Askar 151 PHQ Review - Part 2: Optical Test

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Published 2023-11-01
This is the second video of a two-part series in which I review Askar's latest astrograph, the awesome Askar 151 PHQ, a monster 6" refractor with a 1,050mm focal length. In the previous video, I did an unboxing and shared my first impressions. In this video, I go over the results of a series of quantitative and qualitative optical tests I ran on this telescope and its reducer.

Support the channel by using the affiliate links below if you want to purchase anything from Agena Astro, my favorite astro retailer :)

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Affiliate Links
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Agena Astro: bit.ly/487tmnj
Askar 151 PQH: bit.ly/3RQFFyJ
Askar .7x reducer for PHQ series: bit.ly/3Q9uvnC
Askar M54 T-Ring for Canon DSLR EOS Cameras: bit.ly/40gsXvp
Askar M54 T-Ring for Nikon F-Mount DSLR Cameras: bit.ly/40cbIvj
Askar M54 Backfocus Adjuster: bit.ly/40c0qal
Askar M54 Female to M48 Male Backfocus Adjuster: bit.ly/3QA5sKx

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My equipment
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* iOptron CEM70 Center Balanced Equatorial Mount: bit.ly/3PzUMuP
* iOptron Tri-Pier: bit.ly/3RhDzYz
* Antlia V-Series LRGB Pro Imaging Filter Set: bit.ly/3LHcRVJ
* Antlia SHO Narrowband 3nm Pro Imaging Filter Set: bit.ly/3Rj3yii
* ZWO 8-Position Electronic Filter Wheel: bit.ly/488uvuW
* ZWO ASI533MM Pro Cooled Monochrome Astronomy Camera: bit.ly/4887g4b
* ZWO ASI174MM Mini Guide Camera: bit.ly/469sJYv

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Follow me!
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* Instagram: www.instagram.com/darkskygeek/
* Facebook: www.facebook.com/julien.lecomte

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Music credits
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* Scott Holmes Music: Feeling Home
* The 126ers: See You On The Other Side

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Image credits
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* Third quarter moon by Thierry Legault - www.astrophoto.fr/

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Links mentioned in the video
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* Cloudy Nights thread about the Askar 151 PHQ: www.cloudynights.com/topic/879859-the-brand-new-as…
* GitHub repository containing the Python notebook used to estimate the amount of longitudinal chromatic aberration in a refracting telescope: github.com/jlecomte/chromatic-aberration-estimator
* Roland Christen's notes on star testing refractors: www.csun.edu/~rprovin/roland/startest1.html

CHAPTERS
00:00 Introduction
01:15 Disclaimer
01:47 Quick Collimation Check
02:31 Visual Test
06:12 Longitudinal Chromatic Aberration
10:47 Wavefront Analysis
13:27 Imaging Performance
17:57 Conclusion

All Comments (21)
  • @darkskygeek
    Support the channel by using the affiliate links below if you want to purchase anything from Agena Astro, my favorite astro retailer :) ----------------------------- Affiliate Links ----------------------------- Agena Astro: bit.ly/487tmnj Askar 151 PQH: bit.ly/3RQFFyJ Askar .7x reducer for PHQ series: bit.ly/3Q9uvnC Askar M54 T-Ring for Canon DSLR EOS Cameras: bit.ly/40gsXvp Askar M54 T-Ring for Nikon F-Mount DSLR Cameras: bit.ly/40cbIvj Askar M54 Backfocus Adjuster: bit.ly/40c0qal Askar M54 Female to M48 Male Backfocus Adjuster: bit.ly/3QA5sKx ----------------------------- My equipment ----------------------------- * iOptron CEM70 Center Balanced Equatorial Mount: bit.ly/3PzUMuP * iOptron Tri-Pier: bit.ly/3RhDzYz * Antlia V-Series LRGB Pro Imaging Filter Set: bit.ly/3LHcRVJ * Antlia SHO Narrowband 3nm Pro Imaging Filter Set: bit.ly/3Rj3yii * ZWO 8-Position Electronic Filter Wheel: bit.ly/488uvuW * ZWO ASI533MM Pro Cooled Monochrome Astronomy Camera: bit.ly/4887g4b * ZWO ASI174MM Mini Guide Camera: bit.ly/469sJYv
  • @neilhankey2514
    You know, I forgot how much I enjoy watching proper astronomy channels. Thanks for the video's.
  • @jimbub1001
    One of the best and most thorough telescope reviews that I have ever seen! Well done - the qualitative AND quantitative analyses are outstanding. As a fellow 151PHQ owner, this review is representative of my experiences with the scope as well. Nicely done and THANK YOU!
  • @tostativerdk
    Love your extremely high bar for testing equipment, keep it coming :)
  • @surgeon1000000
    Congrats on the thorough optical test and wavefront estmation. Probably the only channel doing that. Keep it up!
  • Thanks for your very detailed analysis. It was interesting to find out about these refractors.
  • @wallbke
    Really excellent and interesting. Adding pieces to the puzzle for my next scope. Thank you!
  • @KingLoopie1
    Alright, Alright.... You got me about halfway through. New sub! I love optical analysis and you're making it understandable for an uneducated id such as myself! πŸ‘πŸ‘
  • @southbronxny5727
    The review was so excellent, I think you sold it all out on the site. I wonder how it compares to their new 185apo which I hope they send you to test also. 2 Thumbs up for the video. Thanks.
  • @hael8680
    Great review!! You are more critical of corners than I am...
  • @Astro_Px
    I am just in awe at this wonderful presentation. Wow, I cannot say enough! Just perfect speech/pace - invaluable thorough review with great information. Learned so much about aberration. I was wondering if you would consider a follow up or maybe in the future about a quantitative/qualitative comparison of actual images taken with the scope, such as tilt, flatness. Again, I would like to really congratulate you on such a great video. Sometimes it is hard to follow because people (without experience) tend to speak way too fast and it makes it hard on the listener to latch on to all the details - you pace is perfect - Just really impressed - THANK YOU SO MUCH for putting this together.
  • @physmc1
    Comparing to the RC was an excellent idea. I'm convinced the spectrograph test is a very good assessment of the CA performance.
  • @MountainFisher
    Interesting to see how the testing is performed. I used Agena all the time, I'll use your link next time I buy something.
  • @Rob_1472
    Sometimes I don’t comment on videos but this was actually a very balanced review given people good insight to reflect on. Hope all manufacturers send more to you. Sharpstar Z4 next. 100mm refractor at a fair value for its aperture and 6 lenses. Sharpstar if you’re watching, send him the OTA for review.