SW Skymax 150 - First Light, First Thoughts

[scarp15]

Progressively following this thread, I too wonder whether roof currents, central heating thermals might be the situation explaining for the Mak's poorer performance? My most recent Lunar sessions have been with my TV85 in our backyard, I can set up for quite a good southerly aspect, but there are defiantly thermals to negotiate, from our own heating system and roof tops of ours and adjoining neighbours to the south east before there is a clear south aspect above a wall. The TV85 performed in this circumstance absolutely fine, at least as far as my eye pieces could stretch, x150. My 8" F6 dob 1/10 PV mirrors can produce excellent Lunar views, yet this has mostly been at other gardens, locations where by there has been open space or good clearance well away from roof top interference, central heating vents.  

[nightfisher]

4 minutes ago, scarp15 said:

Progressively following this thread, I too wonder whether roof currents, central heating thermals might be the situation explaining for the Mak's poorer performance? My most recent Lunar sessions have been with my TV85 in our backyard, I can set up for quite a good southerly aspect, but there are defiantly thermals to negotiate, from our own heating system and roof tops of ours and adjoining neighbours to the south east before there is a clear south aspect above a wall. The TV85 performed in this circumstance absolutely fine, at least as far as my eye pieces could stretch, x150. My 8" F6 dob 1/10 PV mirrors can produce excellent Lunar views, yet this has mostly been at other gardens, locations where by there has been open space or good clearance well away from roof top interference, central heating vents.  

That is a good point, perhaps Mike should try the 150 Mak at a more open site

[Alfian]

9 minutes ago, iPeace said:

We'll soon know.

OOOOoooooo!

[Timebandit]

4 minutes ago, iPeace said:

We'll soon know.

 

You will be competition to FLO soon with all these scopes?

I take it poor Stanley will have to best not only the 150 Mak , but the new kid in town a 150mm newt . 

Go on Stanley do your best ? 

 

 

[iPeace]

4 minutes ago, scarp15 said:

Progressively following this thread, I too wonder whether roof currents, central heating thermals might be the situation explaining for the Mak's poorer performance? My most recent Lunar sessions have been with my TV85 in our backyard, I can set up for quite a good southerly aspect, but there are defiantly thermals to negotiate, from our own heating system and roof tops of ours and adjoining neighbours to the south east before there is a clear south aspect above a wall. The TV85 performed in this circumstance absolutely fine, at least as far as my eye pieces could stretch, x150. My 8" F6 dob 1/10 PV mirrors can produce excellent Lunar views, yet this has mostly been at other gardens, locations where by there has been open space or good clearance well away from roof top interference, central heating vents.  

Great, so now it's a road show...

Good points, actually. This location may just not be suitable...which would defeat the purpose. But it's worthwhile to find out just what the deal is, so we'll get out to a better location as soon as we can swing it.

[iPeace]

2 minutes ago, Timebandit said:

 

You will be competition to FLO soon with all these scopes?

I take it poor Stanley will have to best not only the 150 Mak , but the new kid in town a 150mm newt . 

Go on Stanley do your best ? 

 

 

Stanley has nothing to worry about and knows it. After all, you only name the ones you keep.

He's the benchmark; I'm glad I got him early on, it helps to know what's good.

[nightfisher]

When is the 150 Newt likely to arrive, just need to think about used values 

[iPeace]

Just now, nightfisher said:

When is the 150 Newt likely to arrive, just need to think about used values 

They haven't given me shipping notice yet, perhaps due to the 1:10 focuser upgrade which they'll have to stick on. I'll let you know, maybe it merits a separate thread.

Shipping cost might turn out to be a spanner later on; a bridge to either cross or turn back from, we'll see.

[Paz]

This continues to be a super interesting read! Looking forward to the next installment and would be particularly interested to know more about how the comparison breaks down into contrast performance and detail performance.

[iPeace]

2 minutes ago, Paz said:

particularly interested to know more about how the comparison breaks down into contrast performance and detail performance

All right, here's where I learn something.

How do I tell the two types of performance apart? As I recall, it seemed to be that the view through the frac was so much sharper that it showed both more contrast and more detail. But I may well be interpreting those terms in a different way.

Care to have a go at bestowing enlightenment?

[nightfisher]

Your looking for a combination of Resolution, contrast and general sharpness at the EP

[Stu]

7 minutes ago, iPeace said:

All right, here's where I learn something.

How do I tell the two types of performance apart? As I recall, it seemed to be that the view through the frac was so much sharper that it showed both more contrast and more detail. But I may well be interpreting those terms in a different way.

Care to have a go at bestowing enlightenment?

Not sure I can answer that question directly Mike, but to me you need to isolate the aesthetic from the ultimate performance of the scope.

If, for example, you try to see how many craterlets in Plato you can see with each scope, this gets away from aesthetics and just tells you which scopes shows more that the other. If you try for threshold objects in both scopes then you will begin to see the true differences in performance.

This has nothing to do with which scope you prefer and which scope you keep. I enjoy my Tak, knowing that it won't show as much as a similar quality larger aperture scope, but really enjoying the aesthetics of the view. My suggestion would be to give these targets a go and see what it tells you.

[iPeace]

2 minutes ago, nightfisher said:

Your looking for a combination of Resolution, contrast and general sharpness at the EP

Makes sense; I think Paz wants to know which scope shows better contrast, and which more detail - and I'm not sure how to separate the two.

[iPeace]

17 minutes ago, Stu said:

Not sure I can answer that question directly Mike, but to me you need to isolate the aesthetic from the ultimate performance of the scope.

If, for example, you try to see how many craterlets in Plato you can see with each scope, this gets away from aesthetics and just tells you which scopes shows more that the other. If you try for threshold objects in both scopes then you will begin to see the true differences in performance.

This has nothing to do with which scope you prefer and which scope you keep. I enjoy my Tak, knowing that it won't show as much as a similar quality larger aperture scope, but really enjoying the aesthetics of the view. My suggestion would be to give these targets a go and see what it tells you.

OK - so if scope 1 shows me specific blurry dots on a blurry background, while scope 2 cannot show me those specific dots at all, but the whole picture it does show is a lot sharper, then scope 1 has better ultimate performance?

Goodness, this could mean I've been reading raves about blurry stuff all along without realizing...

It's all right, I can handle it should this be the case...

EDIT: Just to clarify, this is not meant to take the mick. This could be a pretty profound turning point.

[RobertI]

6 minutes ago, iPeace said:

OK - so if scope 1 shows me specific blurry dots on a blurry background, while scope 2 cannot show me those specific dots at all, but the whole picture it does show is a lot sharper, then scope 1 has better ultimate performance?

Goodness, this could mean I've been reading raves about blurry stuff all along without realizing...

This could get interesting.....

[nightfisher]

6 minutes ago, iPeace said:

OK - so if scope 1 shows me specific blurry dots on a blurry background, while scope 2 cannot show me those specific dots at all, but the whole picture it does show is a lot sharper, then scope 1 has better ultimate performance?

Goodness, this could mean I've been reading raves about blurry stuff all along without realizing...

It's all right, I can handle it should this be the case...

What is best is always going to be subjective, to different people, for me i will always prefer to see Luna features in sharp contrasty detail, rather than being able to just about make out some difficult hard to see features

[Paz]

I agree with Stu that this kind of thing is not the same thing as what is aesthetically better and therefore might not tell you which scope is better for you but my question is just about understanding the scopes in a particular way. For what it's worth here's what I sometimes do...

To test detail I would pick one of the Maria and in each scope fish around for the smallest crater you can make out and then (1) see if you can see it in the other scope and (2) if you can then look for a smaller one and when you've found one then go back to the other scope until you hit a limit. (3) then find out the size of the smallest things you saw in each to find out their true angle. This would give a rough idea of power to resolve the detail available

Contrast is (for me) how dark are the dark bits and how sharp are the boundaries between bright bits and dark bits. My favourite targets for comparing this are mountain tops or crater edges at the terminator where they are detached from the moon and seemingly floating in space. How black is the blackness around them and how clean/tight or how flared and washed out is their shape. The next best targets for me are central peaks in craters when the crater floor is in shadow but the central peaks are lit up.

And the ultimate reason for the question is that personally I find that on the moon for me most of the time contrast beats detail when it comes to what image I find preferable.

That's a straight answer to the question but that's just my take, which is probably more nerdy than most.

[Stu]

13 minutes ago, iPeace said:

OK - so if scope 1 shows me specific blurry dots on a blurry background, while scope 2 cannot show me those specific dots at all, but the whole picture it does show is a lot sharper, then scope 1 has better ultimate performance?

Goodness, this could mean I've been reading raves about blurry stuff all along without realizing...

It's all right, I can handle it should this be the case...

EDIT: Just to clarify, this is not meant to take the mick. This could be a pretty profound turning point.

One way to answer this is to quote from a post I made recently.

'Krieger looked lovely, with smaller Van Biesbroeck embedded in it. I could see the even smaller Rocco next to it, but Ruth was not visible.'

See the attached image; in my Tak I could not see the crater Ruth, but in a larger scope the additional resolution might well have shown it, despite perhaps not being as aesthetically pleasing a view.

Contrast is an important factor. For instance Gavstar's 160mm TEC Fluorite has the most amazing contrast, and he managed to see 9 of the Plato craterlets whilst I believe John has 'only' managed 10 or 11 in his 12" scope which has higher resolution.

A scope may show you more, in a way you don't like as much! Give me the choice between an 8" SCT and my 4" Tak on Jupiter, and I'm quite likely to take the stable, beautifully presented muted colours in the Tak over the more vibrant and detailed, but ever changing, wobbly one minute, sharp the next views in the SCT. It's just what I prefer, others would take the SCT every time.

Any help?

[iPeace]

3 minutes ago, Paz said:

I agree with Stu that this kind of thing is not the same thing as what is aesthetically better and therefore might not tell you which scope is better for you but my question is just about understanding the scopes in a particular way. For what it's worth here's what I sometimes do...

To test detail I would pick one of the Maria and in each scope fish around for the smallest crater you can make out and then (1) see if you can see it in the other scope and (2) if you can then look for a smaller one and when you've found one then go back to the other scope until you hit a limit. (3) then find out the size of the smallest things you saw in each to find out their true angle. This would give a rough idea of power to resolve the detail available

Contrast is (for me) how dark are the dark bits and how sharp are the boundaries between bright bits and dark bits. My favourite targets for comparing this are mountain tops or crater edges at the terminator where they are detached from the moon and seemingly floating in space. How black is the blackness around them and how clean/tight or how flared and washed out is their shape. The next best targets for me are central peaks in craters when the crater floor is in shadow but the central peaks are lit up.

And the ultimate reason for the question is that personally I find that on the moon for me most of the time contrast beats detail when it comes to what image I find preferable.

That's a straight answer to the question but that's just my take, which is probably more nerdy than most.

That's an excellent answer. Thank you. I will strive to contribute in these terms in future installments.

[iPeace]

4 minutes ago, Stu said:

One way to answer this is to quote from a post I made recently.

'Krieger looked lovely, with smaller Van Biesbroeck embedded in it. I could see the even smaller Rocco next to it, but Ruth was not visible.'

See the attached image; in my Tak I could not see the crater Ruth, but in a larger scope the additional resolution might well have shown it, despite perhaps not being as aesthetically pleasing a view.

Contrast is an important factor. For instance Gavstar's 160mm TEC Fluorite has the most amazing contrast, and he managed to see 9 of the Plato craterlets whilst I believe John has 'only' managed 10 or 11 in his 12" scope which has higher resolution.

A scope may show you more, in a way you don't like as much! Give me the choice between an 8" SCT and my 4" Tak on Jupiter, and I'm quite likely to take the stable, beautifully presented muted colours in the Tak over the more vibrant and detailed, but ever changing, wobbly one minute, sharp the next views in the SCT. It's just what I prefer, others would take the SCT every time.

Any help?

Another excellent answer, thanks!

I can deal with this distinction.

DISCLAIMER - This might be a good moment to insert tongue into cheek...

It does indeed all suggest that when geezers rave about the level of "detail", it's time for me to politely yawn and glance at any timepiece I may have to hand.

All personal preference, of course. But still...with all possible respect, this could really mean that there's a lot of appreciation being shared for what to me is blurry stuff, in terms that suggest otherwise to my intuitive mind, such as it is.

Blurry stuff can be fun to track down and see - think fuzzies - so I do follow, to a point, I think. I'll get used to it.

Meanwhile, there's a subroutine running in my brain, writing the introductory chapters of What Astronomers Really Mean When They Talk Amongst Themselves.

By the way, if you, dear reader, prefer "detail" over "contrast", please don't take offence at this pitiful casual geezer's preference for HD shallowness. I've been spoiled by fracs; the road to redemption will be long and I may never make it.

[Stu]

22 hours ago, iPeace said:

Another excellent answer, thanks!

I can deal with this distinction.

DISCLAIMER - This might be a good moment to insert tongue into cheek...

It does indeed all suggest that when geezers rave about the level of "detail", it's time for me to politely yawn and glance at any timepiece I may have to hand.

All personal preference, of course. But still...with all possible respect, this could really mean that there's a lot of appreciation being shared for what to me is blurry stuff, in terms that suggest otherwise to my intuitive mind, such as it is.

Blurry stuff can be fun to track down and see - think fuzzies - so I do follow, to a point, I think. I'll get used to it.

Meanwhile, there's a subroutine running in my brain, writing the introductory chapters of What Astronomers Really Mean When They Talk Amongst Themselves.

By the way, if you, dear reader, prefer "detail" over "contrast", please don't take offence at this pitiful casual geezer's preference for HD shallowness. I've been spoiled by fracs; the road to redemption will be long and I may never make it.

I know there was a lot of tongue in cheek going on there, but don't dismiss other scope types. In many cases the detail seen will be very nicely presented, even if it is not a frac.

I think the views in a Newt may suit you better. Somehow SCTs have never quite hit the spot with me, I'm sure because stars tend to have a certain fuzziness around them rather than the razor sharp beauty of a frac. Once you get below a certain magnitude (where diffraction spikes don't show) the Newts can show very nice star shapes too.

Along similar lines to my previous post, larger SCTs can split tight double stars at high power, but to me the star shapes just aren't clean enough for it to be fun, even though the ultimate limit of the SCT may be higher.

[GavStar]

It does seem to be that individual preference is key here. For me, the sharp aesthetic views of a refractor can’t be beaten even if some of the details or light gathering ability is lost. But I can see for others that bigger aperture is better.

It’s good to hear that the tv85 is performing really well for you. I like my TV85 (it’s the first refractor and second scope I ever had). However, more and more, I think that 85mm is a bit small. The jump in planetary and lunar resolution that a 5 inch scope gives you is very obvious imo.

I think you would be very surprised how much more the scope in the link below shows you compared to the tv85.

http://apm-telescopes-englisch.shopgate.com/item/3336313838

 

[25585]

Ultimately it boils down to viewing pleasure based on expectation. Which optical combination of scope & ep gives you the most pleasing memorable image of what you want. 

How are your TV settings? Mine have more contrast, less brilliance, neutral colour, cool tone. I like HD detail, watch Blu Ray or upscale. But good SD is acceptable. Older movies & shows can be fine, the modern image processing TV can compensate for otherwise flawed visual quality, provided any area is not too magnified. 

Thus it is with visual astronomy. The subject, area, magnification and processing can vary, depending on equipment design and capability. Different tweaks and settings may be needed to level and compensate. Purely ocular - same ep &/or magnification & sky would not be enough. 

 

[jetstream]

The views through a large newt with top optics and in a good structure will leave the jaw dropped on the ground. I have viewed with obstructions up to 37% and had good luck and with predictable results. The 15" obstructed 21% gives "refractor" like views as far as contrast and detail is concerned ( a 12 incher that is) but there is coma smear to deal with at f4.8 in the outer field. I have heard there a few "gems" in the mass produced SCT's, Cass's etc and that superb views are had through the likes of Intes scopes.

All this said I am trying to buy a top name refractor for the views they give and other reasons. The SW120ED performs very well and the APM GavStar mentions should be better again.

iPeace, from the sounds of things maybe a different scope might meet your expectations, whether they are obstructed or not. Seeing and thermals ( scope,roof tops, ground etc) play a major role in scope selection IMHO.

[iPeace]

Fourth Light

Hot on the heels of some very interesting thoughts, out comes the Moon and I can confirm that we're fully grab-and-go. Both scopes were up quickly, and my first look through the Mak told me this was going to be a better session. I did try a summary collimation check on a star - nothing immediately obviously out of order, but this will take some practice. The view of Luna did set my mind fully at ease - there can be nothing inherently wrong with this Mak; it was already having a much better night.

The most interesting and dramatic view was of the region from Langrenus down to Furnerius, so that's where we spent most of our time. I started the Mak at last session's sweet spot, 164x (ish) with the 11mm Nagler, while Stanley still had the 3.5mm Nagler in the diagonal for 171x from last time out. We had a good couple of hours with conditions that must have been quite a bit better than last time; I was pushing the Mak to 200x and 257x in short order, with Stanley keeping pace at 200x and 240x. We finally went up to 300x in both scopes, just to see, and this time, the Mak made it all the way up without any head-scratching on my part. This was so much more like it!

General Impression

I maintain my impression of the most immediately obvious difference between the views: colour. Yes, I know, the Moon has none, but still the Mak shows the light stuff as a tad whiter than does the TV-85. I'm also still inclined to express the difference as the Mak giving a more 'open' view - seems appropriate in light of its larger exit pupil. But tonight the question of "best" was finally the close-run thing that I was hoping for and had dared to expect. Yes, the frac was more "crisp", but the Mak had fewer floaters dancing around at 200x and up. The frac was more consistently sharp while the Mak was riding the surf, but whenever the Mak was at the sweet spot, it was very impressive indeed for those few moments.

Contrast

Here's where it gets challenging for me to describe the perceived differences between scopes. My overriding impression is that while both show very distinct differences between light and dark, and both show the edges between light and dark as well-defined, the TV-85 shows the edges a bit sharper. In the Mak, the light bits are lighter and in the frac, the dark bits are darker. I'm hard pressed to express a preference based only on contrast; I think the frac's more stable image gives the impression of higher contrast while this may not be entirely so.

Detail

Although I may have disqualified myself from commenting on this , I did make a conscious effort to discern between what was actually "there" in either scope. And this is not easy to do. First off, if there's as much to see as there was tonight, I tend to get lost in the grandeur of it all, overwhelmed by all the features so beautifully displayed, and quickly give up trying to put names to stuff. But this is a good thing too, and both scopes were doing it for me. I would spend a few moments counting pinhole craters and wrinkles adjacent to the larger features, then switch over to see if they were still there; I finally concluded that there was nothing I could see through the one that I could not see through the other - but the TV-85's more steady picture made it easier to find and recognize individual bits. They were there in the Mak, too - just fading in and out. Tube currents? I don't know. I think the view through the Mak may have been improving slightly towards the end of the session, but it's hard to be sure.

Sooooo....

...so, so, sooooo much better than last time, this has redeemed my expectations of what a 'Big Mak' should be able to do. In fact, I'm inclined to think it can do even better - on even better nights, or perhaps in better surroundings - and we'll be trying that, even though the Mak is not really meant to go on the road. We're far from done here, so no time for decisions, but it did occur to me that I may well want to keep a Mak around - only not sure which - visions of a Mak 180 on the mount opposite the Mak 150 to see which one stays. In any case, I'm confident I have a good one and I really like using it; I may even have gotten a glimpse of what the Big Mak Fans like to rave about.

Then again, another candidate for Big Lunar Scope should soon be on its way...