Ready reckoner for newbies

[AstroMuni]

On this forum we keep getting posts asking for advice on which telescope to purchase, so I thought a simple chart  with traffic lights like this may help. This is a first draft so please let me have your suggestions so we can define something useful for folk new to the hobby.

 

Edited September 3 by AstroMuni

[Astronomist]

IMO Dobsonians should be green for bright planet imaging and fainter DSO observing.

Lots of incredible planetary imaging is done with dobsonians, and they are the perfect scopes for observing fainter deep sky objects.

[Ratlet]

To be honest if you are talking about tracked mounts for imaging then a dobsonian can image.  There's a massive guide to doing it somewhere.

[happy-kat]

Not sure the dobsonium column gives anything as put that mount on a tracking base whether altaz or eq platform and the column would be green, just the exposure length capability would vary. What about naming the column  static mount as that then isn't telescope type dependant.

[Elp]

You haven't factored in LP which has a massive bearing on what's possible.

Imaging also requires the right equipment, you cannot just say it's possible or not.

Another point, those that can observe DSO, aperture also plays a part.

Edited September 3 by Elp

[bosun21]

Your column for dobsonian scopes needs revising. They are good for observing faint DSO's and are good for imaging all planets. They can also image DSO's if on a tracking platform although more EAA than AP.

[Richard N]

2 hours ago, AstroMuni said:

On this forum we keep getting posts asking for advice on which telescope to purchase, so I thought a simple chart  with traffic lights like this may help. This is a first draft so please let me have your suggestions so we can define something useful for folk new to the hobby.

 

The complete beginner may need the terms imaging and observing to be defined - at least in the context of your chart. 

[AstroMuni]

3 hours ago, Elp said:

You haven't factored in LP which has a massive bearing on what's possible.

Imaging also requires the right equipment, you cannot just say it's possible or not.

Another point, those that can observe DSO, aperture also plays a part.

Its exactly these complications which confuse the beginner. Hence this is only meant as a guide not the definitive answer. Its trying to provide an idea of what type of scope do they need to narrow their search to. I was thinking of adding aperture in the mix but then wasnt sure where would be the cutoff of a decent one for a beginner. We would also need to define some assumptions that have been made in coming up with this RAG. Once they have narrowed their search then would come the next set of questions of Mak vs SCT vs RASA and on and on 🙂 

[AstroMuni]

4 hours ago, Ratlet said:

To be honest if you are talking about tracked mounts for imaging then a dobsonian can image.  There's a massive guide to doing it somewhere.

I should have been more clear about Dobs. I was assuming an untracked one

[Cosmic Geoff]

No mention at all of SCTs. And why have an added column for Dobsonians, which are Newtonians of unspecified size?

[AstroMuni]

Draft version 2 based on comments above :

EDIT: Updated to reflect comment from @happy-kat below.

 

Edited September 3 by AstroMuni

[happy-kat]

I like the amendments, though for good imaging tracking is not essential, it depends on target. Good Moon or planets can be good from a static mount, harder but possible. How about tagging on the end of sentence ....assumes you are using a tracking mount for imaging but is not essential for some targets like brighter planets.

 

[Richard N]

I would run it by a few non astronomers. You might discover that things you think are obvious, are not!

[AstroMuni]

13 minutes ago, Richard N said:

I would run it by a few non astronomers. You might discover that things you think are obvious, are not!

I am sure there are lots of those questions that will spring to mind or be unclear. We dont want to make this forum redundant 😉 The only way to really test this is when a newbie comes along and sees this table

Edited September 3 by AstroMuni

[John]

So nothing seems suitable for observing fainter DSO's ?

 

Edited September 3 by John

[Elp]

37 minutes ago, John said:

So nothing seems suitable for observing fainter DSO's ?

 

Due to my LP, I don't think any scope will work, hence my previous comment. Even with 6 inches I need to use averted vision for something like m13 and even then it's a very very faint haze, I wouldn't call that satisfactory viewing if I was a beginner. Planets however look "okay", haven't managed to see the outer planets yet.

DSO imaging also requires some knowledge of post processing (as does good planetary but not essential), you'll get little result of DSO without it unless the software applies the necessary stretching/stacking of data.

The revision is better but I dont think you can summarise it so easily, someone looking at the green may think they'll expect perfect views or photos, when I've had people look through my scopes/images and say "is that it?", it's something that perhaps is better illustrated with supporting visuals.

Edited September 3 by Elp

[bosun21]

I've already stated that dobsonians are capable for viewing faint DSO's. I view them frequently. As already mentioned there are so many variables that will have an effect on viewing these. I am in bortle 5.9-6.2 depending on where I look up. I get amazing views of M13 both with my 10" dob and 180 Mak. They both show great detail with the propeller easily seen. I actually like hunting down the faint galaxies. I also do enjoy using the dob for EAA to really bring them to life.

[AstroMuni]

So I could make that an Amber for observing fainter DSO. I am not really an observer so dependent on more experienced folk in that area for advice.

[Kon]

What is your definition of brighter and fainter planets/DSO? Observing DSO depends on the sky quality and experience in observing, so it is hard to say what you can really see or not. Additionally, binoculars (depends on their power) will show the fainter DSO and planets.

I would personally find such table more confusing and rather have the 'Which telescope shall I buy for my xyz circumstances?' question from new comers.

[AstroMuni]

1 hour ago, Kon said:

I would personally find such table more confusing and rather have the 'Which telescope shall I buy for my xyz circumstances?' question from new comers.

The idea was not to discourage newbies from asking that question but to give them some prior knowledge so their questions could be more specific. But from the varied comments above, it looks like I am not anywhere close to even that. 😞 Back to the drawing board

Edited September 4 by AstroMuni

[Jules Tohpipi]

Maybe you could type a white-coloured number in some cells to represent a nominal minimum aperture that overrides the cell colour. 
 

As a very rough and ready example, some of the red cells for fainter DSO in the Observing section, you could display 8” (or whatever) to indicate the necessary minimum aperture for a yes (depending on the suitability of the instrument). 
 

Not thought this through to all ends. But just an idea that cropped up. 
 

 

 

 

[AstroMuni]

2 hours ago, Jules Tohpipi said:

As a very rough and ready example, some of the red cells for fainter DSO in the Observing section, you could display 8” (or whatever) to indicate the necessary minimum aperture for a yes (depending on the suitability of the instrument). 

Thats a good idea. But there are too many variables at play as others have pointed out. Also the perception of what is good also varies from person to person. I remember when I first saw Saturn it was awesome - and all it showed was as a little dot with a minus sign across it. But that may not be the same feeling for someone else.

[Jules Tohpipi]

Oh well. I thought you gave it a nice try. 

Meanwhile, I’ve drafted up a handy decision tree for those starting out.* All I need do now is think of some questions for the boxes.

* Jokes don’t necessarily reflect my actual opinions 😆

Edited September 4 by Jules Tohpipi

[ONIKKINEN]

Sorry, going to throw an additional curveball here...

How do we define "wide field" imaging? Given that a less than 600mm fl refractor is green, i think we can conclude that an image of around two or three degrees in width could be called wide field if we are using what seems to be the most common size of camera sensor: APS-C. However, this kind of image can of course be taken with a one meter focal length reflector by mosaicing. Which i have done, with M31 and the Heart nebula, requiring 4 and 6 panels respectively so its not an absurdly difficult thing to do either. I will admit that its more difficult than just taking a single panel or a 2-panel image, but it shouldn't be red and maybe yellow instead.

Appreciate the effort you have put into this, but the reason we dont have this kind of guide for what telescope to purchase is because the number of variables on what the newcomer would like to do, and how difficult they want it to be is almost limitless.

[steaven1325]

Not sure the dobsonium column gives anything as put that mount on a tracking base whether altaz or eq platform and the column would be green, just the exposure length capability would vary