Celestron Skymaster 25X100 and Tasco Sonoma 10X50

Since I owned my 4.5" Newtonian reflector before I purchased my Tasco Sonoma 10X50 binoculars, I didn't think I would be using them much for astronomy, since my telescope would not only let in more light but would also be capable of higher magnifications. I soon found that these binoculars also had their purpose under a dark sky.

I couldn't tell you how wide the field of view they provide is in degrees, but it is much wider than any of my telescopes is capable of even at their lowest power. I do know that I cannot quite fit all of the stars in Brochi's cluster (the coathanger) in most of my telescope's field of view at low power, or for that matter the Hyades cluster as well. My 10X50 binoculars will easily fit them in. They are also useful for scanning areas of the sky to aid in locating brighter star clusters and even a few galaxies.

My Celestron Skymaster 25X100 binoculars are a different story entirely. Several years ago, I went out shopping with the intention of buying my 4" shorttube refractor. At the time I had my 4.5" reflector, and my 6" F8 refractor. I thought it would be nice to have something with a little light gathering ability that could show wider fields of view than my telescopes.

I had seen giant binoculars before, but had never even considered buying them due to their high cost. My good friend Bob gave me a flyer from a store that specialized in HAM radios and communications equipment that was trying to add astronomical gear to their inventory. As an introductory offer they were advertising Celestron Skymaster 25X100 binoculars for the unheard of price of $269 Canadian (at a time when our dollar was worth about .75 U.S.). I though for sure that this was one of those "bait and switch" tactics-you know the kind: you arrive at the store and they say "we're all sold out, but we do have some of these other ones for twice the price". I decided to try anyway.

I arrived at the store and was surprized to learn that they actually had 2 pairs available. I inspected one pair and stood outside the front door of the store to give them a try. The focussing mechanism is different that on most binoculars. The eyecups are individually focussed by rotating them, and they stay focussed when you alter the distance between them. I have used them several times in the field at night during observing sessions. They are quite heavy (just over 10 lbs.), and I do not yet have a tripod strong enough to hold them. A good mount capable of holding these monsters would cost $500 or more, so I am presently in the process of building one. As you can imagine they are quite heavy for handheld use, and it is difficult to keep them steady for any length of time. The high 25X magnification doesn't help either as it amplifies any shakes.

As for the view these binoculars provide, it is quite unique. Despite the fact that these are binoculars of high quality, the image is a lot sharper than I expected. It is not soft or "washed out", and the starpoints remain coma free to the edge of the field of view. The 4" lenses let in a lot of light, and the fact that the observer is using both eyes gives the image a 3-dimensional feel. Brighter globular clusters really stick out, and M81 and M82 look as good as they do through any of my telescopes. Areas of the sky full of goodies, such as above the Sagittarius teapot are a joy to look at in the 3.5(approx) field of view. As for the milky way, I was astonished at how many dim stars showed up in the background. I am sure once I finish constructing the mount and tripod for these binoculars they will become a regular part of my observing arsenal. I did still purchase my 4" shorttube refractor that day. The only downside to that day is that despite my offer, Bob did not want me to pick up the other pair for him. I think he has regretted it ever since.