrument of choice for this telescope. However, if a monochrome camera coupled to a filter wheel is used, the chromatic aberration problem is overcome as the user merely needs to refocus the telescope when changing filters.
Bright reflections were observed off my test subject, Antares. This was observed regardless of optical add-on in use and was seen when both the UV/IR and HEUIIB filter was used. However, ASKAR suggested that I change the ZWO filter drawer, but I did not have a second. Hence, this finding is inconclusive.
Note: At the bottom of this page are links to several images viewers can download and inspect. Some images are debayered to half the original size and to their individual channels.
Below: ASKAR V at 80mm. Note the prototype dew shield (the inner part of a toilet roll) for the guide scope. Patent Pending.
M8 ASKAR V 80mm FL with reducer. 5 x 5 minute exposures.
Build Quality:
The telescope is solidly built as are the 3 supplied optical components. All aspects of the telescope demonstrate quality engineering and production. The built in camera rotator is very smooth as is the focus mechanism. I attached a ZWO EAF to the telescope which was used very successfully for remote focusing. The 80/60mm objectives unscrew smoothly.
Adaptability:
This is the most exciting aspect of the ASKAR V. The user has a choice of objective and when switching from 80mm to 60mm, the user is required to adjust the chosen optical add-on. This is made very easy by the design and does not leave any room for doubt. The user loosens 3 set screws and then rotates the optical part until it comes to a stop at the ‘60’ mark. It is now ready to be matched to the 60mm objective. What is very handy is the fact that the backfocus for each of the optical add-ons is identical, so you do not need to change the optical line up behind the add-on at all, just the focus position of the telescope.
Resolutions:
80mm with Reducer - 2.32 arcsecs per pixel
80mm with Flattener - 1.57 arcsecs per pixel
80mm with Extender - 1.25 arcsecs per pixel
60mm with Reducer - 2.8 arcsecs per pixel
60mm with Flattener - 2.15 arcsecs per pixel
I was able to change out the optical add-ons in just a few minutes, adjust the focus position of the scope, and I was underway imaging again.
In addition to these very useful and clever features, the scope is equipped with an extra long Vixen dovetail that can be moved back and forth as required for balance purposes. It is also supplied with a finder scope bracket and a Vixen style saddle on top of the scope. I used this for my guide scope as seen in the image above, but it could have easily been fitted into the finder scope bracket.
Image below: Close up of the optical line up. Plenty of room for a FW and OAG.
Image above: ASKAR V in 60mm mode
Because I was using a OSC camera I had to introduce a UV/IR cut filter as the QHY cameras cover slip is only AR coated. So I chose to introduce a ZWO Filter Slider and tested the scope with both a Cyclops Optics UV/IR cut filter and an IDAS HEUIIB filter which also isolates the Ha emission line (see reference to reflections above). The backfocus of each of the optical add-ons is 55mm, so there is enough room there to add a FW to a monochrome camera AND an OAG.
portability:
The telescope is supplied in a smart, airplane carry-on friendly, black case filled with pre-cut foam. It is a perfect scope for a field trip with a lightweight mount such as the one used in this review.
Value for Money:
The telescope retails here in Australia for around $3000 AUD and given the build quality, imaging options and performance, this is very good value for money in my opinon. It is lightweight, well made, airline friendly and offers the user multiple widefield imaging options.
Questions:
I am happy to take questions or have a discussion. Please contact me at mpastro2001 at yahoo dot co dot uk