Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Beginner Just Joined and Got myself a toy

  1. Aug 8, 2011 #1
    Hi All,

    I am an enthusiast and love the sky... always wanted to develop the hobby to observe the sky, but here in UK we have very narrow period of clear skies during the year.. however this year I have decided to start doing it anyway..

    Found a near by bunch of enthusiasts who meet once a month to discuss and show off their gadgets and photos.. So I will be joining them soon in the next meet.. they have a good observatory with a 12" GOTO Meade telescope free for members use..

    Budget perspective I didn't want to spend more than 100quid.. so after reading few reviews ordered this one..Celestron PowerSeeker 675 here http://direct.tesco.com/q/R.206-0114.aspx ; have read mixed reviews about it.. bought it anyway, can return it if I don't like it..

    Will be using some sky maps and Google sky on the phone to spot the celestial bodies.. but the first object I would like to see would be the moon.. up close and personal :).. then mars, saturn and jupiter when they show mercy on me :)..

    Not sure if can spot any faint objects with this one, but i will give it a try..

    Also I have got a Olympus e500 dslr.. but not sure if I can get a T-mount to attach it to the telescope to take any photos.. please help me here..

    Thanks a lot for your help and suggestions in advance...
  2. jcsd
  3. Aug 8, 2011 #2


    User Avatar
    Science Advisor
    Gold Member

    Looks like you got a 3" objective, which is the most important number. The 675x magnification is just a shameless marketing ploy. You can get any magnification your heart desires out of any size objective, but, the practical limit is 40-50x the objective diameter [in inches]. And it will be a rare night you can coax 150x usable magnification out of an objective that size. For the money, a good pair of 8 or 10x50 bino's would probably be more enjoyable.
  4. Aug 8, 2011 #3
    HI Chronos.. the telescope is also known as 114EQ... it has a 4.49" objective and a 900mm focal length.. optimum zoom is 225...

    I read turbo's beginners guide to buying a telescope.. but couldn't convince myself to buy a pair of binos..

    for the money i have seen a 10x50 binos.. if I am not satisfied, would return this and buy them..

    are spotting scopes any good? that way i can attach them to the camera also to take any pictures?
  5. Aug 8, 2011 #4


    User Avatar
    Science Advisor
    Gold Member

    Understood. My first scope was a 6" f8 and it was a lot of fun [and somewhat awkward]. The link was a little vague on aperature size. 4.5" is more realistic. Spotting scopes are designed more for terrestrial use, but, are usually pretty fast [which is good for photos]. They are basically half of a large binocular. Astrophotography is, however, tricky business. Exposures longer than a handful of seconds requires a mount and various other accessories that can easily [and usually] cost more than your scope.
  6. Aug 8, 2011 #5
    HI Chronos.. Thanks for the tips..

    Yeah.. the description on the link i gave was very vague and 675x zoom was inappropriate as well..

    i am not rushing into astrophotography.. just was reading about it.. and thought to myself.. "i have the camera, i bought the scope and all i need is an adapter :) might aswell give it a try"..

    you said, spotting scopes are "fast", what do you mean by that? is it the time to setup.. or time to get object into focus?

  7. Aug 9, 2011 #6
    Hi rednus6 and welcome to PF! I'm a big enthusiast too and adore everything that's related to sky, space and cosmos. I live in Sweden at the countryside with moments of totally fantastic and cristalclear view over the night sky (at the winter), with no pollutions.. But still there is very much clouds here too often. I'm definitely not rich and when it comes to my budget, I keep it very tight.. Anyway, with a 50x zoom watch at the Moon, it feels like you're there, almost.. And get a view over Saturn's rings and Jupiter's moons. I hope I can invest in a better telescope soon. Almost no one in my class at high school or around me aren't interested or even aware of the fantastic things in space. Sadly though. You ever tested http://www.stellarium.org/ ? This is a great program if you don't have it. Anyway, Goodluck!
  8. Aug 9, 2011 #7
    Hi Gliese, thanks for the warm welcome.

    I usually come out at night and keep staring at the sky.. it always amazed and amused me.. so I thought why not stare at it with a bit more tech.. I will be getting my scope tomorrow.. will test and let you know how it is..

    hey.. which part of Sweden are you from.. do you get to see Aurore.. Northern lights.. if so.. i can lend you my scope as long as you let me camp in your fields.. :)

    And yes.. I use Stellarium.. and Google Sky maps to identify the sky at night.. they both are good..
    Last edited: Aug 9, 2011
  9. Aug 9, 2011 #8
    No, unfortunately I don't see the northern lights. I live in Östergötland (Ostergotland) (copy it to googlemaps). The aurora can slowly "drag" it self to here but that just happened one single time. I've worked this summer and got plenty money, so I can perhaps invest in one of my interests for once. Yeah please, come here. You just have to like one thing to camp on my fields: Enjoy being alone from people because that's what I'm everyday. Lol. Thank you for letting me know later how it went! :)
  10. Aug 9, 2011 #9


    User Avatar
    Science Advisor
    Gold Member

    Fast refers to the f number of the objective which is the ratio between focal length and aperature. A scope rated f6 or less is generally considered fast. The advantage of a fast scope is it reduces exposure time required for photography. For example, an f4 scope only needs 1/4 the exposure time an f8 scope needs to photograph the same object [it goes by the square of the ratio between different f numbers].
  11. Aug 9, 2011 #10
    Chronos... Thanks for the explanation..
  12. Aug 10, 2011 #11


    User Avatar
    Staff Emeritus
    Science Advisor

    Correct me if I'm wrong here, but I think the focal ratio changes the amount of zoom you get with any particular eyepiece or camera. A short focal ratio gives you less zoom and so the resulting light from the object is focused on fewer pixels. A longer focal ratio spreads the light out onto more pixels so that it takes longer to get enough light to grab a decent image, however you are now zoomed in further. So "fast" means less zoom than "long".

    Just throwing this out because if it is true then I don't want anyone to be confused and not realize this and then be dissapointed when they are zoomed in too much or not enough for what they want to view.
  13. Aug 11, 2011 #12
    Hey Gliese, I see that you quite south of Sweden.. hey if you buying something try ebay, get a used one to save some money..

    Staying alone is what I like when I am watching the sky.. thanks for the offer to camp.. will try.. :)

    I have got my scope yday.. and damn it was a very cloudy day here.. so I was reading and watching videos about polar alignment and collimating etc.. and about midnight i saw bit of clear skies.. rushed out with my scope.. didn't had any time to do the polar alignment etc.. but just pointed the scope at the moon, it was too bright and not ideal for observing, and was unable to get it into focus, by the time i got focus on clouds were back on.. not sure why it was so difficult to get the focus on moon.. but i was telling myself not to get disappointed..

    so then looked around the sky for any clear parts.. saw one clear corner in-front of the house.. with a bright object in the sky towards east.. quickly used my android to determine that its J-U-P-I-T-E-R.. front of the house is highly polluted by the street light.. so not expecting a lot, set up the scope in the shade of the garage pointing to jupiter.. took a while to get jupiter into objective, then used 24mm ep to get it into focus.. took a long time because jupiter was moving away quite fast, about 10 to 15 seconds to move away from one corner to the other corner of my scope's objective, finally managed to get focus on.. and wwwoooooooooooowwwwwwwwwwwww.... i did it.. it was still a small dot.. i didnt expect to see the clouds or anything like the g.red spot.. but i could make it out clearly.. the image was not stable, due to weather conditions, lot of strain on my eyes, but enthu killed the strain.. i need to use a patch on one eye from next time around.. then i used the 3x barlow lens with 24mm ep to get a bit more of the features, but it only lasted short time..

    but over all i was satisfied with my first experience of the scope and sky.. i hope we get more clear nights ahead and more joy stargazing..

    Chronos or anyone else, can tell me if i can see anything else with a 4.5objective apart from the moon and jupiter.. saturn is not in question because he is only in the horizon after 2am, too late for me.. any nebule? or messier objects etc?
  14. Aug 11, 2011 #13
    Thank you for telling me about your success rednus6. However, I didn't thought about it until you actually mentioned it. It's summertime, which means the worst months of the year if you'll look at the night sky, as you probably know. You mentioned that there are barely no notable bright objects available at the sky these days. I've that problem here too. Since the Moon has no straight orbit (I think), it can actually go quite "high up" here over the horizon some days. Otherwise, the tilt of this planet and the light nights is making it very hard for people in the north to see these planets at the summer. About that, when you were going to look at the Moon, which apparently was to bright. I wonder if there maybe are any dimmer or ISO control or something on your telescope? Which may be good. . Despite the clouds are covering your position sometimes and the light pollutions is disturbing the sight, I hope there will be more opportunities for stargazing. Speaking of Jupiter, I used a binoculars with 50 x zoom (for bird watching, lol) one time, and I saw the dots of its moons and so, which totally amazed me. Which also was the first time I ever looked consciously at another planet/moon, than the Moon.

    I've no acces to Stellarium right now but I've an idea of where I might saw some infomation of that Mars is going over the horizon and aren't visible until 01.00 or something like that, (local time) . How about Uranus & Neptune? Are they visible. I'll look more for any nebulea later. :) (Sometimes if you zoom in too much, the sight gets too blurry and as you said: the planet is moving too fast out of the objective..) :)

    Have you told me before, or I maybe forgotten but, where do you live and how old are you? Please write some personal information here or on your profile. :)
  15. Aug 11, 2011 #14
    I've no good knowledge of how visible certain nebulae can be in a telescope as yours but what about NGC 6611 or NGC 6618 tonight? What do you think? (probably too far away....) Or is it perhaps to much air/light pollution for that? NGC 7293 is perhaps visible, it's "only" 700 light-years away...
  16. Aug 11, 2011 #15
    Hey gliese, 7293 has magnitude of 13.5 and I don't think I can see anything of it with my scope. It has a limit of 12.8.

    Probably I will try to get more of Jupiter and if my camera ring is delivered then try to get some photos as well.

    Oh btw I am from uk, live about 50miles north of London.
  17. Aug 11, 2011 #16


    User Avatar
    Science Advisor
    Gold Member

    I use sunglasses to view the moon, works great [poor man's moon filter]. Your scope is capable of resolving magnitude 11.5-12 objects. Even in poor seeing magnitude 10 should be achievable almost anytime it is not overcast. This means you can see [and fairly easily for the most part] just about every object in the Messier catalog!

    Drakith, eyepiece magnification is simply the focal length of the objective divided by the focal length of the eyepiece. For example, rednus's telescope is a 4.5" f9 with a focal length of a little over 1000mm. Combine that with a 26mm eyepiece and you get a magnification of about 40x. He should be able to push that to about 100x and still get very good views. Much past 100x and the image brightness and quality will begin to suffer with that aperature. The 'book' claims usable magnification is about 50x aperature diameter, but, that is assumes ideal viewing conditions and near perfect optics [both rare]. For your average quality scope on a night of average seeing, about 25x aperature is more realistic. You can manipulate telescope focal length using a barlow or focal reducer, but, at a price. The image quality will suffer somewhat in either case. A barlow is handy because you can effectively increase the magnification of all your eyepieces with one relatively inexpensive optical element. It's like having more eyepieces. A focal reducer is nice because you can increase your field of view [and lower magnification]. This is great for extended objects [like open clusters], where field of view is more important than magnification. It too turns all your eyepieces into two eyepieces. If you save all your money up for one premium eyepiece, a barlow and a focal reducer can turn that fabulous eyepiece into 2 additional, almost as fabulous eyepieces for considerably less money. Just remember to keep your barlowed magnification within reasonable limits. Purists [rich people] just buy all three eyepieces because they insist on the 'best possible' image quality from all their eyepieces.
  18. Aug 12, 2011 #17
    Chronos, thanks for the Sunglasses idea.. i will give it a try..

    and yes.. magintude 10 is what i am expecting even though the limit of the scope is 12.8..
  19. Aug 12, 2011 #18
    Rednus6, take a look at the Moon tonight. It's almost full moon. :)
  20. Aug 22, 2011 #19
    Hey.. I have had some success with the scope lately.. attached are some photos.. not so clear but they are alright.. :) First two are Moon obviously.. third of them is Jupiter..

    Attached Files:

  21. Aug 24, 2011 #20


    User Avatar
    Science Advisor
    Gold Member

    Not bad for first try, rednus6, I'm still working on astrophotography. Im vain, so still need a few weeks to post my first light effort.
  22. Aug 24, 2011 #21
    Chronos, yes, I am also satisfied with the results. Not bad for the first attempt. Though the images are taken with a 14mega pixel camera, they are not good when zoomed in because of the bad focus.. I could not get the focus right. And I was able to take only one picture of the Jupiter, even that was out of focus completely.. I will try to take multiple with good focus and stack'em up next time..

    Only problem is we don't get continuous clear nights here in UK.. :(

    hey btw, wish you luck..
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook