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Messages - micfullprovlo

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ATM, Optics and DIY Forum / Re: Making Tripod Legs from a Two-by-Four
« on: February 09, 2018, 10:01:33 AM »
Another way is to get 2X6s and rip to rough width to relieve any stresses in the wood (assuming properly dried stock), and then use a jointer to dress the pieces flat, then run through a planer for final dimensioning. You should then be able to design a good tripod with flat squared pieces that should remain stable for years. The key is to relieve stress first and flatten second. If you don't have the equipment to do this, then rickets will likely be your companion...


At f/3.3 would you need a ladder for it? If not and you can deal with the particulars of care and feeding of a f/3.3 then the comfort of no ladder is the deciding factor in my book.

20" x 3.3 = 66" and the JPA Dob would have a eyepiece height of around the same 66". My eye height is 72". This would easily be a no-ladder scope for me.

So let me ask this after a bit of reading,
will the 20 have the problem with focusing the outer edge of the fov that there are topics on, ie. as a finder eyepiece? because I do have an ES 34mm 68° for that.
if so can that be corrected out with a coma corrector so the entire fov is in focus?
I've already succeeded in that with the ES 5.5 and my CC.

I think you'll love it. I just bought my first dob...the Sky-Watcher 8" goto collapsible. I'd love to have the 12" but I'm disabled, use a wheelchair, and have only one arm, so there's no way I could manage anything bigger than my 8".

I put mine together (one handed from my wheelchair) in just a few hours. My only complaint is that they should have made the cutouts in the base where the bolts are installed much bigger or bevelled a bit. It's hard to get these tightened down with the hex key...just not much room.

As for size, the 8" is really big to me but not too heavy. I think an able bodied person could easily manage the 10" or 12". I don't think it would become a chore or a closet queen. Aside from the finder scope and not making the cutouts big enough, I have zero complaints with mine. In fact, it's a very attractive and well engineered instrument.

Also, it's nowhere near as loud as it sounds on a couple YouTube videos. Mine is only a hair louder during slewing than my Celestron 5SE.Attached Thumbnails

Reflectors Telescopes Forum / Re: A new user, an old question: Eq Platform
« on: February 08, 2018, 05:23:47 PM »
oh ok, in theory it works, but mechanically it's hard since the mount is made to be verticle. Thanks!

It would work at the South pole. At the poles an alt az and an equatorial are the same thing.

Apparently the seeing is good too. One for the bucket list...

Eyepieces Questions & Recommendations / Re: Optimum FLs for product lines
« on: February 08, 2018, 12:22:33 AM »
Docter UWA - 12.5mm

Eyepieces Questions & Recommendations / Re: Explore Scientific 92 17mm
« on: February 04, 2018, 01:11:04 PM »
Hi Dave! Don Pensack mentions a future8.8mm and 6.5mm in this thread:

Oooo! another focal length to be determined. I would really like to see a focal length in the low twenties if the
series could be expanded outward. The 17 sounds almost perfect except it is a little too close tomy ethos 13.

Beginners Forum / Re: Magnification questions
« on: February 03, 2018, 12:26:00 PM »
The zhumel came with a laser colimator, and I have made an apature stop out for it to make the beam tighter. I had a guy from a local club check my collimation with his more expensive laser, and he said "it looks good".

I have not done a star test, and am not really sure how to do one. What am I looking for when doing a star test?Concentric circles?

As far as cool down, with the ac on in the house, I usually set out the OTA of the C90 and the Z8 outside, 45 to an hour before I look through an eyepiece.

... in Des Moines IA and I do use the clearsky page. I think the heat, and high humidity may be the limiting factor, because even when I go to a dark spot out of town, anything over my 12mm eyepiece, the edge of planets like Jupiter start to soften. It is slowly starting to cool off, weather wise, so I will try a 2x on the 12mm, and try my 9mm, and see what happens.

As far as the eyepeices that I have a 9mm, 12mm, 8-24 zoom and a 32mm, and a 2" 30mm. All plossl as far as I know and I have a GSO 2x barlow.

How about the moon, and Saturn?

The moon can easily take 200x with my C90, Saturn reaches 138x, and Jupiter 125x.

If you get lower mags for all 3, and it's not cool down, then it could be humidity at your location, or perhaps your latitude (if you are way up North).

Beginners Forum / Re: Nexstar 8se or Skyquest xt10i...
« on: February 03, 2018, 12:13:38 PM »
Okay guys, it appears that I've made up my mind. Or it's been made up for me  I found a used like newOrion Skyquest xt8i in my area for $450. That's a bargain! I can give it a try, see how I like it, and if I get aperture fever or go-to fever I can always resell and upgrade. The price is great so I can get several nice eyepieces and the wife is happy. Hoping to make some good memories with the whole family.

I'll be starting a new post. Need help with accessory recommendations now.

Thank you to everyone that has contributed to my two posts. I found this website just a couple weeks ago and it's been so awesome. You guys have helped me out a lot. Looking forward to getting some more experience so I can return the favor to newbies in the future.

Beginners Forum / Re: C14 vs. Same-priced 152mm Apo ?
« on: February 03, 2018, 02:15:21 AM »
A 14" SCT compared to a 6" APO will have 14/6 = 2.33 times the resolving power and (14/6)^2 = 5.44 times the light gathering ability. $4,500 will buy a good but not premium APO such as AP or Takahashi.
While Celestron, as well as Meade, SCTs sometimes had poor optical quality a few years ago, It seems that under new ownership quality has improved. Even 1/4 wave is diffraction limited.

That is a very good comment, there are a lot of people out there that have never owned anything but a Schmidt Cass. Most are figured around 1/4 wave and have been for quite a while.
Some may be better or worse. The thing that I am getting at here is 1/4 wave is NOT a bad system!

UO 12mm HD Ortho. Very common for me to pull that out and use it for awhile.

For a short focal length 1.25" focuser rich/wide field telescope, a 32mm Plossl is also favorite, actually.

Beginners Forum / Re: "How far can your telescope see?"
« on: January 31, 2018, 05:04:24 AM »
I just usually tell folks how far a light year is and then how far away many objects are, and then how far they can see naked eye. We always end up agreeing that it is much further than many politician's sight, even if the market has good seeing.

People can be told how far a light year is, but it's really tough for the human mind to conceptualize just how huge the distances are when you're looking at a long string of zeroes. The best one I've heard so far goes something like this:

"Imagine the sun is an ordinary Major League baseball sitting on home plate at the Rogers Centre in Toronto. The Earth would be a ball-point-pen ball sitting about halfway out toward the pitchers' mound, and the outermost planets would be orbiting out beyond the outfield where the circular rails guide the retractable roof. Our nearest neighbouring star, Alpha Centauri four light years away, would be another baseball sitting on home plate at the Houston Astrodome."

Once people have digested that jaw-dropping sense of how puny humans really are, it's interesting to move on and talk about things that are a few hundred times further than Alpha Centauri (some nearby nebulae), a few thousand times further (some globular clusters), or a few million times further (some galaxies generally visible in an amateur telescope).

I looked at M45 last night with my 20 mm IP It looked pretty nice then I switched it to my 26 mm and it even look better then I put a 10 mm in and I can only see a handful of stars if that’s the case with the lower magnification eyepieces why would you ever use a seven or 10 mm?

Depends on the night, the scope, and the target.
I use up to ~500x on Uranus, Neptune, and many small planetary nebulae.
But I rarely go above ~300x on most other targets.
And the large ones seem to be best a 90-150x, so it just depends.
M45 is huge, and looks fantastic at 15X in a small refractor.
The Trapezium in M42 is nice at ~150x, but if you want to see the faintest stars (G, H1, H2, I), you'll need 300x and more.
[needless to say, you'll also need fantastic seeing].

A good example is M31, fantastic at 60-90x, but the small M31 globular G1 needs 300x or more.
It's all about the target.


It seems like a lot of people learned from HA Rey's book, which I never used. As child, I checked out from my school library Henry M. Neely's A Primer For Stargazers more times than I can remember. It had a system of equating different charts to different times of night and days of year that was very easy to follow. I wish I could see a copy of the book again to see what I saw then. It is available used, still.

I remember a book, probably Neely's, that had you do calculations or tabulations to figure out in which direction and how high up in the sky to look for a particular star at a particular date and time. Maybe it was trying to make us do a right brain task using the left brain. Or is it the other way around? I didn't find to it to be any help at all.

Rey's book was much easier.
Yeah, perhaps it wasn't as easy to follow as I thought. I really can't remember. I thought there were graphs of the night time sky with diagonal lines saying when things rose or set at different times of the year, kind of like the Skygazer Almanac that Sky & Telescope publishes every January. I think they told you which picture to use when. I read the book, dreaming fo seeing everything in the book, but as a practical matter, never really got much fo a good look at the actual sky.

Mounts Questions & Expirience / Re: AP Mach1 GTO Body Changes?
« on: January 26, 2018, 05:28:31 AM »
Actually the new gearboxes WILL be available as an upgrade, per a conversation I recently had with George at AP. It sounds like they are getting close to announcing prices etc, but in my experience "close" with Astro-Physics is a relative term. Could be next week, could be next year.

Well, I'll look for that, but it could be well over a thousand dollars to replace both gearboxes. In fact, given that the new control box is $1200 and GUESSING that each gearbox could be upwards of $1000 you might be better off selling your existing Mach1GTO and buying a completely new mount.

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