Jump to content

NLCbanner2024.jpg.2478be509670e60c2d6efd04834b8b47.jpg

80mm refractors

Caldwell 14

Recommended Posts

LukeSkywatcher

LukeSkywatcher

Posted
Posted
I honestly do not have an answer to that, although I have enjoyed using my secondary refrac while others were waiting for their scopes to cool down.

What I can tell you is my eyes may not be dark adapted immediately, but my camera is, so I can start imaging on my primary refrac instantly.

Allan

True.

Thinking about it. When my 90mm refrac was my only scope i would take it out and set it up and start observing right away. Great views.........even with my non-dark adapted eyes.

If i had set up and then had to wait about 40 mins for my eyes to adapt before observing, i might have gotten a tad bored and cold.

I'm sure even though a refrac is ready to go almost by the time you set up that the views would be better with dark adapted eyes.

I just dont have the patience to test the theory.

P.S.~~~i'm going to spend some serious time this weekend looking at my EQ mount and planning on converting it to an Alt-Az.

First thing i need to do is try to remove the counter weights. They have become jammed into the mount.

Anyone got a plasma cutter?

The scope for the mount is a 90mm (f11) refrac. Its a planet killer (great views).

Link to comment
Share on other sites
  • Replies 72
  • Created
  • Last Reply
Moonshane

Moonshane

Posted
Posted

I much prefer dobs and have two. I also have a 90mm f5.5 achro and this is nice for wide field views and half OK on planets to about 100x or so.

in truth I don't really get on with it although I cannot seem to bring myself to sell it as I know I'll regret it.

Link to comment
Share on other sites
Stu

Stu

Posted
Posted

Paul, you are totally right of course about dark adaptation, but the benefit of observing jupiter is that your eyes don't need to be totally adapted because it is a pretty bright target.

To answer your question, there's nothing magic about refractors, a properly cooled newt with dark adapted eyes will be better on dso's than a frac with non dark adapted eyes. It's simply the very quick cool down and set up time of wide field refractors which makes them quick to use. For a quick look at the moon or planets it's a very convenient way of observing.

Stu

Link to comment
Share on other sites
LukeSkywatcher

LukeSkywatcher

Posted
Posted

It's simply the very quick cool down and set up time of wide field refractors which makes them quick to use. For a quick look at the moon or planets it's a very convenient way of observing.

Right, so without over analyzing (as i have done)..................the simple fact is that the main benefits of refracs is zero cooling and quick setup time.

I know it goes deeper then that, but on a basic level.

Its why i love them.

Link to comment
Share on other sites
MjrTom

MjrTom

Posted
Posted

I am a bit of a fan of refractors and intend upon getting a larger one when funds allow.

As mentioned already it's the fast setup & cooling which appeals to me.

Optically you just can't beat a refractor with it's pin point stars to the edge of the field, pleiades and the double cluster this evening through the 102mm refractor and the 35mm Panoptic were a sight to behold.

The one thing that really puts me off newtonians is coma. I just can't abide it at all. Probably because I hsve been spoilt with my two scopes :)

Link to comment
Share on other sites
Stu

Stu

Posted
Posted

I would agree with what's been said. Quick setup and fast cool down are some of the benefits. Optically though they are, for me, the purest scope to observe with. Pin point stars with perfect diffraction patterns, and also superb contrast are what I really enjoy. This is due to the unobstructed optics and lack of diffraction spikes from the secondary vanes.

A good apo is wonderful on open clusters where the wide field allows objects like m45 to fit in the fov entirely and the contrast and tight star shapes are fantastic. With a middling f/l, they are also capable of enough magnification to show lovely detail on planets, with the contrast showing up some of the more subtle details. Smaller scopes can also cut through poor seeing better too.

I have two apo's, a 66mm doublet and a 106mm triplet. I've just picked up an f16.7 60mm achro which to be honest I have yet to try out properly but hopefully it should be fun on doubles and the moon. Will be interested to see how it is on planets too.

I do struggle with accepting false colour, in the past I had a 6", 1200 mm f/l helios achro and didn't really get on with it but probably because I was expecting colour free views of planets and the moon when really it would be best on dso's at lower magnification where the contrast would really come in to play.

So in summary, my preferences are for f6 or f7 ish apo's, or f12 or more achros where the CA is well controlled or virtually non existent.

I am a purely visual observer so my requirements are quite different to imaging folk out there.

Mark, I assume you are saving for the monster achro we saw at PSP? Very nice :-)

I'll stop rambling now

Stu

Link to comment
Share on other sites
MjrTom

MjrTom

Posted
Posted

Mark, I assume you are saving for the monster achro we saw at PSP? Very nice :-)

Stu

Haha yeah in a way, although I need to move house and build an observatory before a 6 inch f12 refractor can have a place in my telescope arsenal.

More realistically in the mean time I am looking at picking up an Equinox 120mm which I will moonlite straght away :)

The standard focusers on the Equinox scopes although fairly good by Chinese standards it is not a patch on a Moonlite or Feathertouch focuser and a scope of this calibre is worthy of such an upgrade. :)

Link to comment
Share on other sites
Stu

Stu

Posted
Posted

You should be able to see them all with the mak under the right conditions, although the field of view will be too small for some of the bigger objects, m45, m42, andromeda etc. maks excel on planets and smaller dso's like globular clusters and planetary nebulas

Stu

Link to comment
Share on other sites
Stu

Stu

Posted
Posted

Of course, you are absolutely right Mark, we were just putting the case for the little refractors who get squashed under the weight of all these big dobs :-)

The key message is that no scope does everything, and that anything which allows you to see the stars and all the other wonders up there is a good thing :-)

Stu

Link to comment
Share on other sites
John

John

Posted
Posted
Short Tube 102 at 6.5 - V - Short tube ED 7.5

Depends on what you want to view.

For lunar, planetary and binary star viewing, I'd go with the ED 80mm. Having experienced first hand the impact of removing chromatic and spherical aberration from a 6" F/8 chinese achromat I'm now very aware how much these issues impact the resolution and contrast needed to spot fine detail on the above subjects.

The ED80 produces virtually no CA when used visually, the ST 102, understandably, plenty.

Link to comment
Share on other sites
  • 2 years later...
  • 2 weeks later...

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.