Am I still doing something wrong

[Dave scutt]

Hi all.

As the title says am I still doing something wrong. 

I have a 12"skywatcher dob and I still can't get much more detail on the planets. 

On jupiter I see the 2 bands and sometimes the red spot but nothing else.

On Saturn I think I might have seen the cassini division once. 

I had a look at what you should expect to see, and I don't think I'm using my dob to it's full potential. 

I let it cool down for a long time and even put the fans on to help , I think my collinmation is ok  star tests look good.

Would buying a chair and sitting down being relaxed and taking more time at the ep help instead of spending 5 minutes here and there.

Dave

[Stu]

23 minutes ago, Dave scutt said:

Hi all.

As the title says am I still doing something wrong. 

I have a 12"skywatcher dob and I still can't get much more detail on the planets. 

On jupiter I see the 2 bands and sometimes the red spot but nothing else.

On Saturn I think I might have seen the cassini division once. 

I had a look at what you should expect to see, and I don't think I'm using my dob to it's full potential. 

I let it cool down for a long time and even put the fans on to help , I think my collinmation is ok  star tests look good.

Would buying a chair and sitting down being relaxed and taking more time at the ep help instead of spending 5 minutes here and there.

Dave

There are a few things to consider, but your last paragraph may be as important as anything else. I was looking at Jupiter last night, albeit only in a 76mm scope and spent a couple of hours at the eyepiece. You don’t need that long, but certainly I would spend as much time as you can looking. The benefit is that you catch the moments of better seeing, and over time your brain builds up a better picture of what is there to see.

A quick glance last night showed just two fairly bland bands, but longer viewing showed some detail in the NEB, the GRS with separation from the SEB and some vague detail behind it in the SEB. Not so much, but still rewarding. I also caught the Moon Europa showing brightly against the limb darkening, just before it left the disk.

A 12” under good conditions will show much more.

Other things to try.... well, make sure you are not observing over houses or tarmac/concrete as much as possible as these give off a lot of heat and spoil the seeing. Observe on grass if you can.

The early hours of the morning are often the stillest as the heat has largely dissipated from the land and buildings. At the moment Jupiter is high up at around 3am, so that is a great time to observe. When the planets cross the meridian in the South they are at their highest so you are looking through the least atmosphere so they will be more stable.

An observing chair can certainly allow you to concentrate better and keep your eye in the right place So is well worth using.

Finally, pick the best magnification for the conditions. Jupiter is often beat at around x180 if the seeing is good, too much more and the low contrast features get washed out. Play around with mags and see what works, though smaller and sharper is generally better than bigger and fuzzier.

Good luck 👍

[Kon]

It will depend a lot on seeing conditions as well. This morning Mars and Jupiter looked pretty good with nice details. The GRS was showing nicely and quite a bit of banding on/off. I could not go higher than my 6.7mm this morning so it is worth playing with different magnifications. Take your time. The other night I was observing Saturn and the seeing was on/off and Cassini division and planet banding was coming and going within seconds. Other nights both looked as a bright fuzzy mess, like looking through a swimming pool.

Keep on trying and hopefully the seeing will be good.

[mcrowle]

I owned a Meade Starfinder 12.5" dob for many years, and it gave superb views of the planets. Jupiter showed incredible detail within its many bands - and that's despite it then being low along the southern ecliptic as it has been in recent years.

Sadly, I sold that scope for a pittance as I was moving to a smaller house. 

I was later tempted to buy a GSO 12" Newtonian. I don't know how that compares with the Skywatcher Dob, but I have never had planet views approaching those with the old 12.5" Meade, or those with my Meade 5" ED refractor. That's despite replacing the mirror springs with stronger ones and tweaking the collimation before every use. Like Dave, the best I've seen in 10 years of use on Jupiter are the 2 main bands and no more than a hint of some detail within the bands. Wish I still had that Starfinder Dob!

Regards, Mike.

[LukeSkywatcher]

It could be many factors: seeing, transparency, light pollution etc.

There are definitely advantages to observing from a seated position. The main one being stood over a scope with your neck bent forward can actually hamper the blood flom frow your heart to your head. Also when in this position, the pressure build up in your eyes is greater.

 

Edited August 31, 2022 by LukeSkywatcher

[AstroMuni]

3 hours ago, Dave scutt said:

I had a look at what you should expect to see, and I don't think I'm using my dob to it's full potential. 

Take a look at this site and change the parameters to the equipment you have and you should get a rough idea of what to expect. As others have said there are many factors that impact what you can see. https://www.stelvision.com/astro/telescope-simulator/

 

[Pixies]

As James said: "Sit down"!

I find it really helps. You can stay at the eyepiece for 10-15 minutes. Avoid dark-adaption too. I keep the kitchen lights on and look up occasionally, otherwise the view is just too bright and 'bleached' out. Just getting comfy and relaxed means you can see more - not just with planets. But with the bright exterior planets (M, J & S), being able to sit and stare for a long while means you can catch the moments of good seeing. with an 8" dob, I've seen dark spots, barges, etc. not just bands.

Of course, if the seeing is rubbish, so will the view be. A big dob will have a lot of atmosphere to look through!

Edited September 1, 2022 by Pixies

[Spile]

Jupiter and Saturn were the best I have seen last night. Nice sharp features and well presented with the moons. With the zoom and Barlow combination I was able to go beyond 300X but slightly under that worked best for me so seeing was very good. 
I totally agree with the recommendation for relaxing on a chair. It does make a difference especially with dim fuzzies like M110 which I was delighted to see for the first time as well.

Edited September 1, 2022 by Spile

[sorrimen]

Important thing that may not seem obvious; are you viewing over buildings? The rising heat will cause any seeing conditions to appear very poor. Ideally you want 360 degrees of flat grass around you, but at least no buildings in the direction you’re observing. 

Another thing is make sure your collimation doesn’t just seem ok. You want to really nail it, even just with a collimation cap. 

[Davesellars]

Hi Dave.  I think the 12" dob is quite capable for planets but is also much more difficult to get the conditions suitable to actually use it...

Collimation has to be absolutely dead on.  One of the things I've found that during the evening the primary mirror can shift lightly depending on the altitude and so I've always collimated at the same altitude as the planet.

Contrast is not as good as my 102ED.  With the brightness of Jupiter and 12" capturing so much more light, imho it's more difficult to control - going to a level where it's sufficiently dimmed may not be suitable for the seeing conditions.  Therefore, seeing conditions have to be excellent in order in order to use the dob.  I've not used a filter to dim Jupiter.  180x to 220x seems appropriate although at the lower magnification you'll need to spend more time at the eyepiece to let your eye settle into the brightness and adapt.  Ideally you need to be at the eyepiece without moving anyway for minutes rather than seconds (definitely recommend the seated position if possible!)

When are trying to view Jupiter?   The seeing conditions aren't likely to be good enough until it's sufficiently high enough (at least after 1am)

Saturn I haven't really attempted properly using my 12" - it's far too low down and I can't imagine that seeing conditions are ever good enough at the moment for the 12" dob.

Here's a comparison from one night viewing Jupiter with my SW 12" dob and the 4" refractor on the 8th August.  The time I was observing was around 3:30am.

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So, the difference between the 12" dob and the 102ED on Jupiter...  Surprisingly not as large as I'd expected.  I used the 5mm Pentax in the 102ED for 143x and the 7mm Pentax in the Dob for 214x.  Exit pupil was twice as much in the 12" dob as the 102ED, so in theory the contrast should be better(?) than in the 102ED.

Jupiter presented exceptionally well with the 12" dob in times of great seeing.  Undulations in the main belts were quite obvious with darker / light regions becomeing visible with extended viewing at the eyepiece in one sitting.  The lighter southern equatorial belt was obviously split halfway through by a long light patch.  The NEB had multiple darker small blobs sitting in the belts.   The fine northern temperate belts were very obvious.  Colour not really distingishable though with the 12" dob.  Using more power (5mm Pentax) for 300x was really too much for the seeing tonight although occasionally good I didn't feel that the view of any details improved any (actually worse if anything).

In the 102ED by comparison, even though the exit pupil was approx 1/2 that of the dob presented visually seemingly more contrast.  Colour was still visible with a light shade of brown rather than grey.  The image was obviously smaller but comparing the two images it wasn not difficult to see the main features.  Those undulations seen in the dob were still there in the 4" refractor although a bit more time needed to be spent at the eyepiece to really capture them.  Dark and lighter regions were very easy to distinguish particularly the large ones like the lighter "streak" through the SEB as seen in the 12" dob was very obvious.  The much more subtle temperate belts are still present although finer.  The 12" dob picked up more finer detail within the belts although it was necessary to stay at the eyepiece for 20 to 30 seconds to really get these and pick them up as subtle whorls within the main belts.  That kind of detail was very difficult with the 102ED in my view.  For pure sharpness and contrast the refractor killed it and probably gave 90% of the detail of the 12" dob, however that extra 10% that the dob gave was quite spectacular to see those extra little details that occasionally popped in to view.

-----------------------------------

An addendum to this is that since binoviewing with my 4" refractor it's actually shown me more detail than I have previously with my 12" dob (just in a smaller scale...)  I haven't had a an opportunity yet to BV my dob!  Observing Jupiter is all about patience sitting through the seeing conditions and very easily washes out with too much power so no point in general going much more than 200x imho

[ED Splitter]

What eyepieces are you using? When I bought my 100ed I purchased a vixen 5mm eyepiece to give me a high mag view of Jupiter. I have since bought a 9mm eyepiece that gives far greater contrast in the presentation of Jupiter’s disc. This is a far greater viewing experience and whilst smaller is not so noticeable that it diminishes the experience. It is now my chosen eyepiece for planetary viewing. 
I have only recently seen the Great Red Spot when viewing from a bortle 3. Not seen it at my usual bortle 5 garden. 

[Stu]

22 minutes ago, ED Splitter said:

I have only recently seen the Great Red Spot when viewing from a bortle 3. Not seen it at my usual bortle 5 garden. 

LP shouldn’t affect planetary performance really. I’ve seen GRS easily in 4” scopes from Bortle 7 skies, and sometimes look at bright lights to stimulate my cones to see more colour. I saw GRS in a 76mm this week from probably Bortle 5 skies, quite straightforward.

[dweller25]

@Dave scutt

I think I recognise your problem - assuming good cooldown and collimation….

The image is too bright.

I had the same issue and found a neutral density filter sorted the problem - contrast increased significantly and so did planetary detail.

[Elp]

I find you need to sit and concentrate your vision without looking away, not taking in stray light, not changing eyes if mono viewing etc. That way your brain resolves detail which is hard to distinguish though a lot depends on seeing. You are acutely aware of this vision adaptation happening when solar viewing as it normally looks like a blur at first, same happens at night.

[Mr Spock]

Looking at Jupiter a few nights ago with the 102 I could see plenty of detail in the belts at x198. It looked so good I got the 12" out. I allowed it to cool a bit, despite being in a shed, and at x211 there was more detail, especially fine shading, but not as much as I though there would be. 
The reason was tube currents. My collimation was spot on but defocussed rings showed movement. Some some blurring due to that was the culprit.

1 hour ago, dweller25 said:

The image is too bright.

I had the same issue and found a neutral density filter sorted the problem - contrast increased significantly and so did planetary detail.

I've never understood that. It defies logic. I want the image brighter to get more contrast, putting a filter on would make the image darker and so would have less contrast.

[CraigT82]

I also use a neutral density filter on my 12” as the image of Jupiter is very bright even at high magnification. Unfiltered it kind of looks like an overexposed image and hard to make out any detail

The ND filter is a bit like wearing sunglasses on a bright day and looking wispy clouds on the sky, it takes the edge off the brightness and allows you to see more detail in the wisps (if you get what I mean - not explaining very well)

[dweller25]

44 minutes ago, Mr Spock said:

Looking at Jupiter a few nights ago with the 102 I could see plenty of detail in the belts at x198. It looked so good I got the 12" out. I allowed it to cool a bit, despite being in a shed, and at x211 there was more detail, especially fine shading, but not as much as I though there would be. 
The reason was tube currents. My collimation was spot on but defocussed rings showed movement. Some some blurring due to that was the culprit.

I've never understood that. It defies logic. I want the image brighter to get more contrast, putting a filter on would make the image darker and so would have less contrast.

Whatever works for you 👍