90x Per Inch!!...How?

[andrew s]

2 hours ago, John said:

I was just being honest Andrew - hope that is OK ?

Never doubted by me. Regards Andrew 

[jetstream]

2 hours ago, Stu said:

So, I think reporting failures should be encouraged

I got one,well many. I can easily see Barnards Loop, the Witch Head, Pleiades Bubble complex and traces of IFN etc. What I can't confirm is the Erdidanus Loop and I've tried many many times. I'm hoping for the 24" to show me hope on this one. I should be able to see it.

Oh yeah, then there is Einsteins Cross... and...

 

[paulastro]

2 hours ago, mikeDnight said:

I feel I've caught glimpses of the Pup in fleeting moments of good seeing, but then I really can't be certain. I've never been able to pinpoint it with any degree of certainty as the image never stops dancing all over the place, plus observing Sirius with prior knowledge of the Pup's position and distance from the primary has the potential for biasing my observation. Sirius always seems to be in a turbulent atmosphere from my site, so I'm seriously hindered by that. I may never see it for absolute certainty. It's a tough life!

Another location?

Bigger telescope?

(Tak of course Mike 🤗)

Edited August 18, 2020 by paulastro

[mikeDnight]

Just came in after a 500X viewing of Zeta Hercules (1.6mm HR),  a superb view of M92 at 235X (3.4mm HR),  and a spectacular view of M57 with its northern edge ablaze with brilliant nebulosity, and lets not forget the 13.2 magnitude star close to its following periphery - again 235X and 3.4mm HR.  But believe it or not and try as I might, I didn't glimpse the central star despite the Kryptonite lens of my 100mm frac. 😟

[vlaiv]

12 hours ago, John said:

Honest opinion needed here Stu:

- Do you think I was imagining splitting Zeta Herc when I first reported it with my ED120 back in 2013 when the pair were closer ?

- Do my frequent reports of splitting Sirus with my 12 inch dob and my 130mm refractor seem plausible ?

I'm starting to doubt my observations currently

 

As far as I understand, neither of these two statements should be called into question with respect to talk about resolving power of the optics.

Zeta Herculis had angular separation of about 1.3" back in 2013, right? Dawes limit is 4.56/D which for 120mm scope translates to 0.9652" angular separation. Rayleigh criteria places that at ~1.07" for light at 510nm. Both are smaller than said 1.3".

Sirius is 3" at smallest separation if I'm not mistaken (11" at largest) - again this is not related to resolution but rather to difference in magnitude and scattering of light.

Vallis Alpes and Saturn rings represent something else and again are not related to resolving power of telescope. These are linear features and similarly to single stars - continue to show regardless of resolution loss imposed by aperture - they just end up having less contrast in smaller apertures (to the point of blending in with surroundings).

 

 

Edited August 19, 2020 by vlaiv
For some reason there was a graph ...

[chiltonstar]

What an interesting and informative thread this is!

Maybe the only definitive way to consider this issue of whether expensive refractors can "beat the laws of physics" would be from images of bright, close (eg 1 arcsec), similar magnitude double stars with different scopes, or maybe using an artificial star pair? This would remove the human subjectivity factor. I agree with @vlaiv above that linear features are something else, doubles are a better test.

Chris

 

[vlaiv]

46 minutes ago, chiltonstar said:

What an interesting and informative thread this is!

Maybe the only definitive way to consider this issue of whether expensive refractors can "beat the laws of physics" would be from images of bright, close (eg 1 arcsec), similar magnitude double stars with different scopes, or maybe using an artificial star pair? This would remove the human subjectivity factor. I agree with @vlaiv above that linear features are something else, doubles are a better test.

Chris

 

Either doubles or if one wants different type of feature, we could take two small craters on the Moon next to each other to be resolved as two features or maybe two mountain peaks - what ever needs to be actually resolved - or determined there are two things.

Problem with artificial stars is to make one that has proper separation. Two artificial stars that are 1" apart need to be ~0.4mm at a distance of 100m. For longer distances we probably need stronger light sources and for closer distances we have issue with separation.

Most telescopes also need barlow for camera to properly sample so one might always argue that we are not measuring optics itself and that barlow somehow "impeded" perfect optics.

Another obstacle that we need to consider is sharpening of photographic results. Any sharpening that we often do in planetary imaging is effectively giving us better resolution than the scope is capable of.

By sharpening, we are effectively restoring resolution that has been lost in area I marked in above graph. We can't sharpen past highest frequency as these are effectively cut off - zero so no way we can determine what they were before, but for any non zero value - we can restore it to some extent.

[chiltonstar]

2 hours ago, vlaiv said:

Either doubles or if one wants different type of feature, we could take two small craters on the Moon next to each other to be resolved as two features or maybe two mountain peaks - what ever needs to be actually resolved - or determined there are two things.

 

 

I've used 36 And in the past:-

36 And

And

74359

00 54 58 +23 37 42

STF 73 AB

2018

733

334

1.20

6.12

6.54

0.42

Y

Chris

[jetstream]

20 hours ago, John said:

Honest opinion needed here Stu:

- Do you think I was imagining splitting Zeta Herc when I first reported it with my ED120 back in 2013 when the pair were closer ?

- Do my frequent reports of splitting Sirus with my 12 inch dob and my 130mm refractor seem plausible ?

I'm starting to doubt my observations currently

 

Why the self doubt John?

Personally I report what I see nothing more nothing less and could care less if people doubt it.

Edited August 19, 2020 by jetstream

[mikeDnight]

9 hours ago, chiltonstar said:

What an interesting and informative thread this is!

Maybe the only definitive way to consider this issue of whether expensive refractors can "beat the laws of physics" would be from images of bright, close (eg 1 arcsec), similar magnitude double stars with different scopes, or maybe using an artificial star pair? This would remove the human subjectivity factor. I agree with @vlaiv above that linear features are something else, doubles are a better test.

Chris

 

The trouble with that is that its about the human eye and how it sees the detail. Camera's can't answer that, because how the eye and brain sees and distinguishes detail isn't the same as how a camera and computer records detail.  When I've compared images of Jupiter and Mars with visual sketches I've made at the eyepiece, although the features are in the same position, the detail I visually recorded was at a different level of subtlety. With Mars, where I see dark albedo features, I also see the subtlest hints of mists and clouds that are rarely ever shown in an image. It's as if the camera sees at a different level of intensity and isn't as sensitive to the subtleties of detail. What's seen by a camera isn't what's seen by the eye/brain.

[chiltonstar]

46 minutes ago, mikeDnight said:

The trouble with that is that its about the human eye and how it sees the detail. Camera's can't answer that, because how the eye and brain sees and distinguishes detail isn't the same as how a camera and computer records detail.  When I've compared images of Jupiter and Mars with visual sketches I've made at the eyepiece, although the features are in the same position, the detail I visually recorded was at a different level of subtlety. With Mars, where I see dark albedo features, I also see the subtlest hints of mists and clouds that are rarely ever shown in an image. It's as if the camera sees at a different level of intensity and isn't as sensitive to the subtleties of detail. What's seen by a camera isn't what's seen by the eye/brain.

But surely Mike, the camera never lies....

Chris

[jetstream]

7 minutes ago, chiltonstar said:

But surely Mike, the camera never lies....

Chris

The camera might not but the processing might embellish a squeak😀

[chiltonstar]

2 minutes ago, jetstream said:

The camera might not but the processing might embellish a squeak😀

Just as the brain does.... at least sharpening is only recovering information that is actually there?

Chris

[jetstream]

15 minutes ago, chiltonstar said:

Just as the brain does.... at least sharpening is only recovering information that is actually there?

Chris

How about this- I'll observe a nebula for 3 seconds and then we'll compare notes from a 3 second camera exposure?😀 Maybe the Pleiades bubble using my H130?

ps no processing...

Edited August 19, 2020 by jetstream
no processing

[mikeDnight]

27 minutes ago, chiltonstar said:

But surely Mike, the camera never lies....

Chris

I used to believe that too Chris. However, when I think back at how my girlfriend of 40 years ago (now my wife), idolized my stunning good looks and Greek god like physique; then I compare the once reality with the Kodak instamatic photo's of that era, I'll never trust a camera again. 

[chiltonstar]

I'm thinking of witness statements describing an event, which may differ a lot - why the Court tends to believe the CCTV footage...

Chris

[Stu]

11 minutes ago, chiltonstar said:

I'm thinking of witness statements describing an event, which may differ a lot - why the Court tends to believe the CCTV footage...

Chris

The camera never lies eh? 😉

Trouble is, I’ve always found high Mag views of double stars very tricky to image, and the visual view has always been better, with tighter cleaner stars. I’m sure there are techniques to be used to counter this, by proper imagers!

[scarp15]

23 hours ago, Stu said:

So, I think reporting failures should be encouraged as it does then increase knowledge of what works and doesn’t work, and lends credibility to successful reports if that makes sense?

Definitely, failure or uncertainty is reasoning for enlightened further investigation; i.e. on here. My own experiences, with all optimum factors, the capacity for visual integrity becomes boundless. I am not a dedicated star splitter, concerning deep sky, probably grasping the Little Veil complex in Cygnus is my own boundary. Such as Gerry had mentioned, gradually having learnt to visually understand considered threshold subjects, such as The Horse Head and an extended proportion of Barnard's Loop, that in the right conditions pose no uncertainty.