ZWO and SVBONY 30mmF4 Guide Scope Review 

Thank you for the feedback and kind words.

Glad I could help!

I am actually in manufacturing myself and do a lot of this stuff. I did take each completely apart once just to see how they are made. I would say they are most likely not made in the same factory as the machining style is way different. However you do bring out a good point that most of this Chinese imports are made in the same factories.

I should have mentioned this in my video. Next time ;)

@@TheNarrowbandChannel Not a crit at all, they are very similar quality though. Great for what they are made for.

I would try one but am so bad with drivers I am afraid to.

Can you post a link ?

@@freddylq67 www.svbony.com/categories/astronomy-camera/

Glad to hear!

I will work. A mono version would work better but i know they do not make a mono 224

farpointastro.com/products/farpoint-parfocal-ring-1-25-inch-eyepieces?variant=40161548042393&currency=USD&

@@TheNarrowbandChannel This $10 ring just saved from picking up a $130 helical focus scope. Thank you!

Go with the 30mm. You will need the higher weight. Also I would not use your 2x teleconverter. Astro objects are huge. 300mm Fl is plenty. Also, sorry I said that twice, we do not use equivalency in astronomy. :)

@@TheNarrowbandChannel Thanks for the reply, did you mean 'lower' weight with the 30mm scope? Could you explain about not using 'equivalency' in Fl, as you know my Olympus is a 4/3 system and half the focal length of a FF system which I assume are equal to normal telescope focal lengths so in comparison my 300mm would equal a 600mm!

@@Redsnaper yes I meant lower weight. In astrophotography we do not count crop factor. Only in angle of view. So we imputes sensor dimensions then focal length to determine angle of view. Using equivalency would be far too complicated and confusing.

@@TheNarrowbandChannel I now understand, thank you for the explanation.

A very good question. I am sorry I do not have the answer to that one. Ill ask around.

I have an answer. They already have a product called an SV120 but its a rifles scope so they had to use a different name. What the 165 is for though remains a mystery.

I actually like to use a Red filter. It cuts down on any haze in the atmosphere and removes some atmospheric disturbance that messes with guiding. The most important thing though is that your stars are well above the noise floor.

I had to really research this one because its a tuff question. The svbony sensor is newer however its not mono so the 120mm gets the approval from me for guiding. Always us a mono guid camera.

It should be able to handle that weight. I would though recommend that you get a wedge so you can polar align it. Then field rotation will not be an issue and the longer FL will do even better.

Depends. If I thread on the camera then I rotate the barrel that holds the glass. If I am using a mini camera that is held like an eyepiece then I just slide it in and out till it hits aprox focus. By the way BIG tip. You do not want it to have exact focus. The software can better calculate the central point if it is a little out of focus.

One thing i've done is temporarily switch the main camera with the guide camera in the ASI air app. That way I can use the focus function of the ASI to get the guide camera focused.

@@xox1011 I do that too. Good little trick.

Orienting the camera on its x and y axis just speeds up calibration. This applies more strongly to those of us running off of older computers or rasberi pies. As for Bruce comments on focusing. He is wrong. There are plenty of well-reputed authors out there. Charles Bracken and Chris Woodhouse to name a few that state quite plainly in their books that slight out of focus improves the centroid detection. If I were to get technical about why it is bene facial to be slitty out of focus some statistics is in order. 68-95-99.7% rule is the standard for a normal distribution and this presents the algorithm with the best centroid detection. Using this method centroid detection can resolve the central point of a star 10x smaller than the pixels of the camera.

@@TheNarrowbandChannel First of all, thank you for posting the review of the cameras. I found it very informative and interesting. For speeding up calibration, I would think that you have to be running on a very, very old computer or rasberi pie to see a significant difference in the calculation of sines and cosines need to resolve the difference in x-y axes and RA/DEX axes. These computers would also struggle with running things like planetarium software, USB data transfer, image capture and storage, etc. As for the focus issue, Bruce's specific comment is "there is some old advice that is no longer relevant". The references I think you cite (Deep Sky Imaging Primer, Charles Bracken, 2013 and The Astrophotography Manual, Chris Woodhouse, 2017) are at least 4 years old. But I am impressed that you invested in these expensive reference materials and have developed a deep knowledge of astrophotography. To me, astrophotography is as much of an art as it is a science, so we each can decide on the approach we'd like to take!

Been thinking about this myself. No real way that I know of yet besides getting rings that have setting screws.

@@TheNarrowbandChannel I tried to find ring for this scope, but no luck. Smallest are for 50 mm tube, nothing for 30 mm out there :(

@@zippis333 Found these. They would work. www.ebay.com/itm/234303367700?hash=item368d91aa14:g:ei4AAOSwlblhnp3f

@@TheNarrowbandChannel Wow, thank you very much for the info! Will try them.

I fiddled around with mine on a RedCat51 and could get them close to the same spot. With the 2 screws, there is a little bit of lateral wiggle room. You could try a thin shim, and/or tinker with the attachment foot.

They do not need to be exactly aligned.

@@TheNarrowbandChannel I looked into that and if you are not polar aligned or at least not close it affects the time duration of exposures. so im not doing 9 hour photos so probably OK

Never mind, I saw your reply in an older post Thanks!

@@KennyHurstPhoto No Problem. I am going to do another video about this little guid scope and how to improve it. So stay tuned.

You will not have to calibrate and you can also choose where the USB cord comes down to keep it a lower profile.

It's good. It is light so it makes for a good match with the lightweight rig.

@@TheNarrowbandChannel yes, that is what I am looking for. I am using a Canon 90D and one of my lenses is the Sigma 100-400mm which weighs 3 lbs by itself!

@@TheNarrowbandChannel I have been doing photography for years, but I am new to Astro. Just got the Sky Adv a few months ago, it works well for anything under 100mm for less than 30 secs. But anything over that, I find it very difficult to get no star trails. So I figure auto guiding is necessary for very long exposures and higher focal lengths!

@@-WhizzBang- Should make a great combo.

You're welcome!

Its a 1.25" lens focus par focal tool. These are pretty common on eyepiece for telescopes but are always sold as a separate accessory.

This is a really good question and I do not know for sure. I know the camera does not have a guid port but no one uses those anyway. Have you reached out to SVBONY? Or maybe asked on the FB groups for SVBONY? I would actually be curious to know myself too. It seams like it would work with something like Nina or Indigo A1

It is because I am lousy at color grading. I was using Premier back then. Switched to Davinci so I do a little better job now.

@@TheNarrowbandChannel Just my 2 cents... you're over-producing it. No need to color grade for RU-vid channels, as most video is excellent right out of the camera.

@@billjobes1851 Yes these days I have settle more or less on some presses. Video is not something I am good at but then again I do not devote very much time to this either.

Mainly people using star trackers would consider it an issue. Sorta wish someone made a guid scope that was a 20mm f4.

@@TheNarrowbandChannel For sure. I'm not being completely serious. :)

@@Mrcloc I figured.

Good idea. Ill have to do an imaging video with one then.

Thank you. I change it. :)

ess vee bony?

I think so. Will pronounce it that way in the future.

Interesting observation on the optics of both. I had not thought to test to see which had better optics. With both of them bing double achros and at a very fast f4 I can see they would have a lot of optical issues.

Star shape? Are you referring to the optics only, or focussed/unfocussed target for guiding?

@@andysPARK As mentioned above, the optics reminds me if looking through the bottom of an old glass coke bottle. Focusers are as crude as can be.

Watch this Jeff. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-SmSJXC6_qQ8.html

It is a 33% difference.

What is the unit of measure on English speed limit signs? What units do typical English people give for their weight and height? (Answers: miles/hour, stone & pounds, feet & inches.)

@@ronstewtsaw mph, cm and kg.

@@OzzMazz yes I know. I worked with standards, I even ran an international primary standard. But it beggars the question why USA doesn't use metric like everyone else. Working with american scientists and technicians gave us headaches when they persisted in using obsolete units and the attendant conversion errors. Astronomy is an international science hobby.

I would assume so.

@@TheNarrowbandChannel i want to buy the SVBONY but I'm not sure if it will work, I like the nextguide because it doesn't need a computer