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Will I see DSO's with a Reflector?


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Just come in due to cloud cover after a wonderful evening following Jupiter and trying to get to grips with searching for DSO's on my manual EQ5 mount.

I set myself up with my laptop and Stellarium in order to get a good indication of the location of the Clusters/Nebulae in the sky.

Originally I began with locating Aldebaran and moving to Pleiades with ease and the goal was to work across to M34 (Spiral Cluster).

This proved tricky as Stellarium represents M34 with an array of detailed individual star clusters, yet I never managed to view any such detail with my EVOSTAR 120 Refractor?

I then went to Orion and the Great Nebula in Orion, which is a site to behold.

After viewing Orion I decided to stay in this region and look to locate the Heart-Shaped cluster. Again I located Sirius and Procyon with ease and the Heart Shaped cluster should be almost halfway between these 2 points, using the viewfinder I could locate the dim light of the feature and with an 8mm BST eyepiece in the EVOSTAR 120, I could see about 3 stars in close proximity, but no gas cloud or the high concentration of stars that I can view in Stellarium.

I would like to upgrade to a goto mount to help locate DSO's and an EQ6 or HEQ5 mount appears to be much better value as a package with an 8" or 10" reflector. Would the 10" reflector view the DSO's with a great deal more clarity than  my EVOSTAR 120 Refractor and would I see the gas clouds on DSO's or can I view this already with a decent Filter on my Refractor?

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Using the Messier catalogue as a sort of reference then a lot of "DSO's" are clusters, and the Evostar should be fine on these.

Of the planetary nebula then boarder line and similar on galaxies.

Will question how they describe it (M50) as "heart shaped". The image of it seem pretty indistinct and I would have said easily missed, although sites say it is easy.

A reflector tends to have a bigger objective and so you should get brighter objects unless you push the magnification. And certainly a 250mm reflector will show more then the 120mm, it is collecting over 4x the light.

Yes dust/gas clouds will be more apparent but you will need a dark sky, simply because they are very dim and easily lost in any background light.

Half my concern is that the 250 would be a nice big step up, but also not as easy/quick to set up and use.

Sort of it may collect 4x the light but may get used less then 1/4 the time that the 120 does.

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Personally I find large Newts cumbersome on EQ mounts. You have to deal with the meridian flip and the EP being in odd places at times. I'd rather have a 10 inch GoTo Dobsonian for visual observing. Really the EQ mount, now that Alt Az mounts can deliver go to and tracking, is really only needed for photography. The German EQ mount also invents the need for counterwieghts, which become a part of your setting up chores...

Olly

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I have 4" f10 achro and a 10" Dob and occasionally I like to compare views between the two scopes. On galaxies, planetary and emission nebulae, globulars, there is simply no comparison. The 10" resolves significantly more. The image is brighter, fainter stars are seen, the DSOs are more vibrant and with greater depth, and so on. Objects which would have been extremely faint or near impossible in the 4", become possible in the 10".

What Olly says also makes a could deal of sense, and is advice that merits careful consideration.

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Just a couple of points to add here. Dark skies and dark adaptation.

You don't mention what your skies are like? If reasonably dark then it makes sense to get a good sized dobsonian to use at home, it will certainly outperform the frac.

If your skies are heavily light polluted then I would probably still consider a Dob but with priority on one you can easily get to a dark site. That will make far more difference to the views than almost anything else. To give you some context, under a very dark sky in Tanzania, I had views of DSOs in my 66mm refractor which rivalled those with an 8" scope at home. It is all about contrast between sky background and the object being viewed.

Which comes on to the second point of dark adaptation. If using you laptop for Stellarium, it is likely that you weren't giving your eye much chance to dark adapt. It can make all the difference between seeing nebulosity and not. Again it depends upon your observing site, if light polluted then getting properly adapted may be difficult, but you can still avoid looking at bright lights etc.

If your site is dark, then after 30 or even 45 minutes you will be amazed how much more you see.

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Just a couple of points to add here. Dark skies and dark adaptation.

You don't mention what your skies are like? If reasonably dark then it makes sense to get a good sized dobsonian to use at home, it will certainly outperform the frac.

If your skies are heavily light polluted then I would probably still consider a Dob but with priority on one you can easily get to a dark site. That will make far more difference to the views than almost anything else. To give you some context, under a very dark sky in Tanzania, I had views of DSOs in my 66mm refractor which rivalled those with an 8" scope at home. It is all about contrast between sky background and the object being viewed.

Which comes on to the second point of dark adaptation. If using you laptop for Stellarium, it is likely that you weren't giving your eye much chance to dark adapt. It can make all the difference between seeing nebulosity and not. Again it depends upon your observing site, if light polluted then getting properly adapted may be difficult, but you can still avoid looking at bright lights etc.

If your site is dark, then after 30 or even 45 minutes you will be amazed how much more you see.

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The sky I have is pretty good, although Im yet to go to an area of perfectly light free pollution which I will do in the next couple of weeks to compare.

This is great advise guys and will try to get and view through a Dob before I purchase.

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  • 1 month later...

I'm not a big fan of goto telescopes...half the fun is in the search..If you just want to see the image and then move on, call them up on the internet. I had friend tell me he saw 100 objects one night. really?  is that what astronomy is about. I use the goto between my ears and spend the money on optics. I do confess though...I use setting circles on occasion, but I still push the telescope around myself.

Nothing worse that feeling you have an obsolete telescope because your goto computer has rev 3 firmware in it and now they are selling rev 4. my grey matter goto doesnt need batter....ie....s....................what were we talking about......lol

Brian K9WIS

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I certainly understand your point, Brian. I believe, though, that the two can be complimentary. That one can indeed learn the night-sky from a GoTo - if one is paying attention and not playing MARATHON.

And one can learn the sky, most certainly, by learning the sky the "Old Fashioned Way." Pushing the scope about with - Egads! - their hands! :eek::grin:

Read: I believe any way you go is a good one, as long as it keeps you off the streets and out of the house! There is no "Wrong Way" if one is finding pleasure and enlightenment from the night-time sky.

That's My Two-Pence,

Dave

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  • 2 weeks later...

I certainly understand your point, Brian. I believe, though, that the two can be complimentary. That one can indeed learn the night-sky from a GoTo - if one is paying attention and not playing MARATHON.

And one can learn the sky, most certainly, by learning the sky the "Old Fashioned Way." Pushing the scope about with - Egads! - their hands! :eek::grin:

Read: I believe any way you go is a good one, as long as it keeps you off the streets and out of the house! There is no "Wrong Way" if one is finding pleasure and enlightenment from the night-time sky.

That's My Two-Pence,

Dave

True Enough Dave...I'm not religious about it..Just my personal preference..your right..if it get you under the stars then it works for me...

Brian

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