In our club there are three ways of viewing an object: DV, or direct-vision, AV, or averted-vision, and AFV, or averted-fred-vision… I am not quite sure that the Averted Fred Vision is an accolade. As a matter of fact, I’m pretty sure its not. J
I can usually get a second opinion and I’m always (well mostly always) vindicated when I ask the person who claims the object is not there to use one or more of the following techniques and take another peek.
There are at least thirty three things you can do to help you see an object in the eyepiece. Thirty three things that most people never try before they give up and move to another object.
These are things that I learned from the ETX 90RA and other telescopes I’ve used. Things that greatly increase the things you can observe. These things really work. Not just for the ETX either, but for any telescope.
- Averted vision: This is one that most folks know. Look to one side of the FOV and your eyes will see dimmer objects in the center.
- Darkest spot: Most folks know to go to a dark spot. But there are darkest spots no matter where you are. In the shadow of a building that blocks a street light, or behind a tarp that you put up on a stand. Find the darkest spot and go for it. It may be in a fully lit parking looking toward but between the fewest number of lights.
- Move the telescope: Jiggle the tube. Most folks know this one.
- Dark adapted: Patience. Most folks are impatient and the first thing they look at simply is not there and they don’t try again for it all night. It takes my older eyes a good 45 minutes to really open up. One errant depressed brake pedal or open car door and I’m 45 minutes away from any more really faint objects.
- Telescope cool down: A lot of folks know about this. Again, patience. Wait for the optics to cool down and those double stars just might split and those details on the planets just might materialize.
- Collimation: Again, take the time to check and to touch it up if its needed. This is a scary thing to do at first but it gets easier. Your eyes and your optics may be better than you realize.
- Be quiet… the less you talk the more you can see. You don’t have to be a Zen Master but if you can focus – excuse the pun- on observing, you will see more. Try it.
- Change power: Get out of your rut. Try different magnifications. One night your lowest power may give the best resolution and contrast and the next night (or the next hour) the medium may show detail that you have never noticed before.
- Look through someone else’s scope to see what the object looks like: I’m not kidding. You may have been looking at the object the whole time and just not recognizing it. That faint reflection or subtle change in contrast may be what you have been looking for. Get someone to point out the elusive object in their scope.
- Wait for the object to get higher in the sky: Again, patience. The higher the object, the less atmosphere you have to compete with for a good view. It’s a rare night that you can get real clarity before an object gets above 40 degrees off the horizon around here.
- Don’t look over roof tops and buildings/steady air is a necessity. Buildings, parking lots, bridges, railroad tracks and other objects hold heat and the rising hot air will distort the view big time. You may need to move your scope or the location entirely.
- Know your scopes capabilities: this one can not be stressed enough. It goes right along with the next one. My 90mm of obstructed perfection can only do so much. As much as I would like to tout its ability to split sub arc second separation… its not going to happen. Learn what your scope can and can not do and be realistic in your expectations.
- Know the sky for the night: all nights are not created equal. Learn to evaluate the brightness, transparency, and seeing of the sky. Some nights of poor transparency are also great for seeing and vise versus. Your telescopes capabilities do not change from night to night but the sky can change from hour to hour.
- Cloth over head: This may look goofy to the uninitiated but you’ll just have to let them laugh. This works. An amazing amount of stray light is all around the area between your eye and the eyepiece. It affects how open your iris’ are and it is a distraction. It can cause actual reflections of your eye in the eyepiece. Cover your head and all this goes away.
- Cloth under feet: this goes along with the previous one. There is a small amount of open space between a cloth over your head and the telescope itself. Place your telescope on a dark ground cloth to mitigate this.
- No cigarettes: Medical fact folks. Read it and weep. Smoking constricts the blood flow in the eyes and diminishes your ability to see.
- Know how to read your star charts: Not just the bright stars but the faint ones too. The faint ones can be much more valuable in finding things. Most star charts go down to at least Mag.9. There are very few spots out there that have absolutely no stars in the background somewhere. Know the background stars and you’ll be able to concentrate on where the object is before you can see it.
- Use a scope that tracks if possible: The longer you look at an object the more detail you will see.
- Be rested: A rested mind can see better… More of that Zen stuff. I don’t know about the Zen part but I do know that if my head is clear I can see better!
- Wait for it… two things here. One, you will see more details the longer you watch. Two the sky changes from hour to hour and in some cases from minute to minute. There will be periods of clear where something, some subtle detail is there now where a minute a go you couldn’t see it or it was just a blur.
- Comfortable chair: this is soooo important! It goes along with the other things we discussed above. You can focus all your brain at seeing something if you’re not in a strain.
- Red lights: This one most folks know about. Don’t make it a bright one! Some of the red lights I’ve see folks use could bake a pot pie.
- Warm hands/feet/head/derrier make you happy: Again, if you’re comfortable you can concentrate on the eyepiece instead of shivering.
- Know the size of the object and your eyepiece FOV: Most folks have no idea of what FOV their eyepiece is showing them. This is a simple calculation to make. Better yet, learn how to time star transitions to measure the true FOV. If not this hard core at least learn how to calculate the AFOV. Then imagine how big the object is going to appear.
- Know the brightness of the object (apparent brightness): This goes along with some of the previous items about knowing the capability of your scope and being able to evaluate the sky conditions for a particular night.
- Use filters: These are not good for all objects but the right object/filter combination can make all the difference. OIII and UHC filters are good for certain emission nebulae. I’ve never had good luck with Skyglow and other light pollution filters. They cut out the wavelengths of light usually associated with light pollution. Other swear by them. Hydrogen beta filters are good for a very small group of specialized objects like the Horsehead. Very limited but make the difference between seeing these objects and not seeing them. White light and Hydrogen alpha filters for the sun. Hydrogen alpha is REAL pricey but the views are incredible. Moon filters really cut down the brightness and ease the strain on your eyes. Different colored filters help bring out subtle details on planets.
- Flock the inside of the tube/dew shield : Minimizes reflections and greatly increases contrast.
- Breathe right: Don’t fog up the lense
- Don’t hold your breath either
- Know your FOV orientation: Reversed, inverted, both, etc. This may explain why you can’t follow those star charts and moon maps… J
- Use an aperture mask to increase your large aperture scope’s F/ratio: Long focal length scopes show more detail.
- Try different types of eyepieces: Some are better for some objects and some for others. Some are suited for fast scopes and some for slower. Some are in the middle.
- Make sure the optics are clean: don’t be overly concerned about dust on the primary of a Newtonian and follow the numerous guidelines out there for carefully cleaning the eyepieces. They all have their own secret cleaning solutions and they all begin with gently removing any grit with air or a special very soft brush.
I’ve also seen a few scales that people use for how difficult something is to see. We use a scale of 1 – 5:
- The object is obvious with direct vision.
- The object is obvious with averted vision.
- The object is obvious with averted vision if you jiggle the tube.
- The object may be there… (this is sometimes confused with FAV)
- It’s just not there no matter what you do.
There are probably more things you can do to eke out every photon that is available but this will get you started. Try them.