Good versus bad seeing?

[Macavity]

Hmmm... Sadly my attempts to make better images of "Barlowing  
my Lunt50" did not end well! The most obvious symptom was a big
drop in Registax "good" frames from the usual >50% to 10%!

I would LIKE to attribute this to "Bad Seeing" (not something else
wrong)! Just intrigued what others might make of the video data?
Can you SEE the difference (a/b) Do you agree with my claim for:

(a) "Good" Seeing - Wednesday p.m.)
https://www.youtube.com/watch?v=3-tAJkEYegA

(b) "Bad" Seeing - Thursday p.m. - Today!)
https://www.youtube.com/watch?v=ZBEvTk8F3UI

If it's not "Bad Seeing", I may have to start worrying a bit more! 

 

[laudropb]

Sorry can only view your good seeing video. It says the other is private.

[Macavity]

Thanks! Almost inevitable? Hopefully fixed now...

[laudropb]

I think it is down to bad seeing. I have never seen the seeing deteriorate so quickly as it did today. Early morning was good, but by about 10 it was pretty bad.

[Macavity]

Well, that would be comforting. [irony]

I must admit it was a "first" for me? It was indeed quite dramatic. 
Eventually I decided to postpone my activities pending investigation!

I think they did say the jet stream was on the move for the end of the week?

[Iainp]

Hi Chris, yes a good assessment of the conditions I would say! Seeing here (Cambridgeshire) was ok at 8.00am, and just awful later in the afternoon.  

Iain 

[michael.h.f.wilkinson]

Seeing really affects the results, and will affect Barlowed images more due to increased magnification. I rarely use more than 10% of frames in H-alpha, I should add.

[Pete Presland]

To be honest I think I have imaged in far worse than that, but that is not saying it is good seeing.  I also only use around 10-15% of my data to stack.

[Davey-T]

Really annoying when you some nice blue sky and rubbish seeing and conversely little blue holes in the cloud and good seeing.

Late afternoon when the Sun has warmed all the roof tops it looks like a mirage shimmering on the screen

I recently chucked a load of AVI's in AS2 and had it set to use 100% instead of 10%, after 60mins I got a load of rubbish and had to start again 

I usually use the Quark with .5X f/r as the seeing is rarely good enough to use it without. 

Dave

[Macavity]

Hmmm. A concensus seems to be emerging. Something "fairly" dramatic
happened (early yesterday) re. the seeing. Default Registax "acceptance" 
does seem to provided a useful TEST of likely success (If my eyes fail!)

Yes, the key to this is more data / funding! Do I Sound like Brian Cox?
But I think it is generally TRUE. My trusty Samsung NC Notebooks yield
a creditable *eighteen*  fps but limit me to the role of mere dabbler...

Levity aside, a new Laptop for this (and "planetary") would be useful!

Having someone / thing to blame is essential - I propose:
http://www.metcheck.com/UK/jetstream.asp
Sadly, these sites delete previous data.
It's all a CONSPIRACY etc. etc. 

P.S. Genuine question to the 10-15 perecenters... Of WHAT? <grin>
Seriously, what *total* frames would one use for typical H-Alpha?

[Davey-T]

I sometimes run the vid's through PIPP first to cull the worst frames before putting through AS2, convinced myself that this gave better results  but probably deluding myself 

Dave

[Iainp]

24 minutes ago, Macavity said:

My trusty Samsung NC Notebooks yield
a creditable *eighteen*  fps

Hi Chris, is this with full frame recording or with a cropped area? My laptop limits me to 8 fps using the whole sensor but selecting a smaller Region Of Interest means I can easily get 40 fps, and selecting an even smaller area gives thousands of frames in a minute or two.

Iain 

[Macavity]

44 minutes ago, Iainp said:

Hi Chris, is this with full frame recording or with a cropped area? My laptop limits me to 8 fps using the whole sensor but selecting a smaller Region Of Interest means I can easily get 40 fps, and selecting an even smaller area gives thousands of frames in a minute or two. 

Almost a topic in itself? I do enjoy appreciate these free-form discussions!

I think it well worth considering Region of Interest! Indeed, I am certain that
I have not explored all the possibilities therein. For most of us, it's finding the
the time for a bit of creative thought? "So many ideas, so little time"? lol.

FWIW, I sense I WILL buy a newer (more capable) Laptop with USB3 at
some stage (soon-ish). I think I may just about internally justify that?
And then, I would love a little more "camera chip real-estate" etc. etc...

To quote Davey-T:

Quote

Defo get a wedge - Defo worth the money, you can't take it with you...
and you don't want to be financing a big expensive wake for all the
relly's when your dead.

TRUE indeed. But Defo ignore this person! A BAD influence? lol.
(Ironically, I did recently take out a fair-sized funeral insurance...)
"Die Young - Stay Pretty. Live fast, 'cos it won't last" (Debbie Harry)

[Iainp]

Great, do give it a go! I use Fire Capture, and on a PC  you just hold down Shift while Left Clicking, then drag a box to the size you want.  I'm told it's the vertical dimension which slows things down more than the horizontal dimension. In other words a  rectangle  with a long horizontal and short vertical will give a faster frame rate than a shorter horizontal and longer vertical

Iain 

[Davey-T]

You don't need a brand new all singing and dancing laptop, there are loads of good once on a well known auction site for a couple of hundred pounds with Win7, probably a bonus to avoid Win10 

One thing that does make a lappy fly is an SSD  but this can generally be fitted afterwards.

Dave

[Peter Drew]

From a visual experience I can confirm that at least here, the seeing conditions were awful at 10am on Thursday compared to the previous day. My minimum magnification for Ha these days is 150x as I like the high res views, if the seeing is not up to it, too bad!   

[paulastro]

I was out early on Thursday, and the seeing was not too bad early on.  It soon started to go downhill however and I packed up about 8ish I think.  Experience has taught me that there is usually no point in trying later as if it changes it nearly always gets worse.  Some late evenings can be ok, but not so often or as reliable as the early mornings.  Of course it's not necessarily only the fact the seeing itself is changing  -  seeing will also be affected by topography and buildings in the line of site as the sun moves around the sky. Hence, some sites are better at different times of day.