Mars still looking good

[jock1958]

Just now, John said:

The seeing thus far is not co-operating. I'll keep at it for a while longer but so far the Martian features are rather indistinct and keep breaking up as the atmosphere (of Earth) intervenes

Can't win them all !

 

 

Same over here John, I persevered for close on 2 hours with barely any improvement, the cold wind not helping either!

[globular]

Is it jetsteam related do you think? Or more localised?  If it is the jetstream it should improve as the night goes on as it's clearing from the south west heading north east.
Maybe keep your kit out for another hour or so just in case?

Cloud here so I'm in the warm watching the snooker 😧

Edited November 6, 2020 by globular

[ShrewView]

Was quite good here a couple of hours ago but patchy cloud keeps coming over and the seeing has got worse too. Much more indistinct. I'll keep going though for now.

[John]

Things did get a bit better but not really as nice as previous nights this week. I guess the Jetstream might be responsible ?

It's clouded over now and that looks pretty solid so I've packed up the scope.

 

 

 

 

Edited November 7, 2020 by John

[Paz]

12 hours ago, ShrewView said:

 patchy cloud keeps coming over and the seeing has got worse too.

Thats what I found too.

[orions_boot]

Had clear sky from 1930hrs onwards albeit a lot of mist lower down and smoke from fireworks.

Seeing however had no issues with.  Got the magnification around ~360x and could make out the Southern ice cap plus all the darker detail along the equator.  I won't give the proper name as despite looking at the map I'm still not sure.

 

Edited November 7, 2020 by orions_boot

[Stu]

Clouded over here now, but I had some good views earlier on. Initially I was using the Leica Zoom and x2 AP Barcon, but then I switched to binoviewing and felt like it improved the views noticeably; got rid of my floaters and contrast seemed better. The seeing was not the best, but still picked out some decent detail, southern polar cap, northern ‘frosting’ an various dark features showing some finer detail when the seeing settled every so often.

Binoviewing is much more relaxing than cyclops, and my eyepieces have good eye relief so it was a nice comfortable session.

[John]

I've seen Mars occasionally for a few minutes between the clouds over the past few nights but other than that, no observing possibilities.

Going through a "lean patch" here, observing-wise

 

Edited November 12, 2020 by John

[Stu]

Packed up now, but had an enjoyable session. Seeing got a little better, probably just as Mars got higher, but it remained pretty variable.

Syrtis Major was just edging into the disk, with Mare Cimmerium, Hesperia, Syrtis Minor and also Mare Chronium showing well.

I shall continue to use the binoviewers for Mars, they certainly improved the view, and also reduced the visibility of the diffraction spikes which was a nice surprise.

[chiltonstar]

10 hours ago, Stu said:

 

I shall continue to use the binoviewers for Mars, they certainly improved the view, and also reduced the visibility of the diffraction spikes which was a nice surprise.

 

Why was this, I wonder? The binoviewer splits a single beam, so why should it reduce image artefacts?

Chris

[F15Rules]

9 hours ago, chiltonstar said:

Why was this, I wonder? The binoviewer splits a single beam, so why should it reduce image artefacts?

Chris

This is a perennial question Chris, and one I don't have a scientific answer to. All I can say is that, like Stu, I just find that binoviewing on planets and the moon is much more rewarding for me personally.

I find binoviewing (on Planets and lunar) more relaxing, more enjoyable, easier to tease out fine or vague details and less tiring. Last Tuesday night I found Mars quite difficult, with mediocre to poor seeing: with a single Morpheus 17.5 and 2.25x Baader Barlow, I could make nothing of the disk..a mushy mess, with only intermittent hints of the southern polar cap..I was using my FS128, so the scope wasn't the problem!! I then tried a pair of Morpheus 17.5mm with a W.O. 1.6x nosepiece in the bv, and immediately I could make out the southern polar cap all the time and the large dark land mass (looking a bit like the top half of Australia, with the prominent north pointing feature (Syrtis Major?) looking quite like the outline of India). It wasn't a pleasing view, nothing was that evening, but the bino view was vastly better than the Cyclops one.

Of course, Mars is still so bright at the moment that quite possibly the slight dimming brought about by the splitting of the light beam had a positive effect on contrast and visibility of surface details?

Finally, I would say also that I still prefer cyclops viewing for stellar images or star clusters, starfields etc. For double star viewing I am a bit ambivalent..some nights I prefer two eyed views, another I prefer solo views. Don't ask me to explain it in technical terms. But, for prolonged viewing of most objects, I definitely find binoviewers more comfortable. 👍😊.

Dave

[RobertI]

17 minutes ago, F15Rules said:

I find binoviewing (on Planets and lunar) more relaxing, more enjoyable, easier to tease out fine or vague details and less tiring.

I've only started using binoviewers recently, and only with my 100mm frac, but I've found the same. Floaters seem to have less impact too. I think it is a combination of dimmer images both reducing the effect of 'artifacts' and providing increased contrast, and the use of two eyes allowing the brain to better percieve patterns. The brain bit could be nonsense though! 😄

[F15Rules]

No, I think your logic is sound Robert! Totally agree on floaters, I forgot to mention that!

My right eye has deteriorated noticeably in the past 3 years, and if I could only use that eye to observe I would have given up, seriously.. instead, I trained my left eye (which is still good) to be my cyclops eye..however, the odd thing is that my combined good left eye and poorer right eye still combine together through binoviewers on Lunar and planets to give better images than cyclops with my good eye😵⁉️

Dave

[Stu]

20 minutes ago, RobertI said:

and the use of two eyes allowing the brain to better percieve patterns. The brain bit could be nonsense though! 

I don’t think it’s rubbish, but think it’s more like a form of noise cancellation; slightly different signals getting to both eyes, and different floaters in each eye so they cancel each other out.

I’m not sure I understand the improved contrast bit though, although it seems a real effect. I think the slight dimming is likely to be what reduces the diffraction spikes.

[chiltonstar]

I've not looked up a scope with a binoviewer so I can't comment from a practical point of view, although it does seem illogical to strive for more aperture to see fainter objects, and to then halve image brightness by splitting the light beam into two (worse if there are losses at the optical surfaces). I did have a peer up a binocular newtonian arrangement at a conference in the US, which was a pair of 8" newtonians side by side - that was very impressive, although I didn't look at high mag where I suppose any collimation errors between the two tubes would show up. That did cancel the spider artefacts to some extent as the two spiders were set at a slight angle to each other.

I can see good theoretical reasons why binoviewing would cancel out any issues caused after the beam was split (eyepieces, eyes) but I would have imagined that anything before the spit such as seeing the spider artefact would be additive, as both eyes were seeing it.

Must have a look some time though.

Chris

[Stu]

8 hours ago, chiltonstar said:

I've not looked up a scope with a binoviewer so I can't comment from a practical point of view, although it does seem illogical to strive for more aperture to see fainter objects, and to then halve image brightness by splitting the light beam into two (worse if there are losses at the optical surfaces). I did have a peer up a binocular newtonian arrangement at a conference in the US, which was a pair of 8" newtonians side by side - that was very impressive, although I didn't look at high mag where I suppose any collimation errors between the two tubes would show up. That did cancel the spider artefacts to some extent as the two spiders were set at a slight angle to each other.

I can see good theoretical reasons why binoviewing would cancel out any issues caused after the beam was split (eyepieces, eyes) but I would have imagined that anything before the spit such as seeing the spider artefact would be additive, as both eyes were seeing it.

Must have a look some time though.

Chris

I still prefer cyclops views for many objects Chris; double stars, and most, if not all DSOs. I use Binoviewers for solar exclusively, and I mix it up for lunar and planetary. For the latter two sometimes I feel I see more fine detail in cyclops (often the case on Jupiter), other times like on Mars it was definitely better with binoviewing.

The key benefit for me is reduction in floater visibility and more relaxed viewing.

[F15Rules]

8 hours ago, chiltonstar said:

although it does seem illogical to strive for more aperture to see fainter objects, and to then halve image brightness by splitting the light beam into two (worse if there are losses at the optical surfaces).

Chris,

Although it's true there is some light loss when using binoviewers, I don't believe it's anything like 50%..

When I had my previous Baader Celestron angled binoviewers serviced by Denis Levatic (who specialises in servicing and "turbocharging" binoviewers), he sent me the pictures below of the prisms inside. I was surprised to see that one of the prisms is MUCH larger than the other..I had thought they'd be the same or similar.

Denis also said that using binoviewers loses between about 0.5 and 1.0 full magnitude of brightness.. so noticeable, but nothing like a 50% loss. On bright or extended objects it's not really noticeable.

A good example is M42 - the nebula can look great with two eyes, really almost 3D! However, I have never yet seen the E & F components of the Trapezium with a binoviewer, whereas I have done so many times in cyclops mode, with the same scope. So I think that faint point sources like stars react differently to two eyes and single eyed viewing. I also find that for me, averted vision works much better with one eye than with two. Discuss!!😱😂

HTH,

Dave

PS The first image shows the  prisms before cleaning, the last one after cleaning..quite a difference!

[Nik271]

>Denis also said that using binoviewers loses between about 0.5 and 1.0 full magnitude of brightness.. so noticeable, but nothing like a 50% loss. On bright or extended >objects it's not really noticeable.

Each magnitude is 2.5 less brightness (the fifth root of 100 to be precise). So 50% light loss in a binoviewer  in each eye indeed corresponds to losing about .8 stellar magnitude visually.

Our eye's perception of brightness is not linear so actually 50% loss is not that noticeable. The best way to test this is to compare a photo taken at 200 ISO with a photo at 100 ISO and all other setting being equal. Sure the 200ISO photo will look brighter, but nothing dramatic compared to the 100ISO.  

Edited November 14, 2020 by Nik271

[Stu]

2 hours ago, F15Rules said:

I also find that for me, averted vision works much better with one eye than with two. Discuss!!😱😂

That’s very true I think Dave. Observing with binoviewers for me tends to involve concentrating on-axis and panning the scope around to see different features on the Sun or Moon. Planets I normally view on axis too (using an EQ mount or EQ platform) so that works well. I do find that if I try to move my eyes around the field of view it is a bit of a strain and you tend to lose one channel or the other. So, much like using binoculars, I keep my eyes centred and move the scope.

With cyclops, you can obviously look around the field of view of a widefield eyepiece and take it all in, no problem, and as you say, using averted vision is much easier I find.

[RobertI]

5 hours ago, F15Rules said:

The first image shows the  prisms before cleaning

Very interesting to see the innards of a binoviewer. I have noticed that the view through the right eyepiece of my WO binoviewer is not quite as good as the left, feels slightly darker and not as easy to get the full field of view, although the images of Mars were identical - very difficut to explain, wondering if there is some slight vignetting? Looks like whatever the reason, it is probably caused by the differing length prisms?

Edited November 14, 2020 by RobertI

[John]

Meanwhile, back with one eyepiece and using one eye, having my 1st view of Mars for quite a few days just now. The clear gap won't last long but the details showing at 225x and 257x with my Tak FC100 are quite nicely defined. All the dark stuff is in the southern hemisphere with this side of Mars. Two clear bands of darker surface with a paler strand in between them. South polar cap tiny but visible. Paler areas close to the northern polar limb - probably clouds ?

The more northerly of the dark bands is the Mare Cimmerium I think and the more southerly one the Mare Chronium perhaps with the paler Eridania area separating them.

The angular diameter of the Martian disk is 17.5 arc seconds currently, which is about as large as it will get at the next opposition, 2 years from now.