5' Refractor Shootout

Products reviewed:

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❤️ Patreon ❤️
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Contents
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0:00 Why am I testing these three telescopes?
4:25 ES AR127 - Physical Characteristics
7:34 Svbony 122 - Physical Characteristics
11:28 Sky-watcher Esprit 120 - Physical Characteristics
17:21 Rainbow Black (sponsored segment)
18:43 Imaging Tests
31:41 Credits (Patreon)

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Video Disclosures
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The Explore Scientific AR127 was bought at retail with proceeds from Patreon.
The Svbony SV550 122mm F7 was lent to me by Svbony for review.
The Sky-Watcher Esprit 120 ED was lent to me by Sky-Watcher USA for review.
The ZWO ASI6200MM and MC are were lent to me by ZWO for use on this channel.
This video is sponsored by Rainbow Black, a novel by Maggie Thrash.

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Channel Disclosures
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[thos]

Good review Nico, however, I do wish you were able to include the Askar 120 apo also

[supermario]

So the ES AR127 was used at F6.5, the Svbony 122mm at F5.6 and the Skywatcher Esprit 120mm at F7 ? Doesn’t the F-ratio play an important role in the intensity of the chromatic aberrations? Wasn’t the Svbony disadvantaged because of the lower F5.6 ratio and the Skywatcher Esprit advantaged because of the higher F7 ratio?

[dfxvoodoocards]

Chromatic aberrations shouldn’t be a problem at all with the Svbony ED triplet since nobody would use no way near that extrem level of saturation.

[RaisinEnjoyer]

The svbony isn’t bad at all, for the price that’s pretty good performance

[ampamp]

A very nice comparison Nico, thanks! When I was shopping around, I found the Orion EON 130ED APO (fk61 glass) to be the best value trade-off in this class. In the last 3 years I've really enjoyed using this fantastic visual and AP scope. Performance and build quality were far better than I expected, and you do get the full 5" (plus a bit), so I think Orion deserve a shout. That ES is amazing though in mono. It really makes you think! The reduced contrast is of course due to the spreading of that out of focus light (being just a doublet) rather than anything to do with coatings. You can't get that data back, but the cosmetics can be managed in processing.

[TerminusCodex]

As always excellent and informed, well spoken, and explains astronomy in a way that is easy to understand without being a professional astrophotographer, thank you!

[NametagNametag-ve]

The Svbony clearly was disadvantaged being used with reducer at F5.6 and the Esprit at F7. Why didn't you use both at F7 since the Svbony is an F7 refractor just like the Esprit ?

[gary]

Interesting results. With the vignetting, the skywatcher has the advantage because it's shooting at it's full focal length . With the reduder it would be very similar i guess. I would like to see the difference between a fpl-53/Lanthanum doublet compared to the triplets?

[gabewrsewell]

very well put together comparison, thank you. also i’ve got a question for you, i’ll be shooting the eclipse and i also have the sigma 40mm f/1.4 that i’ll be using to try to get the comet in the same frame just like you! im wondering how you’ll be framing it, will you try to get venus in the very corner and jupiter in the other, with the comet and sun in between? or will you forego venus and get the sun, comet, jupiter, and the pleiades in the frame? im not sure which i’ll go for, im curious what your plan is

[uschi]

It'd be interesting to see how well the achromat could hold up with RGB mono imaging. The broader bandpass of RGB filters would make the difference in focal planes for the shortest and longest wavelengths of each filter on the achromat stand out more, but how much. The difference in wavelengths between the long end and short end of each color filter is a lot less than you got shooting with the color camera, just how acceptable it is has me wondering.

Anyway, thanks for another excellent review video, Nico.

[BurningFlame]

Excellent comparison. A comparison on the planets and the Moon would also be very interesting.

[MattVentureNL]

Really enjoyed the video, love how you took this opportunity to help with some of the astro myth busting (or validation!) wrt apo and mono.

[cjmenagh]

Great video, great subject. Does the Sky Watcher have slightly pinched optics? Seen best on pixel peeping hyper saturation.

[RaffaelMarx]

Hi Nico. I actually own a SV550 122 and I have ~20hrs of data with it and my results are just like yours. It indeed has a bit of color fringing but the correction is good enough to justify its price.
Thanks for the review

[alcosound]

Thank you. I was always saying that the Svbony 122 triplet is "a poor man's Esprit 120".
And this test proves the theory that when shooting with narrow band filters and a monochrome sensor, an ED doublet is 'good enough' (and you can spend your savings on the optical tube on NB filters and mono sensor)

[anakinskywalker]

6:00 Yes that's what it's for:) I'm using an HEQ5 Mount and all my dovetails are scratched pretty bad and have dents from the screws except for my Explore Scientific scope. Great Vid as always

[strykker]

Another great video, Nico. Thank you. Are you going to the Cherry Springs Star Party in June?

[StereoSpace]

Most interesting was the narrow band filter result with the inexpensive scope. Useful for people on a tighter budget to know you can still get great results.

[snakegodtod]

i love your content. it got me in to astrophotography

[seventhsun]

As always, great review Nico! Thank you!