skywatcher 150pds I need eyepiece advise

[Missy Astro]

hello, I am new here and nee to this hobby 😁A few weeks ago I bought my first scope. the skywatcher explorer 150pds. And now I am thinking to buy a barlow lens/eyepiece  for visual and later on for astrophotography. 
I saw in a youtube video about how you can calculate the max magnification and  stuff: 

it's a 6inch, which mean 6 x 50=300x 
so my max magnification is 300x
telescope fc is 750mm and the eyepiece I have is a 28mm 
so 750/28= 26,78....
so it is  okay to get the 5x barlow? because 26,78.. x 5 = 133,9x ? (if I use the 28mm eyepiece)

I was thinking to get an another eyepiece (this one: https://www.amazon.nl/gp/product/B07Z64NK65/ref=sw_img_1?smid=A3ICDZYF91YIY1&th=1   ) +  2x barlow lens

OR 

this one ( SVBONY SV170 1.25" Eyepiece Zoom Eyepiece FMC Green Film Zooeye for Telescope (10-30mm) https://amzn.eu/d/5pJSPrj )

 

- Is this a good eyepiece to get?  and can I use this eyepiece on my telescope? Which one do you recommend? 

- Does the size of the eyepiece influence the visual and for astrophotography? 

- Do you guys have any advice what I should get?

 

I am really looking for to get in deeper in this hobby

 

Sorry for my poor english language, english is not my first language 😁

 

thankyou!

Edited April 16, 2023 by Missy Astro

[Guest]

Your english is fine so no worries there.  A 5x is one strong barlow.  The slightest movement will make whatever you are looking at appear to be in a earthquake. I started with a 2x barlow and when paired with the correct eyepiece that is usually plenty of magnification.  As to how much magnification, well that will depend more on the sky above then your scope. My scopes are rated to 500 and 800x, but the sky limits me to about 300x most of the time.   Remember its not always about the magnification, its about the best image. 

Edited April 16, 2023 by Mike Q

[bosun21]

Don’t buy a 5x barlow as this would greatly extend the eye relief of your existing 28mm eyepiece rendering it virtually unusable. You would be better to add say a 12mm or a 15mm and a 5-6mm and then you can add a 2x barlow for those nights with good seeing. Or you could just get a 7-21mm zoom eyepiece similar to the one you highlighted, but not the 10-30mm as you already have that covered with the 28mm you already own. Good luck with your new hobby.

[Cosmic Geoff]

A 5x barlow is an extreme device, only useful (maybe) for planetary imaging with a f5 newtonian like yours.

You need a set of three or more eyepieces of good quality, plus a x2 barlow lens.

[RT65CB-SWL]

Hi @Missy Astro and welcome to SGL. 

A 5x Barlow lens, as said above, is way to much power for your 'scope. Primarily targeted for use with a modded webcam is doable, but visually it is a 'No!'

I have a cheap 7-21mm zoom [not Svbony] that I purchased years ago and is good enough for when I wish to travel light with a 'scope a few fixed focal length eyepieces. Svbony is a young company and giving the older companies some serious competition selling optical equipment at affordable prices.

[Missy Astro]

Hi everyone first of all thankyou for replaying

So I am not going to buy a 5x barlow 😃

I am going to get the eyepiece I mention before, the Svbony 7-21mm and a 2x barlow. 

I have another questions: 

- Can I use a 1.25inch barlow on a 2inch eyepiece? 
- How do you know what your sky limit is? 
 

thankyou again @Mike Q @bosun21 @Cosmic Geoff  @Philip R 😃

clearskies 

Edited April 17, 2023 by Missy Astro

[bosun21]

No you would need a 2” barlow to use a 2” eyepiece but you can use a 2” barlow with both the 2” and 1.25” eyepieces with the addition of a 2”-1.25” adapter. You will discover the sky seeing conditions by observing a target and gradually increasing the magnification until you suddenly lose the sharpness of your image. That’s a good indicator of the seeing conditions.

[Cosmic Geoff]

33 minutes ago, Missy Astro said:

- Can I use a 1.25inch barlow on a 2inch eyepiece? 

No. A 2" eyepiece will be large and low-powered. The small barlow will block some of the light.   If you need more magnification, just use a 1.25" eyepiece of suitable focal length, or a zoom. 

35 minutes ago, Missy Astro said:

- How do you know what your sky limit is? 

That looks ' lost in translation'.  If you mean, how bad is your night sky, you should be able to find an appropriate chart online somewhere.

[Guest]

I will second a two inch barlow with a 1.25 inch adapter.   As to reading the sky, well i just look up.  If the stars are nice and bright and not twinkling that tells me that the air up there is pretty steady and stable and i usually have a pretty decent session.  As Bosun says there will be a point where everything just falls apart  and nothing looks good.  

[Missy Astro]

27 minutes ago, bosun21 said:

No you would need a 2” barlow to use a 2” eyepiece but you can use a 2” barlow with both the 2” and 1.25” eyepieces with the addition of a 2”-1.25” adapter. You will discover the sky seeing conditions by observing a target and gradually increasing the magnification until you suddenly lose the sharpness of your image. That’s a good indicator of the seeing conditions.

So it’s better to get a 2inch barlow, because you can use it for both 🤔

 

oh okay 😃

thankyou!

[Missy Astro]

Thankyou!! 
@Mike Q @Cosmic Geoff @bosun21

[Guest]

Just now, Missy Astro said:

So it’s better to get a 2inch barlow, because you can use it for both 🤔

 

oh okay 😃

thankyou!

Just make sure it comes with an adapter for 1.25 inch and you are good to go.  On a side note, barlows are worth spending a little extra money on.  Eyepieces will come and go, but a good Barlow is forever. 

[RT65CB-SWL]

If your ‘scope accepts 2” e/p’s, then the Baader 8-24mm zoom can be used as either 1.25” or 2”. They come with the threaded 2” nosepiece included.

Edited April 17, 2023 by Philip R

[Missy Astro]

22 minutes ago, Mike Q said:

Just make sure it comes with an adapter for 1.25 inch and you are good to go.  On a side note, barlows are worth spending a little extra money on.  Eyepieces will come and go, but a good Barlow is forever. 

Oh okay that’s good to know! Thankyou so much! 😊

[bosun21]

37 minutes ago, Missy Astro said:

So it’s better to get a 2inch barlow, because you can use it for both 🤔

 

oh okay 😃

thankyou!

I actually prefer a 1.25” barlow due to the 2” eyepieces I have are long focal length (30mm) for example. Using a barlow with this is pointless as I have that magnification covered by other eyepieces (as will you if you buy the 7-21mm zoom. Also again a 28mm-30mm eyepiece already has a considerable eye relief (the distance from the eyepiece lens to your eye) and this could become uncomfortable to use if you were to double it with a 2x barlow. A barlow increases the eye relief as well as magnification.

[rwilkey]

Hi, I found the 2" Barlow cumbersome and sold it.  I much prefer a 'shorty' 1.25".  Sooner or later you will get 1.25" eyepieces and a 2" Barlow will seem a bit overkill, especially if you only have the 28" LET eyepiece to use it with, I tried 2" low power ep's with the 2" Barlow and found it simply did not work, anyway, that defeats the object of having a low power eyepiece.  Your next best move is to consider 1.25" eyepieces, in a zoom or otherwise, in my opinion.

Edited April 17, 2023 by rwilkey

[Missy Astro]

3 hours ago, bosun21 said:

I actually prefer a 1.25” barlow due to the 2” eyepieces I have are long focal length (30mm) for example. Using a barlow with this is pointless as I have that magnification covered by other eyepieces (as will you if you buy the 7-21mm zoom. Also again a 28mm-30mm eyepiece already has a considerable eye relief (the distance from the eyepiece lens to your eye) and this could become uncomfortable to use if you were to double it with a 2x barlow. A barlow increases the eye relief as well as magnification.

Oh okay, 

I am going to order the eyepiece first, 7-21mm zoom today 

 

 

[Missy Astro]

And I will get the barlow 2x (1.25inch) 😊

[Mr Spock]

Good choices. The 7-21 will allow you to settle on a magnification better suited to your target and conditions. It’s good to have flexibility when you are just starting. 

[Missy Astro]

Thanks again everyone for helping me 😊

[Missy Astro]

My eyepiece 7-21mm zoom just came in  

I am so excited to try it out later

I hope the weather stays like this, no clouds

[Elp]

If you're in it for long term, and will likely get deeper into imaging, especially planets, a Televue powermate will be a better investment due to its optical correction, the 2.5x one will do. Its expensive but it's edge correction and sharpness is very good. You can get good results with a standard Barlow, I've used a few, the Celestron Omni is okay as is a Meade telenegative. At the beginning I made the mistake of buying a basic 5x Barlow and never used it after testing it.

[Missy Astro]

6 minutes ago, Elp said:

If you're in it for long term, and will likely get deeper into imaging, especially planets, a Televue powermate will be a better investment due to its optical correction, the 2.5x one will do. Its expensive but it's edge correction and sharpness is very good. You can get good results with a standard Barlow, I've used a few, the Celestron Omni is okay as is a Meade telenegative. At the beginning I made the mistake of buying a basic 5x Barlow and never used it after testing it.

I checked the  Televue one, I think in the future I will get it but not now, for now I think I will get the Celestron one  thankyou for the recommendation  and I will get the 2x barlow one