Why settle with reflector scopes when refractors have no collimation?

[niallk]

I've a portable 15" truss dob:

* it takes 5 mins to assemble

* it goes into my car

* I can set up on my own in the dark

* with the barlowed laser method, I get good collimation in ~1 min in the dark

* 15" aperture means very good planetary views in addition to being great for DSOs of course

.... hard to get all that with a 15" frac - cost & portability 😉 oh and all at f4.5 for no ladder....

 

But you are absolutely correct: one must invest a bit of time in learning how to collimate to unlock all the potential of a Newtonian at least.

Edited April 29, 2021 by niallk

[faulksy]

you need a big newtonian telescope so that you can see things properly. a large newtonian will show a image as good as a photo but with less colour, this will be live or as live as you get it.

so that is why you need a reflector 😁

[ollypenrice]

1 hour ago, faulksy said:

you need a big newtonian telescope so that you can see things properly. a large newtonian will show a image as good as a photo but with less colour, this will be live or as live as you get it.

so that is why you need a reflector 😁

There are lots of things nobody has ever seen in a telescope but which can be photographed...

Olly

[iapa]

1 hour ago, faulksy said:

you need a big newtonian telescope so that you can see things properly. a large newtonian will show a image as good as a photo but with less colour, this will be live or as live as you get it.

so that is why you need a reflector 😁

Hmmm

I want to be able to look back at what I have seen - in my head, seeing is OK, but being able to look back at what I saw at any particular time is better; more so as I get older and forget what I was replying to

[JemC]

Just thinking aloud here 😁 because i know i am going to have to attempt collimation at some point on the RC6 that i have (not looking forward to it going of other responses about it 🤔 )

Is this not something that could be demonstrated in the form of a collimation lesson at one of the SGL star parties when they are back ON? 😀

 

[Pitch Black Skies]

I think collimation is actually part of the fun. I love tinkering with things. 😁

That, and light gathering power of course.

[iapa]

26 minutes ago, Pitch Black Skies said:

I think collimation is actually part of the fun. I love tinkering with things. 😁

That, and light gathering power of course.

I think I have probably spent more time getting the “right” things then getting everything “right” and not imaging.

What a waste of money.

Just costed the main expenditure over past few years - ignoring anything under £200 - and I am tempted to sell it off and get another HD Road KIng

 

[Pitch Black Skies]

32 minutes ago, iapa said:

I think I have probably spent more time getting the “right” things then getting everything “right” and not imaging.

What a waste of money.

Just costed the main expenditure over past few years - ignoring anything under £200 - and I am tempted to sell it off and get another HD Road KIng

 

To be honest I don't know anything about astrophotography, only that it can probably get a bit expensive judging by things.

Haven't said that, Harley's aren't exactly cheap either.

I had a bike once, absolutely loved it.

Another hobby that our proxy weather has no consideration for.. 🙂😂

Edited April 29, 2021 by Pitch Black Skies
Typo

[mikeDnight]

You need a large reflector so you've something to vent your anger on, and then sell off cheap after you look through a much smaller refractor.

[faulksy]

1 hour ago, mikeDnight said:

You need a large reflector so you've something to vent your anger on, and then sell off cheap after you look through a much smaller refractor.

you put that on before mike. it is funny

i remember being at brecon star party a few years ago, one of the members of here had a 4" ish apo. he said come and look at the veil mike. when i looke at it i said are you sure. then i put my dob on it and looked . his face was a picture, he nearly kicked his apo over with disgust , true story that mike. proper funny and a gentleman he is

[jetstream]

1 hour ago, mikeDnight said:

You need a large reflector so you've something to vent your anger on, and then sell off cheap after you look through a much smaller refractor.

My offer is still open Mike!

You can view through my TSA 120 and then immediately switch to my 15" and tell me what you see!

I might humbly suggest that if the TSA120 shows more an eye exam might be required!!

[jetstream]

24 minutes ago, faulksy said:

you put that on before mike. it is funny

i remember being at brecon star party a few years ago, one of the members of here had a 4" ish apo. he said come and look at the veil mike. when i looke at it i said are you sure. then i put my dob on it and looked . his face was a picture, he nearly kicked his apo over with disgust , true story that mike. proper funny and a gentleman he is

I might believe that the true refractory members can't take a bit of a joke? one little emoji and things fall apart

[johninderby]

I. like most on here, own both refractors and reflectors and enjoy using both. Depends on the night and seeing conditions as to which I use and of course what I want to look at.🤔

[Quetzalcoatl72]

I just adjust the secondary mirror, as long as it looks centered I don't care, the primary is probably the one that gets 'banged' the least and I don't drive so I'm almost never travelling with it

[faulksy]

7 hours ago, jetstream said:

I might believe that the true refractory members can't take a bit of a joke? one little emoji and things fall apart

it was pig gerry🤣

[cloudsweeper]

7 hours ago, johninderby said:

I. like most on here, own both refractors and reflectors and enjoy using both. Depends on the night and seeing conditions as to which I use and of course what I want to look at.🤔

That sums it up nicely!  I enjoy the different experiences using fracs, the SCT, and the reflector - also varying the mounts used (where possible).  The reflector gathers the light for sure, but for really crisp star images (which I appreciate), the fracs can't be beaten.

As for reflector collimaton, much has been said and it can be viewed as something formidable.  In reality - and after actually doing it - it is quite straightforward.  We each have our own favoured approaches - do whatever you are comfortable with.  I have only ever done it by eye, then finished off the primary with a cap costing a few quid.  This has served me well, and only requires the occasional fine-tuning.

Doug.

 

[kirkster501]

20 hours ago, ollypenrice said:

I don't like messing about with optics so I use refractors. That means two things: I'm lazy and I enjoy astrophotography...

😁lly

^^^100% this, especially for astrophotography.  What with seeing, guiding and everything else going on, there are already enough variables up in the air to be worrying if the scope is collimated.

I use SCT for lunar photography and the planets because aperture is more important for that and the said variables do not apply.  All that said, I have no fear of collimation and do so all the time with the SCT and dob.

[neil phillips]

Bang for the buck is my biggest reason. Try getting a refractor that cost around £100 new for the tube assembly to do this. Collimation is tolerated 114 Newtonian

961232407_24THMARCHSGL.png.2d1dcc5373faccf117dbf299f1b78edc.png (2654×3054) (stargazerslounge.com)

1389280986_Lastredosgl.png.2db2a9f6801e327bfd6557f5c628ef7d.png (3150×5978) (stargazerslounge.com)

Edited April 30, 2021 by neil phillips

[ollypenrice]

A point I would make is this: it is fundamentally unscientific to say that all reflectors can be easily and successfully collimated.  All anyone can say is that they have successfully collimated the ones on which they have worked.  Sometimes individual instruments may have defects in construction which prevent them from behaving in accordance with the theory. I tried, unsuccessfully, to help a guest with a GSO RCT one time. We watched all sorts of tutorials, including Steve's (Kirkster's) and we kept encountering interactions between adjustments which were not covered by any source of information we could find.

Singlin's excellent thread on sorting out a Quattro is instructive in this regard.

Olly

[CraigT82]

12 minutes ago, ollypenrice said:

it is fundamentally unscientific to say that all reflectors can be easily and successfully collimated

It is equally fundamentally unscientific to say that refractors don't require collimation (not that you said that, but many do).

Edited April 30, 2021 by CraigT82

[wookie1965]

On 28/04/2021 at 23:50, johninderby said:

The CC is better for lunar / planetary and the RC is more suited to DSO imaging.

I have the CC8” and a 125mm APO  so the best of both worlds.

John,

           Have you ever tried the 125mm on double stars if so how good is it and how much does the OTA weigh please.

Paul

[johninderby]

Haven’t done any double star work with the 125 yet now have the Sissy Haas book. 🙂 Impressed with the scope so far. Think it is a step up optically over the SW doublets.

OTA is about 7.6kg so no lightweight but solidly built and beautifully finished.

[niallk]

Ah, a good old (respectful & witty) refractor vs reflector spat is always entertaining! 😄

While I mentioned just how great a dob is (- my comments are only for visual), for balance and full disclosure, I also have a frac - a little 50mm Lunt for Ha solar... and I luv it.  So convenient, zero fuss, plonk it down and immediately start enjoying the views... 😉

 

(Now, if only I had a 15" version...)

Edited April 30, 2021 by niallk

[ollypenrice]

1 hour ago, CraigT82 said:

It is equally fundamentally unscientific to say that refractors don't require collimation (not that you said that, but many do).

Indeed. I once bought a Genesis very cheaply because the front cell was out of collimation. It was very easy to fix once I'd had a chat with TV, who were extremely helpful.

Olly

[alacant]

On 29/04/2021 at 00:32, Quetzalcoatl72 said:

buying a 8" RCT

Hi

Good choice. The same outlay would buy you only a miserably dim refractor.

I wish I hadn't taken the advice of the masses with an 80ed as my first telescope. It took me all night to get anywhere near the quality my mate got with his 200mm reflector in just a couple of hours. Not to mention awful fat blue stars.

The amount of time you save having a larger aperture, more than makes up for the minute or so you spend collimating. Having seen the results from modern f2 mirrors recently, I'm convinced that that's the way to go and whilst i see attractively priced RASAs, I don't see many 11" f2 refractors on the market!

Cheers

Edited April 30, 2021 by alacant