Rambling through Orions with some Canon IS
Setup
I’d picked up a pair of Canon 15x45 Image Stabilized binoculars earlier in the day and decided to spend my evening observing the wonders of a specific constellation that evening. For those who are’nt familiar with the Canon IS binoculars, they are simply put, a rather unusual pair of binos. What makes them distinct is their electronic image stablized component that is activated with a button which resides on the top right portion of the binos. For most people, 15x binoculars are too high power to hold steady as the image jitters and jerks around. With the Canon IS you simply depress the topside button and the image is “stabilized” – perfectly handholdable.
My “equipment” this evening consisted of a 3-piece poolside lounge chair (the type you lay on and can adjust the angle of the sitting), a small table, a Winnie the Poo thermos filled with cranberry-apple tea, Terence Dickinson’s excellent “NightWatch” book opened to the constellation pages, an observational log and my trusty red Orion flashlight. In standing back and looking over my setup I had to laugh, what kind of “serious” observing is this? Like most other times I’ve observed with binoculars I find that I’m simply more relaxed and cares slip away quicker then when I’m fussing around with a telescope.
On to Orion
I hadn’t decided ahead of time which constellation to observe as my house is hemmed in with trees with large patches of the sky framed like celestrial windows by tree branches. Looking to the SW I noted Orion framed in such a window and swung my lounge chair around to observe. Opening NigtWatch to Chart 16 of the Orion constellation, I started my observing run.
Canon’s literature reports the 15x45 models provide a 4.5 deg fov. Swinging up to the 3 stars in Orions belt (Alnitak, Alnilam, and Mintaka) I viewed all 3 stars with roughly a ½ degree left on each side of the outermost stars. Scattered around and between these stars were dimmer magnitude stars that gave the entire view a real sense of perspective. With magnitudes of 1.8, 1.7 and 2.2 respectively, I could’t see even a hint of secondary color on these 3 stars. Chalk one up for the fine optics of the Canons.
Centering the binary star Mintaka within the fov I easily detected it’s 6.8 mag companion star. With a seperation of 53 arcseconds and a magnitude of 6.8 the Canons split this star with ease. Intrestingly enough, theoritical resolution limit of the Canons (using Dawes limit calculation) is roughly 2 arcseconds for a 2” instrument. However, this formula calculates this based upon the upper useable magnification that an instrument can use before it runs out of resolving power. I’m curious how to apply this to a pair of fixed power binocualrs. Anyone know?
Moving down a ½ degree from Alnitak is the quadruple star Sigma Orionis. The main star is mag 3.7 with 6.7, 7.5, and 10.3 mag companions. This is an usnusual sight in small telescopes but alas I could only detect 2 stars. I might have confused a companion star for a nearby star but will need to do a little reseach and try it again.
Moving down to the most known object of the winter skies, I sat on M42 and m43 for a solid 15 minutes. Three stars were apparent in the Trapezium but the nebulosity of m42 was somewhat muted by the limited aperture of the Canons. M43 showed just a hint of nebulosity surrounding the 7th magnitude star at it’s center.
One of the joys of using a pair of binos with a moderate fov (as opposed to the more restrive BT80s) is the sense of context each object gains. With most telescopes ( or binocular telescopes) with a fov less then 3 degrees you trade aperture and magnification for fov. Mid-power binoculars such as the Canons allow you to both view the object but also see it nestled within the surrounding star field. One gains a certain perspective as you actually see the placement of the object within the constellation. If you’ve ever wondered why rich field refractor owners are such a happy lot, this is one of their reasons.
Nudging the binoculars upwards of the Orion nebula centers the open cluster NGC 1981. This is a sprawling structure of rather bright stars. I counted 13 stars and was rather pleased at being able to view both NGC 1981 and M42/m43 in the same FOV. Beautiful!
My last object for the evening was M78, a small 8th magnitude reflection nebula. M78 is ¼ of the distance directly between Alnitak and Betelgeuse. I’ve found M78 to be sensitive to sky glow and my own dark adaption. Unfortunatly, from my viewing location, several yard lights and the occassional passing car tend to ruin my night. I’ve had strong thoughts of late of purchasing a Kendrick shelter tent to block these light sources. This would ease my occassional frustrations of deep sky observing from my back yard.
I could barely detect M78. Just a hint of a smudge with 2 slightly (ever so slightly) brighter points in the center. Unlike the Orion Nebula, M78 is lit by reflecting the light from 2 10th magnitude stars that are contained within it. A rather disappointing site for our tea drinking, lounge chair flopping binocular observing but I felt a swell of pride at being able to detect it. I seriously think a Kendrick tent and proper dark adaption would have made this target much easier. Perhaps a little shopping is in order ......