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cos
member
Reged: 07/17/09
Posts: 27
Loc: Utah
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I hope someone can help me. I have an etx-125pe and I am trying to do some deep sky viewing. I am still a newbie, but I am trying to see some DSO's. I have now spent 3 nights in a row trying see something other than a small smudge. I understand my scope has some limitation on light collecting, but surely there must be something I am doing wrong.
Specifically I spent a huge amount of time trying to see the m13 globular cluster, which appears as a small smudge in my scope. (When I say small I am talking smaller than the surface area of jupiter when I am viewing)
I start out seeing the small smudge with a 40mm lens, (roughly 48x) and keep increasing the magnification, but at around 150x the smudge disappears entirely because its too dark.
How bright should a cluster like the m13 be? To give you an example I let my son look at it at around 90x and he could not tell there was ANYTHING there at all.
How clear should I expect to see a star cluster? Should I be able to tell that there are stars in it? I have seen lots of pics taken with etx-70 scopes that show great detail. Should I be able to obtain a similar view in the etx-125?
I recognize I dont have the MEGA light collection cannon, but shouldnt I be able to see some clusters?
I own an etx-80 as well, but in theory shouldnt I be able to see more with the 125? Unless of course it requires a super wide field of view.
Im open to any changes, (of course my wife might leave me if it involved dropped more money on another scope)
Thanks
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COS
Meade ETX-80BB
Meade ETX-125PE
Garrett Gemini 11x56
Bushnell 8x42
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jgraham
Postmaster
Reged: 12/02/04
Posts: 6760
Loc: Dayton, Ohio
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Hmmm, that doesn't sound right to me unless you're dealing with major light pollution. I've found the ETX-125 does a fine job on deep sky objects and globulars are among my favorite targets. I typically use either my trusty 20mm Erfle or my Orion binoviewers fitted with 25mm Explorer II eyepieces. It's hard to describe how bright a cluster like M13 should be, diffuse objects always look like puffs of smoke, but it should look fairly large and grainy. If I recall right large globulars like M13 fill maybe 1/4 to 1/3 of the field of view. I observe from my back yard under fairly bad skies (mag 3-4ish) and I find it helps to throw a towel over my head to block out stray light (I'm going to make some light shields) and to observe while seated so I can really study a field of view. I've found that as I take it all in I see more and more of the cluster. You might also try hoping around the sky looking at some of the really nice open clusters as these stellar objects are much easier to see than any other deep sky object.
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-John
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Homebuilt scopes from 4.25-16.5"
Meade LXD75-N6/SN6/SC8, DSX-90, ETX-60BB, ETX-125PE, DS-2130
Orion StarBlast, BinoViewers, Coronado PST
Rebel XT/XTi, DSI Pro (I, II, & III), DSI, LPI, Electronic Eyepiece, Phillips SPC900NC
Tasco 60mm Refractors
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cos
member
Reged: 07/17/09
Posts: 27
Loc: Utah
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Thanks for the reply. It sounds like I am am doing something wrong. Im glad to know that it is not a limitation of the scope. I am wondering if there is a possible galaxy or more distant cluster that I am seeing, and that I am missing the big picture.
It sounds like I am in the same situation as you as far conditions and light pollution.
If you suggest that your best viewing is with the 20mm, (which is around 95x) and that fill around 1/3 of the eyepiece, I am definitely looking at the wrong object.
Last night I was up to a 12mm, and the fuzzy was still smaller than 1/20 the size of the field of view.
I have tried some open clusters, but typically end up with 3-4 stars in the field of view. (not really impressive)
BTW, how do you like those binoviewer? Do they loose much light?
I feel relieved to know its not a limitation of the scope, but still am unsure what Im doing wrong.
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COS
Meade ETX-80BB
Meade ETX-125PE
Garrett Gemini 11x56
Bushnell 8x42
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Treehopper
professor emeritus
Reged: 07/29/08
Posts: 582
Loc: Upstate NY
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Hmmm...that's curious. I just checked, and M13 is right around the threshold of naked eye visibility at just under mag6. It's also around 25 arc-minutes which is slightly smaller than a full moon. Even at f/15, the ETX-125PE should be able to easily pick that up.
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Tim
Champion of small aperture scopes everywhere!
Meade ETX-125PE
Meade ETX-80
Celestron FirstScope 76mm Mini-dob
 Updated: 09/16/2009
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jgraham
Postmaster
Reged: 12/02/04
Posts: 6760
Loc: Dayton, Ohio
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Just to refresh my memory I took my ETX-125PE outside for a while this evening and did a sweep of several globulars and open clusters. I started with M13 and 92, then swung through M12, 10, 14, and 2. For open clusters I visited M11, NGC457 and 663. Of course they vary in size and brightness, but overall they looked pretty nice. The globulars looked like little puffs of stardust. M11 looked wonderful as did NGC457. Deep sky observing under light polluted skies is always tough, even with my 16.5", but I'm very pleased with the performance of my ETX. As for the binoviewers, they're very nice. In theory the image is a tad fainter, but your brain likes using both eyes at the same time so you really don't notice it. I've sone quite a few tests using mono and binocular vision and I can always see more with the binos. The real bonus of the binoviewers is the complete absence of eye strain.
Have fun!
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-John
================================================
Homebuilt scopes from 4.25-16.5"
Meade LXD75-N6/SN6/SC8, DSX-90, ETX-60BB, ETX-125PE, DS-2130
Orion StarBlast, BinoViewers, Coronado PST
Rebel XT/XTi, DSI Pro (I, II, & III), DSI, LPI, Electronic Eyepiece, Phillips SPC900NC
Tasco 60mm Refractors
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DNTash
scholastic sledgehammer
Reged: 09/02/07
Posts: 762
Loc: India
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Sounds like you need a darker sky. The nice thing about the ETX-125 is you can take it on the road and find one. It will make a huge difference, especially on something like M13.
Clear skies!
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AT 72
TMB 92
Orion 120ST
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jgraham
Postmaster
Reged: 12/02/04
Posts: 6760
Loc: Dayton, Ohio
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Good point. I'd love to take my ETX out under dark skies sometime. I once had a chance to take a homebuilt 6" f/4.5 Newtonian out under mag 7 skies and it was absolutely amazing. From my back yard the trick is to find the darkest spot I can, which unfortunately is getting harder to find. I gotta get a set of light blinds built.
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-John
================================================
Homebuilt scopes from 4.25-16.5"
Meade LXD75-N6/SN6/SC8, DSX-90, ETX-60BB, ETX-125PE, DS-2130
Orion StarBlast, BinoViewers, Coronado PST
Rebel XT/XTi, DSI Pro (I, II, & III), DSI, LPI, Electronic Eyepiece, Phillips SPC900NC
Tasco 60mm Refractors
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jgraham
Postmaster
Reged: 12/02/04
Posts: 6760
Loc: Dayton, Ohio
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Just for yucks... this is my ETX-60BB (the smaller sibling of your ETX-80BB) sitting next to my ETX-125PE.
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-John
================================================
Homebuilt scopes from 4.25-16.5"
Meade LXD75-N6/SN6/SC8, DSX-90, ETX-60BB, ETX-125PE, DS-2130
Orion StarBlast, BinoViewers, Coronado PST
Rebel XT/XTi, DSI Pro (I, II, & III), DSI, LPI, Electronic Eyepiece, Phillips SPC900NC
Tasco 60mm Refractors
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cos
member
Reged: 07/17/09
Posts: 27
Loc: Utah
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Wow
Thanks everyone for the input. After looking at some pictures and hearing your replies, I am convinced I was not seeing the cluster at all, but was trying to focus on some "other" object.
John, I am curious of your opinion on the etx-60. I kind of had shelved the etx-80 when I got the 125, I figured I would be able to get more light collecting power and better views from the 125. I also own a pretty good Focal Reducer that allows me to get lower magnification on 125. Im my case (which is similar to yours ) Is there any real reason to use the etx-80 when I am doing back yard viewing?
Thanks for your feedback and encouragement, Im hoping to give it another run tonight.
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COS
Meade ETX-80BB
Meade ETX-125PE
Garrett Gemini 11x56
Bushnell 8x42
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Seiko4169
member
Reged: 07/04/09
Posts: 27
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I'm not sure if you managed to confirm whether you were indeed looking at M13 or not but my 5i visual observations sound very much like you're ETX125 ones. M13 is in my scope a greenish fuzzy and disappointing view. The same m13 in my old 8i and 800CPC was stunning and certainly was instantly recognizable as the pictures in the book. I suspect that light poluted areas and these small scopes simply result in these globulars looking very very dim and fuzzy.
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Nexstar 5i
Sky Align Handset
Baader Hyperion 8-24mm zoom
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jgraham
Postmaster
Reged: 12/02/04
Posts: 6760
Loc: Dayton, Ohio
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I don't get my little ETX-60 out very often. I bought it as something to have a bit of fun with and that's what I use it for. It also makes a great little white light solar scope; I have a solar filter originally designed for the ETX-90 that fits the dew shield on the ETX-60BB. I'll often set my ETX-60BB up for solar viewing right next to my PST. I'm curious enough about the ETX-80BB that I'll probably end up picking one up. I just love small telescopes and I still have a couple of classic 60mm Tasco's in my collection that I enjoy using on a cool spring or fall evening. Also when we take trips by car I can't stand the ida of travelling without a scope so I usually throw the ETX-60BB in the back and take it with us. I had it out under really dark skies in the Great Smoky Mountains National Park once and it was a delight to use.
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-John
================================================
Homebuilt scopes from 4.25-16.5"
Meade LXD75-N6/SN6/SC8, DSX-90, ETX-60BB, ETX-125PE, DS-2130
Orion StarBlast, BinoViewers, Coronado PST
Rebel XT/XTi, DSI Pro (I, II, & III), DSI, LPI, Electronic Eyepiece, Phillips SPC900NC
Tasco 60mm Refractors
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rmollise
Post Laureate
Reged: 07/06/07
Posts: 4575
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Quote:
I don't get my little ETX-60 out very often.
I don't either....but when I have, I've had some memorable observing runs with it. I tend to use it as a travel-scope, and once, at the Mount Pisgah Inn at the top of Mt. Pisgah in North Carolina, the little feller just blew me away, delivering beautiful views of any Messier I pointed it at, including the Eagle Nebula.
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Uncle Rod
Rod's New Book:
Choosing and Using a New CAT
Available now!
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cos
member
Reged: 07/17/09
Posts: 27
Loc: Utah
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After reading your comments, I think I will save the etx-80bb as my travel scope, and stick to using the etx-125 in my back yard. I had much better success with the m13 this weekend.
I think it was a combination of much dark skies and doing a better alignment with the scope. The view wasnt photograph jaw dropping, but I could clearly see that it was a cluster and could differentiate some of the stars. I found the view with my 15mm to be the best. Still not sure what I was seeing before, but Im pleased with what I saw Saturday night.
Anyone have any good suggestions for nice DSO, that are relatively easy? I have had good luck with m13 and m22.
I just wanted to thank you guys for your help. I am an IT Director by trade and use a lot of Linux and open source stuff, typically when I ask a question on those forums I get flamed and get single line answers with RTFM in them. Its great to meet people that are willing to share their knowledge and give encouragement.
Thanks again
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COS
Meade ETX-80BB
Meade ETX-125PE
Garrett Gemini 11x56
Bushnell 8x42
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jgraham
Postmaster
Reged: 12/02/04
Posts: 6760
Loc: Dayton, Ohio
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I've found that if I spend a little time with each object the longer I look, the more I see. For example; if I really look at it M13 shows countless little points that are some of the individual red giants that populate the cluster. As for simple, bright objects, you might visit sites that specialize in objects for small telescopes. If I recall right there are a couple of good lists floating around intended for 60mm refractors and these do reall well in the ETX-125. Sue French's "Celestial Sampler" is also an excellent resource. Another that I have enjoyed is E. Karkoschka's "The Observer's Sky Atlas"; I used this book to explore the sky one constellation at a time and I looked at every object he lists for each. The Autostar works great for this kind of sky-hopping.
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-John
================================================
Homebuilt scopes from 4.25-16.5"
Meade LXD75-N6/SN6/SC8, DSX-90, ETX-60BB, ETX-125PE, DS-2130
Orion StarBlast, BinoViewers, Coronado PST
Rebel XT/XTi, DSI Pro (I, II, & III), DSI, LPI, Electronic Eyepiece, Phillips SPC900NC
Tasco 60mm Refractors
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