SVBONY SV555 Review
The SVBONY SV555 is a variable aperture prime focus lens/telescope designed for wide-field astrophotography. Many of you have been requesting a review of an SVBONY telescope for years, and today, I’m excited to share my thoughts on this one.
The SV555 Petzval lens is an interesting option in the competitive market of wide-field refractor telescopes, especially around the 250mm focal length mark.
My contact at SVBONY sent this telescope to me in December, and after some time using it, I’m ready to provide a detailed review. For clarity, I was not compensated in any way for this review, and SVBONY had no influence on my opinions.
This SVBONY SV555 review will discuss my experience and what you can expect if you’re considering this telescope.
About SVBONY
SVBONY is often considered a ‘budget’ or ‘Amazon’ brand within the astrophotography community (at least for now). They make everything from eyepieces to planetary astronomy cameras.
They offer more affordable telescopes and accessories compared to higher-end brands, and over the years, I’ve heard many positive things about their products. The SV555 is the first SVBONY product I have ever used.
Over the years, SVBONY has offered an increasing number of astrophotography telescopes, ranging from inexpensive doublet refractors like the SV503 to higher-end options like the SV555 I tested.
SVBONY sells astronomy equipment exclusively on Amazon.
The SV555 is one of their more exciting offerings, but it’s important to note that there is a lot of overlap in the wide-field apochromatic refractor telescope category.
Deciding which model is right for you depends on your budget and specific needs. A close competitor to the SV555 is the Rokinon 135mm F/2 lens, which has a proven track record in the astrophotography community.
The Rokinon 135mm F/2 is a worthy alternative to the SV555, although it’s significantly wider (135mm).
SVBONY SV555 Features
Optically, the SVBONY SV555 features a Petzval objective lens structure with a triplet lens and ED glass. It has a 44mm image circle to accommodate full-frame image sensors, although I would expect some vignetting.
The SV555 stands out from traditional astrophotography telescopes because it’s actually closer to a lens. It features an adjustable aperture, similar to the Askar SQA55, meaning you can adjust the f-stop from wide open at f/4.5 to as narrow as f/22.
For astrophotography, you’ll likely want to keep it at f/4.5 almost all the time for maximum light gathering. I took all of my test images at f/4.5, as this is the most optimal setting for astrophotography and where most users will likely use it.
The SVBONY SV555 is available on Amazon.
The SV555 also has a manual focus ring similar to a telephoto lens. Some users may not prefer this, but after using a similar system on the Redcat 51 (version 1), I’ve grown accustomed to it.
For those interested, the SV555 is also compatible with an autofocuser, although I didn’t install one for this review. I am certain that many people will want to install a ZWO EAF on the SV555 right away.
Specifications
The SVBONY SV555 is designed for deep-sky astrophotography, featuring a Petzval design with a triplet lens and two ED glasses for sharp, clear images.
It offers a wide field of view (243mm), with a variable aperture from f/4.5 to f/22 to suit different shooting needs.
The fine adjustment and optional EAF mounting capability make it easy to dial in your focus. I did not test the performance of the SV55 using an autofocuser; I just made manual adjustments with a Bahtinov mask.
- Objective Type: Petzval Design (5 Elements in 3 Groups)
- Aperture: 54mm
- Optical Coating: Fully Multi-Coated
- Focal Length: 243mm
- Focal Ratio: f/4.5-f/22
- Focuser Type: Helical
- Image Circle: 44mm (Full Frame)
- Rotator: Lockable 360º
- Mount Type: Dovetail Plate
- Dovetail Plate Length: 184mm
- Front Filter Thread: M72
- Back-end Connection: M48 x 0.75 male thread
- Weight: 5.4 lbs (2.45 kg)
What’s in the Box?
The SV555 arrived in a branded SVBONY box and included a soft carry case for easy transport. In addition to the telescope, it came with a dovetail mount, matching rings, and a riser for the optical tube.
This mounting kit is a nice touch—something you won’t find with a Rokinon 135 lens, for example. SVBONY also included a handy guide scope mount, which is always appreciated.
Additionally, they provided an EAF mount kit, clearly anticipating that I might install an autofocuser right away. However, I’m more of a Bahtinov mask person myself.
- SV555 OTA
- EAF mounting kit
- Handle with vixen saddle
- Mounting rings
- Dovetail plate
- Camera angle adjuster
- Carry case
- Allen keys
The SV555 includes a dovetail mount, tube ring, and a matching red guide scope mount.
Astrophotography with the SV555
Since receiving the SV555 in mid-December, I’ve had two clear nights to test it. I captured two different targets and gathered enough data for smooth, detailed results.
Unfortunately, the moon was nearly full both nights. Test images taken without a filter were not possible, so I will have to update the article once those samples have been collected.
To combat the bright moonlight and city light pollution, I used an Optolong L-eXtreme dual-narrowband filter with my one-shot-color dedicated astronomy camera.
I mounted the SV555 to the highly portable ZWO AM3 mount and used the ASI2600MC AIR dedicated astronomy camera with built-in guiding and camera control (ASIAIR).
- Mount: ZWO AM3
- Camera: ZWO ASI2600MC AIR
- Filter: Optolong L-eXtreme
The following image of the California Nebula is a great example of the wide field of view you can enjoy with the SV555 when paired with an APS-C sensor camera like the ZWO ASI2600MC Pro.
California Nebula with the SVBONY SV555
My Experience: Star Shape
While the images turned out great overall, I did notice something odd with this particular unit. Some might think that review units are “cherry-picked” for influencers or people who review products, but in my experience, that’s rarely the case.
I noticed some imperfections in my star shapes, so I reached out to Cuiv The Lazy Geek, another well-known astrophotographer (who has used this telescope), to get his opinion on my images.
We tried experimenting with the aperture ring to see if something was misaligned. Unlike the Rokinon 135 lens, the aperture on the SV555 doesn’t click into place—it’s a smooth transition between stops. I tried adjusting the f-stop slightly off from the f/4.5 marker, but it didn’t make any noticeable difference in the star shapes.
Despite my troubleshooting efforts, I couldn’t pinpoint the issue. The aperture seemed to be wide open, and there were no obvious obstructions in the field of view.
Discussion with Cuiv the Lazy Geek
For the full discussion, be sure to watch that segment of the video. Essentially, Cuiv thought that there may be a small obstruction inside of the optical path causing the odd star shapes.
Here is a closer look at the brightest star in the California Nebula image. I experienced a similar star shape in my second image of the Jellyfish Nebula as well.
The odd star shapes I experienced in my images taken with the SVBONY SV555.
While I think this may be bordering on ‘pixel-peeping’ territory, I feel that it is important that customers (and SVBONY) know about this.
At this point, I am not ruling out user error – and I will continue testing the SVBONY SV555 and update this article with my results (and SVBONY’s response).
The Jellyfish Nebula with the SVBONY SV555 and ASI2600MC Pro.
Small Refractor Comparisons
Wide-field refractors are a favorite among many astrophotographers. If you read or watch my content, you will already know that I love using small apochromatic refractors.
They are super versatile with their short focal lengths and fast f-stops and are perfect for capturing wide views of nebulae and star clusters.
In addition to the SVBONY SV555, there are many other brands offering similar specs in the 250-300mm focal length. A crowded space means more choices for finding the perfect scope for your wide-field astrophotography setup.
SVBONY SV555 | Askar SQA55 | Redcat 51 V3
Let’s see how the SVBONY SV555 measures up against the competition.
| Features | SVBONY SV555 | Askar SQA55 | William Optics Redcat 51 (V3) |
|---|---|---|---|
| Focal Length | 243mm | 264mm | 250mm |
| Aperture | 54mm | 55mm | 51mm |
| Focal Ratio | f/4.5 (variable up to f/22) | f/4.8 (variable up to f/22) | f/4.9 (fixed) |
| Lens Elements | Triplet Petzval APO | Quintuplet Petzval APO | 4-element Petzval |
| Focuser | Helical | Helical | Internal Focus Design |
| Autofocuser Compatibility | Yes | Yes | Yes |
| Field Flattener | No | Built-in | Built-in |
| Mounting | Dovetail bar and rings included | Dovetail bar included | Dovetail bar, tube rings included |
| Carrying Case | Included | Included | Included |
| Total Weight | 2.51 kg (5.5 lbs) | 2.18 kg (4.8 lbs) | 2.38 kg (5.2 lbs) |
| Price (USD) | $659.00 | $795.00 | $898.00 |
Final Thoughts
The price, design, and overall package of the SVBONY SV555 is impressive. The overall design of the telescope is well thought-out, and the mounting hardware is excellent.
Clearly, others that have used the scope have achieved perfect stars, that hold their own against some of the more premium optics out there. Cuiv’s copy even performed better optically than his William Optics RedCat 51.
In my case, there seems to be an issue with this particular unit, possibly related to factory calibration or quality control. The odd star shapes are present in all of my test photos, which is not a great first impression of SVBONY’s optics.
Overall, the SV555 is a promising step in the right direction for SVBONY, but they will need to do a better job of quality control. I will update this article with the latest developments, including tests of a replacement unit.
If you are considering the SV555, maybe wait until the dust settles, and they can promise a good copy to those who order one on Amazon.
Trevor Jones is an astrophotographer and a valued member of the RASC. His passion is inspiring others to start their astrophotography journey on YouTube so they can appreciate the night sky as much as he does. His images have been featured in astronomy books & online publications, including the NASA Astronomy Picture of the Day (APOD).
Hello Trevor. What you have there related to the “lens” it’s what we called the “light house effect” or the “hourglass effect” in the stars. It’s the parallel latch in one of the screw rings that keeps one of the glass elements in place. Most probably in the back end of the lens or in the first elements. That only happens when the lens or telescope is fully open. Some scopes have that problem as well like the Takahashi FSQ-85EDX, the SkyWatcher on some early versions os the Esprit 100 and even the Samyang 135mm F/2 when fully open. I have that in mine.
The only solution so far that I’ve found is to use photography stepper rings to downsize a bit the aperture (insted of using the diafragm who also creates diffraction spikes). You can use something like these and they are cheap (the link from amazon), and use an aperture online calculator to measure exactly the correct aperture givin by the downstep ring by just measure it the diameter, put the focal lenght and it will give you the f/ stop. This is if that SV555 have threads in the front in order to use it (like the Samyang 135mm F/2).
https://www.amazon.es/dp/B00WQ0C7SU/?coliid=I1O8WZCIQ7HMYV&colid=FFGC41KBZX3C&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it
Here’s a calculator to help with the math: https://www.omnicalculator.com/physics/aperture-area
And here’s a link from a problem in a SkyWatcher Esprrit 100 to help understand the problem of that effect and one way to correct it: https://interferometrie.blogspot.com/2014/08/esprit-tuning-how-we-finetune-esprit80.html?m=1 – Dispite in this situation you have multiple difraction spikes, the origin of the effect is the same.
On a side note: I know you’re a bathinov mask guy, I was also too.. but when you try an automatic focuser and have fully automated, it’s a not way back, since things can even be ajusted for temperature changes in the optical elements in climates like mine and yours. Just give it though on that.
Best wishes,
Cesar
Cesar, thank you very much for this information! This is very helpful 🙂