Viewing Techniques

A few questions about the mechanics of telescope viewing. Thanks in advance
for any answers.

1. I have an eyepiece tray on my tripod. When I change eyepieces I have
been placing them there but have not been putting the caps back on. What do
folks do? Do you replace either or both caps when you are between eyepieces
or just leave the naked until the session is over?

2. When focusing should I "prefocus" my viewing eye at some distance before
looking into the eyepiece. It seems to help if I focus at a distant object
and then look into the eyepiece.

3. How long do you stare at a faint object when trying to get the most
detail. I get tired after about 2-3 minutes and need to walk away from the
scope for a minute or so. Should I "hang in there" and not interrupt my
viewing, or is taking a rest a good idea?

4. I touched one of my filters, what is the cleaning technique? Same as
for a camera lens?

5. Same queston for an eyepiece.

6. Here's the biggie. I need some techniques for determining "direction"
while viewing. In other words, if someing is 2 deg southwest of what I am
looking at, I am having a terrible time figuring out which way to move the
scope (Newtonian on Go-To German mount) while looking though the eyepiece or
finder scope. I assume that all directions are in relation to Polaris, but
how do you figure out which way Polaris is when looking into the scope?

Thanks again.

-John

On Tue, 3 Jan 2006 11:01:45 -0600, John Banister wrote:

A few questions about the mechanics of telescope viewing. Thanks in advance
for any answers.

1. I have an eyepiece tray on my tripod. When I change eyepieces I have
been placing them there but have not been putting the caps back on. What do
folks do? Do you replace either or both caps when you are between eyepieces
or just leave the naked until the session is over?

I cover eyepieces when not in use. Sometimes put them away in their cases.
I have always thought that keeping optics clean is better than cleaning
them.

2. When focusing should I "prefocus" my viewing eye at some distance before
looking into the eyepiece. It seems to help if I focus at a distant object
and then look into the eyepiece.

I've never done this but if it helps you then by all means do it. I just
use the focus to get to what's comfortable. And since I do a lot of
outreach I always tell those new to observing to focus for their own eyes
even if their vision and the person before them are "normal". Each
person's eyes can find a different focus point at the eyepiece.

3. How long do you stare at a faint object when trying to get the most
detail. I get tired after about 2-3 minutes and need to walk away from the
scope for a minute or so. Should I "hang in there" and not interrupt my
viewing, or is taking a rest a good idea?

Take breaks. Spending time is very good, even essential if you want to get
the most out of what you're viewing. But staring for long periods defeats
the purpose. You don't want to get tired. Look away regularly and then
back to the eyepiece. Take a short break and then go back. The more you
look the more you'll see. But don't let your eyes (or brain) get tired.
And taking a short break -- even if it's just a few seconds glancing away
or blinking -- can often help. Sort of like getting a fresh view.

4. I touched one of my filters, what is the cleaning technique? Same as
for a camera lens?

I don't use filters much so I'll leave that to those who do.

5. Same queston for an eyepiece.

I've always found the grease that ends up on eyepieces won't come off
without liquid. A good, safe lens cleaner and a lens tissue or micro-fiber
cloth will do the job. Just dampen (don't soak) the tissue a little so you
don't put enough liquid on the glass to get inside the eyepiece. Others
will have different ideas, I'm sure. A Lens Pen does a good job for a
little cleaning but I haven't found it capable of getting off fingerprints
and other big smears. Always be sure to blow or brush off any particles of
dust first so whatever you do they don't scratch the glass. Always use the
very smallest amount of pressure possible, i.e., a wadded tissue with no
pressure rather than pressing with your fingers.

6. Here's the biggie. I need some techniques for determining "direction"
while viewing. In other words, if someing is 2 deg southwest of what I am
looking at, I am having a terrible time figuring out which way to move the
scope (Newtonian on Go-To German mount) while looking though the eyepiece or
finder scope. I assume that all directions are in relation to Polaris, but
how do you figure out which way Polaris is when looking into the scope?

If you have an equatorial mount it should be easy. One axis is north-south
while the other is east-west. First, think about which way the tube is
moving rather than trying to figure out what's happening in the eypiece.
Then relate the known movement to what you see in the eyepiece. At least
that's what I've always done with equatorial non-go-to mounts. Sometimes I
have to step back and figure out what's happening, then go back to the
eyepiece and sort of re-calibrate my view.

Mike Simmons

"John Banister" wrote:
1. I have an eyepiece tray on my tripod. When I change eyepieces I have
been placing them there but have not been putting the caps back on. What do
folks do? Do you replace either or both caps when you are between eyepieces
or just leave the naked until the session is over?

I put the caps on and store the eyepieces in pockets on my astronomy
(fishing, truth be told) vest, inside my warm coat. That keeps the
eyepieces warm and dry.

2. When focusing should I "prefocus" my viewing eye at some distance before
looking into the eyepiece. It seems to help if I focus at a distant object
and then look into the eyepiece.

Open both eyes and relax. I find that even when not focussing on the
object in particular, I can tell when the scope gets in focus. I find
that if I strain my eyes to focus while focussing the scope, then I'm
stuck with straining thereafter. By the way... I use an eyepatch, too.
That's a phenomenal help for relaxation. If you just want to try it
without buying one, cut out an oval from cardboard and run a rubber
band through it.

3. How long do you stare at a faint object when trying to get the most
detail. I get tired after about 2-3 minutes and need to walk away from the
scope for a minute or so. Should I "hang in there" and not interrupt my
viewing, or is taking a rest a good idea?

Use an eyepatch. And sit on a chair that's appropriate height. I use a
34-inch high bar stool.

4. I touched one of my filters, what is the cleaning technique? Same as
for a camera lens?

I'm not sure. I think it might depend on the filter, some being far
more robust than others.

6. Here's the biggie. I need some techniques for determining "direction"
while viewing.

I can't add anything to Mike's answer.

=============
- Dale Gombert (SkySea at aol.com)
122.38W, 47.58N, W. Seattle, WA
http://flavorj.com/~skysea

John Banister wrote:
1. I have an eyepiece tray on my tripod. When I change eyepieces I have
been placing them there but have not been putting the caps back on. What do
folks do? Do you replace either or both caps when you are between eyepieces
or just leave the naked until the session is over?

If it's not so humid outside, I just put the top cap on and put it back
in the tray. That's usually enough to keep the dew away. Sometimes it
isn't and they go inside my coat.

3. How long do you stare at a faint object when trying to get the most
detail. I get tired after about 2-3 minutes and need to walk away from the
scope for a minute or so. Should I "hang in there" and not interrupt my
viewing, or is taking a rest a good idea?

You're taking this too seriously. Have fun with it. Take a break
whenever you like. It's not hockey.

4. I touched one of my filters, what is the cleaning technique? Same as
for a camera lens?

More than likely, although I've never had to clean a camera lens. The
same sort of optics apply and you don't want to get water between the
lenses in your eyepieces. Filters can be cleaned without much fuss
though.

5. Same queston for an eyepiece.

Someone else answered this better than I.

6. Here's the biggie. I need some techniques for determining "direction"
while viewing. In other words, if someing is 2 deg southwest of what I am
looking at, I am having a terrible time figuring out which way to move the
scope (Newtonian on Go-To German mount) while looking though the eyepiece or
finder scope. I assume that all directions are in relation to Polaris, but
how do you figure out which way Polaris is when looking into the scope?

These directions aren't that great, imho. Do they mean 2 degrees
southwest in alt-az, or 2 degrees southwest in the equatorial
coordinate system? It sounds more like they mean alt-az, since they
have reference to your position on earth (east and west, particularly).
And that's not going to help *you* out, with your german equatorial
mount. Worse still, is that "southwest" could mean exactly at 270
degrees from north, or 265, or 275. In other words, that's not very
precise, now is it?

If your mount has setting circles, it will show whatever coordinates
you're at. If the directions you have are any good, then they'll tell
you that the object B is -1.5 degrees Dec and -1.5 degrees RA from
object A. Or even better, it will just list the actual coordinates of
the object, and you can go right to them instead.

Since your mount is goto, then instead of setting circles, it might
have a digital readout of your coordinates. Assuming the scope is set
up properly, they should be more precise than setting circles ever will
be. Use that to your advantage.

On Tue, 3 Jan 2006 11:01:45 -0600, "John Banister"
wrote:

A few questions about the mechanics of telescope viewing. Thanks in advance
for any answers.

1. I have an eyepiece tray on my tripod. When I change eyepieces I have
been placing them there but have not been putting the caps back on. What do
folks do? Do you replace either or both caps when you are between eyepieces
or just leave the naked until the session is over?

When frost (or dew) is a concern (but no moisture is on the eyepiece)
I cap just-used eyepieces, open my eyepiece box, return the eyepiece
to the box and close the box.

When there's no danger of dew or frost I'll sometimes cap just-used
eyepieces and a) return them to the box and close the box if I don't
intend on re-using the eyepiece any time soon or b) leave the capped
eyepiece on the tripod shelf if there's a reasonable chance of soon
re-using the same eyepiece. At other times, under favorable
conditions when re-use is anticipated. I'll leave *a few* of my
just-used eyepieces uncapped on the tripod shelf (I prefer solid
tripod shelves -- no holes for eyepieces.)

Most often I end up spending relatively long periods of time using one
eyepiece -- preparing to make a sketch followed by making a sketch.
At such times I tend to keep the rest of my eyepieces capped in the
closed eyepiece box.

2. When focusing should I "prefocus" my viewing eye at some distance before
looking into the eyepiece. It seems to help if I focus at a distant object
and then look into the eyepiece.

If it helps you, do it! For myself, I just look into the eyepiece and
adjust the focus from time to time as necessary.

3. How long do you stare at a faint object when trying to get the most
detail. I get tired after about 2-3 minutes and need to walk away from the
scope for a minute or so. Should I "hang in there" and not interrupt my
viewing, or is taking a rest a good idea?

Rest is good! For faint objects I tend to spend a bit of time
concentrating my gaze at one point in the field of view, then a bit of
time at another point in the field, etc. It often takes time and
patience before some of the fainter details register with the eye or
brain.

Sometimes I'll spend some time looking toward a large, dark
terrestrial object or area (darker than the background sky) prior to
looking for faint details in the eyepiece. I do my best to avoid
allowing any light brighter than the background sky to enter my
observing eye at such times. A dark observing site is very helpful!

As for lengths of time, I tend to spend several minutes for a
'serious' observation of a single object. Making a sketch tends to
help me see more detail (provided the red flashlight is dim enough!).
I'll sometimes observe an object for 30 minutes or so before beginning
a sketch; but my observing eye doesn't spend that whole amount of time
at the eyepiece.

4. I touched one of my filters, what is the cleaning technique? Same as
for a camera lens?

I tend to treat all optics as if they're more fragile than they really
are. I never rub or wipe an optical surface with anything that is
dry. When it comes to cleaning, moist is good. I always start with a
bulb-blower to blow away any dust, etc. that is removable in that
manner. After that I'll use either sterile, surgical cotton with
distilled water or prepackaged, moist towelettes (packaged for
eyeglass cleaning). Rotate the moisturized cotton or towelette so
that a different part of the material is always in contact with the
optical surface (if any abrasive grain is picked up that grain is thus
immediately rotated off the optical surface). Avoid wiping with any
part of the cotton or towelette that has already been in contact with
the optical surface. Use only gentle pressure.

The cleaning operation should be meticulous enough to discourage you
from frequent cleanings. It's good to end up with the attitude that
it's better to prevent optics from getting dirty than it is to take
the time and care to clean them.

The above assumes simple, color, eyepiece filters. For interference
filters (Oxygen III, etc.) I would first of all exercise great care to
avoid fingerprints, etc. If cleaning does become necessary I would
exercise great care and minimal pressure.

I make frequent use of a bulb-blower after most observing sessions.
This practice helps to reduce the frequency of more hazardous
'contact' cleaning.

5. Same queston for an eyepiece.

See above.

6. Here's the biggie. I need some techniques for determining "direction"
while viewing. In other words, if someing is 2 deg southwest of what I am
looking at, I am having a terrible time figuring out which way to move the
scope (Newtonian on Go-To German mount) while looking though the eyepiece or
finder scope. I assume that all directions are in relation to Polaris, but
how do you figure out which way Polaris is when looking into the scope?

Turn off the clockdrive. Objects in the field of view will drift
westward. The opposite direction is of course east. Gently nudge the
telescope toward Polaris. The direction in which new stars enter the
field is north. I leave south as an exercise ;-)

Sketcher
To sketch is to see.

Thanks to all for the good info.

-John

"John Banister" wrote in message
...
A few questions about the mechanics of telescope viewing. Thanks in
advance for any answers.

1. I have an eyepiece tray on my tripod. When I change eyepieces I have