About Benoit Guertin

Astronomy Blog: I started out with a 5.1in Newton on EQ3 mount, and developed a passion for photography when I figured how to connect a webcam to the scope. Ever since I've been hooked. My computers and engineering background make for a great match in understanding signal to noise ratio and image processing. Living near a big city, I have little choice but to leave it to the electronic eye and do my "observations" from a computer screen. Toy Review Blog: When I was young boy I took most of my toys and appliances apart to understand how they worked, and see how they were put together and imagined how I could improve them. Now as a father of three kids (one boy and two daughters) I have seen, purchased, received and played with my fair share of toys. I also have a bachelor's degree in Mechanical Engineering, and currently employed as System Architect in the Aviation Industry.

William Optics GT71 f/5.9 Triplet Refractor

My last telescope purchase goes back to about 11 years when I upgraded from a beginner 130mm Newtonian to the 80ED bargain APO refractors launched by Syntha (Orion/Skywatcher) that everyone was raving about. I got one of the light metallic blue Skywatcher (SW80ED) and have been happy with its good optics and versatility for both visual and photographic use. Well actually, I upgraded the focuser as the stock unit didn’t do well with the weight of DSLR, often sliding out of focus or shifting when the tension was adjusted.

Over the past few years I’m been evaluating what should be my next move. From the 80ED there are many possibilities in the $800-$1200 CDN price range:

  • An 8in or 10in fast newton; a good bargain when it comes to pure light gathering power, and the fast ratio is great for photography. However collimation needs to be spot on, and will require frequent adjustments.
  • A 100-110mm doublet refractor will also gather more light and retain the easy of use like the 80ED.
  • Some entry-level catadiaoptric like Ritchey-Chrétien or Schmidt-Cassegrain are interesting with longer focal lengths for planets and galaxies

But with any of these options, the weight of the optic increases, and my current Vixen GP will start to struggle. Changing both telescope and mount was out of the question. I wanted something that could go well with my current gear. Hence a 70-80mm APO triplet started to look interesting, especially the small packages offered by some of the fast ones. After a week under dark skies without my telescope, I decided I needed something portable.  That’s when I jumped on an occasion to grab one of the star party demo units from William Optics: the Gran Turismo 71mm APO Triplet Refractor.

davIt may be a demo, but it looks brand new. Not a scratch on the powder-coat finished white optical tube or even the gold-colored dove-tail. Everything feels solid and the focuser looks like it can easily handle the heaviest DSLR. The SW80ED focuser is screwed to the back of the optical tub while the GT71 is one CNC machined unit, eliminating mis-alignment. As this is designed to be a travel scope, the soft-case that comes with it is very nice, much more portable than my current Orion hard-case. And at 2.2kgs, the weight is well within the range for the Vixen GP mount.

To compare the size, I’ve set it up next to my SW80ED, where it comes to almost half its length. The 80ED shares the same tube as the 100mm version, hence it’s bigger than it needs to be and the dew shield does not retract. Overall, the GT71 is more compact and will pack just about the same viewing power as the SW80ED.

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Below is a view of the optics.  While the SW80ED only has about 5 baffles within the tube, the GT71 has a good 30 of them to keep any stray light from ruining the view.  While both use FPL-53 glass, the SW80ED only has it in the rear element, while the GT71 is used for all three optical elements.  The SW80ED provides views free of chromatic aberration, however it’s designed to perform well in the blue and green part of the spectrum.  Anything is the deep red was falling out of focus, especially if a focal reducer was used.  The GT71 will perform better over a wide range of spectrum.

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I didn’t travel with my SW80ED, but now with a more compact telescope, I’ll be inclined to simply grab it during for my outings.  I just now need a light alt-az tripod to go with it.

Bummed About Missing Totality? Plan for April 8th 2024

The August 2017 solar eclipse will be special, I’m sure the media coverage has repeated it often enough.  While there is a solar eclipse about every year, it often happens over open ocean or remote places.  The fact that the August 2017 event will sweep across all of the continental United States, where millions will be able to simply look up by heading outdoors, many with easy access to digital cameras and social media to share is what makes it special.

However, if you’re bummed that you won’t be able to witness the total solar eclipse because you’re not in the right spot, fear not!  It will happen again… in 7 years.

Mark April 8th 2024 in your digital calendar.  On the map below, the red line will be the best view, the center of the Moon’s shadow. However any spot between the blue lines will get a total solar eclipse. A different group of States will be the lucky ones this time around. And while the folks in Toronto and Ottawa just falls outside, a short drive will easily get you to a better viewing location.

April 8th, 2024 Eclipse Path

April 8th, 2024 Eclipse Path

So don’t throw away those solar safety glasses you will need them again in 2024. Besides, you can use them every day to track sun spots!

Eclipse Viewing in Canada?

With a week left before the August 21st solar eclipse, some of you may be scrambling to find eclipse viewers to safely view the event. Stores appear to be running out of the necessary viewers and ordering online may not make it in your hands on time.  Also there are reports of poor and unsafe gear being sold on the internet, so do the proper research before ordering.  Both NASA and the American Astronomical Society (AAS) only recognize five manufacturers as meeting the necessary ISO standards for solar safety film, these are: Rainbow Symphony, American Paper Optics, Thousand Oaks Optical, TSE 17 and Baader Planetarium.

July/August SkyNews

July/August SkyNews – includes eclipse viewer

One way to get your hands on eclipse viewers is to find a copy of the July/August SkyNews magazine.  The issue not only has great articles how to prepare, observer and photograph the eclipse, but it comes with a free eclipse viewer.

Alternatively you can join one of the observation parties hosted by astronomy clubs, colleges, museums or stores.  Here is a list from the Royal Astronomical Society of Canada of cities hosting observing events.

Next Year: Lights Out For the Perseids

Yesterday, even if I’m located in the light polluted Montreal suburb, I decided to head out at quarter to midnight to see if I could by chance spot one or two bright meteors from the Perseids shower. As luck would have it in the 15 minutes doesn’t looking around Cassiopeia I spotted two before clouds and a rising moon sent me indoors.

But during that time scanning and waiting, it got me thinking… It took me a good minute to find a suitable spot in my backyard free of the light from the neighbours’ houses and street lights. If there was less light pollution we could have darker skies and everyone could enjoy the show.

During Earth Hour people are asked to turn off the lights for one hour to support the fight for climate change. But I always found that pretty pointless.  If you want to fight climate change, it’s an every day affaire, in your daily routine and the choices you have as a consumer, not one hour in an entire year. So the one hour lights out is more of a gimmick, doesn’t really benefit anyone. But if we had an evening of lights out during the peak of the Perseids meteor shower wouldn’t that be great!

The Perseids falls in August when it’s warm and sitting outside past sunset in the cooling air is enjoyable. Kids don’t have school so they can stay up late. And the patio furniture is out, that’s all the required equipment.

So what do you say? Light out for the 2018 Perseids? I think that’s a worthwhile collective movement.

Perseid Peaking Tonight

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The Perseid meteor shower is scheduled to peak tonight, but a large Moon will ruin the show. The best time is tonight (August 12) after 11pm, looking north-east.

While the sky directly overhead may look darker, it’s better to look 45degrees over the horizon to see a thicker “slice” of the atmosphere.

Jupiter Below a Crescent Moon

I have to say with the wet and cloudy weather in the past two to three months I haven’t taken the telescope out for quite some time. The high humidity often produces clouds in the evening and into the night as the air cools. And with the wet spring and early summer, the mosquitoes are rather annoying.

Therefore I haven’t been actively taking part in my backyard astronomy hobby.  However a few days ago, I noticed a  crescent Moon through thin clouds, and what I thought to be Venus just below.  Grabbed the camera and took a few photos at ISO 800 66mm F5.6 1/4sec to see what type of result I could get with that.  I have to say it was hard to find the right setting, and my car’s roof was a poor tripod.

The photo below really doesn’t capture the range and subtle gradients in direct and diffused light around the Moon and the clouds, contrasting with the pin-point bright planet.

Jupiter Below a Crescent Moon (July 28, 2017) - Benoit Guertin

Jupiter Below a Crescent Moon (July 28, 2017) – Benoit Guertin

It was only a few days later when I downloaded the images on the computer and checked to confirm the planet that I was surprised that the it was Jupiter shinning so brightly.

Animation – Movement of Comet 41P

The word “planet” comes from the Greek work “planan” which means to wander. Early star gazers noticed that some bright stars moved with respect to other fixed stars.  Those bright stars are our closest planets: Mercury, Venus, Mars, Jupiter and Saturn. Comets also move a fair bit across the sky, but the origin of the word has more to do about stars “with long hair” than it’s traveling behavior.

Last weekend I managed to photograph comet 41P//Tuttle–Giacobini–Kresák, and I identified in my blog that it’s movement was visible frame to frame. Well I’ve finally gotten around to create a small animation of that movement. For those wondering what’s the comet’s velocity, it’s currently travelling at 37.4 km/s.

Animation of comet 41P/Tuttle–Giacobini–Kresák (45 minutes)

Animation of comet 41P/Tuttle–Giacobini–Kresák (41 minutes)

The above is composed of 32 frames, each a 1 minute exposure spanning a time of 41 minutes. You are probably thinking “it should be 32 minutes, not 41!”. That is because I have a delay between each frame to allow the camera to send the photo to the computer. Hence between the first and last frame, 41 minutes have elapsed.