Celestron 127

[Oliver Gigacz]

Hi
I just got a celestron 127 from Dick Smith for $127 and was wondering how big Jupiter and Santurn and other objects will look?

[stephenb]

Hi Oliver,

Take it out and have a look! If the clouds are clear this weekend, you will be able to see Jupiter, and you will be able to look at the moon when it begins it's cycle next week. in the western sky in the evening. This is quite a change from your original idea in your opening thread here (http://www.iceinspace.com.au/forum/showthread.php?t=48458).

With this aperture (127mm or 5") you will struggle to much more than a very small disc of Jupiter. but you will see the 4 inner moons, Io, Ganymede, Europa and Callisto.

Saturn will not be visible now until next year.

You will only be able to see the brightest of the deep sky objects.

As was explained to you in your previous thread, magnification is not the important factor when using a telescope. Aperture, or the size of the main mirror is the most important thing to consider. The bigger the mirror = more light that falls on the mirror = brighter image.

Good luck.:thumbsup:

p.s. this site here (http://telescope-simulator.com/index.php?option=com_content&view=article&id=45&Itemid=57)has a telescope simulator for you to get an idea on how big some objects will appear to you.

[Oliver Gigacz]

Will I be able to see the cloudbands?

[renormalised]

Yes, you will.

[Oliver Gigacz]

Tonight was clear for sometime and had a look a t Jupiter and I could easily see the Cloudbands. Quite a nice little telescope. Of course I will be looking to buy a much better one in the future.

I was wondering is there a Canon EOS mount I could attach to it to take photographs? I dont care about if it will look right just if it will take a shot of something.

[bmitchell82]

just use a digital camera and take advantage of the A - Focal method aka holding your digicam upto the EP and taking a shot, works for the moon and planets :) Astro photography requires some specific equipment to make it work without wasting your time

[Oliver Gigacz]

Will I see the rings on Saturn? And how about Mars or Venus what could I see there when they come round early next year.

[bmitchell82]

well the rings on saturn are very tight at the moment ( i belive it was last month or early this month they where invisable to us), You definately will see those 3 with venus being the easiest to see/find. if you wanted to use the Afocal method invest in a digital camera holder so you can line it up alot easier and take photos without shaking as the low light needs longer exposures.

[Oliver Gigacz]

I have now used it a bit now. Looking at Jupiter and the Moon. The moon is great. The detail of it is amazing. Jupiter is good and can easily see the four moons and minor cloud band detail. I was using the 20mm eye piece the whole time.

I then tried the 4mm one and the moon is still good but not great and Jupiter is just a disc which is blurry.

I was told that I could easily see the cloud bands of Jupiter and moon shadows of the surface with a 5" telescope which is what this is. Is there a way I can improve it? I live near Melbourne City does this have anything to do with it?

[stephenb]

Hi Oliver,

Well, depending on where you are in Melbourne, and how much light pollution you are subjected to, but I think you have pushed the limit of the telescope, certainly for Melbourne. You will need to travel to a dark sky site to see any more detail.

I am not surprised you are only getting a "blurr" from the 4mm eyepiece. What you have discovered is a valuable lesson in how magnification is not the most important aspect of optics. You can push the magnification too high and the result is a poor image. What other eyepieces do you have, Oliver?

I doubt you will see any shadows pass the surface of Jupiter, escpecailly in Melbourne, but other users of this aperture may have an opinion on this.

regards,

Stephen

[Oliver Gigacz]

I just have what it came with. 20mm, 4mm and a 3x barlow.

[Oliver Gigacz]

I have found a few photos taken with an 127mm telescope will I be able to get the same type of shots?

http://www.flickr.com/photos/torbenh/3780120643/
http://www.flickr.com/photos/torbenh/3817582682/
http://www.flickr.com/photos/ekilby/2280562725/
http://www.flickr.com/photos/thelunarscape/182493199/

[rat156]

Your focal length is about 1000mm, the Mak-Cas type you are comparing to have a focal length of 1500mm. Your image would be smaller unless you use the barlow. Get a cheap webcam and use your Dad's laptop to capture some pictures.

Cheers
Stuart

[g__day]

In perfect seeing you can magnify things about 50x for every inch of apperature. In normal seeing about 30x. So in normal seeing your OTA will be able to magnify an object a maximum of 5 * 30 = 130 times. To do this you'd need a 1000mm / 130 = 7.6 mm eye piece.

Jupiter is about 30 arc seconds in diameter. At 130 x magnification (3900 arc seconds) that's about a 1 degree view - or twice the apparent diameter of the full moon.

To me that seems unachievable. Personally I think in great seeing - on an awesome mount, with top quality eye-pieces and great focusing you'd be able to get it to about half the size of the full moon.

To achieve rock steady seeing you'd need a great mount - as every jerk or bump is also magnified 130 times!

[Oliver Gigacz]

So I should be able to get Jupiter about half that size or bigger?

[Oliver Gigacz]

So what sort of eyepiece should I be looking for to see things bigger and focused?

[g__day]

Maybe try a Vixen or Meade 8mm - 24mm zoom eye piece for the maximum versatility.

Magnify things too far and all you'll get is frustration. A decent zoom eye piece on that OTA will give you 30 - 120 magnification. When I do visual on a 2300mm focal length OTA I rarely go below 13mm (176 times magnification). At 5mm (460 times magnification - I have only done this a very few times). The most usual eye pieces I used were 17mm, 22mm and then 13mm (Vixen LWV).

There are only a handful of objects close enough for high magnification to show detail (Jupiter, Saturn, Mars, Moon). Often wide field, great contrast and excellent focus bring more joy.

[Oliver Gigacz]

The things I will be mostly looking at are Moon, Jupiter, Venus, Mars and Saturn and would like to get some more detail on Jupiter (cloud bands) and would also like to be able to get the most detail on Saturn when it comes round next year. What would be the best eyepiece for these kind of jobs?

[orestis]

Hi Oliver,

I have a 5 '' telescope and i love viewing jupiter.Not so long ago in good seeing i saw a shadow transit.But i have found out in bad seeing you cant see much. Also in good seeing i have seen waves in the cloud bands.
try the 20mm with the barlow and see what you get.i think a 4mm is too much magnification.

have fun with your scope

orestis:thumbsup:

[Oliver Gigacz]

Great thanks, Would a 15mm eyepiece be better though?

[orestis]

15mm with the 3x barlow on jupiter would be 200x magnification.Which i think is too much magnification.I use a 15mm ep with a 2x barlow which is only 120 magnification on my scope and in good seeing it works great any higher magnification and the image gets blurry.Even though the image is small you can still see quite a bit.:).
heres a photo i took just with a generic digital camera to give you an idea afocally.
3x zoom.

clear skies
orestis:thumbsup:

[g__day]

The advice I would give is that there are about 5 levels of eye pieces from $40 Plossls to $900 Televue Ethos. Personally I go mid range around $250 (if you shop or buy second hand - $33o - $350 brand new) Vixen LVW, above this are Televue and Nagler general Type 4, 5 or 6 eye pieces.

Having about ten plossls or ED eye pieces - I can now say after buying 5 Vixen LWV, I never, ever use the Plossls - so I'll probably sell them all.

[Oliver Gigacz]

What is your telescope?

[orestis]

My telescope is a skywatcher 130mm diameter reflector with a focal length of 900mm on a gem mount.

basically the same as yours.

orestis:thumbsup:

[Oliver Gigacz]

Where did you get the 15mm and 2x barlow?

[orestis]

[QUOTE=Oliver Gigacz;501785]Where did you get the 15mm and 2x barlow?[/QUOTE

hi oliver,

i got the 2xbarlow from bintel telescope shop from sydney but i think there is one in melbourne somewhere.

The 15mm came with the telescope but you could probally get one from bintel as well.

i just bought a blue filter from bintel to observe jupiter with.i'll let you know if you should get one too only $20.:)

bye
orestis

[Oliver Gigacz]

I am going to get a 15mm. What sort of barlow should I get.

[Oliver Gigacz]

Got my new eyepiece and I can see some more detail on Jupiter. I was also wondering if when Saturn comes round again I would be able to see Titan.

[orestis]

hi oliver,

Thats great. Yes! you will be able to see Titan, its quite bright.

orestis:thumbsup:

[Oliver Gigacz]

When will Venus, Mars and Saturn be visible early night (ie before 12AM)

[renormalised]

Saturn has set for the year and will not be visible until early morning (after 5am) when it will just be poking over the horizon. Mars and Venus come up later in the evening and early morning, respectively. At 3am, Mars will be nearly 15 degrees above the horizon. Venus won't be visible till it's almost too late to see anything (around 5am).