Help with using eyepieces

[FanofSaturn]

Hi guys.... I was wondering if anyone could help me figure out my eyepiece dilemma? I Have the following lenses: 4mm, 9mm, 12.5mm, and a 25mm. what is best for viewing planets such as Jupiter, Saturn, and Mars? I emailed Celestron and they said the 25mm was best, but when I use it I see a very small dot. If I use the 4mm I can see much more detail, cloud bands on Jupiter,  the shape of Saturn, but these are all very small to see. If I were to buy new eyepieces what should I buy and what sizes? What can I do to increase my viewing experience?

[romx]

the lower the MM the more the magnification 4  and 9 mm are best for planets

[paul mc c]

It would be good to know what scope you have.

[Putaendo Patrick]

The lower the number on the eyepiece, the greater the magnification. The exact magnification depends on the focal length of your telescope, and can be obtained by dividing the focal length by the eyepiece. For example, if the focal length is 1000mm, then the 25mm will give x40 and the 4mm will give x250.

Generally it is best to start with a low magnification and change the eyepiece to gradually increase until you reach optimum results. Normally I view planets in the x120 to x180 range. Often local atmospheric conditions don't allow you to go much beyond this, and on occasions less.

Depending on quality, if the 4mm eyepiece came supplied with a relatively inexpensive telescope, you may find the view poor.

[romx]

just noticed you said small dot even in 4mm that sounds like your scope could be what is lacking as the above posters have hinted at, 4mm is quite a high magnification I use 8mm at the moment and it is small but enough to see seperation of the rings etc

[FanofSaturn]

6 minutes ago, paul mc c said:

It would be good to know what scope you have.

My telescope is a Celestron 114 LCM.

[FanofSaturn]

2 minutes ago, romx said:

just noticed you said small dot even in 4mm that sounds like your scope could be what is lacking as the above posters have hinted at, 4mm is quite a high magnification I use 8mm at the moment and it is small but enough to see seperation of the rings etc

With the 4mm I see alot more detail and the image is bigger. The larger the mm the smaller the image. Celestron told me a 25mm eyepiece is what I wanted to use to see the planets and that is what is confusing me.

[Ricochet]

The planets will always be small disks no matter the eyepiece due to the distances involved. You can calculate the magnification of any telescope and eyepiece combination by dividing the focal length of the telescope by the focal length of the eyepiece. However, a bigger magnification isn't always better as atmospheric conditions will increasingly degrade the view as you up the magnification. In the UK an upper limit of about 200x is often quoted but depending on the conditions on the night you may find that even this is too much or that you can push the magnification up a bit further. 

Atmospheric effects extend to those inside the telescope itself so it is best to give the telescope a good half an hour or so to reach equilibrium with the surrounding air before starting high power viewing. 

Once you start observing a planet try out a range of eyepieces to determine which one is the best for that particular night. You're not always looking for the one with the most magnification but instead the one that gives you the most detailed view. When you have determined which one that is focus your telescope and observe the planet for an extended period of time. You will notice the planet come in and out of focus as the seeing varies. Be patient and watch out for those moments of best seeing, don't continually try to alter the focus to keep up with the continually changing seeing. If your mount is motorised then it should be able to keep track of the planet but otherwise you will have to nudge it every so often to keep the planet in view. Each time you nudge it you will find you introduce some vibrations that will degrade the view so it is usually better to put the planet on the edge of the field of view and then let it drift across the entire field before nudging the scope so that it is back on the side it started. 

[romx]

I honestly dont know why they would suggest something as big as 25MM for planets, the magnification would be too low to see any detail at all really. just stick with your smaller ones and follow what Ricochet has suggested in the post above that is going to give you your best planetary viewing

[paul mc c]

3 minutes ago, FanofSaturn said:

My telescope is a Celestron 114 LCM.

Hello.thats a 4.5 inch with a fl of 1000mm,you are probably looking at around a mag of 120 tops,you would get close to this with your 10mm giving you x100.

[Timebandit]

Hello and welcome to SGL. It would be very helpful to know what scope the eyepieces are used in as the focal ratio calculation  determines the magnification you can achieve out of the individual eyepieces and also helps with eyepiece choice. But to give you an idea of what you should be able to get. The 4mm in your collection is your most powerful and will achieve the highest magnification, this is ideal when looking at planetary detail, Jupiter, Saturn  (skys\ atmosphere conditions allowing). Your 9mm is your second most powerful eyepiece (good for when atmosphere does not allow the use of your 4mm for planetary detail. The 25mm in your collection is the least powerful eyepiece,so will give you the lowest magnification of all your eyepieces (idea for DSO and wider with not such detail views of the moon).                                                                                                                If you wish to add eyepieces then a wide field of view eyepiece such as the televue naglers (at 82D) would certainly give you a more intense view , maybe something  around 6mm so you are not replicating existing eyepieces and this will be good for planetary. Also again a nagler maybe around 20mm would be very good for searching out  DSO with a space walking experience. These naglers are not cheap but good. If you want something a bit cheaper but still quality, the William optics uwan are respected eyepieces. And by the way planets do appear relatively small in most scopes, do not expect to see images like you do in magazines as these scope set ups are usually very expensive , and or even taken by possible space scopes like the cassini orbiter or the Hubble space telescope. I hope the above is helpfull ?.  

[Dave In Vermont]

3 hours ago, FanofSaturn said:

With the 4mm I see alot more detail and the image is bigger. The larger the mm the smaller the image. Celestron told me a 25mm eyepiece is what I wanted to use to see the planets and that is what is confusing me.

Sounds like you got the janitor at Celestron* - answering the phone & mail. The lower the 'mm's' - the bigger the planet becomes in the eyepiece. Patrick very correctly points out that the maximum magnification you can effectively use - depends on the sky conditions. In much of the United Kingdom, the 'seeing' (as sky-conditions are known as) is seldom above 200X on the best of nights. In Kentucky? You'll be our Guinea Pig! So please let us know when you find it!

* - "Golly! I alwaz wanned ta tak to a costumar!" - 'Hello?'

Dave

[LukeSkywatcher]

I'd go with the 9mm for observing the planets. In saying that, i do like observing Jupiter with a 15mm. Yes it gets smaller, but i find it sharper and i can see more detail. 9mm is the one to go with though.

[valleyman]

You can use this link to see what you can expect from your scope.

 

http://www.skyatnightmagazine.com/field-view-calculator.

 

Pat

[skfboiler]

I agree, your 9mm EP will be the best for planets in your type scope.  This will give you 111x.  Your 4mm EP will be too blurry on most nights.   However, when you do use your 9mm and the planets look steady like there is no "waviness" I would then try your 4mm and see what you get.

[cpittman35]

On ‎6‎/‎20‎/‎2016 at 21:46, Dave In Vermont said:

Sounds like you got the janitor at Celestron* - answering the phone & mail. The lower the 'mm's' - the bigger the planet becomes in the eyepiece. Patrick very correctly points out that the maximum magnification you can effectively use - depends on the sky conditions. In much of the United Kingdom, the 'seeing' (as sky-conditions are known as) is seldom above 200X on the best of nights. In Kentucky? You'll be our Guinea Pig! So please let us know when you find it!

* - "Golly! I alwaz wanned ta tak to a costumar!" - 'Hello?'

Dave

LOL I was mid sip on my afternoon cup of coffee when I read that.  That burning sensation I felt was the coffee coming out of my nose from laughter haha. 

[Louis D]

I've found that I can push the magnification in my 15" well beyond what my 8" can do on a given night of so-so seeing (e.g., 350X vs. 200X maximum) in Texas, so seeing is only part of the equation.  If you want bigger, quality planetary images, do what I did and buy a bigger scope.  Used quality truss dobs in the 12 to 16 inch range can be had for under $2000 in the US if they don't have lots of electronics on them.  That's like buying 3 or 4 new Ethos eyepieces.  I don't know what the used UK market is like, though.