Best buys for increased magnification

[Stevewats]

Hi all,

Seasons greetings to all.

I have been gifted a Celestron astromaster 130eq md for Christmas and I am very happy with it as I've always been fascinated with the cosmos and I look forward to using it. I am comllete newbie though.

The question I have is regarding additional equipment I can purchase for it.

The telescope came with a 20mm and 10mm eyepiece, which believe is standard? I have had a look online and watched YouTube videos and there is lots of information which I am finding quite confusing to be honest. 

If I wanted to get the best possible viewing of the moon and the planets what eyepiece should I purchase? I have seen a lot of talk about barlows, I believe there are many different versions? Is a barlow a brand? Which would be the best for me? How are lenses and barlows used together? How does this work? I've seen some videos on fake equipment and to be carful? I'd rather spend more money and buy from a reputable company.

Any help would be greatly appreciated. 

Many thanks 

Steve 

[Ricochet]

37 minutes ago, Stevewats said:

If I wanted to get the best possible viewing of the moon and the planets what eyepiece should I purchase?

I would suggest that you look for a 4 or 5mm eyepiece to start with and see how you get on with that. I would suggest that you look at something like a BST Starguider or a similar eyepiece that has good eye relief. Purchasing a plossl for instance would be a very uncomfortable viewing as your eye would have to be very close to the eyepiece. If you let us know your budget for an eyepiece we can give some more specific advice. 

40 minutes ago, Stevewats said:

How are lenses and barlows used together?

To use a barlow with your telescope you put the barlow into the focuser instead of the eyepiece, and then put the eyepiece into the barlow. Barlows are typically sold as 2x or 3x. Higher numbers are available, but these are specialist photographic items and not useful for visual astronomy. 

If you use a 2x barlow it will double the magnification that a specific eyepiece and telescope combination gives. This is the equivalent of using an eyepiece that has half the focal length. This means that you could buy a 2x barlow and use it with your 10mm eyepiece instead of the 5mm Starguider I suggested above. However, the 10mm eyepiece that is supplied with your scope is not the best so the 5mm Starguider will most likely give better views than your 10mm and a 2x barlow. If you have a large enough budget, you will probably want to also replace your 10mm eyepiece fairly soon. 

I can't say I've ever heard of any fake equipment being for sale. Most of the astronomy equipment available is produced in the same factories and then rebranded so you will often see the same item available under several different names. If you buy from a reputable retailer like FLO, the sponsor of this forum, you won't have any problems with fake or substandard equipment. 

[Stevewats]

Thank you for your reply Ricochet.

As I am very new to all this, just to clarify, the smaller the eyepiece the better the clarity or the more than magnification it gives?

I was to go down to a 5mm eyepiece i wouldn't need a barlow or could I still use a barlow to gain even more magnification?

Many thanks 

Steve

[johninderby]

There is an optimum magnification. Going to a higher magnification can show more detail but use too much magnification and the views get worse. A zoom is useful for experimenting with magnification as you can find the magnification that gives the best views.

Seeing affects the magnification you can use as you will find some nights you can use more magnification and other nights much less.

Edited December 26, 2020 by johninderby

[Ricochet]

33 minutes ago, Stevewats said:

As I am very new to all this, just to clarify, the smaller the eyepiece the better the clarity or the more than magnification it gives?

Magnification is telescope focal length divided by eyepiece focal length so the smaller eyepiece will give more magnification. However, as John says, there is an optimum. Different objects respond differently and for planets 4-5 might be the optimum with your scope. For DSOs you will probably be looking at 10mm and longer, depending on the field of view required to see the object. With regards to "clarity" you will also find that the quality of the eyepiece also plays a part and more expensive eyepieces may yield better results. This will probably require some experience on your part to spot though. 

[Stevewats]

1 hour ago, johninderby said:

There is an optimum magnification. Going to a higher magnification can show more detail but use too much magnification and the views get worse. A zoom is useful for experimenting with magnification as you can find the magnification that gives the best views.

Seeing affects the magnification you can use as you will find some nights you can use more magnification and other nights much less.

Thanks John, makes sense.

[Stevewats]

52 minutes ago, Ricochet said:

Magnification is telescope focal length divided by eyepiece focal length so the smaller eyepiece will give more magnification. However, as John says, there is an optimum. Different objects respond differently and for planets 4-5 might be the optimum with your scope. For DSOs you will probably be looking at 10mm and longer, depending on the field of view required to see the object. With regards to "clarity" you will also find that the quality of the eyepiece also plays a part and more expensive eyepieces may yield better results. This will probably require some experience on your part to spot though. 

So in essence for me to view the planets with my telescope it might be worth me buying a good quality 4mm eyepiece and leave the barlow for now. Could you recommend a good 4mm eyepiece?

[Ricochet]

13 hours ago, Stevewats said:

So in essence for me to view the planets with my telescope it might be worth me buying a good quality 4mm eyepiece and leave the barlow for now. Could you recommend a good 4mm eyepiece?

Without knowing your budget, the 4mm Nirvana gets good reviews without being massively expensive. There is also a 4.7mm ES82 currently available in the classifieds section of this forum if you are happy buying a second hand item. The 5mm BST Starguider or Celestron X-Cel LX would be other good alternatives, or the Vixen SLV is available in 4 and 5mm options. Alternatively, other users on this forum have reported good results by using the 7.2-21.5mm Hyperflex Zoom with a decent 2X barlow.

Having said that, you should be aware that Jupiter and Saturn are very close to the horizon and only visible for perhaps an hour at the moment which will limit your ability to view these objects at the moment. This leaves you with the Moon and Mars (which is now moving away from us and appearing smaller and less interesting). As such you may be better off looking at eyepiece focal lengths more suitable for viewing DSOs as a first purchase or in addition to a short planetary option.

[Stevewats]

8 hours ago, Ricochet said:

Without knowing your budget, the 4mm Nirvana gets good reviews without being massively expensive. There is also a 4.7mm ES82 currently available in the classifieds section of this forum if you are happy buying a second hand item. The 5mm BST Starguider or Celestron X-Cel LX would be other good alternatives, or the Vixen SLV is available in 4 and 5mm options. Alternatively, other users on this forum have reported good results by using the 7.2-21.5mm Hyperflex Zoom with a decent 2X barlow.

Having said that, you should be aware that Jupiter and Saturn are very close to the horizon and only visible for perhaps an hour at the moment which will limit your ability to view these objects at the moment. This leaves you with the Moon and Mars (which is now moving away from us and appearing smaller and less interesting). As such you may be better off looking at eyepiece focal lengths more suitable for viewing DSOs as a first purchase or in addition to a short planetary option.

Great, thank you for all of the information. I have tried to find the classified ad for the 4.7mm ES82 bit cannot seem to find it. Do you have a link for this please? Many thanks, Steve 

[johninderby]

Someone has already sent a PM about it but doesn’t hurt to ask if it’s still available.

 

[Guest]

Hello John. It was the 6.7 mm that they bought. The 4.7 mm is still available.

[johninderby]

15 minutes ago, Grumpy Martian said:

Hello John. It was the 6.7 mm that they bought. The 4.7 mm is still available.

I wiish you hadn’t said that. Have been considering buying the 4.7 for myself. 🤔

If  Stevewats doesn’t have it then I will.

Edited December 27, 2020 by johninderby

[Stevewats]

24 minutes ago, Grumpy Martian said:

Hello John. It was the 6.7 mm that they bought. The 4.7 mm is still available.

Hi there, is this still available?

[Pixies]

2 hours ago, Stevewats said:

Hi there, is this still available?

6 posts and already buying more stuff! Welcome to Star Gazers Lounge! 😉😆

[Stevewats]

On 27/12/2020 at 09:55, Ricochet said:

Without knowing your budget, the 4mm Nirvana gets good reviews without being massively expensive. There is also a 4.7mm ES82 currently available in the classifieds section of this forum if you are happy buying a second hand item. The 5mm BST Starguider or Celestron X-Cel LX would be other good alternatives, or the Vixen SLV is available in 4 and 5mm options. Alternatively, other users on this forum have reported good results by using the 7.2-21.5mm Hyperflex Zoom with a decent 2X barlow.

Having said that, you should be aware that Jupiter and Saturn are very close to the horizon and only visible for perhaps an hour at the moment which will limit your ability to view these objects at the moment. This leaves you with the Moon and Mars (which is now moving away from us and appearing smaller and less interesting). As such you may be better off looking at eyepiece focal lengths more suitable for viewing DSOs as a first purchase or in addition to a short planetary option.

Hi, Would you say a BAADER MORPHEUS 4.5MM EYEPIECE would be a good buy for me? I know it's expensive but they seem like very good quality eyepieces? Any advice on these?

[Ricochet]

39 minutes ago, Stevewats said:

Hi, Would you say a BAADER MORPHEUS 4.5MM EYEPIECE would be a good buy for me? I know it's expensive but they seem like very good quality eyepieces? Any advice on these?

Yes, they are very good eyepieces and one could easily be an eyepiece you never feel the need to upgrade. I believe they have similar optical quality to the Vixen SLV, but with a wider field of view, which makes them heavier and more expensive. 

[faulksy]

use the forum sponsor. top  of the page. banner saying FLO you wont go wrong with them.

and welcome to sgl

https://www.firstlightoptics.com/eyepieces-barlows.html

Edited December 28, 2020 by faulksy

[Stevewats]

On 26/12/2020 at 17:50, Ricochet said:

I would suggest that you look for a 4 or 5mm eyepiece to start with and see how you get on with that. I would suggest that you look at something like a BST Starguider or a similar eyepiece that has good eye relief. Purchasing a plossl for instance would be a very uncomfortable viewing as your eye would have to be very close to the eyepiece. If you let us know your budget for an eyepiece we can give some more specific advice. 

To use a barlow with your telescope you put the barlow into the focuser instead of the eyepiece, and then put the eyepiece into the barlow. Barlows are typically sold as 2x or 3x. Higher numbers are available, but these are specialist photographic items and not useful for visual astronomy. 

If you use a 2x barlow it will double the magnification that a specific eyepiece and telescope combination gives. This is the equivalent of using an eyepiece that has half the focal length. This means that you could buy a 2x barlow and use it with your 10mm eyepiece instead of the 5mm Starguider I suggested above. However, the 10mm eyepiece that is supplied with your scope is not the best so the 5mm Starguider will most likely give better views than your 10mm and a 2x barlow. If you have a large enough budget, you will probably want to also replace your 10mm eyepiece fairly soon. 

I can't say I've ever heard of any fake equipment being for sale. Most of the astronomy equipment available is produced in the same factories and then rebranded so you will often see the same item available under several different names. If you buy from a reputable retailer like FLO, the sponsor of this forum, you won't have any problems with fake or substandard equipment. 

Hi Ricochet,

Unfortunately the 4.7mm ES82 was sold before I could buy it,  so after more research I still find myself undecided. I am more than willing to spend a decent amount of money so I am trying to make sure I get the best possible viewing for my money.

I have had a look on the Celestron website and they state this regarding my particular telescope: 

''For this article, we’ll use the AstroMaster 130EQ as an example. This telescope’s focal length is 650mm. (To find the focal length of your telescope, look at the telescope’s nameplate or retaining ring.) The aperture is 130mm.  The scope’s highest useful magnification is 307x and the lowest is roughly 19x. 

For the AstroMaster 130EQ, the highest useful magnification is achieved with a 2.1mm focal length eyepiece. The lowest useful magnification is achieved with a 34mm focal length eyepiece. Celestron offers several options for eyepieces that fall within these limits.

A 2.3mm X-Cel LX eyepiece will give you 282x, which is close to the highest useful magnification of the optics. An Omni 4mm eyepiece with a 2x Barlow lens will exceed your highest useful magnification at 325x.  It’s unlikely that any eyepiece will be a perfect match, but with the right combinations of eyepieces and Barlows, you can achieve numbers that are very close.''

So, should I be considering a smaller eyepiece size such as a 2-3mm? Instead of a 4-5mm?

Any advice appreciated. Many thanks. Steve

Edited December 30, 2020 by Stevewats

[Ricochet]

2 hours ago, Stevewats said:

should I be considering a smaller eyepiece size such as a 2-3mm? Instead of a 4-5mm?

No, I don't think so. The 307x number comes from an old empirical rule of thumb of the maximum magnification being 60x per inch of aperture. However, this rule is for splitting double stars with slow focal ratio refractors. You are using a telescope with a central obstruction and like almost everyone else, you want your high powers for planetary observations. As such, this number doesn't really apply and is more of a marketing gimmick than anything else. The optimum planetary magnification is generally accepted to be about half of the double star maximum, so you need an eyepiece with with double the focal length. Additionally, once you get into the 150-200x region you will find that you start hitting atmospheric limits in the UK. This means that any eyepieces giving magnifications above that are more of a luxury than a necessity, especially if you have only a few eyepieces. 

[johninderby]

The Televue eyepiece calculator can be very useful when considering which focal length eyepieces will work with your scope.

https://www.televue.com/engine/TV3b_page.asp?plain=TRUE&id=212&NoBack=True&focal_length=480&fl_unit=mm&aperture=76&a_unit=mm&sortby=SortTrueField&_2in=yes&title=Tele+Vue-76&SUBMIT1=CALCULATE

[Louis D]

My best views of Mars during this last opposition were with Arcturus binoviewers, a Meade 140 2x Barlow nosepiece, and 15x wide field B&L microscope eyepieces in my Dob.  The views were so much more detailed and easier to take in than in my 5.2mm Pentax XL or 3.5mm Pentax XW eyepieces.  My point is, binoviewer views of the moon and planets with average eyepieces are generally way better than the best mono view.  Two eyes allow for much better contrast and detail detection.