advice on better planetary viewing

[chris285]

Last weekend with the clear skies I had I took the opportunity to go out into the back garden with my skywatcher 130 telescope, as Jupiter was up I decided to attempt to get some views while the weather was good

I was able to see Jupiter and 3 or 4 of its moons I can't remember exactly the number, however Jupiter was still quite small and all I could make out was the colour change from top to bottom even with a 10mm eyepiece with my 2x barlow lense being used. I currently have a 25mm eyepiece as well but thats all I have at this time

What I would like advice on is what I can do to be able to see more detail in this situation if this is possible, such as should I look at getting say a 7.5mm eyepiece or is my scope itself going to limit what I am able to see?

[russ]

There are so many factors that could result in a poor view of the planets.

The scope needs to be well collimated and cooled for starters. The sky needs to be stable, not just clear. And a good quality eyepiece certainly helps.

Regardless of the eyepiece used, if the first three criteria are not met, the image will be poor. Nothing you can do about the seeing, if it's an unstable sky, shrug the shoulders and try again another day. But the collimation and cooling you can deal with.

The cooling is easy, just plonk the scope out 30mins before you intend to observe. And the collimation looks daunting but there are some good tutorials around to help. Once done a few times it's not so daunting.

The 10mm eyepiece supplied with the scope is not great, so that won't help. Something like a 5mm Planetary Clone would be a big improvement and give a comfortable (for both the scope and skies) 130x. The scope will take more if collimated, cooled and under stable skies.

[DarkerSky]

Great advice Russ

Just like to add that if you are viewing over buildings or any other structure where heat can rise from, that heat transfer can make the air above those structures undulate, so creating a poor image.

Also - seeing can improve (or deteriorate) in minutes. Sometimes you have to stick at the eyepiece for several minutes at a time to catch a moment when the air hits a real nice stable patch, and then all of a sudden your eye will be flooded with detail.

[John]

Excellent advice from Seb and Russ

The only thing I'd add is to spend as much time observing Jupiter or any other object you are interested in, as you can. You eye will sort of "train" itself to pick out the more subtle details but this does take time and practice. After an hour or so on Jupiter I can make out much more detail than when I first start to observe it.

[chris285]

thanks for the advice guys, i always leave my scope outside for 30mins or more to cool down so i know thats covered. I am going to check the collimation again to make sure its good, and when viewing it was over the roof of my house which may have caused detail to be lost

however my main gripe was the fact that juipter was too small in the view to be able to make out any real detail, and so looking for advice on how to maximise what i have to get the best view not including the previously mentioned factors

[John]

however my main gripe was the fact that juipter was too small in the view to be able to make out any real detail, and so looking for advice on how to maximise what i have to get the best view not including the previously mentioned factors

Without suggesting a larger aperture scope I can't think of much more you can do. Viewing over the roof of a house is not ideal because heat will be rising from it, which will affect the quality of the view so perhaps you could do something about that.

What "real detail" do you think you are missing out on ?. Beyond the main cloud belts, other detail on Jupiter, even the great red spot, can be ellusive and subtle at best. It doesn't really "leap out" at you - you have to tease it out during the moments of good seeing.

[LukeSkywatcher]

I also have a SW 130(P) scope and any time i observe Jupiter the only detail i see are the main bands around the planet. So as far as i know.....you are seeing pretty much what you are going to see with your scope(not putting your scope down because i have one). As has been said above.....take your time with Jupiter. If conditions are right then you will get moments of clarity and the image improves. Its the same with all planets. I have yet to observe Saturn with my SW 130P. If my observations with a 90mm scope are anything to go by then i am going to be extremely pleased.

I dont know why but i always find a 9mm EP a nice EP to observe planets with no matter which scope i use.

[chris285]

Thanks for the replies guys, I did wonder if my scope was the limiting factor for viewing which it sounds like it is in terms of what I'd like to see. In terms of what I could see detail wise it was very little but bout sure if it was due to atmospheric conditions, or if I need to collimate my scope which I will do as I think conditions were good.

I am thinking about getting another scope at the end of the year or start of next, something bigger and easier to move about I think

[LukeSkywatcher]

Your scope is limited in what it will see. Any scope is really........even those big 16" light buckets.

You have summed up your situation/thoughts very nicely:

"I did wonder if my scope was the limiting factor for viewing which it sounds like it is in terms of what I'd like to see. In terms of what I could see detail wise it was very little but bout sure if it was due to atmospheric conditions, or if I need to collimate my scope which I will do as I think conditions were good".

Your scope saw/will see exactly what it is capable of seeing. What you want to see/be able to see, is a whole different kettle of fish.

I think the main factor here is that your expectations were set too high? You have seen thousands of images of things in full colour and thought they would appear similar in your scope?

I'm afraid this is simply not the case. It has nothing to do with your scope really. Its more a case that the human eye (as amazing as it is) simply can not see colour/small detail over vast distances. Not even telescopes lens can see that really. This is where cameras come into play. The chip on a camera is so much more sensitive to colours and picks them up a hell of a lot better then the eye even will.

So basically when observing, you really are at the mercy of the atmosphere. Its best to observe celestial objects when they are as high up in the sky as possible because the angle at which you observe them offers much less atmospheric turbulence/distortions etc.

So for planets in particular..................it is best to observe them when they are as high as they can be, and you should get better views.

[michael.h.f.wilkinson]

The colour gradient you observed is probably due to atmospheric refraction, which is always a problem when Jupiter is low in the sky. When imaging, I can correct a bit with RGB alignment, but visually there is little that can be done, other than trying to observe Jupiter as early as possible, when it is still high up. This mitigates any seeing problems as well, because you are looking through less atmosphere.

Cheers

Michael

[perrin6]

I looked at Jupiter with my 13 incher (reduced to 11.75 inch aperture to sharpen the image & cooled to the surrounding temperature) last monday and it was no better than in my 66mm frac - just saw the two equatorial bands, which looked fuzzy with no detail. Sky conditions can be a pain in the eyepiece !

[russ]

I looked at Jupiter with my 13 incher (reduced to 11.75 inch aperture to sharpen the image & cooled to the surrounding temperature) last monday and it was no better than in my 66mm frac - just saw the two equatorial bands, which looked fuzzy with no detail. Sky conditions can be a pain in the eyepiece !

wow that sounds like my view of Jupiter for the last 3 months

[stevelcfc]

I looked at Jupiter with my 13 incher (reduced to 11.75 inch aperture to sharpen the image & cooled to the surrounding temperature) last monday and it was no better than in my 66mm frac - just saw the two equatorial bands, which looked fuzzy with no detail. Sky conditions can be a pain in the eyepiece !

wish i had a 13 incher

[michael.h.f.wilkinson]

wish i had a 13 incher

That is called aperture fever

[chris285]

going to use the scope to look at the moon and just get used to finding objects in the sky for now before i move to something bigger, wondering if getting a filter for viewing nebula's is worth it as well as getting something like a 32mm eyepiece as well

[michael.h.f.wilkinson]

How fast is your scope? If F/5, 32 mm is OK if you are younger than about 35, otherwise the exit pupil (computed as the focal length of the EP divided by the focal ratio of the scope) is larger than you fully dilated pupil. If you are older, a 24 or 25 mm is better. If your scope has a 1.25" focuser, you could consider a 24mm Baader Hyperion, which gives you almost the maximum true field of view possible.

[chris285]

according to the site the 130 is F/6.92 and i am not 30 so sounds like a 32mm may be worth looking at, any advice on filters for viewing nebula's and such?

[themos]

First limit to seeing detail is the atmosphere turbulence, we call that "the seeing". Second limit is thermal currents in the scope. Third limit is the collimation status. And then we get into the actual optics limitations.

If you go to http://www.calsky.com/cs.cgi and click on Planets -> Jupiter -> Apparent View/Data , then input 240 for Output Size and 5" Aperture you will see what the best view for your scope could be.

[chris285]

First limit to seeing detail is the atmosphere turbulence, we call that "the seeing". Second limit is thermal currents in the scope. Third limit is the collimation status. And then we get into the actual optics limitations.

If you go to http://www.calsky.com/cs.cgi and click on Planets -> Jupiter -> Apparent View/Data , then input 240 for Output Size and 5" Aperture you will see what the best view for your scope could be.

Thanks for that, gives me an idea of what to expect for which I should get better than what I have seen in the past so just need to keep working on it. Tried last night but Jupiter was not in the best position despite the clear skies it was just above the roof line again and moon was nearly full as well