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ASKAR FMA180 40mm aperture apochromatic telescope.


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I just received the dedicated Bahtinov mask from Teleskop Express, but haven't had a chance to use it yet. 

It looks a bit fragile, to be honest: the translucid part is actually not solid glass, but a flimsy sheet of plastic glued to the frame. That surprised me a bit, in this hobby we are more used to glass and solid aluminium! I'll use the plastic box of one of my many filters to store it more securely, since Askar just provides a small carton box. 

Other than this apparent fragility, I'm sure it will do the job just fine! The translucid mask and the fine lines should give very usable diffraction spikes. I'll try to post an image whenever I have time to image and a cloud free night... which might not happen until 2024...

I also did some tweaking to the setup itself. I removed the T2 spacer at the back of the scope, which gives me an additional ~28mm of back focus. Instead, I mounted a mounting foot from a salvaged 32mm guider, to which I attached a finder shoe for the autoguider. That's more convenient than the double rings system I used in the past!

I also replaced the Arca Swiss plate for a shorter one, salvaged from a ZWO camera holder ring. It happens to have 4 holes with the correct spacing for the scope's rings, and I can fix this plate to a regular vixen dovetail with 2x 1/4" screws, instead of 1 for the default plate. So, better for the peace of mind, but also I find the shorter plate more convenient for balancing and rotating the scope.

I'm still impressed by the size of the whole thing! That's a perfect match for the AZ-GTi & ASIAIR, even without a counter weight, to fit in a backpack and image from anywhere :) 

Now all I need is time & a cloud free night... the only things money can't buy!

IMG_0167s.JPG

IMG_0166s.JPG

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39 minutes ago, Space Oddities said:

I just received the dedicated Bahtinov mask from Teleskop Express, but haven't had a chance to use it yet. 

It looks a bit fragile, to be honest: the translucid part is actually not solid glass, but a flimsy sheet of plastic glued to the frame. That surprised me a bit, in this hobby we are more used to glass and solid aluminium! I'll use the plastic box of one of my many filters to store it more securely, since Askar just provides a small carton box. 

Other than this apparent fragility, I'm sure it will do the job just fine! The translucid mask and the fine lines should give very usable diffraction spikes. I'll try to post an image whenever I have time to image and a cloud free night... which might not happen until 2024...

I also did some tweaking to the setup itself. I removed the T2 spacer at the back of the scope, which gives me an additional ~28mm of back focus. Instead, I mounted a mounting foot from a salvaged 32mm guider, to which I attached a finder shoe for the autoguider. That's more convenient than the double rings system I used in the past!

I also replaced the Arca Swiss plate for a shorter one, salvaged from a ZWO camera holder ring. It happens to have 4 holes with the correct spacing for the scope's rings, and I can fix this plate to a regular vixen dovetail with 2x 1/4" screws, instead of 1 for the default plate. So, better for the peace of mind, but also I find the shorter plate more convenient for balancing and rotating the scope.

I'm still impressed by the size of the whole thing! That's a perfect match for the AZ-GTi & ASIAIR, even without a counter weight, to fit in a backpack and image from anywhere :) 

Now all I need is time & a cloud free night... the only things money can't buy!

IMG_0167s.JPG

IMG_0166s.JPG

Interesting, where did you get the holder for the guide scope from? 

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I swapped the foot integrated to this guide scope, with standard guide rings. Rings give me a better alignment with the main scope and the 32mm guide scope, while the foot is very convenient to attach the other guide scope to the Askar.

The little guide scope I'm using is a bit lighter (150g!) and smaller than the Astro Essentials one, and is also a better match for the very portable system I'm building. I need my setup to be as light as possible, so I don't need to add any counterweights to my AZ-GTi, which ultimately spares me 1.5 kg in the backpack! Every gram counts! :D

The foot itself has 3x 1/4" holes once you remove the mini dovetail, so I attached a spare hot shoe to the middle hole, and voilà!

Edited by Space Oddities
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22 hours ago, astronomas said:

Hi Adam

I just got the Askar and looking to add a motorized focuser.

are your 3D printer files available to print the scope belt ring and focuser holder?

thank you

 

So long as you use it for your personal use only, don't pass the files on,  or make prints for others, or post them online etc then I am happy to share.

If your happy with that I'll dig the files out and send them to you. 

It will only work with the focus cube but I have a file for the V1 and V2. You may need to tweak the position of the holes if it's the V1 as it was not quite correct when I printed mine. V2 would work fine. 

Adam

 

Edited by Adam J
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Hi Adam

I just got the Askar and looking to add a motorized focuser.

are your 3D printer files available to print the scope belt ring and focuser holder?

thank you

 

Thank you for the reply Adam.

I managed to get something working after some playing around in Tinkercad.

I think I am good for now.  The interesting part is that the focuser has to move to chase the wheel...  I need to test it tonight and set the final location.

askar.jpg

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6 hours ago, astronomas said:

Hi Adam

I just got the Askar and looking to add a motorized focuser.

are your 3D printer files available to print the scope belt ring and focuser holder?

thank you

 

Thank you for the reply Adam.

I managed to get something working after some playing around in Tinkercad.

I think I am good for now.  The interesting part is that the focuser has to move to chase the wheel...  I need to test it tonight and set the final location.

askar.jpg

The belt can't be very tight or you will cause tilt. For that matter it doesn't need to be. I can slide mine on and off without removing the motor unit. 

You really only need to move it an 8th of a turn in total to autofocus it you don't need access to the full range of movement. I made the pullies wider than the belt to accommodate a little slide in the belt. My self and a @PadrePeace have been using it for a while with no issues. 

 

Edited by Adam J
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6 minutes ago, Space Oddities said:

Yes the mechanism isn't autofocus friendly... In DeepSkyDad's version, the EAF actually moves with the focuser. Quite ingenuous! But it feels like the EAF unit is as big as the scope itself...

Yeah my thought was that although clever he had made it more complicated than required. You don't need the full focus range to focus at infinity. Just a tiny little movement once you present the focus position, in which case the movement is insignificant and can be accommodated by the belt. 

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Took this shot of Virgo and some of its Galaxies last night. It represents 82 x 80s subs at 120 gain, -15C taken atop of a iOptron SGP, unguided with a ASI294MC and a 2" Astronomic L3 filter on the front of the scope to reduce blue bloat.  Stacked in APP with Darks, Flats and Dark Flats to suit.  The only post processing was LP removal in APP, Deep Space Noise Reduction on the black areas only, colour enhancement and sharpening on the galaxies only all in PS and that's it. The stars are totally untouched. Enjoy! comment.......

Virgo_Galaxies-L3_80s_G120-St.jpg

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2 hours ago, PadrePeace said:

Took this shot of Virgo and some of its Galaxies last night. It represents 82 x 80s subs at 120 gain, -15C taken atop of a iOptron SGP, unguided with a ASI294MC and a 2" Astronomic L3 filter on the front of the scope to reduce blue bloat.  Stacked in APP with Darks, Flats and Dark Flats to suit.  The only post processing was LP removal in APP, Deep Space Noise Reduction on the black areas only, colour enhancement and sharpening on the galaxies only all in PS and that's it. The stars are totally untouched. Enjoy! comment.......

Virgo_Galaxies-L3_80s_G120-St.jpg

Great image too many galaxies for me to count. Also a good example of the use of the L3 filter as without pixel peeping those stars look great with no apparent bloat in blue. 

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12 minutes ago, PadrePeace said:

Probably needs a tadge more back focus would you say AdamJ?

Now that you mention it just a tiny bit lol. Life is difficult for the perfectionists. 

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  • 1 month later...

Have piggy backed the entire Askar 180 setup on the top rail of my Esprit 100 for when I use it at home. Got the Az GTi for mobile use. 

Makes the Esprit look like a complete beast of a scope. 

 

IMG_20210510_175318634_HDR.jpg

IMG_20210510_175250834_HDR.jpg

Edited by Adam J
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  • 2 months later...

I am finding this little scope to be excellent as my goto holiday rig on a AZGTI with the asiair pro.

Printed some 3D parts to do Autofocus from the link below. Needs to be manually in the ball Park unlike the Deepsky dad version as the whole front camera assembly moves with the focus ring but once you have stars then this takes care of autofocus throughout the night perfectly. Belts and Pulley are both readily available on Amazon. 

http://grapeot.me/auto-focus-solution-for-sharpstar-fma180.html  

Heres a test shot not fully processed yet but you get the idea and photos of the rig.

Heart_Nebula-Stacked-basic-PS.jpg

IMG_6814.jpg

IMG_6816.jpg

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  • 1 month later...

Thanks for the thread, useful information here

 

I see Askar have brought out a slightly bigger brother, the FMA 230 which appears to be a scaled up version of the 180.

 

Has anybody bought and tested this scope, and how do you think this would compare to the Redcat 51 for use with a cropped sensor DSLR/Fornax Lightrack 2 set up?

I was thinking of getting the Redcat but it appears that the Asakar FMA 230 lens may be a comparable alternative. 

Edited by 900SL
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I haven't seen any test yet, but I don't think it will be optically as good as the RedCat. Which is okay, considering it's also cheaper.

It's only a guess of course, based on my experience with the FMA180: despite the "APO" in its name, it's not a true apochromatic telescope (probably due to the use of cheaper glass), and as a result, some stars show a blue fringing. That's a drawback that is easily corrected either in post or using a filter (Astronomik L3, Baader fringe killer, Baader Semi APO, etc.), and that is also counterbalanced with the low price, IMO.

I suspect the FMA230 to be the same kind of scope, with the same drawback ultimately. When a manufacturer uses high quality glass, it's generally printed in bold and underlined in the specs :)  Which would makes the RedCat optically superior (but more expensive)!

If you're looking at the best image quality, an alternative could be the Askar ACL 200mm. It's not too far off in terms of focal length & aperture, compared to the FMA230, but optically, from what I've seen at least, it's way better than the FMA180. Probably just as good as a RedCat in fact. But beware of the weight, it's 1.8kg!

So I would say, it all boils down to what is more important to you, between weight, image quality and price. Between the FMA180, FMA230, ACL200 and the RedCat, you have 4 solid options that can suit your needs :) 

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Thanks Space Oddities and Ive been thinking along the same lines. I think I will opt for the Space Cat as I like to keep the weight down given my latitiude (24 degrees north), plus it has a little longer reach. 

I have the Samyang 135 and Askar 180 with a Nikon D610 and D5600 so have the widefield covered pretty well.  Also an ASIAirpro and 30mm guidescope which I havent really used yet. 

The other option is the TS Optics  TSAPO71Q   version of the Meade 70mm f5 6000 but thats a big jump from where I am at the moment, as I will have to start guiding and think about my set up. 

 

 

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Just tested my FMA 180 from TE on a Nikon D5600 for the first time. 

Shot around 12 frames in bortle 7 on a random target overhead. Getting significant internal comatic aberration down the left side of the frames, pretty bad in from the left corners to about 30% of the frame.

Top right is good, bottom right shows some elliptical stars. Is this likely to be a field flatness issue or a lens issue? I'll post some images later, they are pretty rough with the LP and the heat here (36C evening)

At the moment I'm not too happy with this scope but hopefully there's a fix somehow.

 

 

Corner.jpg

Edited by 900SL
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3 minutes ago, 900SL said:

Just tested my FMA 180 from TE on a Nikon D5600 for the first time. 

Shot around 12 frames in bortle 7 on a random target overhead. Getting significant internal comatic aberration down the left side of the frames, pretty bad in from the left corners to about 30% of the frame.

Top right is good, bottom right shows some elliptical stars. Is this likely to be a field flatness issue or a lens issue? I'll post some images later, they are pretty rough with the LP and the heat here (36C evening)

At the moment I'm not too happy with this scope but hopefully there's a fix somehow.

You may have a duff copy, post some images. 

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That looks brilliant -both the image and the rig.  Nice to see you sharing the STLs etc for the wider astro community too.

On 12/07/2021 at 14:41, andyonroad1969 said:

I am finding this little scope to be excellent as my goto holiday rig on a AZGTI with the asiair pro.

Printed some 3D parts to do Autofocus from the link below. Needs to be manually in the ball Park unlike the Deepsky dad version as the whole front camera assembly moves with the focus ring but once you have stars then this takes care of autofocus throughout the night perfectly. Belts and Pulley are both readily available on Amazon. 

http://grapeot.me/auto-focus-solution-for-sharpstar-fma180.html  

Heres a test shot not fully processed yet but you get the idea and photos of the rig.

Heart_Nebula-Stacked-basic-PS.jpg

IMG_6814.jpg

IMG_6816.jpg

 

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7 hours ago, Adam J said:

What corner am I looking at here? Can you post the whole image please? 

Apologies Adam, here's the stack of 11 images, 30s ISO 400 D5600. Center is pretty good, top and bottom right inward coma, Full size jpgtest.thumb.jpg.2fb50a39daa3ea40b792c4703fe0e687.jpg

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