can an f5 telescope see both dso's and planets in our solar system in decent detail?

[Hudster]

hi, i am trying to get into astronomy and want to buy a telescope.

i am currently looking at a celestron 130mm newtonian (f5) telescope that is about 490 cad (in my budget). my goals for astronomy are to look at messier objects and many nebula but also want to look at the planets in our solar system, and heard that f5 telescopes are recommended for dso's, but viewing of jupiter, saturn, etc. may be poor quality. i would like to look at both things in reasonable detail for the price point. 

should i go for an f5 or something with a higher focal ratio?

i am sorry if i have used incorrect terms to describe things, i am new to telescopes.

Edited Monday at 04:32 by Hudster

[Bivanus]

Hello @Hudsterand welcome on SGL. The best telescope that does it all and it's also affordable to anyone is sadly still in development 😄 So one has two ways: buy one and happily use it understanding it's inherent limitations or buy several ones dedicated by their best use. 

The 130mm f/5 Newtonian is a rather good scope, but be advised it's performance is directly influenced by the mount it's on. This is true for all and and any telescope, so buyers be ware. You want visual, so in my mind that would mean a Dobsonian mount , something like this:

https://davidastro.com/en-eu/products/sky-watcher-classic-150p

However, a good equatorial mount would really make a tube shine (but drill a hole in the pocket) Here's an article you may find informative for your choice, I like it because it shows side by side how one could see the planets in many types of telescopes - including the 130mm f/5 from SkyWatcher 

https://astro.ecuadors.net/planetary-shootout-jupiter-with-refractor-maksutov-newtonian-schmidt-cassegrain/

EDIT: The newt used in the article is the equatorial mounted one, while you can do a bit of imaging with a Dobsonian , it's not the easiest thing to do.

Edited Monday at 05:22 by Bivanus

[RT65CB-SWL]

Hi @Hudster and welcome to SGL. 

Like with camera photography, the f:ratio determines the speed. At f5 it is not to bad and should be OK for basic lunar and planetary imaging if you are not expecting ‘high quality’ ESA or NASA quality images.

[Elp]

The planets won't be poor quality at F5, they'll likely be bright and may show edge distortion depending on your eyepieces though in a reflector telescope I doubt the latter, you tend to see it in refractors. For excellent planetary viewing longer f ratio scopes are usually better, but you can achieve a longer f ratio by using a barlow lens, I believe a 2x barlow on an F5 scope will give you around F10, it'll also provide you 2x the magnification as well as dimming the view.

I've viewed planets at a similar F5-6 and they look fine, the moon however can sometimes be very bright so a variable polarising filter can help make it more comfortable, you don't need such a filter for planets.

To be able to see DSOs you really need aperture as more aperture means more light into the scope, and more critically you need dark-ish skies devoid of light pollution, viewing in LP means you'll rarely see any detail, just very faint smudges if you're lucky and usually you have to use averted vision (you look away from centre/target and the object appears due to using more light sensitive parts of your retinas). Your eyes are also more sensitive if they become dark adapted which takes 20 odd minutes being in complete darkness.

Edited Monday at 10:06 by Elp

[Tiny Clanger]

5 hours ago, Hudster said:

hi, i am trying to get into astronomy and want to buy a telescope.

i am currently looking at a celestron 130mm newtonian (f5) telescope that is about 490 cad (in my budget). my goals for astronomy are to look at messier objects and many nebula but also want to look at the planets in our solar system, and heard that f5 telescopes are recommended for dso's, but viewing of jupiter, saturn, etc. may be poor quality. i would like to look at both things in reasonable detail for the price point. 

should i go for an f5 or something with a higher focal ratio?

i am sorry if i have used incorrect terms to describe things, i am new to telescopes.

Welcome to SGL.

You mention 'cad' on your budget, is that Canadian Dollars ? So a budget of up to approximately £280 GBP . It helps to know what country a person is in to give the best advice, the majority of posters here are in the UK, and are likely to default to linking to UK available kit and retailers as well as assuming any amount is £ !

Can you see planets and DSOs in reasonable detail in an f5 Newtonian ? Yes, you can. I have. You need to set it up well, use it properly and spend some time learning how to 'see' through a 'scope ... sounds weird, but it's a skill and the brain and eyes need some time to get the hang of it ...

The 'f5' measure is not really the one to think about though, it's less relevant than the light gathering aperture (in general, bigger is better for DSOs, 130mm is okay) and the magnification you can achieve with your combination of 'scope and eyepieces for looking at Mars, Jupiter and Saturn. You can see features on these best when they happen to be at their closest to us, and ideally with magnification of around 100x or more. Find the magnification by dividing the focal length of the 'scope by that of the eyepiece , so for a 650mm fl 'scope with the usual skywatcher highest power eyepiece, a 10mm, you would get 65x. A bit low for planetary. Not a disaster though, as there are other eyepieces (and things called barlows) but that's extra expense.

I'd suggest you scan through the vast (280 page !) discussion about a US 130mm f5 tabletop dob here:

https://www.cloudynights.com/topic/463109-onesky-newtonian-astronomers-without-borders/

The 'scope is 130mm F5 650mm FL, and known in the UK and probably other markets as the Skywatcher Heritage 130 tabletop dobsonian. If prices where you are are similar to the UK, it should be well within your budget and leave you enough to buy an eyepiece or barlow and a copy of Turn Left at Orion 🙂 . Alternatively, the 150mm version

https://www.firstlightoptics.com/heritage/sky-watcher-heritage-150p-flextube-tabletop-dobsonian.html is probably within your budget. It was my first telescope and it did (and still does) for me what you want.

 

[Bivanus]

 

3 minutes ago, Tiny Clanger said:

Alternatively, the 150mm version

Yup, I also think - especially because OP said he wants to start with observing-that the 150mm SW in Dobsonian form might be better suited. The link is for a Montreal based store, funny enough for international it gives the prices in $ but from Canada ones see them in CAD.

[Mr Spock]

f ratio has no bearing on planetary detail. What does is the quality of the optics and eyepieces. With a x2 or x3 Barlow you can easy make the scope f10 or f15 to get higher magnifications. 

For example, a 130mm f5 with a x2 Barlow and a 7mm eyepiece would give x185 - about the maximum practical magnification for that scope. 

[malc-c]

In answer to the OP question, yes you can, but not without some compromise.  These images are form 2011 taken through an 200P (8" f5 reflector) to give you some idea.

 

 

This was the result when connecting the camera directly to the scope at f5.  Granted the camera wasn't anything special, and I was at the start of my journey with this scope.

However, with some really dodgy coupling of two 2x barlow lenses and slightly better conditions I got the image above (both images have been processed in stacking software).  The second image may also have been taken under better conditions.  But they are no where near as sharp and detailed as an image through a 12" f10 Cat.

 

An f5 200mm reflector is however ideal for imaging DSO's, even with a cheap Canon DSLR.   Now I only have the one scope so have no idea if an f11 or greater 4" refractor would get the same result, at least not without fitting focal reducers etc, and then aperture plays its part.

As mentioned that perfect scope is still in the design phase of its development so for now people tend to own two scopes, one more suited for DSO, and another for planetary.

 

 

[Cosmic Geoff]

An f5 Newtonian should not be at a disadvantage for looking at planets or double stars, provided it is of good quality and used with suitable good quality eyepieces.

[wookie1965]

I had a Skywatcher 150p (F5) for many years when I started this hobby I saw loads in that all the planets and plenty of DSO`s 

[Gonariu]

I heard that the 130 mm f/5 Newtonians can have a spherical mirror, if you want to buy this type of telescope make sure that the main mirror is parabolic and not spherical. If the mirror is spherical you can only observe at low magnifications because of too much spherical aberration for the focal length of the optic in question (650 mm).

[Tiny Clanger]

43 minutes ago, Gonariu said:

I heard that the 130 mm f/5 Newtonians can have a spherical mirror, if you want to buy this type of telescope make sure that the main mirror is parabolic and not spherical. If the mirror is spherical you can only observe at low magnifications because of too much spherical aberration for the focal length of the optic in question (650 mm).

The 130 and 150 Heritage dobs are parabolic.

[Hudster]

3 hours ago, Tiny Clanger said:

Welcome to SGL.

You mention 'cad' on your budget, is that Canadian Dollars ? So a budget of up to approximately £280 GBP . It helps to know what country a person is in to give the best advice, the majority of posters here are in the UK, and are likely to default to linking to UK available kit and retailers as well as assuming any amount is £ !

Can you see planets and DSOs in reasonable detail in an f5 Newtonian ? Yes, you can. I have. You need to set it up well, use it properly and spend some time learning how to 'see' through a 'scope ... sounds weird, but it's a skill and the brain and eyes need some time to get the hang of it ...

The 'f5' measure is not really the one to think about though, it's less relevant than the light gathering aperture (in general, bigger is better for DSOs, 130mm is okay) and the magnification you can achieve with your combination of 'scope and eyepieces for looking at Mars, Jupiter and Saturn. You can see features on these best when they happen to be at their closest to us, and ideally with magnification of around 100x or more. Find the magnification by dividing the focal length of the 'scope by that of the eyepiece , so for a 650mm fl 'scope with the usual skywatcher highest power eyepiece, a 10mm, you would get 65x. A bit low for planetary. Not a disaster though, as there are other eyepieces (and things called barlows) but that's extra expense.

I'd suggest you scan through the vast (280 page !) discussion about a US 130mm f5 tabletop dob here:

https://www.cloudynights.com/topic/463109-onesky-newtonian-astronomers-without-borders/

The 'scope is 130mm F5 650mm FL, and known in the UK and probably other markets as the Skywatcher Heritage 130 tabletop dobsonian. If prices where you are are similar to the UK, it should be well within your budget and leave you enough to buy an eyepiece or barlow and a copy of Turn Left at Orion 🙂 . Alternatively, the 150mm version

https://www.firstlightoptics.com/heritage/sky-watcher-heritage-150p-flextube-tabletop-dobsonian.html is probably within your budget. It was my first telescope and it did (and still does) for me what you want.

 

should i go with a skywatcher? it is well within my budget and after looking at some reviews it should work for me. do you experience any glare from street lights as the tube is exposed?

[Tiny Clanger]

1 minute ago, Hudster said:

should i go with a skywatcher? it is well within my budget and after looking at some reviews it should work for me. do you experience any glare from street lights as the tube is exposed?

No problem with the open tube section, as I've made mine a simple light shroud out of 3mm closed cell foam sheet. This video is one of many you can see with ideas how to do it:

 

[Hudster]

20 minutes ago, Tiny Clanger said:

No problem with the open tube section, as I've made mine a simple light shroud out of 3mm closed cell foam sheet. This video is one of many you can see with ideas how to do it:

 

Ok good I didn't want unwanted light getting obviously lol, that's a good mod for it too ill try to make something similar to that, thank you.