RobertI

Excellent sketch and notes. I was also observing last night with my 4” refractor with binoviewers, in not very good conditions, and I also clearly saw the gap pretty much as per your sketch. 👍

2 hours ago, JeremyS said:

more info on the BAA Mars Section blog

1 hour ago, Peter Drew said:

Well worth looking at the Mars section blog for a great selection of images and sketches of Mars 2020.     🙂

The blog is a fascinating read, there are some really dedicated people doing some great work there. I never knew there was so much happening on Mars! 

5 hours ago, JeremyS said:

https://britastro.org/node/25021

Thanks for the heads up Jeremy.  I wonder what instrument he was using. 

Lovely observatory in a beautiful setting, thanks for sharing. 🙂

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?

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! 😄

I had fabulous views of this through my 10x50s at the pitch black skies of Kelling Heath recently. But through my scopes back in my less dark back garden.....hard to spot and pretty underwhelming when (and if) found,

Really looking forward to this one. Thanks for the additional useful information. 

Great vid Chris, you captured the cloud detail really nicely in your second image. Imaginatively put together! 

There have been a few threads about this recently, definitely a growing trend. Only a matter of time before one of my neighbours does the same. Our small development of 150 houses has a facebook group and I regularly point out interesting things happening in the night sky and encourge them to take a look and reconnect with the universe around them. I was also going to host a regular 'sidewalk astronomy' session outside my house to show people the moon, planets, etc. Covid put a halt to that but hoping to resurrect it in 2021. I'm hoping that getting people out into their back gardens at night and looking up might....just might.....make people think twice about these stupid illuminations. Unfortunately it only take one idiot.

5 hours ago, Atlas629 said:

A few years ago I learned the fate of the universe, and my exact place in it - hit me pretty hard. Anyone else share similar experiences?

Why don’t you share a bit more about what you found out and why it’s bothering you? 

Personally I have always found that contemplating the universe is comforting as it puts my every day problems into perspective. But I have been into astronomy since I was 14 and so I probably never went through the process of contemplating the wider questions such as the reasons, significance, context and impact of the universe on our human existence. For me, it’s just there to be discovered! 

Lovely report, I love binoculars, it’s a great time of year for them, so many interesting objects. The Hyades are one of my favourites, one of a few objects that are best seen through binoculars. That would make an interesting thread - “Which objects are best through binoculars?”. 🙂

Lovely report, NGC457 is one of my favourites, must have looked great through a 10” Dob. 
 

52 minutes ago, Nik271 said:

I agree with Mr. Spock this is not a fault of the scope, in fact the secondary is visible at low powers in all obstructed scopes. The reason is the large exit pupil: In a 35mm EP the exit pupil is massive 7mm of which the secondary is close to 2mm, so you can easily see it in daylight. In fact during the day the eye pupil is smaller than 2mm so you can get a blackout if you eye is positioned dead center on the EP axis.

Nice explanation. As you get older your pupil’s dilation decreases so some people may only be reaching 5 - 6mm eye pupil diameter, making the situation even worse! 

Very nice!

Very enjoyable report, those dark skies must be something else. I’m especially impressed with you getting the spiral structure in M33 and bagging the California Nebula. Well done. 👍

34 minutes ago, Paz said:

p.s. how do you get a Skytee 2 set up line that to have a two scopes on the same axis instead of using the standard offset second mounting point?

The two scopes don't really line up! Initially I drilled two holes to mount the top saddle on the side (over the hole for the counterweight bar) and the altitude could be adjusted to line up with the other saddle (there are grub screws on the mount which allow this) - this actually got fairly close. However the arrangement you see is slightly different, with a more secure saddle (I didn't trust the one that came with the mount) which slips over the end of the counterweight bar. This doesn't line up so well, but I'm sure I could get it close with some fettling!

Good tip about using the glass path corrector on the C8, I'll bear that in mind.

Fascinating stuff. I assume ‘glare stops’ are what we now call ‘baffles’. 

26 minutes ago, Peter Drew said:

I've also been comparing different telescopes observing Mars and have come to similar conclusions.  The main comparison has been between a 16" SCT and its SW 150ED "finder".  In general, the refractor gives a neater, consistently more stable image than the SCT and the colours are more pronounced but at high magnification around 400x the image in the refractor becomes dim whereas the SCT, presenting a larger exit pupil remains more than bright enough.  I tried a whole range of colour filters but all were disappointing.  I've yet to try a couple of the more recommended specialist filters.  Overall, the best image of the night has been with the SCT which is probably to be expected, if only there was that perfect night!  I also have a vintage orange C8 that puts up excellent images, almost as good as the 150ED but noticeably different in presentation.  My experience over the years leads me to believe that there is small incremental difference in planetary detail as apertures increase, visibility of faint DSO's is a different matter.    🙂 

Interesting comparison Peter, as you say similar experiences but on a bigger scale. Looking forward to trying the binoviewers with the C8 and getting the 6" F8 Newt out at some point.

18 minutes ago, Peter Drew said:

and its SW 150ED "finder"

🤣

6 minutes ago, AstroTim said:

I have tried a moon and sky glow filter and it can tease out a little more detail on occasion (although possibly just when the moon is nearby). I also find that I achieve more magnification when using the Binoviewer with the C8 (Binoviewer with 20mm eyepieces and 1.6x nosepiece barlow is the max I’ve managed), hence my earlier question. I’m beginning to wonder whether it is down to the light being split in the Binoviewer, resulting in less glare from the surface at the higher magnification and therefore more detail visible than in cyclops mode. I am hoping to get hold of a variable polariser at some point to see if dialling down the surface brightness might increase the magnification and detail achievable.

 

Tim

I haven't tried the binoviewer in the C8, but will do, should be good. From my calculation you should be getting around 180 - 200x with the C8+binoviewer+20mm eyepieces+1.6x nosepiece. In theory it should be 162x (2032mm x 1.6 / 20mm) but from reading up on this, it looks like using the binoviewers in an SCT increases the focal length to around F12 (as the main mirror has to move closer to the secondary to reach focus with a binoviewer, and the secondary magnifies this change in distance by a factor of 5) so you may be closer to 180x - 200x. What do you think? 

30 minutes ago, Stu said:

Hope it kept your nose warm Robert? 🤣

Excellent report, thanks very much. It matches my experiences with my 4” scopes and the 8” f8. It is only when the seeing stabilises that you really start to see the additional resolution available in the larger scope, but even then, as you say, I find it hard to describe the differences, it’s just like a higher resolution image with more subtle variation visible.

I had some great views early on last night in the f8, unfortunately it clouded over before Mars transited, I reckon it would have been excellent as the setting was good here. Just caught Syrtis Major coming onto the disk.

Thanks Stu. I've not viewed Mars yet using the 6" F8 Newt, so next time out I'll set this up next to either the 4" frac or the C8 (I'm open to suggestions! ). I'm still really amazed by what a decent 4" frac can achieve on planets especially with a binoviewer. I'm going to say something controversial (and very unscientific), but so far for me the binoviewers seem to be adding another inch to the aperture compared to cyclops viewing! 

40 minutes ago, markse68 said:

Hi Robert, interesting report and lovely sketch  Sounds like the seeing conditions were quite poor and that old saying that larger aperture suffers more in poor seeing must be true from your description! Interesting too that the colours and contrast were better with the smaller aperture. I noticed similar when playing with my toy celestron bird jones thing the other week- it gave a small but sharp disk in a nice dark reddish pink compared to bright very subtly pinky orange in my dob, but i put it down to using lower magnification but sounds like it’s more aperture related from your comparison. I guess it’s just more light captured, brighter image, over saturated eye sensors? and probably why the orange filter can help improve contrast on a larger aperture. But then you’d expect an nd to do similar but I don’t remember that being the case when i was playing with my variable polariser the other week. And the colour is definitely there as witnessed in images taken with large aperture scopes but then i guess they can play with levels like we can’t! Perplexing  🤔🤷‍♂️

Mark

I did think about using some of my coloured filters, but ran out of time. I haven't found coloured filters reveal any more detail, but change the viewing experience as they can highlight certain features. My feeling was that they might be worth a go with the C8, perhaps I'll try this next time out.

6 hours ago, AstroTim said:

Interesting report. I have a C8 myself but have been wondering how the views from a 4” refractor might compare. Did you try the Binoviewer on the C8 to see how that configuration compares too? What sort of magnification were you able to achieve in the C8, and was that similar to what you could achieve in the 102? I seem to be struggling to get much above 226x (9mm eyepiece) with mine in cyclops mode, and only a little more with the Binoviewer (maybe 250x).

 

Tim

Hi Tim,

I was using around 170x with the binoviewers (difficult to know exactly as I was using a barlow with unknown spacing). I had a zoom on the C8 and went up to a maximum of 250x, but I found the best views were to be had around 170x (again approximate due to use of zoom), coincidentally the same as the binoviewer. I find magnifications beyond 200x rarely yield any extra much of the time, unless seeing is exceptional. I might live in an area of permanently bad setting though! 
 

All magnifications stated are  very approximate, I’ll try a measure the true magnification at some point. 🙂
 

1 hour ago, ShrewView said:

Very good description of the differences in the views and the benefits of using more than one scope 😁.

Nice set up you have there too. Glad you're getting on with the binoviewers, i enjoy mine but the dew last night was awful and I found the eyepieces wouldn't stay clear. Did the dew straps work well with those? Must invest in some for mine if so.

Thanks  🙂 The dew straps worked really well, I wrapped a long single dew strap around the both bino eyepieces as an experiment and it kept the dew at bay, but did get in the way of viewing as it straddled the gap between the eyepieces - I have a couple of proper eyepiece dew straps on the way. The scopes were dripping with dew by the end but the eyepieces and corrector plate were clear. The refractor lens was also clear without a dew strap thanks to the very long dew shield. 

Tonight I thought I'd try viewing Mars with the 102ED-R (plus binoviewers) alongside the C8. With a very dewy night on the cards, I put some dewstraps on the binoveiwer eyepieces (which became unuseable last time due to dew) and the SCT corrector plate. It was very enjoyable switching between the two and teasing out detail from the red planet and interesting to comparing views. Seeing was ok. It is actually very hard to describe the different views through the two scopes, but in summary I would say the 102ED-R with binoviewers was very nearly able to show the same as the C8 in cyclops mode, however the gap apeared bigger when also using the smaller scope in cyclops mode. The appearance of the planet was very different in both scopes but the difference in detail was subtle. Through the 102ED-R it was easy to get a sharp focus on the disc (partly thanks to the lovely focuser). The planet was a light pink and the variations in darkness on the surface very apparent. In the C8 the planet was brighter and whiter. Focus was harder to achieve, the edges of the disc being less sharp, and the clarity seemed to vary from moment to moment far more than in the smaller scope. But certain types of features were easier to see, for example the sharply defined edges of the dark regions was easier to discern as was the polar cap. In moments of clarity there seemed to be a lot more there but hard to get on paper. However I would say the differences between the light and dark regions was more prominent in the 102ED-R than the C8. I felt that the C8 had more to give though and on a night of excellent seeing it would have pulled further ahead in the amount of detail visible. Different experiences, but both extremely enjoyable. Amazing what a diminuitive 100mm frac with binoviewers can achieve though.

Below is my attempt at a sketch, a comparison from Mars Mapper and a pic of the scopes in action.