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How many bands on Saturn can you see in your 3" and 4" apochromat.

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#26 Magnetic Field

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Posted 19 May 2019 - 01:37 PM

I don't really care what you believe! I get very detailed views of Saturn through my apos that punch above their aperture class but my seeing has to be able to support those views. This does happen, but rarely. Granted, I don't get the same image size(you never elaborated upon that) but I do see the details! I detect much jealousy in your comments!!

There is no jealousy (because I know you don't see what the sketch shows).

 

I asked can you see more than 1 or 2 bands on Saturn's disc in a 3" or 4" instrument. And I gave a link to what I mean.

 

And you said you can see more than 2 bands: "I've seen several(never really counted them) bands on Saturn's globe with my 3" and 4" apos."

 

For me this means you see 4 or 5.



#27 Magnetic Field

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Posted 19 May 2019 - 01:41 PM

Two things – not wanting/asking to get embroiled here....but feel cautioned to keep a wary eye...

 

Firstly a decent 6-8” scope of any regular sort would get most of the detail rendered there.......as I tend to seek discrete hues on the planet (light grasp figures there) it’s often at the cost of finer detail.

 

I have a long practiced eye and my credentials are acknowledged by very seasoned and highly skeptical-inclined BAA Section Directors – in this age of imagery they still come to me for stuff.  I can sketch what I see with recognized accuracy (BAA) so with me its illustrations not words – show not blow........ needs only be an annotated line sketch – nothing fancy....

 

Second whilst I recorded steady Seeing and good Transparency; at the 13º altitude I’m looking through a long path length of particulates as compared to higher.  Thus there is another factor there that affects the crispness of the planet regardless of steadiness.  The view I got the other morning I might count on another couple of times rest of the apparition at the enduring lo-altitude– tho’ have been a little luckier than that recent ones.   As I said in my thread systematic observing is virtually out – maybe till the mid 2020s.

 

That D-K (see attached) has served me well these 4+ decades and I use for much more than planets.  I have never looked through a similar sized refractor but some visiting seasoned/eminent-even have and they all comment on the refractor-like views but without the chromatic issues...

 

During the 1990s apparitions I was getting upwards of 150 transit timings per apparition (CMTs) of features (some quite delicate/fleeting) on Saturn.  Recent years Richard McKim analysed these along with others including imagers and got good zonal rotation periods for many of them.

 

Those reports are here.... https://www.britastro.org/node/13307

 

Here is another recent thread with my old 3” refractor used... https://www.cloudyni...jupiter-saturn/

 

DG.

attachicon.gif DK and DGray.jpg

I am more surprised by your good seeing.

 

I don't live far away from your place and also near the coast but still wait for good seeing.

 

I think on the coast in the South of the UK seeing conditions are generally better in summer?



#28 Rutilus

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Posted 19 May 2019 - 01:43 PM

My drawing below was typical of the views I had with my 4 inch Apo when Saturn was well

placed in the sky from my location. The drawing made with the 6 inch Achromat shows the 

Dragon storm that was visible about 10 years ago.

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  • Saturn-cn.JPG

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#29 Magnetic Field

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Posted 19 May 2019 - 01:59 PM

Two things – not wanting/asking to get embroiled here....but feel cautioned to keep a wary eye...

 

Firstly a decent 6-8” scope of any regular sort would get most of the detail rendered there.......as I tend to seek discrete hues on the planet (light grasp figures there) it’s often at the cost of finer detail.

 

I have a long practiced eye and my credentials are acknowledged by very seasoned and highly skeptical-inclined BAA Section Directors – in this age of imagery they still come to me for stuff.  I can sketch what I see with recognized accuracy (BAA) so with me its illustrations not words – show not blow........ needs only be an annotated line sketch – nothing fancy....

 

Second whilst I recorded steady Seeing and good Transparency; at the 13º altitude I’m looking through a long path length of particulates as compared to higher.  Thus there is another factor there that affects the crispness of the planet regardless of steadiness.  The view I got the other morning I might count on another couple of times rest of the apparition at the enduring lo-altitude– tho’ have been a little luckier than that recent ones.   As I said in my thread systematic observing is virtually out – maybe till the mid 2020s.

 

That D-K (see attached) has served me well these 4+ decades and I use for much more than planets.  I have never looked through a similar sized refractor but some visiting seasoned/eminent-even have and they all comment on the refractor-like views but without the chromatic issues...

 

During the 1990s apparitions I was getting upwards of 150 transit timings per apparition (CMTs) of features (some quite delicate/fleeting) on Saturn.  Recent years Richard McKim analysed these along with others including imagers and got good zonal rotation periods for many of them.

 

Those reports are here.... https://www.britastro.org/node/13307

 

Here is another recent thread with my old 3” refractor used... https://www.cloudyni...jupiter-saturn/

 

DG.

attachicon.gif DK and DGray.jpg

Funny though someone in Leicester (UK) made a drawing of Saturn on the 12th May 2019 with a 50cm Dall-Kirkham:

 

http://alpo-j.asahik...19/s190512z.htm

 

Interesting also he in Leicester used 153x (I think you used 385x with a bino viewer).


Edited by Magnetic Field, 19 May 2019 - 02:01 PM.


#30 BillP

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Posted 19 May 2019 - 02:10 PM

You need a scope with really good contrast to see the bands.  That means a really smooth good figure.   

 

There are oodles of factors involved in contrast.  It is not really just a single variable nor is any single variable that is most important as they all can easily destroy contrast because any weak link in a chain of course makes the entire chain weak.  The smoothness of polish of course reduces scatter so that is a factor, as is any SA or CA in the design.  The cleanliness and preciseness of the coating application is also critical as that can introduce lots of contrast robing scatter from particulates trapped between layers and any imperfection on the original glass surface being magnified with each coating layer.  The internal light suppression treatment of the OTA, focuser draw tube forward facing surface and interior, back wall of the OTA can all add light reflections.  Back end accessories like extension tubes, 2" to 1.25" adapters, diagonals can all have reflective surfaces and in the case of diagonals they can add significant scatter like with less than very perfect dielectrics since they can have 40+ coating layers.  And of course we then have the eyepiece as well which can show lots of scatter.  Finally, pick an evening to observe when there is a high water vapor content in the atmosphere or observe at sea level and you get lots of contrast robbing scatter from the atmosphere.  So many many factors are involved and the OTA really needs to be "engineered" well for it to not add a lot of unwanted scattered light.


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#31 David Gray

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Posted 19 May 2019 - 02:41 PM

I am more surprised by your good seeing.

 

I don't live far away from your place and also near the coast but still wait for good seeing.

 

I think on the coast in the South of the UK seeing conditions are generally better in summer?

It’s getting out looking every opportunity to catch those rare conditions – especially low down.  How many do that I wonder to be sure there was not good seeing – in fact it gets a bit instinctive with me to catch such seeing – not infallible but gets me the goods – don’t look don’t see!. Involving getting up 2/3am on morning after morning if I even half expect there is clear sky in prospect – that is about 30-40 times since Feb.

 

From the s’east to ss’west (then the house!) I am looking across miles of open country – the terrain sloping away quite abruptly and steeply which I think is a big factor.  Was never so seeing-blessed at my previous home  8 miles east of here(1955-76).

 

As I say I have the long-practiced eye that can grab fine detail in even very brief better spells – the ‘planetary eye’...that involves what Alika Herring once said in S&T “Don’t just look at a planet look on it.....”. 

 

With the naked-eye moon I can ‘walk’ my eyes (control) around such features as Mare Crisium and note slight shape departures from a smooth circle/ellipse and shade-variance etc.; of course that is virtual perfect seeing conditions compared to telescopic challenges.

 

So on so forth.........getting carried away, but simply to get the best from this hobby best to master difficulty; relish it even – paradoxically perhaps, part of my joy with the hobby.  When things deliver great/fantastic otherwise be philosophical: best when things go awry to have a plan B (B to Z even); or just go back to bed.......!


Edited by David Gray, 19 May 2019 - 02:47 PM.

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#32 Steve Allison

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Posted 19 May 2019 - 05:45 PM

There is no jealousy (because I know you don't see what the sketch shows).

 

I asked can you see more than 1 or 2 bands on Saturn's disc in a 3" or 4" instrument. And I gave a link to what I mean.

 

And you said you can see more than 2 bands: "I've seen several(never really counted them) bands on Saturn's globe with my 3" and 4" apos."

 

For me this means you see 4 or 5.

This is silly.

 

The word "several" means different things to different people, although the dictionary defines it as more than two but not many. 

 

Barbie says she really never counted the bands, so for you to question what she saw based on your own interpretation of her use of the word is, well, silly.


Edited by Steve Allison, 19 May 2019 - 05:49 PM.

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#33 Magnetic Field

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Posted 19 May 2019 - 05:57 PM

This is silly.

 

The word "several" means different things to different people, although the dictionary defines it as more than two but not many. 

 

Barbie says she really never counted the bands, so for you to question what she saw based on your own interpretation of her use of the word is, well, silly.

Cambridge dictionary:

 

several adjective [ not gradable ]
us ​ /ˈsev·rəl, -ər·əl/

(of an amount or number) more than two and fewer than many; some:
I’ve seen "Star Wars" several times.

 

Btw: If someone tells you he or she has never counted his or her money, you wouldn't think he or she is talking about counting 1 or 2 dollars only.


Edited by Magnetic Field, 19 May 2019 - 06:00 PM.


#34 Steve Allison

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Posted 19 May 2019 - 06:01 PM

So how do you come up with 4 or 5 when the person using the word herself doesn't know how many?

 

Forget it. This whole discussion is silly!


Edited by Steve Allison, 19 May 2019 - 06:01 PM.

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#35 fred1871

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Posted 19 May 2019 - 09:23 PM

An interesting discussion, despite the comment above in #34; particularly useful to have David Gray's input, and the sketches by Astrojensen, among others.

 

I can't contribute with observations of Saturn through a 3-4-inch apo, as I've only observed it in recent decades with larger scopes, from 5.5-inch upwards. But back in the 1990s when Jupiter had multiple comet fragment impacts, I was quite surprised at how well the markings in the cloudtops showed with a 4-inch fluorite refractor. The shape and pattern of the bigger markings showed clearly, not just a contrast darkening. 

 

The 4-inch views were not as good as those through a 7-inch apo and a C14 at the same place and time, but were quite usefully detailed nevertheless. It was something of a revelation to me as to the possibilities of smaller apertures of very high quality.


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#36 Steve Allison

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Posted 19 May 2019 - 09:43 PM

I only meant my discussion with Magnetic Field was silly...



#37 starman876

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Posted 19 May 2019 - 09:54 PM

This has become an interesting thread.  More controversy than I would expect to see in such a simple post.   I am sure this will get more interestingfingertap.gif



#38 Magnetic Field

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Posted 20 May 2019 - 12:52 AM

This has become an interesting thread.  More controversy than I would expect to see in such a simple post.   I am sure this will get more interestingfingertap.gif

Okay there are 90mm and 4" Maks out there.

 

But the 3" and 4" class of apertures is populated by refractors.

 

I have always wondered does it ever change what one can see with a 3" or 4" refractor (or in my case Vixen VMC 110L) on Saturn:

 

1 or 2 bands (maybe 3) and the other "permanent features" (e.g. Cassini division).

 

Compare this to Mars or especially Jupiter. The moon yes doesn't change but I imagine even in a small instrument there will always be something new that can be observed on the moon.



#39 Muffin Research

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Posted 20 May 2019 - 03:12 AM

Well yeah it changes always throughout the decades, the way it's angles changes, detail becomes more visible depending on our orbits and distances, so you need good seeing on the moment of opposition to really be blown away by detail so get ready it's in July but it's gonna be too low for us to be of any real advantage.

 

I still remember views of Saturn and Mars & Jupiter from years ago.. Mars being a red dot in the C8 for most of the time but then suddenly polar caps and surface features..  and Saturn and Jupiter often deliver satisfactory views in that scope but on those special nights you notice a lot more finer detail in the bands. And those views stay with you. 

Also the more you observe to more you learn to see detail? 

When I first got my scope the first few weeks of observing everything was white.. colour on Saturn and Jupiter wasn't obvious for me, but the more evenings I observed colours and shades became a lot more apparent. 

 

And yes people with a 4" refractor are probably better off with spotting finer detail than you with a 4" reflector with a central obstruction and vanes, as those will make it punch below its 4" aperture unfortunately.
So don't be surprised when people see more detail through their equally sized apos.


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#40 Asbytec

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Posted 20 May 2019 - 07:33 AM

1 or 2 bands (maybe 3) and the other "permanent features" (e.g. Cassini division).

It's kind of like Jupiter, Saturn is divided into belts and zones from the equatorial region, the tropical region, the temperate region, and the polar region mirrored on both northern and southern hemispheres. Each has a belt (darker) or a zone (lighter) or both.

Edit: https://britastro.or...8-4 Foulkes.jpg

Belts: On Saturn you should see the (North or South) equatorial belts (NEB/SEB) pretty well, maybe the temperate belt, and certainly the darker northern polar region (NPR). So, that's two belts if you're lucky, seeing is good, and the planet is cooperating, and a polar region. These belts can be broad or narrow. The NEB tends to be pretty broad and normally darker along the southern edge is shares with the equatorial zone. Sometimes the northern edge of the NEB darkens and you might see a third "belt" there. At times, a fourth belt might be seen along the equator called the equatorial belt (EB). The EB, northern NEB (really part of the NEB) and the Northern Temperate belt can be very low contrast and may or may not be easily seen. It depends on Saturn's weather and often on Saturn's tilt.

So, potentially one might see the EB, NEB, NTB, and the NPR. The NEB and the NPR seem to have the best chance of being seen, so you may only see 1 belt and the polar region when Saturn is low, when seeing is not cooperating, using a small aperture, poor contrast, or the activity in Saturn's atmosphere is not conducive. My guess is, most times we'll see the NEB and a very weak NTB along with the polar region. That was my view back in 2011/2012 apparition. The NEB was broad and fairly solid and the NTB a little further north was barely visible.

Zones: You should see the equatorial zone directly below the rings easily enough. You might make out the northern tropical zone (NTrZ) between the NEB and the NTB and the northern temperate zone (NTZ) below the polar hood. So, that's potentially 3 zones: equatorial (EZ), tropical (NTrZ), and temperate (NTZ).

Thomas seems to show a stronger divided NEB in his sketch above, but not the very weak and low contrast tropical band (NTB) further north. He also shows the equatorial zone well, and probably the tropical zone, too. Sasa shows the same with a hint of the NTB. So, that's really 2 belts that looks like 3. Also, Sasa shows the obvious EZ and probably the NTrZ. If he saw hints of the NTB, then it was likely divided by the NTrZ between the NTZ (gets confusing sometimes) and the northern polar region. David Gray shows all of them.

So, I'd expect on most nights in a modest aperture we'll see the EZ topped by the NEB bordered by the NTrZ which might seem to merge with the NTZ as a very broad zone and all of that capped off by the polar region. However, on a good night and with luck, the NTrZ and NTZ might be split by the very weak NTB, making 2 belts and 3 zones - and the polar region - visible in a modest aperture. David Gray (Correct me if I am wrong or not using enough acronyms to describe it) shows the equatorial belt, the northern equatorial belt, and the northern temperate belt. But, he does show some variation in the northern edge of the NEB and in the southern edge of the NPR. Both of which appear to be different belts. He also clearly shows the equatorial zone (split by the equatorial belt), the tropical zone, and the temperate zone. Edit: The NEBn (north equatorial belt north) and NNTB (north north temperate belt)...just like Jupiter.

So, does that answer the question? lol.gif Probably 2 belts maybe three (depending) along with 2 or 3 zones and a polar region most of the time are likely to be visible in a modest aperture when seeing is good.

Rings: The rings, IMO, is where it's at. Starting from the inner rings, we may be able to see the Crepe ring as kind of eerily transparent. Inside that is the B ring with some of it's features. It appears darker on the inner most edge and has a brighter ringlet bordering the Cassini division. That darker inner edge is not the "spokes" we hear of, not to my knowledge. Then working outward, of course Cassini division is seen between the B and A rings. Outside of that is the A ring with it's features starting with another bright ringlet bordering just outside the Cassini division. The a little further out, the Enke minimum *might* be seen near the middle of the A ring. This is not the Enke Gap, it's merely a portion of the A ring with lower surface brightness. Forget the Enke gap in the apertures we're talking about, seeing that requires larger aperture and good seeing.

That's my opinion and experience, but I have not observed Saturn since the 2012 apparition when Saturn was well placed in excellent seeing not far from the tropical zenith. Things change and some have keen eyes for such things, the proper magnification may play a role, at least good optics with good contrast and the rest of it.

Saturn 13 Apr 2012 1600UTa.png

http://alpo-j.asahik...2/s120413b1.jpg

Edited by Asbytec, 20 May 2019 - 08:24 AM.

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#41 David Gray

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Posted 20 May 2019 - 09:53 AM

 https://britastro.or...8-4 Foulkes.jpg  David Gray (Correct me if I am wrong or not using enough acronyms to describe it) shows the equatorial belt, the northern equatorial belt, and the northern temperate belt
 

I have to say Norme, me as a (embarrassed) BAA member find that belt/zone diagram crude: huge arrows distracting..........tho’ unsurprising as they did a hatchet job on my sketches in the latest Saturn Report: thick lines to indicate subtle features – not obscuring but seriously distracting – I have grandkids that could do better with a marker pen.......no wonder I slowly drift from the Association – and that Report coincided with my 50-yrs contributing to the Saturn Section!

 

Attached is a sketch I posted in response to a request to label Belts/Zones .  Not the best one for Minor Ring Divisions as it was very close to opposition where the Seeliger/Opposition Effect renders them lo-contrast/soft due to no inter-shadowing of the particles. See this image: http://alpo-j.asahik...16/s160506z.htm

 

We risk information overload here......blush.gif...... such is the situation with planets - chopped a lump off this post!!......maybe later.......Dave.

 

2016 apparition the NEB region was a bit anomalous – Saturn does its own thing regardless of our labellings! NB: Cm not a Belt (C Ring).

SAT 2016 Jun 5 2350 Nomen.jpg


Edited by David Gray, 20 May 2019 - 10:18 AM.

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#42 Asbytec

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Posted 20 May 2019 - 10:31 AM

Thank you, David. Much nicer, gonna hang onto it. Not that I hope to see such detail. Beautiful, though.
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#43 Magnetic Field

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Posted 20 May 2019 - 11:19 AM

My drawing below was typical of the views I had with my 4 inch Apo when Saturn was well

placed in the sky from my location. The drawing made with the 6 inch Achromat shows the 

Dragon storm that was visible about 10 years ago.

Where credit is due: very good drawing (post #28 as it is impossible to  insert your sketch here) of Saturn with your 4" apochromat.


Edited by Magnetic Field, 20 May 2019 - 11:21 AM.


#44 Magnetic Field

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Posted 20 May 2019 - 11:26 AM

It's kind of like Jupiter, Saturn is divided into belts and zones from the equatorial region, the tropical region, the temperate region, and the polar region mirrored on both northern and southern hemispheres. Each has a belt (darker) or a zone (lighter) or both.

Edit: https://britastro.or...8-4 Foulkes.jpg

Belts: On Saturn you should see the (North or South) equatorial belts (NEB/SEB) pretty well, maybe the temperate belt, and certainly the darker northern polar region (NPR). So, that's two belts if you're lucky, seeing is good, and the planet is cooperating, and a polar region. These belts can be broad or narrow. The NEB tends to be pretty broad and normally darker along the southern edge is shares with the equatorial zone. Sometimes the northern edge of the NEB darkens and you might see a third "belt" there. At times, a fourth belt might be seen along the equator called the equatorial belt (EB). The EB, northern NEB (really part of the NEB) and the Northern Temperate belt can be very low contrast and may or may not be easily seen. It depends on Saturn's weather and often on Saturn's tilt.

So, potentially one might see the EB, NEB, NTB, and the NPR. The NEB and the NPR seem to have the best chance of being seen, so you may only see 1 belt and the polar region when Saturn is low, when seeing is not cooperating, using a small aperture, poor contrast, or the activity in Saturn's atmosphere is not conducive. My guess is, most times we'll see the NEB and a very weak NTB along with the polar region. That was my view back in 2011/2012 apparition. The NEB was broad and fairly solid and the NTB a little further north was barely visible.

Zones: You should see the equatorial zone directly below the rings easily enough. You might make out the northern tropical zone (NTrZ) between the NEB and the NTB and the northern temperate zone (NTZ) below the polar hood. So, that's potentially 3 zones: equatorial (EZ), tropical (NTrZ), and temperate (NTZ).

Thomas seems to show a stronger divided NEB in his sketch above, but not the very weak and low contrast tropical band (NTB) further north. He also shows the equatorial zone well, and probably the tropical zone, too. Sasa shows the same with a hint of the NTB. So, that's really 2 belts that looks like 3. Also, Sasa shows the obvious EZ and probably the NTrZ. If he saw hints of the NTB, then it was likely divided by the NTrZ between the NTZ (gets confusing sometimes) and the northern polar region. David Gray shows all of them.

So, I'd expect on most nights in a modest aperture we'll see the EZ topped by the NEB bordered by the NTrZ which might seem to merge with the NTZ as a very broad zone and all of that capped off by the polar region. However, on a good night and with luck, the NTrZ and NTZ might be split by the very weak NTB, making 2 belts and 3 zones - and the polar region - visible in a modest aperture. David Gray (Correct me if I am wrong or not using enough acronyms to describe it) shows the equatorial belt, the northern equatorial belt, and the northern temperate belt. But, he does show some variation in the northern edge of the NEB and in the southern edge of the NPR. Both of which appear to be different belts. He also clearly shows the equatorial zone (split by the equatorial belt), the tropical zone, and the temperate zone. Edit: The NEBn (north equatorial belt north) and NNTB (north north temperate belt)...just like Jupiter.

So, does that answer the question? lol.gif Probably 2 belts maybe three (depending) along with 2 or 3 zones and a polar region most of the time are likely to be visible in a modest aperture when seeing is good.

Rings: The rings, IMO, is where it's at. Starting from the inner rings, we may be able to see the Crepe ring as kind of eerily transparent. Inside that is the B ring with some of it's features. It appears darker on the inner most edge and has a brighter ringlet bordering the Cassini division. That darker inner edge is not the "spokes" we hear of, not to my knowledge. Then working outward, of course Cassini division is seen between the B and A rings. Outside of that is the A ring with it's features starting with another bright ringlet bordering just outside the Cassini division. The a little further out, the Enke minimum *might* be seen near the middle of the A ring. This is not the Enke Gap, it's merely a portion of the A ring with lower surface brightness. Forget the Enke gap in the apertures we're talking about, seeing that requires larger aperture and good seeing.

That's my opinion and experience, but I have not observed Saturn since the 2012 apparition when Saturn was well placed in excellent seeing not far from the tropical zenith. Things change and some have keen eyes for such things, the proper magnification may play a role, at least good optics with good contrast and the rest of it.

attachicon.gif Saturn 13 Apr 2012 1600UTa.png

http://alpo-j.asahik...2/s120413b1.jpg

Thanks for the lengthy elaborate post. I will study it.

 

One more thing which is impressive with the Dall-Kirham drawing: the colour rendering (yes it probably says more about the observer and his ability).

 

Maybe I am wrong*** but I doubt you get that "colour perception feeling" of Saturn's bands and regions in a 4" apochromat. Or lets call it the depth and wealth of colours that you can see.

 

 

***No funny jokes about me being wrong.


Edited by Magnetic Field, 20 May 2019 - 11:27 AM.

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#45 mikeDnight

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Posted 20 May 2019 - 01:09 PM

The two attached sketches of Saturn are my most recent. Saturn from the UK has been very low so visually detail is hindered by the thick, turbulent atmosphere. I'd no intention of ever showing these half hearted outlines, but I'm sure you'll forgive any imperfections.

 

I'm looking forward to seeing Saturn high in the sky again, when the ring detail can be breathtaking!

 

IMG_0699.jpg IMG_0698.JPG


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#46 David Gray

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Posted 20 May 2019 - 01:45 PM

One more thing which is impressive with the Dall-Kirham drawing: the colour rendering (yes it probably says more about the observer and his ability).

 

Maybe I am wrong*** but I doubt you get that "colour perception feeling" of Saturn's bands and regions in a 4" apochromat. Or lets call it the depth and wealth of colours that you can see.

 

 

Colour a very contentious area – beware ye who enter..............

 

Just to say I do not claim absolute colour but simply strive to accurately render/represent what the eyepiece presents- that is a very different thing to claiming a definitive hue/tint etc.

 

Ball-park is the best that can be hoped for and Corel-tinting gives me much wider latitude than art media.  There is the option of effectively endless tweaking to narrow down to what we seek – try that with pastels etc. and a mess soon manifests.....

 

Ok we get happy enough we get it scanned and our carefully rendered hues look all wrong.  Corel offers all sorts of ways to get that scan back nearer the original – I’ve tried it and it can take hours with the stress getting off the scale, head trashed.....life is too short

 

Which is why I ‘scan’ (digital camera shot) the original pencil sketch and tint it in Corel Photo Paint. 

 

Sparing the details here of that process (usually 30-40 minutes): great; we have something we are happy with.  Then considerably reduce it for posting – already that knocks the fidelity back in varying degrees: hues and contrasts somewhat flattened.  Finally it is posted then is subjected to being viewed on all sorts of screens whose settings we cannot anticipate.

 

Once when we had a family gathering we had two desktops (mine) and four laptops all reset to default and viewed some of my work.  All of them showed quite different hues – one so bad I almost lost heart to ever post anything again – even grayscale....!!

 

Add in individual colour sensitivity/perception (one person's dull brown being another's brick red); and maybe technology has narrowed some of the disparity by now.  Even so I have little to no idea how they look to each of you out there – the whole tech thing is a mixed blessing at best.

 

My own colour sensitivity: well, the Moon has always been a rich palette of subtle hues to me - even now at 75...I've looked after my eyes, to the point of hypochondria, since my late teens. 

 

But I can say with regard to colour: in general larger does it better.  It takes a large bright-enough image scale to get good colour conveyance/differentiation.  A few who have used scopes of 1 metre up to the 2 metre at Pic have said they were shocked as to how vivid planetary colours looked compared to what even a 40-50cm shows.  Things like Ring C looking almost royal blue, Mars’ deserts the most vivid salmon pinks and strewn with hues from pale blue to ochre. My 41.5cm D-K somewhat exceeds the best my old 25cm Newt showed; and much more vivid than when the D-K is stopped down to 15cm (off-axis).  Which is the nearest I get to an apo albeit an f/45 one.....grin.gif


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#47 Magnetic Field

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Posted 20 May 2019 - 02:06 PM

Colour a very contentious area – beware ye who enter..............

 

Just to say I do not claim absolute colour but simply strive to accurately render/represent what the eyepiece presents- that is a very different thing to claiming a definitive hue/tint etc.

 

Ball-park is the best that can be hoped for and Corel-tinting gives me much wider latitude than art media.  There is the option of effectively endless tweaking to narrow down to what we seek – try that with pastels etc. and a mess soon manifests.....

 

Ok we get happy enough we get it scanned and our carefully rendered hues look all wrong.  Corel offers all sorts of ways to get that scan back nearer the original – I’ve tried it and it can take hours with the stress getting off the scale, head trashed.....life is too short

 

Which is why I ‘scan’ (digital camera shot) the original pencil sketch and tint it in Corel Photo Paint. 

 

Sparing the details here of that process (usually 30-40 minutes): great; we have something we are happy with.  Then considerably reduce it for posting – already that knocks the fidelity back in varying degrees: hues and contrasts somewhat flattened.  Finally it is posted then is subjected to being viewed on all sorts of screens whose settings we cannot anticipate.

 

Once when we had a family gathering we had two desktops (mine) and four laptops all reset to default and viewed some of my work.  All of them showed quite different hues – one so bad I almost lost heart to ever post anything again – even grayscale....!!

 

Add in individual colour sensitivity/perception (one person's dull brown being another's brick red); and maybe technology has narrowed some of the disparity by now.  Even so I have little to no idea how they look to each of you out there – the whole tech thing is a mixed blessing at best.

 

My own colour sensitivity: well, the Moon has always been a rich palette of subtle hues to me - even now at 75...I've looked after my eyes, to the point of hypochondria, since my late teens. 

 

But I can say with regard to colour: in general larger does it better.  It takes a large bright-enough image scale to get good colour conveyance/differentiation.  A few who have used scopes of 1 metre up to the 2 metre at Pic have said they were shocked as to how vivid planetary colours looked compared to what even a 40-50cm shows.  Things like Ring C looking almost royal blue, Mars’ deserts the most vivid salmon pinks and strewn with hues from pale blue to ochre. My 41.5cm D-K somewhat exceeds the best my old 25cm Newt showed; and much more vivid than when the D-K is stopped down to 15cm (off-axis).  Which is the nearest I get to an apo albeit an f/45 one.....grin.gif

I am on a 15" MacBook Pro with Retina plastic glass.

 

Your Saturn looks pretty good on my screen.


Edited by Magnetic Field, 20 May 2019 - 02:09 PM.

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#48 Magnetic Field

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Posted 20 May 2019 - 02:13 PM

The two attached sketches of Saturn are my most recent. Saturn from the UK has been very low so visually detail is hindered by the thick, turbulent atmosphere. I'd no intention of ever showing these half hearted outlines, but I'm sure you'll forgive any imperfections.

 

I'm looking forward to seeing Saturn high in the sky again, when the ring detail can be breathtaking!

 

attachicon.gif IMG_0699.jpgattachicon.gif IMG_0698.JPG

Your second drawing is the one I was referring to when I said this is what we see in our small 4" telescopes.



#49 David Gray

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Posted 20 May 2019 - 03:28 PM

Funny though someone in Leicester (UK) made a drawing of Saturn on the 12th May 2019 with a 50cm Dall-Kirkham:

 

http://alpo-j.asahik...19/s190512z.htm

 

Interesting also he in Leicester used 153x (I think you used 385x with a bino viewer).

508mm/154x=3.3mm exit pupil: that’s enough glare from Saturn to shrink the eye-pupil to effectively stop-down the scope and relatively enlarge the central obstruction....

 

and in....shocked.gif ...... Antoniadi IV seeing: Poor seeing, constant troublesome undulations of the image............No further comment – rather not go there/be involved..........!!!

 

But to say that my preferred 270x-385x: with binovu and apodizer gives me just the right level of a glare-free Saturn on the 415mm D-K in decent transparency.  Lower, no Apodizer & Binovu and it becomes white-out for me..........If the seeing does not stand those powers then I’m unlikely getting what I’m after with lower on planets – finding the contrasty-gain, as also with stopping down, unproductive/spurious (e.g. where is that sought fine belt/zone structure etc. – still unseen/seeing-smeared that’s where – if it’s there at all that is)  Better I find grabbing the moments (patience, patience) with higher; or Plan B with something else!

 

Another UK observer, and a similar size D-K to mine, is Richard McKim (BAA Mars/Mercury & Venus). Lives near Peterborough and by 2016 November had >90 drawings of Mars (when it was pretty low). This closing (dusty) apparition I expect he has a good number from that too – like me he lives in rural surrounds which seems to make the difference for catching those lo-alt good spells.

 

To those who wonder I’m in the UK too – as you soon spotted.  Seems my Longitude/Latitude is insufficient clue...smirk.gif.... so have amended my 'Location' (approx.) below the Avatar.....!..........*Ower Yonder* - local dialect: means Over There.


Edited by David Gray, 20 May 2019 - 03:49 PM.

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#50 Asbytec

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Posted 20 May 2019 - 07:48 PM

As for rendering color, my sketch is wrong too. With millions of hues to chose from, it's difficult to pick the right hue. Ball park at best, and I am not sure I am in the ball park. Color requires some image brightness to stimulate the eye, so we do not want a small exit pupil. Rather one that is just right.

 

Interesting David was at 154x and 3.3mm exit pupil with his technique of beating the seeing, I operate closer to 0.5mm exit pupil and twice the magnification without any specialized technique. No glare up that high, but Saturn was in much better tropical seeing near the zenith years ago. Some color was still available with a descent image scale. 

 

To me, Saturn was mainly amber or tawny generally with brownish or tan features.  Never saw any rusty or green hues as we might see in some images. I do not remember, really, been 7 years since I laid eyes on Saturn, but it's color is likely close to grey scale. Not unlike Jove in a modest aperture. Color almost demands aperture, but we can learn to discern some soft hues from one another. Calling it or replicating it is another problem. 

 

I hit Saturn years ago as a budding planetary observer without much experience, and only learned to see color in the years that followed by observing Jupiter intensely. It took me over two years to get my Jupiter palate where I want it. Too red, too purple...too something. I do not have a refined standard Saturn color palate. 


Edited by Asbytec, 20 May 2019 - 07:49 PM.



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