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Askar 203mm APO testreport

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#51 Wildetelescope

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Posted 13 March 2025 - 08:35 AM

So, my take home is more or less from what Paul and Jeff and the folks that own these are been saying about the 185 and 203 scopes in all these different threads.  There are clear and obvious, BUT NOT UNREASONABLE compromises that have been made to achieve the price point for these telescopes.   For DSO imaging, especially when using the flattener/reducer,  They will likely perform reasonable well.   For visual, under normal seeing conditions, up to ~50X per inch mag, you will likely get comparable or better results to a decent C8.   Once you start going over 50X per inch in really good seeing conditions these scopes will fall behind higher end competition visually.   The mechanical fit and finish are generally considered to be very good.  

 

So, at the end of the day, if you want a large refractor for DSO imaging and/or would be happy with the visual performance described above then this scope is more or less fairly priced for what it is and would make you happy, barring any quality control issues.   HOWEVER, if you are used to running your scope up over 50X inch(looking at you Chas:-) and are used to the highest quality visual experience that can be had, then you would be better off either saving your pennies, or going for a good quality smaller refractor.  

 

My entirely personal preference would be to go with a 6 inch scope of higher quality.  I have one so that niche is filled, but if I did not, I would be looking for one of the TMB 152 mm LZOS triplets used, or considering the AT 150 mm EDL Doublet.   Honestly, I think that the TMB would give you everything these larger scopes would in terms of performance and be easier to mount.   At one point they were going for ~4K on the used market (wished I had jumped on one at that time) which is crazy given what they are.   I would guess they would cost more now, but probably be in the same range as the Askars.   They come up every once and a while.  

 

JMD


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#52 Psion

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Posted 13 March 2025 - 09:23 AM

I have a Zerochromat, which is a 200mm refractor with a corrector, and the imaging quality is at a semi-APO level. I can confirm that you can see more details on the Sun in the 200mm refractor than in the TEC 140ED. The aperture size is truly noticeable.


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#53 denis0007dl

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Posted 13 March 2025 - 09:51 AM

I have experience comparing TSA 120 vs Askar 185.

On high magnif Askar show tons more details on Jupiter than TSA 120 show.

On DSO Askar eat TSA, and price of both scopes in EU are approx same.
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#54 denis0007dl

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Posted 13 March 2025 - 09:54 AM

But TSA 120 was actually great finderscope for Askar 185.
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#55 garret

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Posted 13 March 2025 - 01:18 PM

What I rarely read in all the reactions regarding large telescopes, is the combination factor of more light/aperture and the increase in the resolution of the optics.
M13 in my 100mm Binocular telescope is like a nebula, in my 30 cm SCT it is full of stars... increased aperture and resolution is what you need.



#56 fedele

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Posted 13 March 2025 - 04:08 PM

But TSA 120 was actually great finderscope for Askar 185.

Ok. Actually even if they cost the same they don't have the same value. The one who loses financially is you.
Keep your askar....among other things even with that shXXy color



#57 fedele

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Posted 13 March 2025 - 04:11 PM

Moreover, at the first impact or with the changes in temperature, or simply with the passing of time, the triplet and the cell will deform and you will throw away your money forever...all



#58 Psion

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Posted 13 March 2025 - 05:30 PM

The TSA 120 is certainly a nice telescope, but it is also losing value like everything else, 5 year olds can be bought for $3500 (today's price for a new refractor is $5200). I myself have a limited edition TAK FC-100DL/F9 at an excellent purchase price, so I wouldn't lose out on selling it.

Interestingly, my colleagues and I have always dreamed of some kind of 200mm ED refractor, and when it is available at what I think is an excellent price, they don't rush to buy it. I got a Zerochromat 12 kg heavy, so for me, it is no longer interesting, as well as CFF and LZOS scopes with unacceptable prices, although they are of great quality.

I ended up going with the great APO binocular APM 120, which has a range on stars and DSO similar to the 175mm refractor, albeit with less resolution.



#59 VNA

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Posted 14 March 2025 - 03:44 PM

 

 



#60 Psion

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Posted 17 March 2025 - 05:19 PM

I took a test picture of the M42 without guiding, Bortle 4, 15 second exposure, Sony A7sII, ISO 2000. Processed in PixInsight.

Attached Thumbnails

  • M42_A7sII_small-1.jpg

Edited by Psion, 18 March 2025 - 01:13 AM.

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#61 PKDfan

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Posted 17 March 2025 - 05:27 PM


A Very Beautiful M42 Psion !


CSS
Lance
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#62 Joe G

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Posted 17 March 2025 - 08:47 PM

Assume that M42 is with minimal post processing?



#63 Psion

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Posted 18 March 2025 - 07:05 AM

The picture is processed in PixInsight. With a 15 second exposure, you cannot count on the image being well exposed and free of noise or other defects. It is essential that there is no chromatic aberration on the stars. Another very interesting observation is that at 1420mm focal length, the stars are very good to the edge on the FullFrame sensor, which is a pleasant surprise for me.


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#64 drprovi57

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Posted 18 March 2025 - 10:36 AM

I had the same results with the Askar 185 - the sensor I used was a APS-C size sensor and the stars showed very little chromatic aberration and were very well defined in the edges as well when using the 1x Askar field corrector.  As noted by the others, the "sweet spot" of the large Askar APO's is astro imaging - but also provides pleasant refractor-like views smile.gif


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#65 Psion

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Posted 19 March 2025 - 04:46 PM

I tried a test today with the Canon 1100D, which has an inconveniently small pixel size of 5.2 um. For this telescope, the ideal pixel size is 8-9 um. It showed up in a small chromatic aberration around two stars. You always need to choose the right camera.
This is a 4x 4 minute image, ISO 1600.

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  • IC434_1100D_small-1.jpg

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#66 kgb

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Posted 19 March 2025 - 08:02 PM

I tried a test today with the Canon 1100D, which has an inconveniently small pixel size of 5.2 um. For this telescope, the ideal pixel size is 8-9 um. It showed up in a small chromatic aberration around two stars. You always need to choose the right camera.
This is a 4x 4 minute image, ISO 1600.

Does anyone who owns this telescope use it with a camera that has 8-9 um pixels?

#67 Psion

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Posted 20 March 2025 - 12:36 AM

I own a Sony A7sII camera (pixel 8.4 µm) and I took the M42 image a few posts above with it.


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#68 garret

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Posted 20 March 2025 - 01:35 PM

I took a test picture of the M42 without guiding, Bortle 4, 15 second exposure, Sony A7sII, ISO 2000. Processed in PixInsight.

 

Other astro-imagers spent many, many hours on M42 with almost the same result!


Edited by garret, 20 March 2025 - 01:36 PM.

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#69 Psion

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Posted 20 March 2025 - 04:16 PM

After a very long time I pulled out the Zerochromat 200 mm/F12, and found it to be visibly inferior to the Askar 203 mm. This is a 7x10 s exposure.

Attached Thumbnails

  • M42_Zerochromat-1.jpg

Edited by Psion, 20 March 2025 - 04:18 PM.

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#70 denis0007dl

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Posted 20 March 2025 - 05:19 PM

...just found your article about Zerochromat 200mm

https://www.cloudyni...mat-is-in-home/

Nice to know Askar is better.
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#71 Psion

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Posted 21 March 2025 - 01:00 AM

Zerochromat has an advantage in its weight of 14 kg. The image is certainly not bad, but the Askar 203 mm is better.


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#72 Psion

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Posted 22 March 2025 - 05:55 PM

My review of Askar 203 mm.

 

https://posec-astro-...&_x_tr_pto=wapp


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#73 drprovi57

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Posted 22 March 2025 - 06:56 PM

Excellent review - thank you for sharing.   Enjoy your Askar 203!


Edited by drprovi57, 23 March 2025 - 11:23 AM.

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#74 SandyHouTex

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Posted 22 March 2025 - 08:32 PM

My review of Askar 203 mm.

 

https://posec-astro-...&_x_tr_pto=wapp

Yes, and excellent review and a very nice telescope.  Congratulations.


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