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#1 Elvis1118

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Posted 26 March 2020 - 01:59 AM

Hey gents I recently was able to get a Orion skyquest xt4.5 and I had a question..I was looking to perhaps upgrade the eyepieces  which I have already started doing and was particularly  intrigued  by the Orion stratus eyepieces more specifically  one of the eyepieces in the 3.5-5mm range for viewing planets...now where my question comes in is with the eyepieces I currently have the planets just look like bright stars and there's no real detail to speak of..would an eyepiece like that improve  the views some or is this scope just not powerful enough to give that kind of view...I know not to expect miracles with scopes like this which is why I'm asking before I shell out the dough  thanks guys!



#2 Anony

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Posted 26 March 2020 - 02:41 AM

Hey gents I recently was able to get a Orion skyquest xt4.5 and I had a question..I was looking to perhaps upgrade the eyepieces  which I have already started doing and was particularly  intrigued  by the Orion stratus eyepieces more specifically  one of the eyepieces in the 3.5-5mm range for viewing planets...now where my question comes in is with the eyepieces I currently have the planets just look like bright stars and there's no real detail to speak of..would an eyepiece like that improve  the views some or is this scope just not powerful enough to give that kind of view...I know not to expect miracles with scopes like this which is why I'm asking before I shell out the dough  thanks guys!

 

 

What planets are you referring to?

 

I recall seeing the rings of Saturn as a kid through my toysrus 3" cardboard reflector and probably the worst eyepieces imaginable. So if you mean Jupiter/Saturn, you should certainly see some nice details with a 4.5 reflector. If you are trying to see details on Venus or Uranus/Neptune ... well, that ain't going to happen.


Edited by Anony, 26 March 2020 - 02:43 AM.


#3 sg6

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Posted 26 March 2020 - 03:05 AM

The scope is 114 and 900 FL, so says F/7.9, close to 8.

Generally I would not go much below a 6mm eyepiece, that is 150x.

 

Which planets have you observed?

At present unless you get up in the morning there are not really any around.

 

Next - No of planets. My opinion there are 2 = Jupiter and Saturn. Mars will be a complete pain to observe almost immaterial of the scope. Mars falls into the very small and so specialised area. Mars needs it seems at least 250x and 300x is more that requirement. Both are dificult to achieve, maybe 1 night in 20 and you have to be outside observing that night and at that time.

 

Venus is a cresent shape soft fuzzy ball. All you get there is a "big" (actually very small) bright partial disk. The others are weird colored stars in effect. One Blue/Green the other Green/Blue.

 

Now 150x will show Saturn pretty well - depends on how good the scope optics are, and your conditions. Jupiter is easier all you need for Jupiter is 60x-80x.

 

Adding magnification will most likely fail. There is a lot of talk of scopes but ultimately they are not high precision optical instruments. They are mass produced at a cost in China.

 

Planet observing means collecting eyepieces, preferably in 1mm increments from 3mm or 4mm to 12mm. Then on the chosen night you take the lot out and see which just happens to work best that night. And yes I do have a 3.2, 4, 5, 6, 7, 8, 9, 10, 11, 12, plus others longer.

 

Anyway at what is close to f/8 I would not expect to get much use from an eyepiece shorter the 6mm, most of the time. Occasionally a 5mm will/may work. In effect you buy the 6mm for a good amount of use and the 5mm for those rarer nights. But that is 2 eyepieces, that on paper are somewhat similar.

 

Do you intend to get a bigger scope at any time? No problem with sticking to the Orion as it will do a lot and in my mind why spend out unnecessarily. Ask simply as it means buy for and only for the Orion or buy with future changes in mind.



#4 DLuders

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Posted 26 March 2020 - 03:44 AM

The Orion Skyquest XT4.5" Classic Dobsonian Reflector has an aperture of 4.5" (114mm), a focal length of 900mm and a f/8.0 focal ratio.  For seeing the planets, generally speaking, the more magnification the better (within the limits of this "Rule of Thumb"):

The maximum effective magnification of a telescope = 30x-50x the diameter of the primary objective (measured in inches).
For average Seeing Conditions, maximum magnification = 30 x 4.5 = 135x.
For better-than-average Seeing Conditions, maximum magnification = 40 x 4.5 = 180x.
For rare, exceptional Seeing Conditions, maximum magnification = 50 x 4.5 = 225x.

Magnification = (Focal Length of Telescope) / (Focal Length of Eyepiece)

 

Your telescope came with two eyepieces:

Sirius Plossl -- 25.0mm and 10.0mm (1.25" dia.).

Magnification with included eyepieces = 36x and 91x, respectively.

 

With a 25mm eyepiece, Magnification = (900mm) / (25mm) = 36x.
With a 10mm eyepiece, Magnification = (900mm) / (10mm) = 90x.

 

With the proposed Orion Stratus 5mm eyepiece, Magnification = (900mm) / (5mm) = 180x (pushing the limit of "Better-than-average Seeing Conditions").
With the proposed Orion Stratus 3.5mm eyepiece, Magnification = (900mm) / (3.5mm) = 257x (too much).

 

If you over-magnify your telescope view, the planets will become a mushy mess, like this:

 

Saturn Over-Magnification.JPG


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#5 NorthernlatAK

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Posted 26 March 2020 - 04:20 AM

This Oct Mars will be a decent size in a scope. Don't let anyone tell you that you won't see detail on Mars in a 4"! At opposition, if you magnify Mars 100×, maybe a bit more, it will be close to the size of a full moon naked eye (not magnified). And of course you can use a bit more than just 100× mag. What is your budget?
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#6 Waddensky

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Posted 26 March 2020 - 04:45 AM

Don't forget to gain experience before you invest in new equipment. Take your time to study an object, observe it over and over again, and you will be able to see much detail even at 90x magnification. At first glance, Jupiter will look like a yellow disk with two indistinct brown bands, but after a while you'll be able to see other bands and details in them, maybe even a hint of the Great Red Spot or a shadow transit of one of the moons. A shorter eyepiece is not a magical tool to suddenly see photographic detail on a planet.

 

My equipment allows me to magnify up to 300x, but when it comes to planets I rarely go over 100-150x because higher magnification will wash out much of the contrast. Let alone that the seeing on my observing sites usually doesn't allow me to use magnifications over 150x anyway.



#7 Bean614

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Posted 26 March 2020 - 05:28 AM

"Hey gents.."   ??????   Really?  You're relatively 'new' here, but, in case you haven't noticed, CN isn't limited to 'gents'.


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#8 Tony Flanders

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Posted 26 March 2020 - 05:47 AM

The SkyQuest 4.5 is an excellent planetary scope, given its very low price and relatively small aperture. However, it is a small-aperture scope with a spherical mirror, so you can't expect too much.

 

The provided eyepieces are actually quite good, especially considering this telescope's "slow" f/7.9 focal ratio. The focal lengths are very useful, and the optical quality is at least 90% of the way to perfection. The 90X that you can achieve with the 10-mm eyepiece is all that you could usefully use on Mars, Jupiter, and Saturn for the next two months, given their extremely low altitude in the morning sky. Higher magnifications are useful only when your target is reasonably high above the horizon, and when the atmosphere is steady. I strongly second the recommendation to see what you can achieve at 90X before proceeding to higher magnifications. That will show Jupiter's belts in considerable detail, and give glorious views of Saturn's rings.

 

In my opinion, the shortest focal-length eyepiece that's likely to yield good results in this scope would be 5 mm providing 180X, and even that would be too much magnification for the planets, except possibly Mars. In general, ultrahigh magnifications are useful only for tight double stars, the Moon, and maybe Mars. The cheapest and most effective way to achieve 180X would be to purchase a 2X Barlow, which would create an effective 5-mm eyepiece in combination with your stock 10-mm eyepiece. A Barlow is a useful accessory in its own right.

 

To a large extent, planetary observing means Jupiter and Saturn, the only planets that show significant detail throughout most of their apparition cycle. For those planets, with this particular scope, I find that a 6-mm eyepiece is just about perfect on a night of superb seeing. So if you're looking to purchase a single high-power eyepiece, that's the focal length I would recommend starting with.


Edited by Tony Flanders, 26 March 2020 - 06:11 AM.

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#9 Elvis1118

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Posted 26 March 2020 - 06:37 AM

See this is why I love posting questions here because you guys are great with the responses...the only planet that's clearly  visable in the sky that I'm aware of right now is venus and me being a total noob I just assumed that there might be a way to see more detail with a more magnifying  piece ..as you can see I still have a lot to learn having not dabbled in this hobby since I was a young kid 

 

I don't intend to upgrade at least not in the foreseeable  future only because portability is something important for me as I like to take my scope to the beach every year i go and also because of my job and other things I can't devote the amount of time I'd like to for this hobby.

 

Someone asked what my budget was..I guess I shouldn't go above 150-200 because and I'm just kind of assuming here but buying something like a 300 dollar eyepiece for a 240 dollar scope seems kind of back asswards  to me ..I suppose I'm just interested to know what the general consensus  is of the knowledgeable  people here as to how low is the max i should go for this scope like i saw someone mention 6mm and after that what are some of the good 6mm eyepieces out there ...sorry for being long winded lol



#10 Elvis1118

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Posted 26 March 2020 - 06:44 AM

"Hey gents.."   ??????   Really?  You're relatively 'new' here, but, in case you haven't noticed, CN isn't limited to 'gents'.

I am well aware that it's not limited to "gents" here it was just a generalization  term like how when I go to work and say hey guys even though  I don't work with just "guys" no need to be anal about it 


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#11 JohnnyBGood

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Posted 26 March 2020 - 08:05 AM

I used to have an optically similar scope (d=114mm, f=900mm) and was perfectly happy with 32mm, 12.5mm, and 10mm Ploessl eyepieces with a 2x Barlow. It gives a wide range of magnifications, and the scope was very sharp at 180x looking at the moon. The 32mm eyepiece gives you a wider field of view and makes it easier to find things than the 25mm, and the 2x Barlow doubles your eyepiece collection and makes the moon and planets more fun to look at. There's a BIG difference between 90x and 180x when looking at the moon. Both are relatively inexpensive.



#12 vdog

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Posted 26 March 2020 - 10:48 AM

I started out with a 4.5" reflector (the f/4 Orion Starblast), and I used 150x with pretty good results in that scope.  I could see Great Red Spot transits on Jupiter, the Cassini division (along with Titan) while observing Saturn, and, using a 13% neutral density filter to cut the glare, I could even just make out the maria on Mars, but you have to really work for Mars in any scope.

 

So, I agree that a 6mm (or thereabouts) would probably be your best bet. 



#13 LDW47

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Posted 26 March 2020 - 11:02 AM

I am well aware that it's not limited to "gents" here it was just a generalization  term like how when I go to work and say hey guys even though  I don't work with just "guys" no need to be anal about it 

You are correct, the planet has gone crazy ! Nothing wrong with your ‘ slang ‘ expression !  Clear gentle skyis !  PS:  Thats a nice little scope that anyone should be happy to own, to have some fun with, you will progress to some sort of larger scope soon enough so enjoy !


Edited by LDW47, 26 March 2020 - 11:04 AM.


#14 SeattleScott

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Posted 26 March 2020 - 11:12 AM

The Meade HD-60/Celestron Xcel LX 6.5mm is very sharp for the $75 or so price, not quite as good as a $250 Delite but pretty close considering the price difference. If you are looking for something near premium for under $100 you can’t beat it in this price range. The 6.5 Morpheus is also in your budget at current sale price, and offers a wider view. But it is bigger and heavier and could cause balance issues with your small scope. An Explore Scientific 6.7 82 AFOV would also give a wider view and not as heavy as Morpheus, more like the Meade/Celestron. Also would fit your budget. The wider AFOV would mean you have more time to observe before nudging the scope to compensate for the Earths rotation. Is that worth $150 or so instead of $80 or so? Your choice.

Scott

#15 DLuders

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Posted 26 March 2020 - 11:13 AM

Back on topic:

*  You could utilize the Stelvision Telescope Simulator and click on the "Detailed Simulation -- Choose Your Eyepieces" option to see what the planets will look like with your telescope.  You could download the Buyer's Guide to Eyepieces spreadsheet and see what's available.     Eyepiece selection will involve some tradeoffs (budget, quality, Field Of View, etc.).


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#16 Dave Mitsky

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Posted 26 March 2020 - 12:09 PM

You may want to consider the Astro-Tech Paradigm Dual ED line of eyepieces, Elvis1118.  These eyepieces have larger apparent fields of view and more eye relief than Plössls.

http://www.nightskyinfo.com/eyepieces/

 

Purchasing them from Astronomics will help to keep Cloudy Nights running and you'll get a bit of a discount.

https://www.astronom...gm-dual-ed.html

https://www.cloudyni...y_discount.html

An alternative is purchasing a 2x Barlow lens.

https://www.astronom...-eyepieces.html

 


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#17 Dave Mitsky

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Posted 26 March 2020 - 12:23 PM

Venus is a cresent shape soft fuzzy ball.

Venus varies from being a completely circular (ball) shape to being the thinnest of crescents when it nears inferior conjunction.  At that time, it is the largest planet in apparent (angular) size.

https://www.eso.org/...4-if11-fig4.jpg

 

https://www.curtrenz.com/venus06.html

 

https://www.curtrenz.com/venus04.html

 

https://medium.com/s...th-d95f2f72a8f8


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#18 Dave Mitsky

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Posted 26 March 2020 - 12:47 PM

BTW, astronomical "seeing" varies considerably depending on optical tube currents due to inadequate telescope cool-down, local heat sources, local topography, and the jet stream.  It can change from minute to minute.  You may live somewhere where the seeing is usually very good and higher magnifications can be employed or somewhere where it is uniformly bad.

 

http://www.damianpeach.com/seeing1.htm

 

http://www.damianpea...seeingscale.htm

 

https://skyandtelesc...ing-the-seeing/

 

https://www.schoolso...ollution/seeing

 

https://content.mete...stronomy-seeing



#19 SteveG

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Posted 26 March 2020 - 12:56 PM

Hey gents I recently was able to get a Orion skyquest xt4.5 and I had a question..I was looking to perhaps upgrade the eyepieces  which I have already started doing and was particularly  intrigued  by the Orion stratus eyepieces more specifically  one of the eyepieces in the 3.5-5mm range for viewing planets...now where my question comes in is with the eyepieces I currently have the planets just look like bright stars and there's no real detail to speak of..would an eyepiece like that improve  the views some or is this scope just not powerful enough to give that kind of view...I know not to expect miracles with scopes like this which is why I'm asking before I shell out the dough  thanks guys!

Welcome Elvis!

 

Your 4.5” is a very good scope - I have one.

 

It should do well on the planets, provided you don’t try to use too much power. I agree with those suggesting a 6 mm eyepiece, or perhaps a 2x barlow to use with your current eyepieces. 

 

I would use that scope scope to view (6) of the planets:

Mercury: When well placed, but very tricky to get a clear view due to how low it sits on the horizon.

Venus: You should get excellent views. Start early, as soon as you can see it, and use lots of magnification.

Mars: This year should be a very good one for Mars. I’ve seen detail in 4” scopes. It handles high power well.

Jupiter & Saturn: These are the showcase planets, but they are low on the horizon for the next few years. 

Uranus: You should be able to get a good but small view of this blue-green disk.

 

As for eyepieces, the Astro Tech eyepieces recommended by Dave are a very good start.

 

Good luck!



#20 Elvis1118

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Posted 29 March 2020 - 04:37 PM

Again thank you guys so much for the replies you've given me plenty to think about.




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