Antoine & Dalia Grelin
Nov 11, 20226 min
Updated: Nov 1, 2023
The Apertura 75Q is a small and light refractor telescope with an aperture of 75mm, a focal length of 405mm, and a focal ratio of f/5.4.
It is full-frame-ready and was designed as a Petzval telescope, meaning it has a built-in reducer/flattener and will not give you any issues with back focus!
In this post, we’ll put this small refractor telescope to the test from our Bortle 9 city backyard. We’ll use our full-frame monochrome camera and see how the telescope performs when imaging different deep-sky objects. Be sure to watch our review video on YouTube!
Watch our full video on YouTube
Before we start, let's be fully clear about something: the Apertura 75Q telescope from High Point Scientific is, in terms of optics and specs, exactly the same as the Radian 75 telescope, previously sold by OPT (now out of business).
High Point Scientific decided to revive this telescope under the Apertura brand, and are very transparent about it. We reviewed the Radian 75 telescope in the past and loved it, so we're happy to know that High Point decided to keep it alive under its own branding!
We also like the fact that HPS makes it clear that this telescope is built by Sharpstar, and even inscribed this directly on the telescope dew shield!
Tables of Contents
Introduction
What's in the Box?
Imaging the North America, Pelican, and Cygnus Loop Nebulae
Apertura 75 Specs & Price
Imaging the Cygnus Loop with the Apertura 75
Final Thoughts
The Apertura 75 telescope comes in a matte black box, which includes everything you need to start imaging. Below is an overview of what came in the box:
The box includes:
The Apertura 75 Telescope
Tube Rings with Handle
Vixen-Style Dovetail Plate (11.25” V series)
Losmandy-Style Dovetail Plate (11.75” D series)
Dust Covers
1.25" Eyepiece adapter
The image below was taken from the Apertura 75Q's online manual, and shows what adapter to use for both visual and photographic use of the telescope. You can use this if you need help and aren't sure how to connect your eyepiece or camera!
Before we go into the specifications of the telescope, let's go over a few targets we imaged with this telescope (these were taken with the Radian 75 but the optics are exactly the same. We also shot new pictures with the Apertura 75 which you will see later in this post).
Below you will find images of the North America and Pelican Nebulae, along with the Cygnus Loop.
We imaged this part of the sky from the city in the backyard, and spent a total of three nights on it.
The camera used was the QHY600M which is a full-frame monochrome camera, along with narrowband filters (S, H, O).
Pairing a full-frame camera with a small refractor like the Apertura 75 is perfect because it gives you an enormous field of view, which is why we were able to fit both NGC 7000 and IC 5070 in the frame!
Check out the full picture below! The telescope did a really good job because our stars were very clean, free of distortion, and the details within the gases of the nebulae were very well-defined. We combined the channels as S/H/O, also known as the Hubble Palette to get these vibrant orange and blue colors.
NGC 7000 and IC 5070 in narrowband
Want to process your images following our own workflow? Get our guide HERE!
GEAR USED:
Camera: QHY600M
Telescope: Apertura 75
Mount: GM1000HPS
Guiding: ZWO ASI 290MM Mini
Accessories: Pegasus Astro Ultimate Powerbox
Power: Jackery Lithium Battery
Processing: Pixinsight, with RC-Astro plugins
ACQUISITION DETAILS:
Total Exposure Time: 15 hours
Exposure Time per frame: 10 minutes
Filters: Chroma 3nm Ha/Sii/Oiii
Gain: 56
We spent 2 nights on the Veil Nebula, which, like the North America Nebula, also lies in the constellation Cygnus!
Now when I say "Veil Nebula", I meant... the entire Veil Nebula Complex, also known as The Cygnus Loop. Yes, with this wide refractor and full-frame camera, I was once again able to image a huge part of the sky without having to bother doing a mosaic.
Here you can see what each channel looked like (H and O). The nebula is very bright in both channels. I did not bother shooting with the SII filter because the Veil Nebula complex is one of the best targets to image in bi-color!
And here is the final image. This is 12 hours total from our Bortle 9 backyard using the QHY600M. This combo did once again a terrific job at photographing this large area of the sky, and it was a perfect fit for the job!
The Cygnus Loop in bi-color
GEAR USED:
Camera: QHY600M
Telescope: Apertura 75
Mount: GM1000HPS
Guiding: ZWO ASI 290MM Mini
Accessories: Pegasus Astro Ultimate Powerbox
Power: Jackery Lithium Battery
Processing: Pixinsight, with RC-Astro plugins
ACQUISITION DETAILS:
Total Exposure Time: 12 hours
Exposure Time per frame: 10 minutes
Filters: Chroma 3nm Ha/Oiii
Gain: 56
The Apertura 75 is a quintuplet refractor telescope that weighs 5.7 pounds (tube only) and is 386mm long in length. It has an aperture of 75mm and a focal length of 405mm. It has a fairly fast focal ratio of f/5.4. The two best features of this telescope in our opinion are its petzval design, meaning you do not need to worry about back-focal distance, and its portability. It also has an image circle of 44mm, allowing you to use full-frame cameras without issues.
Aperture: 75mm
Focal Length: 405mm
Focal Ratio: f/5.4
Design: Quintuplet Petzval
Dew Shield: Included
Image Circle: 44mm (full-frame)
Telescope Connection: M76, M54, M48
Back Focal Length: 74mm from M48 thread
Tube Length: 386mm
Weight: 5.7 lbs (2.6 kg) without dovetail
And below is a drawing showing the size of each component on the telescope. The camera can be attached either with the M48 or the M54 thread. The telescope has a built-in manual rotator and a dual-speed rack and pinion focuser.
The Apertura 75Q telescope uses an FCD100 extra-low dispersion element for the optics. Here you can see a graph that shows the aberration levels of the telescope, assuming you can understand it. I honestly never learned how to read these graphs and probably never will, but here it is in case you're interested!
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The Apertura 75 telescope is priced at $1,699, which is lower than the Radian 75 was originally. There are also sales going on regularly. At the time of writing this review, the Apertura 75 is on sale for $1,399.95.
I made a review video of the Apertura 75 telescope which you can watch on our YouTube channel. In the video, I image two nebulae from my Bortle 9 city backyard using a One-Shot-Color camera and a dual-band filter. The two chosen targets were the Elephant Trunk Nebula, and the Soul Nebula.
You can see the result of these images below, taken with 10 hours of exposure time. Like I explain in the video, the only problem I encountered, which definitely affected the quality of the pictures, is the fact that I did not use an electronic focuser on this telescope. Indeed, the temperature throughout the nights dropped a lot as we are in between the Fall and Winter seasons, and I did not want to wake up every two hours to manually refocus! This gave me a few bloated stars, but I decided to stack it all anyway and deal with it.
Overall though, the results look great and both targets fit perfectly right in the field of view of this telescope.
The Elephant Trunk (left) and Soul Nebula (right) with the Apertura 75
GEAR USED:
Camera: ZWO ASI2600MC-Duo
Telescope: Apertura 75
Mount: ZWO AM5
Accessories: ASIAir
Power: Jackery Lithium Battery
Processing: Pixinsight, with RC-Astro plugins
ACQUISITION DETAILS:
Total Exposure Time: About 10 hours each
Exposure Time per frame: 10 minutes
Filters: Askar 6nm Color Magic H+O Filter
Gain: 26
What do we think about the Apertura 75 after trying it?
Some key points about the Apertura 75 telescope to summarize this review are:
It is a good beginner refractor telescope
It is a Petzval design, meaning you do not need to worry about back-focus issues
The Apertura 75 has a focal length of 405mm, a focal ratio of f/5.4, and an aperture of 75mm
It comes with two dovetail plates, Vixen and Losmandy style
It can accept full-frame cameras and still yield a flat field
It is compact and portable enough to be a good telescope to take on the field
The base price is $1,699
We hope you found this Apertura 75Q telescope review useful. If you would like to purchase this telescope, you can do so at High Point Scientific!
Do you already have this telescope? If so, feel free to attach some of your images in the comments section! We'd love to see what you were able to get with it, and it will also help others decide if this telescope is a good fit for them. Also, do not hesitate to ask us questions in the comments if we forgot to cover something important!