All I Want To See Are Planets

[Charic]

1 hour ago, Stu said:

the visual view is much better than this shot

Always the case.......time, conditions and patience is whats required, as you mentioned earlier.

My memory is etched when I saw the Moon shadow of Io, transiting across the face of Jupiter, can't wait for the next.

I'm sure all this is mind numbing for ansonmaddox, nothing is so straight forward when it comes to making a decision regarding purchases?
I wonder if there are any binoculars in the household?  that could make for an interesting evening, looking for and learning about the  constellations, and with so many more Stars visible under lowish magnification, satellites too, something real to look for.

[Stub Mandrel]

A bit radical, but even if you won't want to image, a decent webcam or better something like a ZWO ASI120MC used with a 2 or 3x barlow and a 1200mm f/l scope will let you see a remarkable amount of detail on a computer screen. Your eye picks the best frames and detail from video just as it does from looking through an eyepiece, and I find an inch or two diameter Jupiter on a screen is easier to look at than a little dot one, if not quite as magical

[ansonmaddox]

Ben: Those are some great values!  Thank you!

Stu: I printed out your post for reference.  I appreciate it.

Side question: Would it be possible to attach a CCD to the 12" Dob for video?  If so, I could string a long USB through the window and stay outside working the scope while the family sat inside and watched it on the monitor.  This might defeat the "connection" that I am trying to establish with the kids between the sky and what's in the book, but they would be warm and dry at least.  I found this:

https://www.celestron.com/products/skyris-236c

while I was hopping around looking at Ben & knobby's suggestions.  Just a thought.

[Cosmic Geoff]

Your 12" GoTo Dob will be a tough instrument to beat for viewing the planets, so the question is, do you really need to buy another telescope, and why??

If you decide you do need another instrument, be aware that one sees a variety of telescope designs and sizes suggested as being good for planetary viewing. Leading the pack are apochromatic refractors, which are unfortunately expensive, especially in the larger sizes.  I have found that the Celestron C8 SE alt-az GoTo SCT does a good job.

You don't need GoTo to track Jupiter, as an equatorial mount with RA drive would do the job well enough. But it would be worth having the GoTo anyway, as last night the excitement of looking at planets would soon have ended after looking at Neptune (tiny bland disk, probably needs GoTo to locate it in the first place) and Uranus (tiny bland disk).   If you do not really, really need an equatorial GoTo, this complication is best avoided and an alt-az GoTo is easier to set up (especially with Starsense where you basically haul the kit outside and turn it on).

[billyharris72]

17 hours ago, ansonmaddox said:

From cruising these forums for the last few days, I'm guessing I need a refractor for planets?

I'd stick with what you have and make sure you have the collimation etc as good as you can get it. You categorically don't need a refractor for planets. While an (apo) frac will definitely outperform a reflector aperture for aperture, the aforementioned aperture accounts for a lot. A 120mm apo (any 120mm apo) is not going to beat a 300mm Newtonian (properly collimated, and assuming the seeing is good).

The bit about the seeing is important, and can swing the argument in favour of a refractor (as can faster cool down and a nicer "aesthetic"), but you would need to spend a lot to beat a 12 inch Newt in terms of the detail that you can see.

As for other optical designs, both SCTs and Maks tend to have a larger central obstruction than a comparable Newtonian (though check as a 12 inch Dob will have quite a fast design and this can require a larger secondary - though the extent to which is does is actually quite small as fast systems tolerate undersized secondaries better than slow ones) and have lower light throughput due to the corrector plate. The main benefit (at least in my view) for these scopes is ergonomics rather than optics. They also suffer less from coma, but suffer more from field curvature and other astigmatisms. Plus coma is almost irrelevant when viewing planets as they are always small and in the centre of the FOV.

What I would add is that people often overestimate what they will see, or the ease of seeing it. Very few people are going to visually observe Jupiter and see white oval clouds first (or second, or third) time in pretty much any scope. The idea that you are going to get a massive improvement by changing the design of the scope (to me at least) does not hold water. Unfortunately for anyone wanting a quick fix, the answer to how to see great detail is to sit for hours, over and over and over again, patiently observing recording what you see. Maybe not what your wife wants to hear, I appreciate, but visual astronomy is not a pastime that is very amenable to quick fixes.

Hope this helps.

Billy.

 

 

[Buzzard75]

I have the XX12g myself and it's a fantastic piece of equipment. Very similar to the XT12g. I take mine to public club events regularly. Other members refractors, Mak's, and other dobs, but they're all smaller. If we're all looking at a planet, say Jupiter or Saturn, I tend to get the biggest reaction out of people because I can push the magnification to 300x. The rest of them can't do that because they just don't have the focal length or the aperture that I have. That's not to say that the views they get aren't good, they just aren't as big and bright. You just need to make sure that your wife understands she won't be getting the same magnification or resolution out of a smaller, more manageable scope, at that price point and that she'll have to manage her expectations. It's very hard to beat a dob for the money.

As for the position of the planets, come June and July we should be getting some pretty good views. In early June, Venus will still be high in the sky after sunset and in July, Mercury, Venus, Jupiter and Saturn will all be up in the evening. And come late July/early August, Mars will start to show above the southern horizon. Of course a lot of that is really dependant on your latitude. I live considerably further south than the UK so I'm somewhat blessed. The downside is, I have a lot more humidity I have to deal with.

[25585]

Children want and need to see the sky itself and what is there. Starting them on screen watching will just be like another TV or VR video game experience. Gratifying maybe, but not the direct phyical contact of looking up to the heavens.

Perhaps change approach to stages? Look what is there, magnify image and resolution with smaller instrument, increase both with larger. Etc.  I often assess the sky that way before deciding what and how much to use. 

 

[Geoff Lister]

16 hours ago, ansonmaddox said:

Side question: Would it be possible to attach a CCD to the 12" Dob for video?  If so, I could string a long USB through the window and stay outside working the scope while the family sat inside and watched it on the monitor. 

I have found that the high USB2 data rates do not work well along long cables. The Skyris-236C is a USB3 device, so will be more sensitive to cable length and quality.

It would also be difficult to "stay outside working the scope" if you could not see the resulting display. The link, below, gives details of the webcam that is shown in the garden setup in my second photo, earlier in this thread. I believe that I needed a x2 Barlow to achieve focus with my 10" Dob.

http://www.orion-xt10.com/philips-spc900nc-webcam.html

Geoff

[25585]

22 hours ago, Ruud said:

I'd recommend a Maksutov, especially the Rumak variant, if you are mainly interested in planets. Lighter, compact, no colour error, not as expensive. A 5 or 6 inch would be just fine.

A Maksutov has a small secondary mirror which obstructs little light and has little impact on image contrast. The Rumak design allows for better control of aberrations and has a flatter focal plane than the original Maksutov.

 

Which commercial makes and models of Rumaks are there? Not heard of that type before.

[Ruud]

24 minutes ago, 25585 said:

Which commercial makes and models of Rumaks are there? Not heard of that type before.

Hi, the OP also asked that...

21 hours ago, Ruud said:

Here's one: http://www.orionoptics.co.uk/OMC/omc140maksutovca.html 140mm aperture for £760

Just search for buy makstov rumak. Ordinary maks have a silvered spot on the corrector plate. Rumaks have their secondary on a support, like a Schmidt Cassegrain. 

There are more, like this expensive one: https://www.amazon.ca/iOptron-Rumak-Type-150mm-Maksutov-Cassegrain-Telescope/dp/B0030O4ZKO

[happy-kat]

How old are the children you are trying to engage with?

I personally don't like the video TV idea as it isn't involving them they are passengers to being fed an image.

If you know what they might be learning at school you might be able to weave the two together though at the moment the Moon is more accessible.

[25585]

2 hours ago, Ruud said:

Hi, the OP also asked that...

There are more, like this expensive one: https://www.amazon.ca/iOptron-Rumak-Type-150mm-Maksutov-Cassegrain-Telescope/dp/B0030O4ZKO

More expensive than the SW 150, price close to SW 180. 

Do the SW type just have their secondary stuck to the front lens? Is the construction in a Rumak theoretically better?

Orion's deluxe mirrors are 1/6, but their Newtonian mirrors can be 1/8 or 1/10. 

[ansonmaddox]

happy-kat: The children are 4 & 6 - both far advanced for their years, but I guess all dads think that.  They love the Hubble book, and they spend a lot of time with the digital microscopes we got them.

Geoff Lister: Thank you for the link.  That was good reading, and the reference section was great!

[laowhoo]

On 1/7/2018 at 12:44, Moonshane said:

Another option is to make a pair of 'wheel barrow handles' for the big dob so that this can be used by anyone?

That's exactly what we've done (except that ours double as go-to). Good to see.

[JOC]

On ‎07‎/‎01‎/‎2018 at 22:31, Stub Mandrel said:

A bit radical, but even if you won't want to image, a decent webcam

This is just what I was arriving to suggest.  The best and largest image I've seen so far of Jupiter was on the night I saw someone take pictures with a wecam - they had their computer attached to the setup and on the screen in real time I could see a picture of Jupiter that was several cm across.  The gentleman then took the footage, stacked it and produced an image of Jupiter that was beyond anything I could see with my 8" Dob.  I was really impressed and would love to replicate that.  I don't understand the science of of why a webcan cam apparently show a more close-up image than my eye can see.  However, that experience proved to me that it can that's enough for me without people pitching into 'maths' to explain it!

That said I'd love to see Jupiter through a 12" Dob with my Pentax XW 5mm in the mixing pot!

[Stub Mandrel]

14 hours ago, JOC said:

 I don't understand the science of of why a webcan cam apparently show a more close-up image than my eye can see.  However, that experience proved to me that it can that's enough for me without people pitching into 'maths' to explain it!

I don't think it does really, it's just that you can blow it up and observe it at a comfortable distance. Plus, although you probably sacrifice some dynamic range that may actually help smooth the image and make it  easier to observe than a bright patch in a dark field.

[Stu]

15 hours ago, JOC said:

This is just what I was arriving to suggest.  The best and largest image I've seen so far of Jupiter was on the night I saw someone take pictures with a wecam - they had their computer attached to the setup and on the screen in real time I could see a picture of Jupiter that was several cm across.  The gentleman then took the footage, stacked it and produced an image of Jupiter that was beyond anything I could see with my 8" Dob.  I was really impressed and would love to replicate that.  I don't understand the science of of why a webcan cam apparently show a more close-up image than my eye can see.  However, that experience proved to me that it can that's enough for me without people pitching into 'maths' to explain it!

That said I'd love to see Jupiter through a 12" Dob with my Pentax XW 5mm in the mixing pot!

I guess different things appeal to different people. Yes, some of the planetary images on the forum are stunning, fabulous to see and I understand why people do it. BUT, and it is a big but! It is not the same as, for instance, seeing the razor sharp, jet black shadow of a moon slowly passing across the face of Jupiter with your own eye, or seeing detail in and around the GRS. It is a hard thing to do, but all the more rewarding when everything plays ball (conditions, scope, you) and the views are enough to last for a long time.

I genuinely don't know whether children under 10 have the concentration levels to see and understand all this, some will, some won't, but it is definitely worth trying.

I remember showing my daughter a comet through binoculars a while back. I thought it was quite hard to see, but she thought it easy and wasn't that motivated by it. Another child with more interest might be really taken with this. Ultimately I think, with children, it is about presenting opportunities to them and seeing what they like and are interested in, not trying to force anything on them. I would love my older kids to love astronomy, but they just don't! My little one (3, nearly 4) loves talking about the Moon and 'Marvis' (Mars  ) so we will see how she develops  

[JOC]

On ‎07‎/‎01‎/‎2018 at 16:34, ansonmaddox said:

Again, emphasis is "as big and detailed as possible" (she made me recite that a few times out loud).

I think Stu has a point.  I must admit I rather winced at the point above in the OP.  With the best will in world no scope is going to show huge amounts of detail like the shiny boxes that Nat. Geo. sold scopes are supplied in.  In fact I think the OP's wife could be usefully pointed at page one of this thread with the suggestion that she just looks at the pictures:

If I can't get my science inclined teenagers, one with a more than a nominal interest in astronomy excited about looking at the planets through the fairly nice kit that I have (they'll come and have a quick peek to keep me happy, but seldom go 'wow') I think a younger child will get bored even quicker.

If it's possible to add a Goto to your existing system that might be your best bet (it is useful to have something that stays on target with kids in my experience) as I think a 12" Dob is as good a weapon as anything else for being able to blow up something up a bit larger (it must give a better view than I get) - maybe a higher mag EP or two?