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Anonymous
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Deep Space Objects - What magnification?
      #11333 - 09/22/03 08:10 AM

I have a Celestron Nexstar 8i scope. The focal length is 2000mm (it is mm right?). Anyway, what magnification should I be using for dso's like Andromeda? I'm reading that it should be visible to the nakid eye, but I can't see anything. I also tried with binocs. No luck. Am I enlarging too much? I typically use a 25mm or an 18mm on the scope. I spoted what I'm assuming is Pleides (sp?) this past weekend, but I couldn't get the whole thing into the field of view.

I also need opinions from you old hands. Should I look at a 1.25" to 2" adapter, and would I get any benefit from using it? I'm assuming it is not as effective/beneficial as a true 2" scope?


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rboe



Reged: 03/16/02
Posts: 63466
Loc: Phx, AZ
Re: Deep Space Objects - What magnification? new [Re: ]
      #11345 - 09/22/03 10:43 AM

For me, Andromeda looks best through the bino's or a very large dob (16"+). In the 11" it appears washed out and faint.

Pleides are a wide field object: Translation; binoculars or refractor.

Sounds like a good star party where you can steal looks through other folks' scopes. We can describe most of this to you but it won't stick until you can see for yourself. For me, a bunch of lights went on when started checking out a bunch of other scopes (and different eye pieces in the same scope). You start seeing the strong points and weaknesses of each design.

You can compare telescopes to motor vehicles. While all will get you from A to B, sometimes a truck is the tool to use, other times a sedan is better. Like a mini-van, some scopes will do very well in many situations but not really excel at them - a SCT comes to mind. I drive a mini-van!

You may want to check your collimation on the 8i. Poor collimation can be a killer. Your scope should be doing very well: From light polluted skies though you will have problems. With my 16" or 11" there are some objects totally invisible until I'm at a dark sky site.

--------------------
Ron


NS11GPS
Pronto
16" dob
127mm F9 Surplus Shed/Crawmach kit scope
Coronado SolarMax 40 on a Celestron 102 Wide Field



Best of ATM


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Jarad
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Reged: 04/28/03
Posts: 5732
Loc: Atlanta, GA
Re: Deep Space Objects - What magnification? new [Re: ]
      #11348 - 09/22/03 11:47 AM

Andromeda is a big object - it would look better in a wider field eyepiece. That said, you will not see much more by using a 1.25-2" adapter in a 1.25" diagonal. I think the C8 can fit a 2" diagonal - if you buy the 2" diagonal or visual back for it, then you can benefit from 2" eyepieces. There is also a f6.3 focal reducer for SCT's that will shorten the focal length and give you wider views with the same eyepieces. You could put the focal reducer on, 2" diagonal, and something like a 35mm panoptic to get a decent wide field (almost 1 degree).

Of course, this is a lot of work to adapt the scope to wide field use. SCT's aren't really ideal for wide field viewing, they are better at medium to high power work. You might want to consider getting a small wide field scope to complement the SCT - for the same price as a f6.3 reducer plus 2" diagonal plus 35 panoptic, you could go and buy something like an ST-80, or the new Orion 80mm apo, or a nice set of 80mm binos which would make a much nicer instrument for wide field work (Andromeda, the whole Veil, the North American nebula, etc. all look really good in small fast scopes or large binos).

Hope this helps,

Jarad


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Victor Kennedy
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Reged: 05/22/03
Posts: 12190
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Re: Deep Space Objects - What magnification? new [Re: Jarad]
      #11357 - 09/22/03 12:43 PM

The Andromeda Galaxy is better in my 80 mm refractor than in my C8. However, in the C8 with a 28 mm eyepiece I can see M81 and M82 in the same field of view, and that's a nice sight. I can also barely squeeze the double cluster in Perseus into the same field of view in the C8, but that again looks better to me in the refractor. I like the Pleiades best in binoculars. My favorite DSO in the C8 is the Orion Nebula, closely followed by M13, the globular cluster in Hercules, and M27, the Dumbbell nebula. I don't know Dallas, I was there in February and the sky looked bright. DSOs look much better from a dark site (the Dark Side?).

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No matter how hard you push the envelope, it's still stationary.

Edited by Victor Kennedy (09/22/03 12:47 PM)


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Anonymous
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Re: Deep Space Objects - What magnification? new [Re: Victor Kennedy]
      #11368 - 09/22/03 01:34 PM

In my neighborhood, it almost looks like dawn any time after nightfall. The entire northwest horizon has a bright orange glow that pretty much blows out any stars except for the brightest. Spica is visible. Polaris is 'barely' visible. I can view southern objects with 'ok' results. Objects that are Northeast are much harder for me since my house is in the way. I could take the scope out onto the front yard, but the neighbors would probably call the police on me for bizarre nocturnal behavior . Objects in the Southeast are out of the question as well, since I have about 3 differnt street lights all in that general direction. I'm limited to the light polluted southwest, south, directly overhead, and to a limited extent, the northwest.

I have no idea where to find a local star party

I do have a pair of 7x50 binoculars that I bought to tide me over until I got my scope. They are what I ended up using to view Pleiades (beautiful sight!). I haven't even tried the 33mm eyepiece. I'm such a newb. I had no idea that some of these objects were so big. Maybe I'm missing Andromeda for the obvious? I can usually spot Uranus with the nakid eye on a good night, if that gives you any indication. At least I could last month. I can't seem to find it lately. Nebulas are usually extremely rare for me. Clusters like the Wild Duck, viewed via the scope usually show maybe 40-50 stars at best. How big is Andromeda to the nakid eye? I imagined it was tiny, but I'm getting the impression it's not.


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Anonymous
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Re: Deep Space Objects - What magnification? new [Re: ]
      #11413 - 09/22/03 09:11 PM

I use an 8" SCT and always start with a 40 MM eyepiece (50X) and go up from there. The lower magnification will let you find an object easier. Each object is different and some take magnification better than othrs. I step up the power until it stops producing a best picture and go back down a notch. From a fairly dark place andromeda looks like a dim fuzzy star. It does not look very big to the eye but is very bright and large in the eyepiece. Be sure you are looking in the right place for it and try sweeping back and forthe when it is as close as youcan get to where you think it is and still not visible in teh eyepiece.

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Anonymous
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Re: Deep Space Objects - What magnification? new [Re: ]
      #11477 - 09/23/03 07:42 AM

I'll probably have to rely on GOTO to find it if it's faint, even with dark skies. I'm assuming it should be visible in the scope, regardless of light polution? lmckennon, what magnification do you find is best to view it with? Your using the same size scope as me.

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Victor Kennedy
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Reged: 05/22/03
Posts: 12190
Loc: Slovenia
Re: Deep Space Objects - What magnification? new [Re: ]
      #11478 - 09/23/03 07:42 AM

DJ, from your location, finding galaxies and nebulae is going to be frustrating. I used to live in Toronto, and gave up on these things until I could get out of town on holiday. Not that it's impossible, but they will be hard to find, and when you do find them, they will be only a shadow of what you will be able to see from a dark sky.

Planets, the moon, and double stars are fun though (I didn't use to think so until I actually started looking at them). Mars is good right now, and Saturn and Jupiter are becoming visible in the early morning. In the evening, check out Mizar and Alcor (the middle star(s)in the handle of the Big Dipper), and Epsilon Lyra near Vega (the double double). With your scope you should see a good split with an 18 mm eyepiece, just about like this: http://members.cox.net/rmscott/quickcam/epsilon_lyra_20010928.html

______________________

http://www.geocities.com/stormtroopertk421_2000/Yoda-Why_Wish_You_Become_Jedi.wav

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No matter how hard you push the envelope, it's still stationary.

Edited by Victor Kennedy (09/23/03 07:51 AM)


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Anonymous
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Re: Deep Space Objects - What magnification? new [Re: Victor Kennedy]
      #11485 - 09/23/03 09:25 AM

The first link looks like a quad system? two double stars orbiting each other? I've seen Mizar/Alcor. They were the first double I looked at . I'm defintely liking the planetary views. I've seen Mars (and ashamed to admit I'm becomming bored with it..the new camera adapter should help with that). I've also seen Uranus, and I think, Neptune (not sure on that one). I did finally get my first look at Saturn last week before heading out to work (I'm an early bird, leaving for work at 5:30). I was almost giddy for lack of a better word, I'm sad to say. Jupiter is just comming up at 5:30 or so in the morning, so I haven't had a chance to see it yet, but I'm hoping to spot it before the end of the month.

I'm somewhat depressed about the nebula views. I have managed to see three on a very good night. I haven't seen any since. All of them were faint bluish-gray, or just plain gray. Not very exciting to look at, although I was very excited. How does one find a good viewing spot outside of the city lights? Do you just drive until you find a dark spot, pull over, and borrow someone's field?


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rboe



Reged: 03/16/02
Posts: 63466
Loc: Phx, AZ
Re: Deep Space Objects - What magnification? new [Re: ]
      #11496 - 09/23/03 10:20 AM

Saturn is always cool to me. The nebula M42 in Orion should be visible at the same time Saturn is. Orion has always been special to since I was a kid, and I think it's the easiest nebula to see and find. I can make out some light green colour; typical for older eyes.

--------------------
Ron


NS11GPS
Pronto
16" dob
127mm F9 Surplus Shed/Crawmach kit scope
Coronado SolarMax 40 on a Celestron 102 Wide Field



Best of ATM


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Jarad
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Reged: 04/28/03
Posts: 5732
Loc: Atlanta, GA
Re: Deep Space Objects - What magnification? new [Re: ]
      #11498 - 09/23/03 10:25 AM

Mars is the least exciting of the planets to look at - even at it's best, there just isn't much high contrast stuff to look at. Jupiter and Saturn are much more interesting, especially if you are just learning how to see details. Nebula's can be very nice too, although dark skies REALLY help a lot. You should try to get a nice nebula filter (something like a UHC or OIII filter) - that will help a lot on nebulas from light polluted areas. Orion will be up in the evening soon, and the Veil is still up for a while, as is the Swan and the Trifid (although these are a bit far south - you may have trouble seeing them up there). These all look god at medium to high powers. You won't see much color, but with a filter you should see some nice fine structure to them.

Enjoy!

Jarad


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Anonymous
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Re: Deep Space Objects - What magnification? new [Re: Jarad]
      #11504 - 09/23/03 10:39 AM

I think Saturn has also been my favorite so far. I've seen the faintly bluish glow below orions belt, but browsing with the scope didn't turn up much. I suspect I'm trying to magnify too much again ( used a 18mm piece with a 2000mm focal length). I didn't realize some of this stuff just looks good in binoculars.

I think it's funny you mentioned the O3 filter. I ordered one last week Friday, and hope to have it sometime this week. I want to be able to view the Nebulas, but I don't know what kind of results to expect with the O3 filter. I'm hoping for the best anyway. What magnification would you suggest for the Swan and Trifid? I'm down in Texas (or possibly up in Texas for you ). No idea if that's far enough to see those or not. I've got a pair of 7x50 binoculars, and my 8" SCT.


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Jarad
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Reged: 04/28/03
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Re: Deep Space Objects - What magnification? new [Re: ]
      #11512 - 09/23/03 11:01 AM

Sorry - I thought I saw a previous post that you were in Canada - Texas is plenty far south to see them. The swan and trifid are near each other, above Sagitarius in the south. I recommend getting one of the star chart programs so you can make some finder charts for yourself (check out the computers and astronomy forum here for links to several programs). The Orion nebula is naked-eye visible as the middle star of Orions "sword". It should be very obvious in the eyepiece when you find it. For magnification, start with your lowest for all of them to find and center them, then step up until you find the eyepiece that best frames them (it will depend on exactly what eyepieces you are using). From memory, I would guess the will look good at around 100x. The Veil is huge, you won't be able to see all of it at once, but it has a lot of fine structure to it, so it is fun to pan around the loop at med-high power (100-200x).

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Anonymous
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Re: Deep Space Objects - What magnification? new [Re: Jarad]
      #11524 - 09/23/03 01:26 PM

I have Starry Nights Pro. I usually just check it for major stars when doing alignments. 95% of the stars in the sky are not visible in my location due to light pollution. I can see all of Orion easily, and the spot that I think the Orion nebula is located also visible, as a hazy blue spot to the nakid eye. When I looked in my scope, I either had it on the wrong spot (very possible with my crappy laserscope finder thingamajig), or I just had it magnified to much. Since I've been on this forum, everyone has me convinced to break out the 33mm and browse around. I stuck the 2x barlow in my scope when I first set it up, and I haven't taken it out since . I'm probably doing all the usual newb things, thinking more magnification is better. I definately plan to explorer the lower power eyepieces! My O3 filter is on the way. Now if I could only get a clear night to actualy view in!

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Victor Kennedy
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Reged: 05/22/03
Posts: 12190
Loc: Slovenia
Re: Deep Space Objects - What magnification? new [Re: ]
      #11535 - 09/23/03 03:14 PM

Quote:

When I looked in my scope, I either had it on the wrong spot (very possible with my crappy laserscope finder thingamajig), or I just had it magnified to much.




Is your finder collimated? Find something bright, like Mars, in it, then look through your eyepiece to make sure they're both pointed at the same thing. If not, there are some adjustment knobs on the side of the finder.

--------------------
No matter how hard you push the envelope, it's still stationary.


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Anonymous
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Re: Deep Space Objects - What magnification? new [Re: Victor Kennedy]
      #11607 - 09/24/03 07:53 AM

It has a very LARGE laser light 'spot' that is projected onto a glass lense about 3 inches from the emitter. The laser light tends to be about 4 times larger than the target star and the lens is 1X (no magnification is 1X right?), so you can only get a general idea of what your pointing at. When you can't see your target (due to the fact that it's completely covered by this laser 'spot'), you know your in the general neighborhood. To make matters worse, the pointers level/height adjustment knobs are exactly the same as the nob to turn it on/off. When I'm sighting along the finder (basically staring at the spot on the glass lens), I find I often turn the wrong knob to turn the unit on or off, throwing the alignment out of wack. It's not a very good design. I'm already looking at ordering a 'proper' finderscope. Something like a 9x50 scope.

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Dave Mitsky
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Re: Deep Space Objects - What magnification? new [Re: Jarad]
      #11609 - 09/24/03 08:21 AM

"Mars is the least exciting of the planets to look at - even at it's best, there just isn't much high contrast stuff to look at."

I beg to differ. Mars is the only planet that has visible surface features and during this apparition has been a superb object for telescopic examination. I place Jupiter ahead of Mars only because Mars is normally a rather difficult target except for a few months bracketing each opposition and some oppositions leave a lot to be desired. As for Saturn, well, if you disregard its rings and satellites it is really rather mundane compared to Jupiter. Mercury and Venus are for the most part unexciting except for their phase changes. The other gas giants show almost no detail in most amateur instruments and Pluto, if you consider it a planet, absolutely none.

Dave Mitsky


--------------------
Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

Edited by Dave Mitsky (09/24/03 08:33 AM)


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Dave Mitsky
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Re: Deep Space Objects - What magnification? new [Re: Dave Mitsky]
      #11611 - 09/24/03 08:55 AM

"You might want to consider getting a small wide field scope to complement the SCT - for the same price as a f6.3 reducer plus 2" diagonal plus 35 panoptic, you could go and buy something like an ST-80, or the new Orion 80mm apo, or a nice set of 80mm binos which would make a much nicer instrument for wide field work (Andromeda, the whole Veil, the North American nebula, etc. all look really good in small fast scopes or large binos)."

I agree. The Orion ST80 that I bought as a travel scope for the 1998 has given me far more pleasure than I could have ever anticipated.

BTW, a 35mm Panoptic will vignette when used with a focal reducer, IIRC. A 27mm Panoptic will perform satisfactorily I believe.

Dave Mitsky

--------------------
Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.


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cirrus
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Reged: 05/10/03
Posts: 174
Re: Deep Space Objects - What magnification? new [Re: Dave Mitsky]
      #11639 - 09/24/03 01:30 PM

DJ:

Dallas should have at least 3 or 4 astronomy clubs. Just do an internet search. Clubs usually have prefered dark sites for holding star parties. From a dark site, the Andromeda galaxy is a naked eye object. Although I have seen it from dark sites with scopes as large as 22" aperture, my favorite view of M31 and its bright companion galaxies has always been with my 12X50 binocualrs from a dark site. From a light polluted site, the best you can hope for is a washed-out view of the fuzzy nucleus. Very dissapointing.

Everybody needs to go to a dark site every now and then. It's the only way to really see and appreciate DSOs.

cirrus


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Anonymous
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Re: Deep Space Objects - What magnification? new [Re: cirrus]
      #11708 - 09/25/03 07:46 AM

I found one college club. No idea if they accept non-students. The other club I found in Dallas has a dark site in Oklahoma. Not exactly close. I'm suprised they would go so far to find dark skies!

My new set of batteries died yet again last night (my TANK is already on order, but it's a slow shipper..not due until next week). I spent time last night trying to spot M31 with binoculars instead, with no luck. If I did see it, it looked like a faint star to me. Does it have what appears to be a close companion star? Almost like a double in the binocular view. I think I had the right spot, but then again, I can only see Polaris, and none of Ursa Minor. Dim objects are hard for me, and ensuring I've even got the right star is difficult with so few stars to guide by.


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