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  #61  
Old 28-05-2010, 05:00 PM
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Starkler (Geoff)
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Originally Posted by sjastro View Post
Anyone care to place a bet.

The brightness of the sky background is related to the exit pupil not the aperture. The larger the exit pupil the brighter the background.
Agreed and this is exactly why I pipe up when people say big scopes are useless in light polluted places, and better off with a small one.

I say rubbish!

Whilst sky background brightness is a constant vs exit pupil, greater aperture allows the collection of more light from wanted targets allowing presentation at a visual size at which they may be visible.

Light pollution makes small scopes particularly useless in comparison to large ones.

Greater aperture = smaller fov per exit pupil and bigger target!
Less noise, more object!

By the way, I think planetary nebs are a fair dso target for the light pollution affected observer as most are best at high magnifications.
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  #62  
Old 28-05-2010, 05:36 PM
ausastronomer (John Bambury)
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Anyone care to place a bet.
Regards

Steven
Hi Steven,

I am almost prepared to place a bet that you are an engineer of some description? Further, that your discipline is in a field of engineering other than optics ? Actually, I am picking a mechanical or civil engineer. How close did I get ?

Cheers,
John B
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  #63  
Old 28-05-2010, 06:12 PM
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Hi Steven,

I am almost prepared to place a bet that you are an engineer of some description? Further, that your discipline is in a field of engineering other than optics ? Actually, I am picking a mechanical or civil engineer. How close did I get ?

Cheers,
John B
Hello John,

I'm a scientist (applied mathematician) currently on hiatus (probably explains all the bad weather).

Most of my employment has been based on working closely with engineers.

Regards

Steven
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  #64  
Old 28-05-2010, 06:50 PM
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Originally Posted by astroron View Post
YOU KNOW WHAT I MEAN
I DID NOT MEAN AT THE SAME TIME AS YOU ARE IMAGING
Ron I always have two scopes setup, one controlled by computer auto routines snapping pics and a second for visual obs. Problem is where I live a combination of LP and heavy particulates (8km from CBD 100m from the freeway) washout and scatter the light from the universe so much that I can rarely see very much at all, even when the moon is not about. I envy you and your clean dark skies but until I retire this will not be possible for me. I agree that getting all the bits and pieces for long exposure AP can at times be tiresome, but most folks seem to have no such problem with video cameras like the Gstar as they have nowhere near the requirements of long exposure AP. I am not sure why visual astronomers are so adament that people who take pics are not the real deal, especially those who are reduced to narrowband images to see anything worthwhile due to the rotten skies they live under. Without these bits and pieces many of us would just find something else to do as starring at the LP and smog domes that encapsulate most cities offers little for an active and enquiring mind.

Mark
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  #65  
Old 28-05-2010, 07:14 PM
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The Ring Nebula will take as much magnification as you want, I've found.

Video observing is the way to go if your eyesight isn't the best, no squinting through an ep.

You only need a small aperture scope on a goto alt azi mount, a comfy chair and some form of analog display, either a tv or a laptop.
If you feel like taking an image, just click on the capture button.
Tooooo easy.
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  #66  
Old 28-05-2010, 08:15 PM
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Originally Posted by marki View Post
Ron I always have two scopes setup, one controlled by computer auto routines snapping pics and a second for visual obs. Problem is where I live a combination of LP and heavy particulates (8km from CBD 100m from the freeway) washout and scatter the light from the universe so much that I can rarely see very much at all, even when the moon is not about. I envy you and your clean dark skies but until I retire this will not be possible for me. I agree that getting all the bits and pieces for long exposure AP can at times be tiresome, but most folks seem to have no such problem with video cameras like the Gstar as they have nowhere near the requirements of long exposure AP. I am not sure why visual astronomers are so adament that people who take pics are not the real deal, especially those who are reduced to narrowband images to see anything worthwhile due to the rotten skies they live under. Without these bits and pieces many of us would just find something else to do as starring at the LP and smog domes that encapsulate most cities offers little for an active and enquiring mind.

Mark
I agree with so much of what you say here Mark. It was just a revelation for me how much I could do with a pollution filter and DSLR from the backyard.

However, me thinks Ron is also having a bit of a lend of us here - I know damn well he used to do quite a bit of film astroP in days gone by
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  #67  
Old 28-05-2010, 10:17 PM
ausastronomer (John Bambury)
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Originally Posted by sjastro View Post
Hello John,

I'm a scientist (applied mathematician) currently on hiatus (probably explains all the bad weather).

Most of my employment has been based on working closely with engineers.

Regards

Steven
Wasn't far out was I

Cheers,
John B
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  #68  
Old 29-05-2010, 08:43 AM
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Wasn't far out was I

Cheers,
John B
Unfortunately as a scientist working with engineers meant being portrayed as mad as in the Dr Frankenstein mould.........

Regards

Steven
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  #69  
Old 29-05-2010, 09:08 AM
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Unfortunately as a scientist working with engineers meant being portrayed as mad as in the Dr Frankenstein mould.........

Regards

Steven
Your Avatar gives some support to the myth
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  #70  
Old 29-05-2010, 10:45 AM
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Quote:
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Unfortunately as a scientist working with engineers meant being portrayed as mad as in the Dr Frankenstein mould.........

Regards

Steven
I'm afraid I have the dibs on that one...I've been called a mad scientist ever since I was a small kid
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  #71  
Old 29-05-2010, 03:04 PM
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Whooaah! This thread certainly has been busy in the last 24 hours. You guys were doing my head in with the dark side! I see the light by the way, and I'm walking towards it... What I can't see, I'll imagine, or Google (or Look at Rob's pics, I seem to be stalking his web page regularly!). Thankyou for your views from the dark side though.. but I have much to learn, and I want to maintain visual astronomy. You'll do raise a very good point with being able to see so much more in suburbia. But, I just love the rush I get hugging my dob with my eye jammed into an eye piece feeling like I've just put my head into the window of space, nothing around me except for the pure darkness and wonders of space between my eye and eyepiece. And then whilst your being mesmerised at the wonders and endlessness of space, amongst the eerie strange noises coming from the bushes in the wee hours of the morning, a shooting star with immense speed blazes a trail straight across your eyepiece, and it makes you jump back and you realise how much more aware you are of every sound, as Earth seems so far away...

As for the filters, thank you all for your input. Gosh what an entertaining debate that turned out to be.

And poor Ron copped it by defending visual astronomy- and didn't that turn out into another debate. Sorry Ron!

And then the Planetary Nebs.. Thankyou all for your input. I'm excited that I have a list of what appears to be achievable thru my scope. If only the bad weather would buzz off. I bought a Vixen LVW, and there it has sat for the last week and all I can do is look at it and hold it. My Pentax XW has only seen one good run and I got that a month ago. *Sigh* (we need a "sigh" emoticon!) I think a lot of us here have been buying too much lately, judging by the busy for sale forum here! Stop buying everyone, so the weather can clear!
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  #72  
Old 29-05-2010, 03:24 PM
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Visual vs Imaging .....
To each their own I reckon.
We all started by looking through an eye piece.

So it was YOU that bought the rain this weekend. Bad girl.
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  #73  
Old 29-05-2010, 04:01 PM
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You can still observe visually using a GStar...just that you don't look through an eyepiece, but on a monitor

However, you have the luxury of running off some happy snaps if and when you like, without having to fiddle about putting a camera into your focuser It's already there

But it is nice to look through an eyepiece
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  #74  
Old 29-05-2010, 04:12 PM
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Originally Posted by renormalised View Post
You can still observe visually using a GStar...just that you don't look through an eyepiece, but on a monitor

However, you have the luxury of running off some happy snaps if and when you like, without having to fiddle about putting a camera into your focuser It's already there

But it is nice to look through an eyepiece
Sit inside watch the Tely, go outside put a camera onto your Tely scope
and watch the Tely
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  #75  
Old 29-05-2010, 04:55 PM
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Originally Posted by jjjnettie View Post
Visual vs Imaging .....
To each their own I reckon.
We all started by looking through an eye piece.

So it was YOU that bought the rain this weekend. Bad girl.
Sorry for the bias but imaging wins hand down.

Here is an image of the planetary Bran A/B which is beyond visual
detection as its surface brightness is fainter than the sky glow from the darkest sites.

http://users.westconnect.com.au/~sjastro/bran147c.html

Regards

Steven
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  #76  
Old 29-05-2010, 05:24 PM
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Originally Posted by astroron View Post
Sit inside watch the Tely, go outside put a camera onto your Tely scope
and watch the Tely
Bah Humbug!!!!
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  #77  
Old 29-05-2010, 05:52 PM
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astroron (Ron)
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Originally Posted by sjastro View Post
Sorry for the bias but imaging wins hand down.

Here is an image of the planetary Bran A/B which is beyond visual
detection as its surface brightness is fainter than the sky glow from the darkest sites.

http://users.westconnect.com.au/~sjastro/bran147c.html

Regards

Steven
Two orange splogges in between a lot of white dots
All as it's made you is a image processor, you never saw it either
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  #78  
Old 29-05-2010, 06:06 PM
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Originally Posted by astroron View Post
Two orange splogges in between a lot of white dots
All as it's made you is a image processor, you never saw it either
Good one Ron. Uhmmm... Sorry Steven, but that was a good comeback.
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  #79  
Old 29-05-2010, 06:15 PM
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Sorry for the bias but imaging wins hand down.


Regards

Steven
Oh, you don't have to convince me Steven.
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  #80  
Old 29-05-2010, 06:20 PM
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Originally Posted by astroron View Post
Two orange splogges in between a lot of white dots
All as it's made you is a image processor, you never saw it either
And there lies the greater satisfaction of imaging and processing over observing, in being able to confirm the existence of an object that visually isn't there.

Regards

Steven
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