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OneGear
member


Reged: 12/30/11

Re: Newbie Lunatic Needs Advice new [Re: pdxmoon]
      #5947564 - 06/30/13 05:17 AM

I have a very similar setup, but my scope is 60x1000. I have a couple Plossl ep's and wouldn't trade it for money.

I use my binoculars (handheld or on a dirt-cheap tripod) to find targets for the telescope.

I hassle with my clunky wooden telescope tripod because it lets me see things my binoculars never could.

Eyepieces really make or break your experience with a scope. I bought a few used e.p.'s and the value of the scope mushroomed past the dollar investment as a result.

I've got a 26mm, 15mm, and 9mm 1.25" EP's. And a barlow. The scope itself is pretty capable. Your 90 is more capable.

The mount is actually pretty good. Sometimes I hang an empty cloth laundry bag on the objective end of the scope to dampen vibrations from focusing or using the slow motion controls. It works.

I often use mine as an alt-az mount by putting the telescope at 0*. The counterweight hangs straight across from the scope. The hand controls let you go up and down and left and right all you want without hitting the tripod/mount, and are easy to line up by sighting along the scope body.

Any 1.25" e.p.'s you buy now will work in whatever scope you buy later. So before you buy a new scope, buy some new e.p.'s for your current scope. Maybe a 15-sh Plossl, then a 5-10mm and a ~25mm Plossl.

You've got a great scope on a decent mount. Buy some eyepieces for it. You'll enjoy your current scope more and the next scope you buy will benefit from your good e.p.'s.

I really like my 15mm Scopetronix with or without the barlow, but nobody makes a bad eyepiece these days. It really is ridiculous how small an investment is required to get a good view of Saturn, much less the moon. Good new eyepieces are not expensive, and good used e.p.'s are common and cheap. Life is good.


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John Kuraoka
sage
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Reged: 12/12/12

Loc: Sunny San Diego, CA
Re: Newbie Lunatic Needs Advice new [Re: pdxmoon]
      #5947875 - 06/30/13 11:21 AM

Hi Barnum, and welcome to Cloudy Nights!

What Paco means when he mentions "cool-down time" is that the 90mm Mak-Cass needs time to cool down to the ambient outdoor temperature if it's been stored inside, as you likely will do.

I have this scope, and when I called Orion they advised 30-45 minutes from taking the scope outside to using it, depending on the temperature difference between indoors and outdoors.

When the scope isn't cooled down, you see a lot of waviness in the image, like you're looking through a mirage.

The 90mm Mak-Cass packs a lot of magnification into a very compact rig, but be aware that the stock Dobsonian-style mount (the one you get at the $199 price point) doesn't let you take advantage of those higher powers. You'd probably soon want to get something like the Porta II for its added stability and slow-motion controls.

However, I, too, think a 90mm Mak-Cass might not add much to your observing capability - especially for the moon - that you haven't pretty much got with what you have.


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pdxmoon
Pooh-Bah
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Reged: 06/27/13

Loc: Oregon
Re: Newbie Lunatic Needs Advice new [Re: John Kuraoka]
      #5947913 - 06/30/13 11:49 AM

I'm happy to report that I did some lunar observing last night with my current scope and it was wonderful!

I used the 2x Mead barlow with the 25mm Celestron kit scope. By trial and error I set the scope at 0* with the counter weight straight across. That way I moved the scope up/down using the one fine tune tube (don't know what's called) that actually works. I had to manually move the scope left/right because that remote is not working--I turn the tube and it does nothing.

So other than that, which wasn't a big deal, it was awesome.

I'm buying some new eyepieces. I'd love to get even more detail than I got with the 2x barlow. If I were to start with one more, what would you suggest?

Thanks, all!


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pdxmoon
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Reged: 06/27/13

Loc: Oregon
Re: Newbie Lunatic Needs Advice new [Re: OneGear]
      #5947919 - 06/30/13 11:53 AM

Thanks one gear!

Do you have a link to an eyepiece you might suggest to compliment my 2mm and 2x barlow?


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AngryHandyman
sage


Reged: 06/28/13

Loc: Nanaimo, BC
Re: Newbie Lunatic Needs Advice new [Re: pdxmoon]
      #5947925 - 06/30/13 12:06 PM

Consider the Owl eyepieces mentioned by Kenny above, also sold under other names by Orion, Agena Astro, CanadianTelescopes, Sky-Watcher and probably others! The 15mm, 9mm and 6mm will complement your 25mm nicely and will Barlow to fill the gaps and push to higher powers when seeing allows plus give you wider 66 degree views. I have them and for the price I like them a lot.

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pdxmoon
Pooh-Bah
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Reged: 06/27/13

Loc: Oregon
Re: Newbie Lunatic Needs Advice new [Re: AngryHandyman]
      #5947935 - 06/30/13 12:15 PM

Thank you! I think I'll take advantage of the "buy three" sale price!

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pdxmoon
Pooh-Bah
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Reged: 06/27/13

Loc: Oregon
Re: Newbie Lunatic Needs Advice new [Re: pdxmoon]
      #5948096 - 06/30/13 01:51 PM

This is on local Craig's List. Opinions?

http://portland.craigslist.org/mlt/for/3889522489.html


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tim57064
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Reged: 08/23/12

Loc: Southeast South Dakota,USA
Re: Newbie Lunatic Needs Advice new [Re: pdxmoon]
      #5948110 - 06/30/13 02:00 PM

If it is local and you can see them before buying, I think it would be a good deal.Just meet in a public place to see and purchase the items after checking them out to make sure they are not damaged in any way. Just my opinion.

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AngryHandyman
sage


Reged: 06/28/13

Loc: Nanaimo, BC
Re: Newbie Lunatic Needs Advice new [Re: pdxmoon]
      #5948120 - 06/30/13 02:07 PM

For me the high power plossl's are uncomfortably close. My eyelashes brush the lense all the time (6.4, 9.7, 12.4)

The 15, 20, 32 would be useful. The erect image 45 diagonal would be only useful for daytime terrestrial viewing.

I'd still choose the Owl eyepieces myself for the good eye relief at the higher powers which I believe you are after for lunar viewing and wider 66 degree vs 52 degree view of the plossl's.


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pdxmoon
Pooh-Bah
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Reged: 06/27/13

Loc: Oregon
Re: Newbie Lunatic Needs Advice new [Re: AngryHandyman]
      #5948126 - 06/30/13 02:13 PM

Thanks Jeremy. I agree. I also have long eyelashes!

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Jon Isaacs
Postmaster
*****

Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Newbie Lunatic Needs Advice new [Re: pdxmoon]
      #5948232 - 06/30/13 03:23 PM

Quote:

I'm happy to report that I did some lunar observing last night with my current scope and it was wonderful!

I used the 2x Mead barlow with the 25mm Celestron kit scope. By trial and error I set the scope at 0* with the counter weight straight across. That way I moved the scope up/down using the one fine tune tube (don't know what's called) that actually works. I had to manually move the scope left/right because that remote is not working--I turn the tube and it does nothing.

So other than that, which wasn't a big deal, it was awesome.

I'm buying some new eyepieces. I'd love to get even more detail than I got with the 2x barlow. If I were to start with one more, what would you suggest?

Thanks, all!






Glad to hear you had a good session with your scope.

Regarding the "left-right" that is not working. That adjustment is not a gear drive but rather what is known as a "tangent arm." In this case, it's basically a spring loaded threaded rod. It has a limited travel, if you are at either end of the travel, it won't work any more.

I am not exactly sure what is happening here, it's possible that you have run it up against one end of the travel and that the slow motion knob is spinning or the set screw is slipping where it attaches.

(What happens when you try to move the scope side to side? Is it sloppy at first and then it get hard? You should look closely at it when you try to move it and see if you can see what is happening.)

Anyway, with a tangent arm, when you get to the end of the travel, you have to loosen the lock that fixes the motion, back up the tangent are to the middle and tighten the lock. That may be all that is necessary.

This is an Equatorial mount, the geared axis is the RA (Right Ascention) axis which can track an object as the earth rotates. The second axis, the Dec (Declination) is only necessary for centering and fine tuning during tracking, that's why it's a tangent arm.

If you set it up as an equatorial mount, that is the RA axis pointing at Polaris, I think you would be happier.

Jon


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stevenf
sage


Reged: 10/11/09

Loc: Vancouver, BC
Re: Newbie Lunatic Needs Advice new [Re: pdxmoon]
      #5948254 - 06/30/13 03:37 PM

Quote:

This is on local Craig's List. Opinions?

http://portland.craigslist.org/mlt/for/3889522489.html




I have that Meade kit and I've been perfectly happy with them for years.


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stevenf
sage


Reged: 10/11/09

Loc: Vancouver, BC
Re: Newbie Lunatic Needs Advice new [Re: stevenf]
      #5948257 - 06/30/13 03:41 PM

If you're happy with the views that your current scope is giving you (and it does sound like a perfectly fine scope) a solid mount will probably be the best investment you could make in putting together a solid, easy to use and enjoyable experience. The Porta II mentioned above is a good one, the Orion Versago II is also excellent and a bit cheaper (but no slow motion controls) http://www.telescope.com/Mounts-Tripods/Altazimuth-Mounts-Tripods/Orion-Versa...

If you get a new mount you may need to invest in rings and a dovetail as well, not sure how compatible your current setup is with the standard dovetail mounting on these mounts.


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pdxmoon
Pooh-Bah
*****

Reged: 06/27/13

Loc: Oregon
Re: Newbie Lunatic Needs Advice new [Re: stevenf]
      #5948413 - 06/30/13 05:42 PM Attachment (4 downloads)

Jon:

What you describe is exactly what has happened on my mount. I will try and reconfigure it and loosen and reset.

I think I'll leave this mount as is and make it work--meaning, learn how to use it! (BTW--what kind of scope is this? I'm still learning my terms--is it a refractor or reflector? It's the simplest kind of scope--no?)

I really appreciate your help! I think this scope will be fine for backyard use--a bit clumsy to move, but I can deal with it.

It isn't very portable for me, tho, and next up will be to find a lightweight scope that can be moved in the car easier. So let me ask you: are there scopes of this kind with shorter tubes? Anything you might suggest that I could use as a throw it in the trunk scope (I know the 90 mak is very portable, but I'm talking about a scope that uses the same mechanics as my current one, since there is no cool down, etc.)

Finally, here's a crude pic I took last night thru the eyepiece with my iPhone. Over exposed, just held it up to the eyepiece, my lens view was much better, but it's an offering of thanks to all of you for you kind help.

Edited by barnum54 (06/30/13 05:47 PM)


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Jon Isaacs
Postmaster
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Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Newbie Lunatic Needs Advice new [Re: pdxmoon]
      #5948579 - 06/30/13 07:48 PM

Quote:

Jon:

What you describe is exactly what has happened on my mount. I will try and reconfigure it and loosen and reset.

I think I'll leave this mount as is and make it work--meaning, learn how to use it! (BTW--what kind of scope is this? I'm still learning my terms--is it a refractor or reflector? It's the simplest kind of scope--no?)

I really appreciate your help! I think this scope will be fine for backyard use--a bit clumsy to move, but I can deal with it.

It isn't very portable for me, tho, and next up will be to find a lightweight scope that can be moved in the car easier. So let me ask you: are there scopes of this kind with shorter tubes? Anything you might suggest that I could use as a throw it in the trunk scope (I know the 90 mak is very portable, but I'm talking about a scope that uses the same mechanics as my current one, since there is no cool down, etc.)

Finally, here's a crude pic I took last night thru the eyepiece with my iPhone. Over exposed, just held it up to the eyepiece, my lens view was much better, but it's an offering of thanks to all of you for you kind help.




Barnum: (I hope that is your name)

Your scope is a refractor, refractors use glass to bend/refractor the light to a focus. Reflectors use mirrors to reflect the light to a focus. A Maksutov-Cassegrain is both, a Catadioptic or CAT for short, it uses mirrors but has a refractive corrector to correct the aberrations of the mirrors.

Your scope is an achromat. Refractors have the problem that the different colors travel at different speeds in the glass and so they are bent differently. With a single lenses, this is a big problem. The achromat uses two lenses of different glasses and different shapes so that the light is bent equally and comes to a common focus, or nearly so.. It is not quite perfect. On bright stars the unfocused red and blue ends of the spectrum combine to form purple, this is known as Chromatic Aberraton, false color, color fringing. The amount of purple seen increases as the aperture is increased and as the focal ratio is decreased.

Your scope, an 80mm F/11, has visible chromatic aberration but it affects the quality of the image only slightly. I have owned several of 80mm F/11 achromats, currently I own two, unfortunately they are tied up in a laboratory experiment at work.



Choices for a portable scope:

- At some point you might find yourself interested in objects beyond the moon. It's worth considering whether you will want to expand your view beyond the moon and the solar system.

- More compact refractors for high magnification viewing:

As noted above, the chromatic aberration of an achromat increases as the focal ratio decreases. Since the focal ratio is focal length divided by the aperture, a more compact scope means a shorter focal length which means more chromatic aberration.

The solution to this is the apochromat, achromats were invented in the late 1780's, apochromats were invented a 100 years later but did not become a reality for the amateur astronomer until about 30 years ago. Apochromats, "apo's" use fluorite based glasses that allow the designer to achieve essentially perfect color correction. About 10 years ago, Orion introduced the ED-80, it was the first affordable apo, an 80mm F/7.5 for $500.

That's the problem the apos and EDs (similar scopes that use fluorite based ED glass and have very good color correction), they are expensive. An 80mm ED scope will be over $400 new for a basic scope without mount, eyepieces, diagonal, etc...

- If the money is there, an 80mm apo/ED is a very nice, compact scope that is capable of providing as good an image as is possible with an 80mm scope at high magnifications and providing low power, widefield views of 4 degrees or more. A great all around scope.

- If one is fixed on a refractor and an apo is out of the question, then the ST-80 is a viable option. These 80mm F/5 achromats definitely show false color on brighter objects, the moon is not quite as crisp and clear as it is in your 80mm F/11, it would not be my choice as a lunar-planetary scope. On the other hand, I do have an ST-80 and I have spent an hour with it observing the moon, it's not the best but it's certainly enjoyable and it would take a while to run of new features to view. They are affordable, the basic scope is $120, and portable. The scope itself is only 15 inches long. ST-80s are also nice because they are capable of widefield views, up to 4 degrees, with affordable eyepieces... They are pretty good for birdwatching too...

- The third option would be a 90mm Mak. While John was very honest and pointed out the thermal issues with the Mak, I still think the Mak is a viable option for you as a lunar planetary scope. All scopes have their pluses and minuses, the Mak might not be rock-solid steady when first set out but its still quite good, the views of the moon will not be perfect but they will still be quite good.

So there you have it, of course there a myriad of choices, larger aperture scopes that provide better resolution but more thermal issues and more transportation difficulties. We all come to our own balance between optical prowess and the effort required to setup and observe, I call that the hassle factor. My collection of telescopes includes scopes of most every imaginable size but somehow most of the time I find myself using an 80mm or 100mm refractor when I am out in the backyard...

As far as advice.. your scope is a good one, learn to use it, learn to enjoy it. And it's not so difficult to haul it around. Open the clamshell, remove the OTA. Remove the spreader, fold the legs and shorten them if needed. It'll fit in a car without much trouble.

Jon


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pdxmoon
Pooh-Bah
*****

Reged: 06/27/13

Loc: Oregon
Re: Newbie Lunatic Needs Advice new [Re: Jon Isaacs]
      #5948619 - 06/30/13 08:14 PM

Jon, again, thank you.

Are these scopes good choices for lunar/planetary viewing? The price is certainly right and they are portable.

http://www.skyandtelescope.com/observing/home/113230149.html

Thanks again for your counsel.

Edited by barnum54 (06/30/13 08:15 PM)


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AngryHandyman
sage


Reged: 06/28/13

Loc: Nanaimo, BC
Re: Newbie Lunatic Needs Advice new [Re: pdxmoon]
      #5948667 - 06/30/13 08:49 PM

I think your current scope is a better choice for lunar and planetary viewing, these are more suitable for wide field views. They are portable, I have the larger starblast 6 and like it a lot, but a nice alt-az mount for your current scope would probably get you what you're looking for - Ease of use and portability if your current eq mount isn't doing it for you.

Edited by AngryHandyman (06/30/13 08:51 PM)


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Paco_Grande
Carpal Tunnel
*****

Reged: 07/14/12

Loc: Banana Republic of California
Re: Newbie Lunatic Needs Advice new [Re: John Kuraoka]
      #5948698 - 06/30/13 09:14 PM

Quote:


The 90mm Mak-Cass packs a lot of magnification into a very compact rig, but be aware that the stock Dobsonian-style mount (the one you get at the $199 price point) doesn't let you take advantage of those higher powers.




I can attest to this. Orion also suggests placing this mount on a tripod. Ahem... I tried it on a hefty Manfrotto and it would vibrate if a fly farted nearby. That table top mount is a major compromise and just doesn't work well for that scope.


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Paco_Grande
Carpal Tunnel
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Reged: 07/14/12

Loc: Banana Republic of California
Re: Newbie Lunatic Needs Advice new [Re: Paco_Grande]
      #5948714 - 06/30/13 09:20 PM

BTW, keep an eye out for demo sales at Mr. StarGuy. He's a Vixen supplier and often has demo scopes and mounts for sale. He often prices a demo Porta II mount for $180 or so. That's about $100 off new. Porta II's used are hard to come by.

http://www.mrstarguy.com

I can see you set up for lunar with your existing scope on a modern alt/az mount (either the Porta II or that Orion), and picking up a nice, used 8" dob at some point. They would compliment one another quite nicely.


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pdxmoon
Pooh-Bah
*****

Reged: 06/27/13

Loc: Oregon
Re: Newbie Lunatic Needs Advice new [Re: Paco_Grande]
      #5948862 - 06/30/13 11:13 PM Attachment (2 downloads)

Would this do?
http://www.mrstarguy.com/scripts/prodView.asp?idproduct=351

Also, my tube is bracketed to hold it to the scope. I see no way to attach my tube to these.


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