SvBony SV555 Tested and Reviewed

Svbony appeared rather suddenly in the astronomy scene a few years ago with well-built scopes at an affordable price, putting to sleep the old adage that a decent refractor must cost a lot of money. One of their more recent scopes has seen them move towards dedicated imaging with their first astrograph/camera lens… the SV555. 

What makes this a dedicated astrograph one may ask? Basically, it’s meant to be used with a camera only, be it DSLR or an astronomy camera… there is no place for an eyepiece. It also crosses into the realm of a regular camera lens in the sense that you can adjust the F-stop via an internal diaphragm, adjusting from F4.5 (no light is blocked) down to F22 (roughly 87% of incoming light is blocked) for daytime terrestrial photography. 

This is a very sharp-looking, well-built little telescope. From the dovetail and rings to the feel of the telescope itself, it doesn’t appear to skimp on quality. All the adjustable parts (built-in rotator, focuser and diaphragm F stop) can be locked down with a thumb screw. The focuser doesn’t have a lot of travel but if the imaging sensor is close to 55mm from the back of the scope you can reach focus (for those with a dslr this is the distance that the camera and a t-ring adapter add up to). And because it’s a Petzval design there’s no need to worry about flatteners or that critical back focus distance… if you’re in focus you’re at the proper distance. It also comes with a belt and bracket to attach an autofocuser like ZWO’s EAF. 

While the build quality of a telescope is an important aspect, what really counts is how good the optics are… and this is where I ran into a mixed bag.

The scope I tested had a slight issue with the optics and, if I had to take a guess, I’d say that one of the lenses wasn’t perfectly square. This introduced a small flaring across the entire field of view. However, it should be noted the scope I tested was the display model at NEAF and had a lot of handling and possible jarring. I have seen many other examples where the optics are better. 

Here’s an aberration inspection image to show what I was seeing:

With today’s processing software aberrations like this can be easily fixed though, and this allowed me to continue with my testing. 

As an example, here’s the same image with the use of nonaggressive deconvolution in post processing (BlurXterminator in PixInsight):

By nature I’m a long focal length imager, so testing a widefield scope like this was quite a different experience. The field of view with an aps-c sensor (like the asi2600mc) is a whopping 5.5° x 3.7°. This allowed me to catch targets like The Veil nebula, or North American (and pelican) in a single frame, which was pretty exciting for me! 

Using a Bahtinov mask I was able to find focus easily, but because even the tiniest movement of the focuser can set you out there where times when I went to lock it down (tighten the thumbscrew) I lost focus. However, once it was set it held focus very well, even from night-to-night, without needing to adjust it! 

A few examples taken with the SV555 from my bortle 7 backyard:

IC 1396/Elephants trunk nebula

Taken with an ASI2600mc and l-enhance filter. Processed in RGB pallet

Heart and Soul Nebula (IC 1805 and IC 1848)

Taken with an ASI2600mc and l-extreme filter. Processed in HOO

North America and Pelican nebula (NGC 7000 and IC 5070)

Taken with ASI294mm and zwo 7nm narrowband filters. Processed in SHO

My rating (1 to 10):

Build quality and look: 10 out of 10 

Easy of use: 10 out of 10

Optics: 6 out of 10 

Value: 7 out of 10 (with the unit I had… if the optics were better it’d easily be a 9)

Overall: 6 out of 10

While the scope looked and felt great I was expecting a little more from the optics… not a lot due to its price point, but a bit more. If I had bought this scope and wasn’t able to exchange it, I’d be a little disappointed but because the issues are so easily resolved in post processing I certainly wouldn’t think it’s the end of the world.