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Messages - pafunsirep

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General Astronomy & Observing / Re: Observing Alone
« on: February 09, 2018, 08:21:32 AM »
I go out to a nature park 35miles west of my house quite a bit to observe. Sometimes its just me. Other times I have one or two friends join me. When its just me I hear everything. I know my area of Indiana doesn't have bears or mountain lions yet, but they are venturing into our area and will probably be here mating and growing in populations within the next 15 years.

I love listening to owls talking back and forth from one treeline to another. One night I think I heard 4 different species!

Never had the straight through 9X50.  the 9X50 RACI is the standard finder on the Orion Intelliscope line.

I have the finder set up so I can move from the finder to the eyepiece and back while I am still seated.  If I drift off the target or bump the scope while I am changing eyepieces the RACI is soooo easy to get to.

Also, with the RACI 9X50, when I am showing someone else the view, even at moderate mag, I can turn the eyepiece so that it facing toward me, standing on the other side of the scope. While the person is at the eyepiece I can use the finder to help with the tracking or to help them get back on the target if they lose it. 

At outreach where I am probably below 100X this works very well.

Mounts Questions & Expirience / Re: skywatcher azeq6 issues
« on: February 04, 2018, 10:51:30 AM »
no its not the power I hooked it up to the carplug and it does the same thing.

I'll try swapping encoders. wonder where you get new ones???

That won't help. The encoders are not required for goto operation (normally it's best to turn them off).

General Astronomy & Observing / Re: Observe planets and Moon.
« on: February 03, 2018, 04:14:34 AM »
One could say, then, that in order of importance and in relation to planetary observation would be ....:
-The quality of the mirrors
-The focal length (in this case the more the better ..)
- The aperture of the telescope

Assuming that you are talking about reflectors, focal length per se has very little importance. The only reasons it might matter are that reflectors with long focal ratios can potentially have somewhat smaller secondary mirrors than ones with short focal ratios, and that you can get away with a cheaper, coarser focuser if the telescope has a long focal ratio. But as long as the secondary is properly sized and the scope is equipped with a high-quality (preferably two-speed) focuser, reflectors with focal ratios as short as f/3 can make fine planetary instruments.

As for aperture and optical quality, there's no way to say which is more important -- they're both essential.

Beginners Forum / Re: Green Laser Pointer help
« on: February 02, 2018, 10:25:06 PM »
I'm very scared of green lasers. I'm afraid of invisible infrared light burning my retina.

But I have this feeling, this vision, that I'll assemble one some day, with enough safety features so as to not fear it.

And once I have constructed it, my skills will be complete.

General Astronomy & Observing / Re: Heavy firefly activity
« on: February 02, 2018, 06:34:31 PM »
I saw a few at the Naylor Observatory last night.

Dave Mitsky

I looked into harmonic drives - they made precision worm drives look positively inexpensive.

For a sidereal drive with 180 teeth, the worm will advance 1 tooth every 8 minutes. Your problem is to either measure or estimate the worm's position with sufficient accuracy. If you measure the motor's rotation rate, the reduction ratio on the gearbox is your friend. Micromo makes plenty of brushless DC motors that have built in encoders. These are not cheap either. I found I could get the gearbox from a broken LX200 drive to give me enough pulses to control the drive adequately.

Consider what you really need - even the cheapest grade of phosphor-bronze will run you $200 in material for a 6" worm wheel.

Beginners Forum / Re: Doomed newbie
« on: February 02, 2018, 05:12:19 PM »
you can make your own solar filter, it's easy but you better get something now as suppliers are running out because there is such a frenzy over this eclipse.

This 4X4 sheet is all you need for your spotting scope. filter

Or this kit solar filterIf you want to use your scope, get this NOW

Have you ever taken a hot glass out of the dishwasher and filled it with cold water?
But I'm not sure I get what that has to do with cleaning telescope mirrors.
Do people heat up a telescope mirror right before they clean it?
Is a drinking glass made of the same type of glass as a telescope mirror?
Being so much thicker than a drinking glass, wouldn't a telescope mirror be significantly less susceptible to failure due to thermal contraction?

Maybe it will be "...less susceptible to failure due to thermal..." , but I am amazed anyone would seriously consider taking the chance !

Is this somehow a safer, simpler,or more effective cleaning method than the standard 'giving it a bath' procedure ?

Having just had my 17.5" in the kitchen sink last night for it's annual bath reminded me how easy it is to clean a mirror and satisfyingly spectacular it looks afterwards. All done with a bit of distilled water, a little soap, a little alcohol. KISS applies

Beginners Forum / Re: Firstscope to Skyscanner - worth the upgrade?
« on: January 31, 2018, 09:40:23 AM »
I upgraded from a First scope to a Starblast 4.5. The Starblast is a big improvement, but it's bigger and heavier too. I get much better views of Saturn and Jupiter with it.

Ac2aj, Considering that the AP is just $50 more I'm leaning towards it.

Good choice. It's well built, well baffled, super easy to get to the mirror to clean it. Roland guarantees a minimum 1/20 wave, says most of the AP Maxbrights are around 1/40 wave. Hard to beat.

Beginners Forum / Re: New Zhumell Z10 performance question
« on: January 31, 2018, 05:54:33 AM »
The least damage to the mirror's figure would be with a completely flat plate behind the mirror, but that would result in no ventilation for the mirror and too much heat retention.
3 points will suffice for a 10" full-thickness mirror. Adding additional points at the edge just might make it worse.
6 points would be possible with a modification to the cell, but not if they're in 3 lines from the center out.
No, you're fine with the 3 points--just repositioned at the 40% radius.

On the outside edge, the bottom support pads can be 120° apart or 90° apart, but 90° is better.
Here is the thing: the pads should press against the mirror in the center of gravity of the mirror from front to back.
That is roughly 1mm closer to the back of the mirror than the front.
Now, obviously the pads they provide are wider than that, and that's OK. Just position them so the centers of those pads
are at the COG. The pads I see are too close to the back of the mirror. It might be possible to cut them down so the half of the pads close to the back of the cell (back of the mirror) are removed.
That might put the pressure points closer to the COG of the mirror.

If the pads are too close to the back, when the scope points low the top of the mirror will tend to tilt forward like a potato chip and cause "bending astigmatism"
If the pads are too close to the front of the mirror, the mirror can also flex and cause astigmatism. When the mirror is supported in the center of gravity, it neither tilts forward nor backward when the mirror is vertical.
There is a bit of leeway here on a thick mirror. I'm just making you aware of the issue.

My 8" LX90 - purchased last year.

I got into astronomy at the age of 12 with my first purchase: a 4.5" Meade 4500. I subsequently purchased a 16" StarFinder, and ETX. I used them all extensively for many, many years, but I never quite *observed* with them, if that makes any sense. I would star hop to some of the brighter Messier objects, the planets, the moon etc. I would look, take in the view, and move on.

Then I took a looong break from the hobby, and got back into it in earnest last year with the purchase of an 8" LX90, and it's been the combination of scope's capabilities, my night sky, and my age that has changed the hobby from just looking to observing.

I've learned that an 8" scope can show you a wealth of things. I learned how to manage magnification, exit pupils, and filters to hunt for the optimum chance of seeing ultra-borderline objects. I learned how to more carefully observe the details within more common objects. For example, before this telescope, I would look at say, M33, and go "Ok cool." and move on. Now I'm observing spirality in it, as well as numerous star forming regions in it.

I'm more conscious of the effects of transparency and seeing conditions. When I observe planets, I look for specific things now: how many moons I can count around Saturn, how distinct the cloud bands are, and the hexagonal shape on its polar cap. For Jupiter, I look for barges, festoons, and the notch around the GRS. I would pay more attention to its moons, but I don't get enough consecutive clear nights to bother chasing and planning for transits. If I catch one, great, if not, no big deal.

I also learned what I *can't* observe in the scope. Several futile attempts to observe Abell planetaries (aside from A50, which I only just barely detected one night with an OIII at 2.6mm exit pupil and 78x), leads me to believe they are out of reach for this instrument. I likely need 4+mm exit pupil with an OIII filter to give them enough brightness to detect, but the 50x magnification that would produce in the scope is not sufficient to bring them across the visual detection threshold of my eye. I have not tried looking for them in my new 12" yet, but I suspect I will need something closer to 16", which can produce 100x in a 4mm exit pupil, to more easily observe them. A darker sky would help with detection of course.

Beginners Forum / Re: Xt12i arrived. First impression from a newb
« on: January 31, 2018, 03:58:14 AM »
You could also consider a quality x2 Barlow for your excellent existing eyepiece collection. That would effectively add a 2.75, 4.5, 7, & 10mm to your lineup.

Eyepieces Questions & Recommendations / Re: Fantasy ... Dreaming?
« on: January 31, 2018, 03:24:41 AM »
I am not sure if A-P asked for the change or if Baader made the change. I heard rumors of a prism shortage a few years ago.

It's also interesting to note that the T-2 1A mirror diagonal is more expensive than the T-2 Zeiss Prism diagonal.

I have used both diagonals with my Mark V binoviewers as well as monoviewing. The mirror diagonal is a fraction of an inch bigger. Otherwise, you could switch them around and I doubt anyone could tell the difference -- I know I couldn't see any difference.



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