Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.


Recommended Posts

Hey guys. Thought about  starting this thread. I feel like we all should inform eachother and newer members alike about the magngifications that can be achieved on planets,that provide the best sharpness/size ratio,depending on the scope and seeing. After this thread has grown a bit, i feel like this should be pinned,as to provide a little guide to newer members that are not experienced with planetary observing,as many will be fooled with the typical 50x per inch of aperture and get disappointed when they find that that image will be dim and blurry.

For my 8” F/6 Sky-Watcher Dob

For Saturn i like to use 150x in medium seeing and if i want something a bit bigger , switch to 240x ,which will give me a bigger,but blurrier image.iBut In good seeing, i found that 240x was very usable.When we have perfect conditions, i m certainly trying 300x.

Mars, isnt very big in the sky right now,so even at high magnifications like 300x it still appears as a small orange dot. For observing mars,I suggest waiting for it to reach opposition.It benifits hugely from it! However,this happens once every 2 years....But 5ere are other planets to keep you occupied until then, such as jupiter,saturn and   Venus.

For Venusi use 50-100-120 depending on its phase.

For  Jupiter, i like to use 150x, as it provides a very sharp image,with key features of the planet such as bands being very detailed.Waiting on my 6mm UWA Skywatcher to bring it to 200 and see how that plays out. Be careful! Don’t magnify jupiter too much, as it will loose much of its features and sharpness.

Neptune and Uranus: These two will not impress, but are certainly have a nice colour to them. Even ar high magnifications, such as 300x and 400x, they will look like small discs with color in them.Uranus will look be colored green and Neptune a fainter blue.

Mercury About mercury...Havent gotten the chance to observe it ,so the guys will have to inform you about that?

Feel free to give your own opinions as to give members a wider source of information to help them observe better ! 

Cheers and clear skies.



Share this post

Link to post
Share on other sites

I think much depends on local seeing conditions. Often, transparent skies usually have poor seeing due to turbulence,  while good seeing with steady air can often be misty. Its on those steady, misty nights that high powers can be used to advantage. Generally speaking though, my personal feelings are that 180X is just about right for Jupiter and Saturn, and that over magnifying the image of either will offer no gain in detail. With Mars, due to its tiny apparent size and brilliance, higher magnifications can be used to advantage.Mars while at sub 5 arc seconds in diameter can benefit from 250X to 350X and more.The high power enlarges the tiny image scale to a useable disc size, while at the same time dimming the image which allows for fleeting glimpses of its subtle albedo features. Currently, while around 4.5 arc seconds diameter, I find 370X is just about right to give an image scale large enough to reveal subtle and fleeting detail. It is far from ideal but bright areas can usually be detected as the waves of turbulence subside momentarily, and also the subtle darker markings can jump in and out of view. Patience is the key at this size and power!

Venus likes higher powers as it gets closer to a crescent and Mercury like Mars needs powers high enough to create an image large enough to see a disc where albedo markings can be seen at times. 

As a rule of thumb I'd say use Magnifications as high as you can without softening the image. But when the disc size is too tiny to be seen, then power up until the disc is large enough to be useful. Then patiently study the blurry disc for a reasonable time before concluding there's nothing to be seen. 

Share this post

Link to post
Share on other sites

The magnifications that you are using seem well thought through to me and similar to the ones that I use with my scopes.

I do use very high magnifications on Uranus and Neptune but not to try and see disk details (although that would be nice !). I find the very high power helps pick out their faint moons. So far I've seen Triton at Neptune and Titania and Oberon at Uranus. I think 2 more Uranian moons are possible for me if I get a really dark sky and Uranus in a reasonable position.

With some practice and careful observing you should be able to see Triton with your 8" dob at high magnification. I find that the Cartes du Ciel software gives it's position quite accurately.

Share this post

Link to post
Share on other sites

I use a 15" f/4.5, and if seeing doesn't support my 8mm EP for 240x, I don't deem it a good night for observing planets.  I'm in the habit of checking the pesky jetstream forecast beforehand, and allowing several hours of active cooling for my mirrors.  On better nights, my 6mm is my choice ~320x for Jupiter, Mars, Saturn, Uranus and Neptune.  Very rarely I'll go higher with a Powermate.

With my 250px f/4.7 10" dob, I would use a binoviewer at ~208x for planets - which worked great too.  The 15" beats it even though mono;) I've some challenges reaching focus with the binoviewer in my 15", unfortunately. 

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By StarGazingSiouxsie
      Just had the MOST amazing observing session of my life!!!
      I am staying / living in the Blue Ridge Mountains at the moment and am blessed with very dark skies.
      About an hour after sunset, appx 9.50pm, I saw comet NeoWise motoring - could literally see it moving as I watched - up in to the NW twilight and then watched (10x50 bins & Cassie)  it disappear  over the top of the mountain.............. completely, totally, surreal. I saw comet Hale Bopp in 1997 in London and whilst that was spectacular, what I saw tonight was just absolutely surreal. Most comets 'just' appear to hang in the sky, whereas I could actually see Neowise moving. From coming into view to disappearing over the NW horizon must have taken only 20 minutes or so. There were a lot of helicopters up over the mountain watching it. 

      Then, at about 10pm heading north was what I believe was the ISS. I've yet to check for sure but it was nearly as bright as Venus and moving slower than a satellite.
      Then I saw numerous DSOs, globualr clusters and nebulas. 
      Then turning to the SE I saw Jupiter and Saturn, Unlike the other evening when the image was very blurred (atmospheric turbulence?) tonight's images were clear and beautiful. Could clearly see Jupier's cloud belts and the 4 biggest moons. (108x  9mm + 1.5 Barlow)
      Saturn was the best I've ever seen him. Crystral clear ring definition and I am sure I saw one of his moon at about 5 O'clock to his position - maybe Titan? 
      I'm not an experienced astronomer (telescope wise) but I have followed this subject all my life. I don't know much but I do know that not many people will ever get to see what I did tonight all in the course of 2 hours. 
      I am very blessed and thrilled beyond belief!!!! Everything tonight viewed through my trusty 5'" Newtonian, Cassie 😍
    • By Cosmic Geoff
      Here are images of Jupiter and Saturn taken around 00.30hrs BST on 11 Jul 2020.  They turned out relatively well, unlike a set I took a few days ago. I suspect 'seeing' is a major factor.
      Kit: CPC800, ASI224MC, ADC, captured with Sharpcap, processed in Registax6, best 20% of 5000 frames.  The monochrome Saturn image was taken in infrared.
      I did not have a sightline for Mars, or for Comet Neowise.😦

    • By Abhinav
      Hello , I just bought my new Newtonian, reflecter and I looked jupiter and saturn the views were great but when I tried to capture thwn with my smartphone they become white balls then I adjusted the exposure settings on my smartphone everything vanishes . I got a descent photo of saturn with cassini division but jupiter was still looking like a white balls . should I buy a ZWO 120 MC or modify a logitech c270 and if you have a solution  to fix that smartphone problem please help me out .
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.