What do you think is the best scope in the world under 20 inches at the moment? - Page 2

Kunama · #21 02-06-2015, 06:21 PM

My guess is that it is cloudy again in Sydney .............

@ Rene, being new to the forum you may not be aware that these threads sometimes come up, usually on cloudy days or at times when one's imaging gear is being serviced. In this case the OP is a seasoned astrophotographer who produces a string of nice images but sometimes gets bored and throws in some bait for conversation/entertainment.

It is a bit like asking how much water is in a lake, without specifying which lake, which season or like how long is a piece of string.

In this instance the only correct answer is actually " an 18" dob "

Slawomir (Suavi) · #22 02-06-2015, 06:24 PM

Quote:

Originally Posted by Paul Haese

BTW a 4" scope would not qualify as the best scope under my criteria and many others I'll warrant. It might be a good work horse if it got worked.

But a 4" fluorite scope could possibly make "the best" guidescope...

EDIT: It might be impossible to identify the best telescope for astrophotography, but I can tell you that Orion ED80TCF is one of the worst ones...that have a glass lens of course.

Bassnut (Fred) · #23 02-06-2015, 06:31 PM

You know, as you get older, certain truths emerge. Myths, hype, commercial BS subsides and crystal clarity finally smacks you in the face. Its a bit like with cars, in the end, the only things that really count, are Horsepower and a monster Subby in the back. life is for living. For DS Astrophotography anyway, aperture counts, astronomy is about zooming in, after that its a just a matter of time over money. Enough of tiny refractors and high quality wide fields. How many times can you image the same top 10 big objects?, boring, narrow field rules

. The best scope is the largest aperture you can afford balanced with the amount of time you are willing to spend on processing to cover the lack of money you spent on the scope

.

Paul Haese · #24 02-06-2015, 06:35 PM

Quote:

Originally Posted by Slawomir

But a 4" fluorite scope could possibly make "the best" guidescope...

OAG only

. Though for some it might well be a good guide scope.

; expensive but good.

Don't get me wrong I have two Taks and I like both of them, but they are not in the best scope category for me. Good work horses though.

Paul Haese · #25 02-06-2015, 06:39 PM

Quote:

Originally Posted by Bassnut

You know, as you get older, certain truths emerge. Myths, hype, commercial BS subsides and crystal clarity finally smacks you in the face. Its a bit like with cars, in the end, the only things that really count, are Horsepower and a monster Subby in the back. life is for living. For DS Astrophotography anyway, aperture counts, astronomy is about zooming in, after that its a just a matter of time over money. Enough of tiny refractors and high quality wide fields. How many times can you image the same top 10 big objects?, boring, narrow field rules

. The best scope is the largest aperture you can afford balanced with the amount of time you are willing to spend on processing to cover the lack of money you spent on the scope

.

That's why I have two systems Fred. Best of both worlds. Besides as you well know there are more than 10 fields to image Freddo. Quite a few in LMC just for instance.

If you do enough hours on things then you can stretch it out with the wide field stuff.

Bassnut (Fred) · #26 02-06-2015, 07:13 PM

Thats pretty lame, best of both worlds?, whats best about the other one?.
With a woozy enough refractor, you can do the LMC in one go, what then?.

"If you do enough hours on things then you can stretch it out with the wide field stuff". What does that mean?. Stretch (crop) out the wide field shot to look like fake bad NF?. Or once you see something you like on the WF shot, do it again in NF?, why bother?.

gregbradley · #27 02-06-2015, 07:18 PM

I don't know Fred. Consider this. Do you achieve a narrow field of view only with long focal length? Or can you also achieve the same with a wider scope and a small chip effectively giving you a digital zoom.

With the excellent Sony sensors (I know you like QE and these have the highest short of the KAF3200ME) you can get quite a narrow field of view that can come up to the longer focal length scopes of the same aperture.

That's making 2 scopes out of one.

Your 10 inch RCOS with the way smaller ICX694 sensor would get twice the QE in O111 you are getting now and would be super narrow field of view.

Greg.

Paul Haese · #28 02-06-2015, 07:33 PM

Quote:

Originally Posted by Bassnut

Thats pretty lame, best of both worlds?, whats best about the other one?.
With a woozy enough refractor, you can do the LMC in one go, what then?.

"If you do enough hours on things then you can stretch it out with the wide field stuff". What does that mean?. Stretch (crop) out the wide field shot to look like fake bad NF?. Or once you see something you like on the WF shot, do it again in NF?, why bother?.

LOL Fred, I think it is time we had another AAIC to run amok at.

Bassnut (Fred) · #29 02-06-2015, 07:37 PM

The ICX694 sensor has a well depth of 13,000 over 100,000 for the 6303!. I cant even be bothered thinking of the implications of that, its a joke!.

Paul Haese · #30 02-06-2015, 07:40 PM

Quote:

Originally Posted by Bassnut

The ICX694 sensor has a well depth of 13,000 over 100,000 for the 6303!. I cant even be bothered thinking of the implications of that, its a joke!.

Not to mention the over sampling either. Shudder to think.

gregbradley · #31 03-06-2015, 07:44 AM

Quote:

Originally Posted by Bassnut

The ICX694 sensor has a well depth of 13,000 over 100,000 for the 6303!. I cant even be bothered thinking of the implications of that, its a joke!.

Its 20,000. C'mon Fred I thought you were hard core!

The KAF8300 has 25.5K and is producing some of the best images around. How do deep wells help with narrowband anyway as they are typically easy on the saturation of wells. 20,000 would be plenty for most images bar a couple. 40,000 would be heap. 100,000 is a luxury admittedly. I do like the 105,000 wells of the 16803. Its the horrid LRGB image that can cause an issue?

Greg.

gregbradley · #32 03-06-2015, 07:48 AM

Quote:

Originally Posted by Paul Haese

Not to mention the over sampling either. Shudder to think.

It depends on what point you consider oversampling is occurring. Per Stan Moore that would be .5arc secs which his rig is not far from under good seeing.

The only problem with oversampling is a loss of sensitivity nothing else. Its already 77%QE so perhaps it goes down to 65% - still more sensitive than anything else and only 4-5 electrons read noise versus 15 of the 6303.

Greg.

PRejto (Peter) · #33 03-06-2015, 09:06 AM

Quote:

Originally Posted by Paul Haese

LOL Fred, I think it is time we had another AAIC to run amok at.

Here here! Is anything happening on that front? If not I think a group of us ought to get together and plan something. Any takers?

Peter

glend (Glen) · #34 03-06-2015, 09:49 AM

What is AAIC for those of us who are not in the 'in crowd'?

N1 (Mirko) · #35 03-06-2015, 09:59 AM

Quote:

Originally Posted by glend

What is AAIC for those of us who are not in the 'in crowd'?

AAIC is what happens when the focus of the hobby has completed its shift from the sky to the ground.

Shiraz (Ray) · #36 03-06-2015, 10:02 AM

Quote:

Originally Posted by N1

AAIC is what happens when the focus of the hobby has completed its shift from the sky to the gound.

strongmanmike (Michael) · #37 03-06-2015, 10:25 AM

Quote:

Originally Posted by N1

AAIC is what happens when the focus of the hobby has completed its shift from the sky to the ground.

Well, yes, I love Fred to death

..... buuuut at SPSP I can reliably report to the astronomical community that his general knowledge of the sky was indeed extremely lacking

...but luckily for him my impromptu and extensive sky tours went down well with him I think, he actually seemed very interested and even a bit excited, even when I showed him those dreaded things called star clusters

Mike

rmuhlack (Richard) · #38 03-06-2015, 10:34 AM

Quote:

Originally Posted by glend

What is AAIC for those of us who are not in the 'in crowd'?

Australian Astro Imaging Conference

Bassnut (Fred) · #39 03-06-2015, 10:47 AM

Quote:

Originally Posted by strongmanmike

Well, yes, I love Fred to death

..... buuuut at SPSP I can reliably report to the astronomical community that his general knowledge of the sky was indeed extremely lacking

...but luckily for him my impromptu and extensive sky tours went down well with him I think, he actually seemed very interested and even a bit excited, even when I showed him those dreaded things called star clusters

Mike

Yes, I must say your tour was an eye opener and most excellent Mike.

strongmanmike (Michael) · #40 03-06-2015, 10:57 AM

Quote:

Originally Posted by Bassnut

Yes, I must say your tour was an eye opener and most excellent Mike.

It was great mate, first time I had a scope at SPSP since 2005 so I loved it

I was really happy with how the scope performed too, so easy to setup and get going and use and 12" shows plenty under a truly dark sky too.

Mike