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Hi all,

I thought I'd share my observation from this night. At approximately 22:00 local time I was already setup and ready to image Mars and Saturn. As I'm using a mirror diagonal for framing/searching purposes I looked through it and focused using my 40mm LV eyepiece. What I saw in the eyepiece took my breath away. The disc was massive and detailed. I stack Baader Contrast Booster and Neodymium filters for planetary viewing since it does make a considerable difference in revealing detail and increasing contrast.

Mars showed a big disc with two CLEARLY visible patches on both the "north" and "south" (equivalent to earth location polar cap regions). There was a clearly visible dark greenish borders around the white patches. The bottom part was white and crisp with a irregular dark greenish patching bordering it from the pinky orange center of the planet.

The equator region showed some dark markings around where, I think, Olympus Mons is located. Now I'm not saying that I spotted Olympus Mons in my 8" SCT but I'm thinking, and hoping, maybe... there was definitely something there along with other more subtle spots and shades. This was hands down the best view of Mars I've ever seen.

After Mars I had a look at Saturn, it was big and clear although it was not the clearest I've ever seen. Last year I had a clear view of Saturn's cloud bands and a crisp Cassini division surrounded by 5 of its moons (that was the best view of Saturn I ever experienced).

This time the Cassini division was there but not as defined as before and any cloud bands were a struggle to see, and the Cassini division was coming and going. There were 4 moons around it glistening in the dark.

I know some of you might be wondering why I have seen such big discs using only a 40mm eyepiece. The magnification was at least 250X-300X judging by the size of Saturn in my past experience near opposition using nothing but eyepieces and a diagonal. The reason why the magnification was so high with the 40mm was because it was a bit of a distance away from the visual back and I was also using a Celestron 2X barlow, due to me being setup to do planetary imaging. The lineup was a 2X barlow, 1.25"-2" adapter, a Vixen flip mirror, on the mirror the 40mm eyepiece, and behind the flip mirror were a filter wheel and a IS 618 CCD as shown in the pic.

Does anyone know how to work out the actual focal length in a setup situation like this?

The pictures didn't come out as crisp as I though they would after the seeing I was experiencing, I'm thinking that the line up caused a bit too much magnification. When I tried the 2.5X power mate the magnification was less, about 60% of the size with the Celestron 2X barlow, I think the TV 2.5X powermate should be labelled 1.5X. I didn't capture any images through the PM due to Mars moving out of the optimal imaging position, coming down with Bronchitis and starting to freeze through my layers of jumpers so I ended my session.

The views I had I will definitely remember for a long time and I'm looking forward to the next Mars opposition since it'll be another 38% closer and again will move through the zenith visible from my location... now thinking about a 16" dob for those views!!!

Thanks for reading,

Mariusz

 

 

IMG_0216.JPG

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Nexstar 8SE = 2032mm focal length; 203.3 aperture  (f10) scope so divided by 40mm EP = 51x magnification.  Barlow x 2 = 102x. Hence, not sure how you get to 250x? An 8mm EP would be required to produce 254x  (or a 16mm Barlowed x2).

Seeing conditions must be awesome. I reckon in typically light polluted areas, 254x is probably about the reasonable  limit for an 8SCT and Mars might then look like a bright red ball.  I have managed higher x, but on rare excellent seeing conditions.

 

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On 11 June 2016 at 23:05, noah4x4 said:

Nexstar 8SE = 2032mm focal length; 203.3 aperture  (f10) scope so divided by 40mm EP = 51x magnification.  Barlow x 2 = 102x. Hence, not sure how you get to 250x? An 8mm EP would be required to produce 254x  (or a 16mm Barlowed x2).

Seeing conditions must be awesome. I reckon in typically light polluted areas, 254x is probably about the reasonable  limit for an 8SCT and Mars might then look like a bright red ball.  I have managed higher x, but on rare excellent seeing conditions.

 

SCT focal length is not a fixed figure, it is longer if you use a 2" rather than 1.25" diagonal for instance. All to do with mirror positions and where the focal point is I think.

Also increasing the distance from the Barlow to the eyepiece focal plane increase the multiplying effect of the Barlow, so several things are going on here which complicate matters. @YKSEis pretty good at this stuff!!

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True, but seeing conditions must still be awesome. In the UK I  have never seen Mars other than as a red blob.  Have only just made out the twin primary bands of Jupiter. Struggle to see any DSO objects. But the moon is awesome. Saturn is  pretty good too.

Have spent ££££s on light pollution filters and enhanced EP'S.  Best planetary  views in my locality are at about 169x (12mm Televue Delos at 2032mm FL/F10.). Can't believe the local community is demanding the street lights be switched back on.

 

 

 

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13 minutes ago, noah4x4 said:

True, but seeing conditions must still be awesome. In the UK I  have never seen Mars other than as a red blob.  Have only just made out the twin primary bands of Jupiter. Struggle to see any DSO objects. But the moon is awesome. Saturn is  pretty good too.

Have spent ££££s on light pollution filters and enhanced EP'S.  Best planetary  views in my locality are at about 169x (12mm Televue Delos at 2032mm FL/F10.). Can't believe the local community is demanding the street lights be switched back on.

 

 

 

Mars is always quite tricky, and is particularly tough currently as it is low down. Having said that, I've just had some nice view this evening in a C925. Polar region and a number of dark albedo features visible including Syrtis Major. Seeing was pretty average and Mars was just above my neighbours house, so, far from optimal!

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On 6/12/2016 at 08:05, noah4x4 said:

Nexstar 8SE = 2032mm focal length; 203.3 aperture  (f10) scope so divided by 40mm EP = 51x magnification.  Barlow x 2 = 102x. Hence, not sure how you get to 250x? An 8mm EP would be required to produce 254x  (or a 16mm Barlowed x2).

Seeing conditions must be awesome. I reckon in typically light polluted areas, 254x is probably about the reasonable  limit for an 8SCT and Mars might then look like a bright red ball.  I have managed higher x, but on rare excellent seeing conditions.

 

I know what you're saying and understand the math behind calculating magnification.....

On 6/18/2016 at 07:52, Stu said:

SCT focal length is not a fixed figure, it is longer if you use a 2" rather than 1.25" diagonal for instance. All to do with mirror positions and where the focal point is I think.

Also increasing the distance from the Barlow to the eyepiece focal plane increase the multiplying effect of the Barlow, so several things are going on here which complicate matters. @YKSEis pretty good at this stuff!!

... but I do think that, as stated by Stu, there being that much space between the barlow and the eyepiece on a movable mirror system, there has to be different math involved that makes the 40mm eyepiece behave more like 7 or 8mm.

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On 6/18/2016 at 09:45, noah4x4 said:

True, but seeing conditions must still be awesome. In the UK I  have never seen Mars other than as a red blob.  Have only just made out the twin primary bands of Jupiter. Struggle to see any DSO objects. But the moon is awesome. Saturn is  pretty good too.

Have spent ££££s on light pollution filters and enhanced EP'S.  Best planetary  views in my locality are at about 169x (12mm Televue Delos at 2032mm FL/F10.). Can't believe the local community is demanding the street lights be switched back on.

 

 

 

 

On 6/18/2016 at 10:01, Stu said:

Mars is always quite tricky, and is particularly tough currently as it is low down. Having said that, I've just had some nice view this evening in a C925. Polar region and a number of dark albedo features visible including Syrtis Major. Seeing was pretty average and Mars was just above my neighbours house, so, far from optimal!

When Mars is low or during nights of poor seeing the fine details on it are quickly and easily lost resulting in a orange blob, but when the seeing is good, even upto 290X on my 8" SCT I have had some crisp detailed views of Mars and its albedo & polar features.

When talking about light pollution filters I stand by my past comments that the Baader neodymium (Moon & Skyglow) and Contrast booster filters stacked make a considerable about of difference in bringing out the fine details. Last time I observed Mars, Saturn and the Moon, I also added a Polirazer filter to the stack and I think that it also helped with the details to be easily spotted, it's as if the view of Mars and Saturn atmospheric fluctuations were stabilized resulting in views where the Mars surface features and Saturn's cloud bands along with shadow from the rings and Cassini division were constantly visible almost all around the ring!!!... granted that this night was particularly still and I spent a bit of time collimating the mirrors...

Earlier the moon also looked more detailed by stacking a ND15% filter to the mix...

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I was having a bash at these planets last night briefly before clouds set in. Fairly mixed results on Mars and worse for Saturn again.  What looked like some white patching off the southern tip of Mars is making me doubt, and would like to confirm if others are seeing the same?  Other than that I could pick up some dark patches at 129x towards the south, but nothing I feel confident enough about in those poor conditions. 

Regarding getting good obs in the UK, it might be fewer and farther between but good nights certainly happen.  And I recall 2 or 3 years ago there being an awful lot of glowing reports about Mars as it was much better placed in our local skies than it is now. As an aside, we look to be gaining some more altitude with Mars in the Autumn with longer nights and a more oblique ecliptic. 

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3 hours ago, MarsG76 said:

I know what you're saying and understand the math behind calculating magnification.....

... but I do think that, as stated by Stu, there being that much space between the barlow and the eyepiece on a movable mirror system, there has to be different math involved that makes the 40mm eyepiece behave more like 7 or 8mm.

I did some easy measurement here

 

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