Jupiter the size of an orange, how much telescope do I need?

[ronin]

To the Orange analogy:

A mandarin I am about to peel and eat is 7cm across at 1 mtere distance that is an angle of 4 degrees.

Jupiter has a size of 30 to 50 arc seconds, lets pick 40 arc seconds

So to go from 40 arc-seconds to 4 degrees requires a magnification of 360x.

So may on very very rare occasions be possible.

You would need a very good scope as well and my experience of SCT's is they are not as good as I would expect. Seen Jupiter through a 14" and an 8" and my achro refractor beat either of them easily for quality of image, smaller but a lot better.

Another "problem" is the use of wide field eyepieces, that image of Jupiter in a wide field will look smaller then it really is, stick an Ortho in with a narrow field of view and Jupiter will look bigger. It simply fills more of your viewing area and the mind translates this as bigger.

Forget any image you see in a book or on the web, they are processed and do not represent what you will actually see.

Concerning what you see with just the eye:

Jupiter is a bright "star" that looks a little odd. The odd bit is because it appears to have some "size" and is not a point source as is a star. It is difficult to actually see it as a "disk" with the eye. So a big bright star.

Mars with the eye, looks like a red star. If it is near Arcturus then with the eye alone it is easy to mix them up.

They are planets but the name planets came from wandering stars, not wandering big disks. So it implies they have always appeared to be stars, just odd ones that move.

[Pig]

I would say when looking through a 10mm eyepiece and  a scope with a focal length of 2350mm and 235mm aperture Jupiter looks about as big as a 5 pence piece.

I don't know the size of coins in your country.

[Mr Spock]

A while back I produced this pic to show what Jupiter looked like through a C9.25. For a 1600x900 screen size (the one I used to make it) have the screen at arms length. It will give you an idea of size and detail. My most used magnification is x235.

[stevend]

The views are small but using a 5" (127SLT) scope I can make out the bands of Jupiter, the GRS and see the shadows of transits. Likewise the rings of Saturn and some nights Cassini, Mars is very difficult to get any detail.

The quality of what you see is not just down to size. As you increase magnification, and hence size, you also increase eg bad atmospherics so I can often see more detail at eg 125x than at 188x. It surprising just how varied conditions can be even from hour to hour.

Like others, your experience just does not sound right so I would try to find another group/individual from a local star group to get another view.

[jamie56]

Hi yep I would agree with oldpink, I have the same rig and can get Saturn fairly good, at least able to see the gas bands and moons, I think a lot depends on your light quality also, try some clubs and experiment with various scopes before commiting to purchase, I originally got a celestron 114lcm and upgraded to an 8inch skywatcher, much better views gut price goes up also, good luck, and enjoy.

[Pyrodave]

If Jupiter was just a white blob, could it have been that the scopes were out of focus for your family's eyes.

Our eyes are all different and I can rarely look through someone else's scope without having to tweak the focuser.

[Steve_meg]

I think if you looked through a telescope of a decent size and were disappointed, then as harsh as it sounds don't take it up as a hobby.

By this I mean, so people will look through a telescope and be in awe of seeing Jupiter with your own eye.

However others won't see the fuss, my father-in-law is a great example. I was once observing Saturn with my old 10" dob. Father-in-law had a look and his words were "is that it"

[Kropster]

If Jupiter was just a white blob, could it have been that the scopes were out of focus for your family's eyes.

Our eyes are all different and I can rarely look through someone else's scope without having to tweak the focuser.

I was wondering that.

Surely, the focus needs to be altered for each observer?

Even a small error in focus will obscure the detail.

Given the wobbles at high magnification, it isn't something the general public will find easy to do.

[andyman]

I think if you looked through a telescope of a decent size and were disappointed, then as harsh as it sounds don't take it up as a hobby.

By this I mean, so people will look through a telescope and be in awe of seeing Jupiter with your own eye.

However others won't see the fuss, my father-in-law is a great example. I was once observing Saturn with my old 10" dob. Father-in-law had a look and his words were "is that it"

Until  some astronomy retailers stop making unrealistic claims on a telescopes capabilities and showing hubble type images just to sell a product.....then there is going to be some disappointment ....especially those new to astonomy.this is what they are expecting to see....i would be disappointed also.but some people will be disappointed what ever the view...so astronomy i dont think would be for them

[Spikey]

I'm no seasoned observer so won't join in; but Qualia made a fantastic post on expectations vs. reality here http://stargazerslounge.com/topic/196278-what-can-i-expect-to-see/

[RikM]

I use a 10" Newtonian for observing with a 1200mm focal length. The examples given on this website match the views I get almost perfectly. http://www.backyardvoyager.com/eyepieceviews.html 

When using 'field of view' calculators like the excellent 12dstring site above, please remember that the full colour pictures of galaxies, nebulae and clusters displayed are long exposure digital images and although they are the correct size, do not match the views you will get with an eyepiece. Either the backyardvoyager page, or our own sketching forum http://stargazerslounge.com/forum/21-imaging-sketches-and-unconventional/ will give you a much better impression of how objects should actually look through a telescope.

[Koinonos]

Thank you everyone for your thoughtful posts.  Based on your comments and some others I received privately over the last day or two I  think Video Astronomy is just the ticket for my family.  Thanks to a good 1/4' CCD Jupiter can easily be made the size of a golf ball to baseball at arms length on the screen, and with a good 8" SCT I can stargaze, use Video to blow up the image nicely for my family, or do some beginner's Astrophotography.

I am researching the differences between the Meade Lightswitch 8 Lightswitch, and the Celestron 8 EdgeHD. The Meade seems to be made for beginning to intermediate Video Astronomy and can be plugged in directly to a Monitor/Laptop since it already has a 1/4' 640x480 CCD on it, and then once I show how cool this is to my family, later I can purchase the Mallincam Pro JR and a Mallincam Reducer at a later time for more serious VA and some AP. I also really like the Astronomer Inside on the Meade which actually has voice and video on over 1,500 objects for a multimedia presentation on it's own 3.5" LCD or to a computer to include voice, video, and multimedia. (Wow & Cool factor can really help my cause here)

The Star Party Factor
=====================
I also think the Meade would really be a big hit for drumming up interest in Star Parties. I noticed that almost all 200+ people who went to the CBC Planetarium Friday night, and then came over to the observatory + star party grumbled about how small and colorless everything was looking in the lens (The Hubble effect?). I think having the Meade with a Monitor showing a much larger image doing it's multimedia presentation to the un-initiated would be absolute dynamite in trying to drum up support and interest in our local Astronomy club and get them looking in the skies.

I have a feeling that Video Astronomy is going to be a big wow factor for local astronomy clubs to finally draw a larger audience. Yeah, I suppose the purists will have something else to grumble about then just GoTo telescopes (and they have a point), but I want people to fall in Love with the Heavens, and Video Astronomy/DSO sounds like heck of a way to get more people interested.

Meade LS 8 review - http://www.astromart.com/articles/article.asp?article_id=795

Meade LS 8 http://www.meade.com/ls

Kind Regards,

Koinonos

[Joves]

Sorry to disappoint you, Koinonos, but the Meade digital display won't show you a live view of what the scope is pointed at. It will merely play a little video showing Hubble images with a VoiceOver highlighting what you are currently looking at. A pretty cool little feature yes, but not a live video feed like one would naturally assume it might be.

I think, considering your expectations, Video Astronomy could just be the ticket. I have the Mallincam Xtreme2 and love it. The Mallincam Jr Pro looks absolutely fantastic and very hard to beat for the price. That being said, you haven't really suggested much interest in viewing much else other than Jupiter and Mars? Video is good for capturing these objects, plus Saturn, but this will get pretty old very quickly. What video is really designed for is allowing you to see more detail in many of the fainter objects in the night sky, like beautiful nebulas, stunning globular clusters and elusive galaxies. I hope you at least have some interest in viewing these objects as well, otherwise I wouldn't bother going to the effort or expense of buying anything at all, as I fear after the novelty has worn off your shiny new equipment will simply be set aside and not used.

[Dob]

Don't expect astonishing picture on the video either....while it will surely look bigger on the screen, you may not see as much detail as you would see visually. Seeing is a big factor too. The level of detail you can see on a video may vary during the imaging session. From excellent to very poor. That is why in planetary astrophotography video recording is used rather than taking single or multiple pictures.

How much you can see changes during time. As the time passes your eye becomes more trained and you learn more techniques and tips&tricks to see more. It was rather funny when me and some of my friends observed Jupiter (they had their first look through the telescope). Great Red Spot was easily visible but none of them seen it, although i explained them where it is and how does it appear.

Seeing conditions on a particular star party that you and your family have attended may have been bad. It may get so bad that you really cant see anything, especially when telescope is not "cooled" enough.

[Joves]

Here is an example of what you can achieve when capturing and stacking frames from a simple avi file captured from your video camera

And these are examples of what your "live" view on the screen will look like of a few different DSO's. Note, these haven't been stacked, they are a simple frame grab of exactly what was viewed on screen

Hope these help!

[Koinonos]

Thanks Joves, those pictures do indeed help as did your information regarding the CCD.  I am trying to determine now with the Meade LightSwitch if I can increase magnification with the onboard Elint CCD (I assume no since it looks 'built in' to the telescope), and if not then I will most likely be getting the Mallincam Jr Pro and a Barlow + various lenses (suggestions are very welcome) to try and shoot for 200-250x magnification for solar system objects (my son is *really* crazy about the planets which is why I have been focusing on Jupiter & Mars so much), and then I will definitely be looking to try to VA and AP some major Nebulas like Orion.

What do you think of this starting advice from what I have been able to cobble up so far?

Video Astronomy

1. Use the onboard Elint CCD to get used to the scope and the basics of Solar system imaging and perhaps looking at various DSO's.  Pipe it to the laptop via the 6' to 14' USB cable to get it on a computer monitor instead of the dinky 3.5" CCD optional kit.

2. Go get a Mallincam Jr Pro CCD, a Mallincam MFR-5 focal reducer, and a Mallincam 2.5 barlow for DSO.  I assume this can also be used for Solar system VA as well as DSO AP?

Live Viewing

1. Get the Meade 4000 lens kit ($199.00 USD) and use those to start playing with magnificent and barlow on Solar System objects for my son and wife.  They should see the beauty of it with their own eyes as well as with the video feed.

[Dob]

If you show your kids M42 nebula and tell them that the nebula is the huge place where the new stars are born, M81&82 galaxies probably lying to each other just like our galaxy and Andromeda galaxy, M13 cluster which contains hundreds of thousands of suns gravitationally bound together, Ring nebula in Lyra which is a remnant of a colossal interstellar event-ashes of a dying star, etc...

There are many wonders in our universe other than Solar System. Besides, DSO's are not affected by the seeing as much as planets.

[Joves]

You're welcome, Koinonos.

Something you need to be aware of with the Meade LS scopes is that the Eclipse CCD camera doesn't actually take images THROUGH the scope itself. It is designed to take wide field images of the sky to allow for complete automation of the alignment procedure. A handy little feature, but not to be confused for a CCD camera which can take magnified shots of the heavens. It will allow you to take images, but again, not magnified. So, if you're hoping to capture shots of planets with this, the answer is a resounding "you won't be able to". The images will simply look like bright stars, as seen with the naked eye. So, based on what I THINK you're hoping to achieve with it, this pretty much rules out option 1.

As for option 2, you'll absolutely be able to use the Mallincam Jr Pro with this scope for Solar System and DSO viewing/basic imaging... However, I'd be more inclined to go for an 8" LX90 rather than an 8" LS. The single fork arm on the LS series is nowhere near as stable as the double fork on the LX90/LX200 series scopes. For visual use, it's not a major deal. But if you're wanting to capture even short exposures without image blur due to a shaking mount/fork, you'll want the extra stability of double fork arms. Bare in mind that any fork-mounted alt-AZ scope is limited to relatively short exposures, so you won't be able to go as "deep", without star trails in your images, as you can with an equatorial mount precisely polar aligned. This is getting far more advanced than you're wanting to go, though... Not to mention beyond anything I've ever done also, so I'm the last person to give advice in this arena of AP.

You'll require the MFR-5 focal reducer a lot more than the Barlow if you're using a Mallincam on an 8" SCT. They have a small CCD chip, so the field of view is extremely tight (roughly the same as viewing with a 6mm eyepiece if used without the focal reducer), so will already be pushing beyond 300x magnification with an 8" scope with a 2000mm focal length. This is perhaps getting more technical than you're wanting, but understand that using a focal reducer with a Barlow at the same time effectively cancel one another's effects. In short, a focal reducer shortens the scopes focal length and provides lower magnification and a wider field of view... Whereas, a Barlow lengthens the scopes focal length, providing higher magnification and a narrower field of view. Sounds complicated, but is quite easy to understand once you start getting the hang of things.

As for the visual side of things, I completely agree that you and your family should/will want to experience the beauty of what you are viewing with you own eyes, even if the image is aesthetically not as impressive and lacking in any real display of colour as seen in fancy images. The magic of astronomy for me is gaining a small understanding of what it actually is you are lookng at, trying to somewhat grasp the seemingly impossible distance at which it's light has travelled to reach your eye, and then being astounded that I can see anything at all. It was when I started looking through the eyepiece with this frame of mind that tiny grey smudges began being some of the the most beautifully impressive things I have ever seen.

With regard to the Meade 4000 series lens kit, your money can definitely be better spent elsewhere. The focal length of your scope (if you go with an 8" SCT) will render half of them useless to you. Your precious dollars will be better spent on fewer, but better quality, EP's. Sorry if it seems I am negating all of your current considerations. They're not bad at all... I just believe you can do better.

In short (and by short, I mean LONG when looking back at this post), my advice would be to scrap the Meade LS idea and grab an LX90 (or equivalent Celestron double-fork 8" SCT) and get the Mallincam Jr Pro straight off the bat, rather than messing around with, and being disappointed by, the limitations of the LS' Eclipse CCD camera. Like anything worthwhile in life, your new scope and camera will require a slight learning curve to get the hang of, but I believe will provide you the ability to achieve what it is you seem to be wanting to achieve after some time under the stars.

Caveat: there is still a distinct possibility you do all this and still don't get bitten by the astronomy bug, so have a good think about things before you go out and spend your hard-earned. If it does take your fancy, rest assured it'll most likely ignite a passion that will see you spend a lot more of your hard earned in the future!

[RikM]

You're welcome, Koinonos.

Something you need to be aware of with the Meade LS scopes is that the Eclipse CCD camera doesn't actually take images THROUGH the scope itself. It is designed to take wide field images of the sky to allow for complete automation of the alignment procedure. A handy little feature, but not to be confused for a CCD camera which can take magnified shots of the heavens. It will allow you to take images, but again, not magnified. So, if you're hoping to capture shots of planets with this, the answer is a resounding "you won't be able to". The images will simply look like bright stars, as seen with the naked eye. So, based on what I THINK you're hoping to achieve with it, this pretty much rules out option 1.

As for option 2, you'll absolutely be able to use the Mallincam Jr Pro with this scope for Solar System and DSO viewing/basic imaging on this scope... However, I'd be more inclined to go for an 8" LX90 rather than an 8" LS. The single fork arm on the LS series is nowhere near as stable as the double fork on the LX90/LX200 series scopes. For visual use, it's not a major deal. But if you're wanting to capture even short exposures without image blur due to a shaking mount/fork, you'll want the extra stability of double fork arms. Bare in mind that any fork-mounted alt-AZ scope is limited to relatively short exposures, so you won't be able to go as "deep", without star trails in your images, as you can with an equatorial mount precisely polar aligned. This is getting far more advanced than you're wanting to go, though... Not to mention beyond anything I've ever done also, so I'm the last person to give advice in this arena of AP.

You'll require the MFR-5 focal reducer a lot more than the Barlow if you're using a Mallincam on an 8" SCT. They have a small CCD chip, so the field of view is extremely tight (roughly the same as viewing with a 6mm eyepiece if used without the focal reducer), so will already be pushing beyond 300x magnification with an 8" scope with a 2000mm focal length. This is perhaps getting more technical than you're wanting, but understand that using a focal reducer with a Barlow at the same time effectively cancel one another's effects. In short, a focal reducer shortens the scopes focal length and provides lower magnification and a wider field of view... Whereas, a Barlow lengthens the scopes focal length, providing higher magnification and a narrower field of view. Sounds complicated, but is quite easy to understand once you start getting the hang of things.

As for the visual side of things, I completely agree that you and your family should/will want to experience the beauty of what you are viewing with you own eyes, even if the image is aesthetically not as impressive and lacking in any real display of colour as seen in fancy images. The magic of astronomy for me is gaining a small understanding of what it actually is you are lookng at, trying to somewhat grasp the seemingly impossible distance at which it's light has travelled to reach your eye, and then being astounded that I can see anything at all. It was when I started looking through the eyepiece with this frame of mind that tiny grey smudges began being some of the the most beautifully impressive things I have ever seen.

With regard to the Meade 4000 series lens kit, your money can definitely be better spent elsewhere. The focal length of your scope (if you go with an 8" SCT) will render half of them useless to you. Your precious dollars will be better spent on fewer, but better quality, EP's. Sorry if it seems I am negating all of your current considerations. They're not bad at all... I just believe you can do better.

In short (and by short, I mean LONG when looking back at this post), my advice would be to scrap the Meade LS idea and grab an LX90 (or equivalent Celestron double-fork 8" SCT) and get the Mallincam Jr Pro straight off the bat, rather than messing around with, and being disappointed by, the limitations of the LS' Eclipse CCD camera. Like anything worthwhile in life, your new scope and camera will require a slight learning curve to get the hang of, but I believe will provide you the ability to achieve what it is you seem to be wanting to achieve after some time under the stars.

Caveat: there is still a distinct possibility you do all this and still don't get bitten by the astronomy bug, so have a good think about things before you go out and spend your hard-earned. If it does take your fancy, rest assured it'll most likely ignite a passion that will see you spend a lot more of your hard earned in the future!

I agree with all of this advice. From what you say, this is your best chance but you still need to be realistic in your expectations. 

[Joseki]

Hi Koinonos, welcome.  It really sounds like you need to worry less about impressing your family and focus on what you want to get out of it but that's your choice of course.  There may be a few unrealistic expectations there that you(and your telescope) can't live up to.  - Imagine getting your image of Jupiter on the screen and they still say something like - oh that's nice then 10 minutes later they're done - what are you going to do now?  As people have said to get the most out of viewing planets you have to sit there for a good while.  Will your son do that for an hour? two? - well I hope that doesn't sound too harsh.  Your post does read like classic case of not meeting prior (unrealistic) expectations, maybe you should give star parties another go.  My family are interested enough in my hobby but it's my hobby and their interest is only a bonus and they usually only come out for 5-10 minutes at a time.

[cotterless45]

With the right seeing conditions a lot of detail can be seen. We were recently at a public viewing. Some folks had never looked at Jupiter, but within seconds could pick out band details and the GRS.

We usually use from x150 upwards. That particular night , thin cloud helped filtering some of the glare off. It will be under the most exceptional seeing that you can blast magnification upwards and be rewarded by more detail,

Nick.

[Paul M]

I suppose it's a sign of the times.

I'm of an age that back in my childhood, telescopes were rare and very expensive. As a result I spent many years learning about telescopes before I actually owned even a basic usable one. That was a high street retailer's own brand 60mm refractor. I knew what to expect from it because I'd read hundred of books about observing with basic instruments.

I'm not sure how I'd cope in this age of relatively cheap but seriously large GOTO scopes and imaging gear.

I do feel for the OP. Being barreled along by over expectant family I couldn't have coped with that. No chance to learn some stuff first!

If I had to give some technical advice about telescope it would be to at least understand the significance of telescope dimensions. 

A very general rule is that a bigger (aperture wise) scope gives more resolution..up to a point. That relationship breaks down as you reach the natural limitation of looking through our turbulent and optically absorbent atmosphere. 

After that point more aperture will still collect more light making fainter objects more visible but detail on things like planets won't necessarily improve.

Then comes telescope focal length. This is usually denoted in terms of the Focal Ratio. Divide the focal length by the aperture and usually get a number like "F5" or "F10".

Lower focal ratios give wider fields of view. Less suitable for observing planets because you need more powerful eyepieces to increase image size. Higher focal lengths are better for the planets. A smaller field of view needing less powerful eyepieces.

The down side is that the field of view can be too small to fit the whole moon or some star clusters in.

All telescopes need "magnification" and a barlow lens is just another means of achieving a given magnification. With 3 good eyepieces and a good barlow you have a great selection of magnifications.

So all that lot boils down to what has been said already. Much of what you see through a telescope is down to experience and skill. Having the best equipment helps but it can also give too high expectations.

Here in the UK we get only a few really clear nights every year. And only a few of those will coincide with good atmospheric stability or "seeing".

What you see with a 6 in scope one night might not be visible with a 12in scope the next night.

I for one know I'd have my work cut out explaining that lot to my impatient family !!!

Good luck

[Koinonos]

Great points all. 

My interest has been steadily increasing over the last few years and I finally have some disposable income to purchase a telescope.  The great thing is that my son is 11 years old and is starting to get the bug as well as I have been slowly teaching him the visible stars and constellations when we hottub at night for our father/son time and just look up at the stars.  We catch stars, planes, and even satellites over head and it's great fun for us, but the Deep Sky Objects are calling to us both as we watch some of an episode of The Universe Seasons 1-6, go hot tub and check out the sky, and then come back in and later fire up Stellarium to see what 2-3 new stars we picked to learn in the sky are.  So until he discovers girls & console games at 13-14 and forget everything exists I am really running this time to have a great Father/Son bonding opportunity.

Telescope Update:

After taking everyone's advice to heart, and doing some browsing of the Video Astronomy forums I decided to go the Celestron route since they really support the aftermarket community, and some models support removing the secondary mirror to put in a Hyperstar to turn a SCT telescope into a F2 and the results are amazing, but that and a really good Mallincam CCD (Pro Jr?) will be next year's purchase.  After spending about 45 minutes on the phone with Celestron (Meade's are fine instruments, but they are really limited in what they have in the 2-3k budget range for SCT 8"'s IMO), here is what I purchased

Video Astronomy / Light Astrophotography kit that worked with my initial budget of $3200.00 USD including chair and all accessories

- Celestron CCD 8 Deluxe SCT with StarBright XLT HD optics, GPS, NexRemote, Schott, and SkyAlign in a fork mount that can use a Wedge for AP next year and nice quality learning worm drive.  While this scope is not an equitorial, but with the HyperStar install next year (60 minute exposures in 60 seconds as an F2) with a wedge this should be more sufficient for Video Astronomy and Astrophotograpy.

- Celestron Lens kit with 5 Plossl lenses, 6 planetary color filters, moon filter, and a 1.25 and 2x Barlow 1.25" lens.  There are better and more expensive lenses out there but this is a good starter kit for me to make sure the habit 'sticks' before I purchase more expensive gear

- Orion 52095 StarShoot All-In-One 1/3" CCD USB with 1280 x 960 array, exposure range of 0.00002 seconds to 10 minutes, 200 fps, and auto guider.  At $300.00 it is a solid Solar imager/live cam and can do some basic AP until I upgrade to the Mallincam and HyperStar next year.  And it can live stream so that at Star Parties and Outreaches they can see the Jupiter, Mars, or the Orion Nebua in color on the monitor!  Nice little bit of kit for the price.  And I like that there is no A/D, D/A conversion of an analog signal.

- Celestron SkyQ link to remotely drive the Telescope when it's winter time

- Celestron 5 amp AC adapter for when I can get AC power

- Celestron vibration suppression pads

- Orion DynaPro 17ah battery to drive the power for the scope, camera, and laptop for star parties and outreach events

- Nightwatch, a practical guide to the Universe intro to Astronomy book

Future Purchases: (Always willing to listen to suggestions or advice)
Better lenses (??) for live viewing, just enjoying the sky the old fashioned way
HD Pro Wedge for Astrophotography ($399)
Hyperstar secondary mirror kit to turn the scope into an F2 so that I get in 90 seconds exposure what usually take 60 minutes to achieve as an F10 ($799)
Mallincam Pro Jr (analog video, $500) or Celestron Nightscape CCD camers (USB 3, $1000)
Celestron Micro adjustment kit for Astrophotograpy

Kind Regards,

Koinonos

[Joves]

Nice one, Koinonos. I'm sure you and your son are going to absolutely love viewing the night sky together with your new toys. Can't wait til my little boy is old enough to do this together.

One word of caution... Make sure you have the appropriate filter when viewing/imaging the sun!

All the best,

Aaron