AS!2 Drizzle Comparison.

[neil phillips]

It saves automatically in a separate folder within the source folder Rob.

re my "bucking".. i will still stick my head out and say the original is the better image but as I said in the post I'd tweak the wavelets- to me it does appear a bit strong and as Neil has suggested it needs to be somewhere between the two. I feel that the softer larger image benefits from simply being larger and people like large, we all do, but I do feel it has gone too soft and detail has been lost so the Q one has to ask oneself is -what is the reason behind the upscale ? since clearly trying to kill the grain induced from noise has had a detrimental effect on the information.

Yes I'd agree that put one against the other in a straight comparison the drizzle appears aesthetically more appealing but... when that means you give up data .....???

Unless the data can more or less remain intact when upscaled then I can't see the reason for it. [EDIT: I'll admit this is a more recent change in attitude , partly because natural scale is easy to get]

Upscaling and drizzle however you do it will, as Neil suggests, results in more sharpening required to pull the same detail but with added problem of noise so,... it will always be a balancing act.

Bottom line is IMHO is that the smaller image could be improved -and show more detail.

I think your right about that Karlo, i thought at first because wavelet strength is reduced on the drizzle image then extra noise would also be reduced accordingly. However upon using more wavelets to get a similar sharpened strength on the drizzle image there was indeed more noise. I should add i did noise control on both, to make it a fairer comparison. of the same type, Frequency domain, which doesnt blur noise it subtracts it, which one has to be carefeul about as it also can remove detail agreed. I dont always use it, and even when i do, i make sure theres a large enough gap around the information so as to try to not affect it in anyway. Good points Karlo

I should also add the processed shots i did were the drizzle image downsized and full, for no other reason other than that it seems to be the prefered image and was already resized. I wish infact that i had processed the 100% to see if i could swing that view.From what i can see im not sure about any adavantage using the drizzle, other than the rather forced more natural appearance it produces, by the rather more subtle wavelet application it forces on the processer. But i could be completely wrong about that, I havent worked on enough of these images to study its ultimate subtle effects ( other than wavelet effect ) as it might have more to it than that. But certainly the huge difference shown originally does appear to be a lot to do with these effects ive been showing here i believe. Maybe not all but a big part. I belive the comparisons seem to suggest as much.

But its hard to make judgements on two completely different types of images, to even compare, one has to resize the 100% ( affecting that ) or downsize the drizzle image ( affecting that )

What with the wavelet strength being so profoundly affected. its hard to determine ultimate differences isnt it

[Space Cowboy]

Very interesting Neil! I assume you used Reg 5 wavelets? I use linked wavelets in Reg 6 so I guess that's why drizzle suits my method probably due to the de-noise/ sharpening settings I use on each wavelet. As you say different wavelet combinations make numerous results depending on either the Planet or conditions.

Btw your final processed image is that from the drizzle image? Ah yes just read your last post.

[neil phillips]

Very interesting Neil! I assume you used Reg 5 wavelets? I use linked wavelets in Reg 6 so I guess that's why drizzle suits my method probably due to the de-noise/ sharpening settings I use on each wavelet. As you say different wavelet combinations make numerous results depending on either the Planet or conditions.

Btw your final processed image is that from the drizzle image? Ah yes just read your last post.

Yes i used wavelets on reg 5, and yes results will vary, the only thing i dont think is variable is the effect on wavelet strength, i think you will find that will tend to be a constant on drizzle images regardless of planet or conditions or linked wavelets, the noise is a different issue

[Space Cowboy]

That's a cracking image!

I'd be very interested to see what would come out of this sequence if you used the Atrouswavelet tool in Pixinsight and followed the tutorial for it.

PS, prefer the drizzle version too

Thanks Tim! You are welcome to have a play with the TIFFs I've uploaded.

[Space Cowboy]

Interesting thread and comparisons.

I note your comment about Reg 5.....

Do you prefer that to Reg 6 on planetary?

Reg 5 seems a lot more reliable than Reg 6 but AS!2 is the best for speed/reliability.

[AztecastroMcJ]

excellent pics these Stuart

agree with yourself, re the extra pop on 2nd but at this scale agree 1st more natural,

personally i would be reducing size a little to 100-120% and adding even more pop lol

the detail in swirling turbulence next to GRS for me is highlight and i would push this bit more with wavelets or unsharp mask or sharpen,

the large size does have good effect aswell tho and you done well in not overcooking it

[Space Cowboy]

Thanks James. Yeah I've changed my ideas so they are more like my taste in women i.e the natural beauty rather than fake tan and udder (you know what I mean). The version of this image that was shown on sky at night has more sharpening but when I look at it now it's too Katie Price though probably suited TV better lol :

Stargazers Lounge - Space Cowboy's Album: Jupiter - Picture

[AztecastroMcJ]

yep still prefer that one Stuart and it looked great on TV

i just prefer sharper detail on original, but still agree new one looks classier tho

like colour balance the sharpening etc could be debated all day i reckon, and is down to personal taste

think alot of us try to match pics with hubble and spacecraft pics colours etc

forgetting that we are imaging from earth through atmosphere so pics shouldn't really look same anyway

lol thats my excuse

[Space Cowboy]

Maybe the answer is to produce 2 versions on each post.

[neil phillips]

You will keep experimenting, your a lot like me in that regard i reckon. you may also change what you do over time maybe. Im still changing what i do after all these years. I lke the speed of AS2. but i dont like that you can not kill frames, like i use on the vertical slider on reg.

Lately ive been using reg 6 all the time optimizing first on k3 then kill the left over rubbish by using both sliders on reg. ive also been doing all multi points. AS/2 is great for speed, im not sure it has the finest control over bad frames though.

So far reg still seems superiour to me, even though its frame selection isnt consistent, but then AS2 lets in bad frames too. They all do.

which is why ppm centre or optimizing is better first. At one point i was able to optimize on k3 order and crop. them run through ppm center then onto reg. for a 3 pass processing.

But ppm center didnt always like it being optimized on k3 first. It started doing odd things. I havent tried since i switched to a laptop though. might try again.

Just be careful of assuming too much when you do these experiments Stuart, sometimes there can be more than one explanation.

like when i suggested to you my scope was having trouble with falling temperatures. you dismissed that out of hand because you said it was the same temp as a night you had of good seeing. But your scope is not a closed tube like mine and will behave rather more differently.

luis has a closed tube, he runs a fan while imaging and uses a peltier cooler too. Hes images are likely better than what he would be getting with a bog standard GSO, i think mine needs modifying to give its best. yours may fair better because its a open tube, even with a cloak it will behave differently.

[Space Cowboy]

Yep, I'm addicted to repros Neil, half my hard drive is full of them.

To be fair I don't doubt thermals are a problem with sold tube OTAs though you probably have a point I should not dismiss it as a factor even on wobbly atmospheric nights as one of my better Mars shots was from a night of variable seeing but on that occasion I'd had the scope cooling for several hours so maybe that helped the end result though its impossible to tell.

[neil phillips]

Yep, I'm addicted to repros Neil, half my hard drive is full of them.

To be fair I don't doubt thermals are a problem with sold tube OTAs though you probably have a point I should not dismiss it as a factor even on wobbly atmospheric nights as one of my better Mars shots was from a night of variable seeing but on that occasion I'd had the scope cooling for several hours so maybe that helped the end result though its impossible to tell.

Exactly your last point. sometimes it does become a guessing game. sometimes we guess right, other times wrongly. Its just learning and getting more clued up about the finer things that make us better at what your trying do. The best learners accept when they might have been looking at things a little blinkered. Then become more clued up, and more experienced as time goes on, thats true for everyone. Despite if they come across like they know everything. I dont know zilch, but its more than some know if you get my point, its a start. Glad you agree with what i said, its a humble and better man that learns more before dismissing, a lesson for us all especially me at times, And yes ive done this for long enough to know the scope does seem to really stabillize in a big way when its been out on those marathon nights. under reasonable seeing nights, with scope super cooled those have been my best images i think, but not always, just often. the exception is likely falling temps. optics hate them. Bird proved it my using temp readouts from hes primary, and outside air temp. He even found cloud cover affected this falling temperature, when the clouds cleared he had a brief spell where the readouts, where the same. under those conditions he got better images. Its something i will be looking into in the coming months. just not easy to modify is the problem i have. I would have thought these things may affect your setup, but at a guess likely to a slightly less degree. though even open tube, may suffer under continually falling temps, just less severly i would have thought. Another reason maybe why summer is better at my location. This dropping of temps is more gradual and even. Recently we was going from 70 in the evening to freezing by midnight. Even under calmer jet stream high pressure. Those nights you may fair a bit better than me with closed tube

[Space Cowboy]

Is it impossible to tell whether it's atmospherics when the stars are twinkling? On one or two nights even Venus has been waxing and waning in the sky?

Apologies if I'm sounding like a know-all.

[neil phillips]

Is it impossible to tell whether it's atmospherics when the stars are twinkling? On one or two nights even Venus has been waxing and waning in the sky?

Apologies if I'm sounding like a know-all.

No its just what you think, thats all fine, we have opinions, hey im full of them. And yes your right of course twinkling stars indicate poor seeing. ( jet stream ) but as mentioned it can be so much more than that, for example you once said to me i could get good images with vaseline on the primary. under the twinkling star nights. there are so many factors it starts to get silly,

but we can focus on the main ones, which is what im trying to do other than jet streams. which we can do naff about

I know little about open tubes and how they cope rather differently with these problems. it might not be worth your hassle looking any further im not sure.

But if it is ? maybe a mod for you to investigate would be fitting a fan to disturb the boundary layer, not sure open tubes suffer boundery layer like closed designs. But if they do, the mod might be cheap and easy to fit. Not sure if its worth you investigating i dont know.

rubber bands are used to stop vibration of the fan. and its run on when imaging. I have a fan its a naff pc one, not isolated. and when i run it, the images are bad. so i only use it for cooling then switch off. I need a new design. im working on a 8 image jupiter movie 11M FL. what a pain 24 images in k3 24 in AS2 ( yeah coz its quicker ) 24 in winjupos. just for a few secs of the red spot moving, so far its looking promising, im hopeful. we must be nuts im sure

[cgarry]

Is it impossible to tell whether it's atmospherics when the stars are twinkling? On one or two nights even Venus has been waxing and waning in the sky?

Apologies if I'm sounding like a know-all.

It is actually very easy (with a little practice) to tell whether it is atmospherics or tube currents causing the problems using a very defocused star. I have been busy having a lot of fun getting rid of the currents in my C14, I am almost there and the main remaining currents are in my dew shield.

Cheers,

Chris

[todd8137]

Nice your get in some good stuff mate nowdays

[Space Cowboy]

maybe a mod for you to investigate would be fitting a fan to disturb the boundary layer, not sure open tubes suffer boundery layer like closed designs. But if they do, the mod might be cheap and easy to fit. Not sure if its worth you investigating i dont know.

I've been using a desktop fan for the last 6 months Neil. I just sit it under the primary before a session. I do have a diy stand to run it on during imaging but I've not noticed any improvement doing that (it freezes me to death on cold nights too ).

Cheers Todd!

Chris, how does the de-focused star show whether its tube currents or atmospherics?

[cgarry]

Chris, how does the de-focused star show whether its tube currents or atmospherics?

Bad atmospheric seeing generally flies quite fast right through the FOV without interacting with the edges of the scope.

Tube currents will slowly move around the tube and interact with the edges, often circling round the tube. Or tube currents can appear fairly still but always inside the tube. It is hard to explain in words, so I will try with a couple of videos:

This video shows very bad tube currents. Notice the big bubbles and lines forming and sometimes circling the tube.

CeDniSvKsp0

This video shows bad currents mainly in the dew shield (as it turned out):

Cv91yJ_Bg4U

This video was taken just after the video before, but with the dew shield removed. There are still some currents there but it is so much better:

G3aOip5zR10

I hope this makes sense!

Cheers,

Chris

[Space Cowboy]

Cheers Chris that is very interesting! So basically if its tube currents the disturbance is within the image.

[cgarry]

Yes Stuart, that is basically it. You should easily be able to see the currents introduced by placing a warm hand on the lower side of the OTA. That is also useful to do as it allows you to work out which is the bottom of the scope in the view.

[neil phillips]

Yes Stuart, that is basically it. You should easily be able to see the currents introduced by placing a warm hand on the lower side of the OTA. That is also useful to do as it allows you to work out which is the bottom of the scope in the view.

yes edge plumes are a big giveaway had them bad untill i drilled holes on the back of my closed back ( cheap europa ) design, for some reason one edge always gets its worse. I mentioned sometime back my home made dew shield was affecting the scope, like your experiments likely the same reason. ( pics not showing to me )

there whited out. what mods have you done chris. Good thinking on the desktop fan Stuart, it will at least speed up cooldown,unless scopes stored outside

[Space Cowboy]

Might be able to try a star test tonight. Will try the warm hand too!

My gut feeling is the scope cools down very quickly..thinking back to when I took this Jupiter shot it was a last minute decision to go out that night and from a centrally heated house the scope had only been outside just over an hour on a November evening when I captured the image.

[neil phillips]

Might be able to try a star test tonight. Will try the warm hand too!

My gut feeling is the scope cools down very quickly..thinking back to when I took this Jupiter shot it was a last minute decision to go out that night and from a centrally heated house the scope had only been outside just over an hour on a November evening when I captured the image.

being open your scope will cool much faster than ours, your problems are likely less severe but still worth checking

[cgarry]

yes edge plumes are a big giveaway had them bad untill i drilled holes on the back of my closed back ( cheap europa ) design, for some reason one edge always gets its worse. I mentioned sometime back my home made dew shield was affecting the scope, like your experiments likely the same reason. ( pics not showing to me )

there whited out. what mods have you done chris. Good thinking on the desktop fan Stuart, it will at least speed up cooldown,unless scopes stored outside

The big improvement I have made so far is to make a coat for the scope out of radiator foil. Without this the sky side of the tube was 3 to 4 degrees colder than the ground side and this induced tube currents that never stopped.

I want to experiment with internal fans at some point but I really cannot do that yet as the scope may need to be returned because of spherical aberration problems (but that is another story).

The next issue I need to solve are the currents in the dew shield, I have a few ideas I want to try out to solve this one.

Stuart, I think you are right in that your scope will cool quickly. That may not be the end of the problems though, if the top side of the OTA becomes colder than the bottom. The star test should give you an idea if you do have any problems.

Cheers,

Chris

[neil phillips]

The big improvement I have made so far is to make a coat for the scope out of radiator foil. Without this the sky side of the tube was 3 to 4 degrees colder than the ground side and this induced tube currents that never stopped.

I want to experiment with internal fans at some point but I really cannot do that yet as the scope may need to be returned because of spherical aberration problems (but that is another story).

The next issue I need to solve are the currents in the dew shield, I have a few ideas I want to try out to solve this one.

Stuart, I think you are right in that your scope will cool quickly. That may not be the end of the problems though, if the top side of the OTA becomes colder than the bottom. The star test should give you an idea if you do have any problems. as a matter of interest, have you noticed optical abberations in your chinease c14. Vid pic showed but dongle wont play it yet maybe later. from the pic, star test looks ok. whats the problem Chris

Cheers,

Chris

I never really considered one side of the tube being affected differently but now that you mention it does make perfect sense. and goes back to my comments earlier about plumes on one side maybe ? the only thing im not sure about is by using a jacket heat will be dissipated much less effectively it will store it, but in a more even way. maybe once the scope is properly cooled, its not a problem using this foil jacket idea, unless we get our old friend falling temps again. in which case i reckon it will worsen the problem Chris though evenly worse if you see what i mean