twinkle twinkle little star

[Pol]

Re: twinkle twinkle little star

He's just been showing me that hand controller (Autostar) and explaining what it does and how to use it - though the 'scope isn't set up yet. He's busy refreshing his memory plodding through the manual and he's also been spending some time looking at the accessories website for filters, comparing prices etc.

I think it's really gonna happen soon - possibly next week at home and hopefully after Xmas down on the marshes.

Thanks for the info about the LPR/nebular filter. He says he knows what they are but he doesn't have one so that'll be on the accessory list along with a solar filter (to which he already has a link for buying one). He has a folder of links somewhere, though he hasn't used them for ages so he's spent most of his free time today catching up with those as well as getting all his bits and pieces together.

I'm sure you're right about wanting to take pics once we get going properly. At the moment he has a Coolpix 4500 that he once used for digiscoping somewhere about and I think he has a mount for it - but getting going just with the viewing is the first step for now.

Is your PST a Coronado? Not that we're likely to be thinking that far ahead yet!


Pol

[devilgas]

Re: twinkle twinkle little star

Is your PST a Coronado? Not that we're likely to be thinking that far ahead yet!


Pol

[Pol]

Re: twinkle twinkle little star

I take the view that any kit is well worth the money when you're enjoying using it. This is also the sort of kit you can use for years to come, either out in the middle of a field miles away or in your own back yard if the conditions are suitable.

Many thanks for pointing us to scopenskies too. That's a brilliant site and David's been browsing it most of this morning. We definitely need a solar filter, Light Pollution filter and he's also saying he needs/wants a polarising filter - so he's shopping around even as I type.

We need to walk before we can run but I'm sure you're right about wanting to take pictures when I/we start seeing things properly. The Nikon 4500 would be a start and I think David also has a suitable mount for his old Nikon D70 but I was wondering what you're using? Is it your dSLR or do you use one of the recommended 'digiscoping' cameras?


Pol

[devilgas]

[Pol]

Re: twinkle twinkle little star

Thanks for all that, most of which is way out of our league and probably always will be.

We have adaptors and T mount here for both the Pentax and Nikon dSLRs in addition to the Nikon compact (originally used for a Nikon bird spotting scope) so we'll just stick with what we already have and see how things go.

Good luck with your experiments with the CCD imaging. It'll be interesting to watch how you get on with it over the next year or so. Your first image in your original post in this thread's gonna take a lot of beating imho. That really is a cracking good image!

David has now placed an order for various accessories so hopefully they'll arrive before too long so we can make a start just viewing. He ordered a rotating variable polarising filter, anti-light-pollution nebula filter (LPR),
Solar Finder conversion, Solar observing shade and Sol-Vu safe solar observing filters.

Wot fun. We're having a ball already here.

Pol

[devilgas]

Re: twinkle twinkle little star

have managed to squeeze a bit more detail out of the image....


compared to....

[Pol]

Re: twinkle twinkle little star

have managed to squeeze a bit more detail out of the image....

Nice job, definitely more detail. I can see how you must be so thrilled with that AND with it being just the single image off the dslr.

If you can do that with the dslr it's mind boggling what you might achieve with stacking. You wouldn't be wasting your money on one of those CCD Astro-Imagers y'know -when you get to grips with the stacking anyway.

Pol

[devilgas]

Re: twinkle twinkle little star

a dedicated b/w astro CCD is well out of my price range at the moment, so i'll stick with the dslr fro the time being. i still need to try the IR mod'd one i bought from patrick, but clear nights have been few and far between recently

when you want to progress your imaging beyond what you have currently bought, get a copy of "making every photon count" and read that before buying anything else (scope / camera / mount etc) as it can save making expensive mistakes.

stacking only improves the signal to noise ratio (i mistakenly thought it would combine the exposure times, enhancing the detail in the image). the detail is extracted in post processing. what it does mean is that you can use the highest ISO settings and cancel out the noise generated in doing that. as with the solar images, i've quickly learnt that when it comes to astro work a lot of 'cheating' goes on.

[Pol]

Re: twinkle twinkle little star

a dedicated b/w astro CCD is well out of my price range at the moment, so i'll stick with the dslr fro the time being. i still need to try the IR mod'd one i bought from patrick, but clear nights have been few and far between recently

when you want to progress your imaging beyond what you have currently bought, get a copy of "making every photon count" and read that before buying anything else (scope / camera / mount etc) as it can save making expensive mistakes.

stacking only improves the signal to noise ratio (i mistakenly thought it would combine the exposure times, enhancing the detail in the image). the detail is extracted in post processing. what it does mean is that you can use the highest ISO settings and cancel out the noise generated in doing that. as with the solar images, i've quickly learnt that when it comes to astro work a lot of 'cheating' goes on.

Any image at all is beyond my wildest dreams at the moment. I'd be elated just to progress as far as using the dslr for any images and that would be a long time in the future, if ever.

I'm only just beginning to get some basic idea of the possibilities and the vastness of the universe out there. The night sky has taken on a whole new meaning.

David's never really shown any great interest digital image processing either. He's always resisted using Photoshop or LR, still just sticks with Picasa and jpeg rather than RAW. He's the kit man whereas I tend to be the image processing geek.

We'll probably end up reaching some sort of compromise, hopefully without coming to blows en route. We can become quite competetive at times.

Pol

[devilgas]

Re: twinkle twinkle little star

Any image at all is beyond my wildest dreams at the moment. I'd be elated just to progress as far as using the dslr for any images and that would be a long time in the future, if ever.

i think you'll be surprised. once i saw what i could see through the scope, i wanted to capture it. visual is easy compared to imaging, but when you start to see what you can get, you get hooked.

you have a great start in that the scope you have has a driven mount which, when set up correctly, should keep the same object in view. because it tracks in alt/az you won't be able to use l-o-n-g exposures as it will still produce star trails - the centre object will be fine, the outer stars will show some trailing depending on where in the sky the scope is pointed and how wide a view you are capturing. if you do the conversion (basically incline the fork by about 53 deg and point it north) so that it tracks the sky in equatorial mode, then you'll eliminate the main source of star trails. it then comes down to how accurately the scope has been aligned to the heavens and how 'tight' the scope tracking is.

you absolutely *have* to shoot astro in RAW. jpg throws away a lot of data which is harvested in PP.

i'm just starting to learn the PP techniques myself, but try not to fiddle too much as i want the final image to still resemble what was captured. e.g. with the hubble images, there is a lot of false colour processing applied due to the different wavelengths they capture.

in this respect all i tend to do at the moment is stretch the levels, get rid of the light pollution colour cast and reduce the noise.
astro work seems a steep learning curve, but makes sense when you sit and think about it, especially when you get those eureka moments as the penny drops.

[Pol]

Re: twinkle twinkle little star

i think you'll be surprised. once i saw what i could see through the scope, i wanted to capture it. visual is easy compared to imaging, but when you start to see what you can get, you get hooked.

you have a great start in that the scope you have has a driven mount which, when set up correctly, should keep the same object in view. because it tracks in alt/az you won't be able to use long exposures as it will still produce star trails. if you do the conversion (basically incline the fork by about 53 deg and point it north) so that it tracks the sky in equatorial mode, then you'll eliminate the main source of star trails.

you absolutely *have* to shoot astro in RAW. jpg throws away a lot of data which is harvested in PP.

i'm just starting to learn the PP techniques myself, but try not to fiddle too much as i want the final image to still resemble what was captured. e.g. with the hubble images, there is a lot of false colour processing applied due to the different wavelengths they capture.

in this respect all i tend to do at the moment is stretch the levels, get rid of the light pollution colour cast and reduce the noise.
astro work seems a steep learning curve, but makes sense when you sit and think about it, especially when you get those eureka moments as the penny drops.

You have no idea just to what extent you've whet my appetite for this.

I agree wholeheartedly about shooting in RAW, not just for Astro but for everything anywhere! I've just had a word with David and he tells me he knows how to set the scope in equatorial mode and he also promises me he's going to be interested in helping me with getting to use my own Pentax K20D with the scope (because I don't want to feel restricted to using his Coolpix compact or his old Nikon D70. I want to use my own dslr and he promises faithfully that can and will be achieved eventually.

I'm gonna do this and he really does seem to be keen to do it too. He's had the 'scope for a few years now but never really got to using it as much as he wanted for one reason or another. That's all about to change now!

Still waiting for the scopenskies accessories order to arrive then ...

Pol

[devilgas]

Re: twinkle twinkle little star

another thing to look at is piggybacking your camera onto the scope. i'm not sure how much extra weight the 90 can take or whether you could remove the tube and mount the camera directly to the forks. if using an SLR, mirror lock up is essential, as is remote shutter operation.
if shooting through the scope, live view makes focussing a lot easier but you can get there through trial and error if you don't have it.

[Pol]

Re: twinkle twinkle little star

another thing to look at is piggybacking your camera onto the scope. i'm not sure how much extra weight the 90 can take or whether you could remove the tube and mount the camera directly to the forks. if using an SLR, mirror lock up is essential, as is remote shutter operation.
if shooting through the scope, live view makes focussing a lot easier but you can get there through trial and error if you don't have it.

Yes the K20D does have live view. Very useful it is too.

Weight for piggybacking is the something David isn't sure about, though he thinks it'll probably be ok. He says we can experiment with that when the time comes. And I've strongly suggested any of those experiments can be done with his K10D or 20D rather than mine. He's agreed too, he's good like that.

Pol

[devilgas]

Re: twinkle twinkle little star

for a star map, download stellarium. it's free and is a great program. i can use it to directly drive the scope when i connect everything up.
deep sky stacker is another bit of free software that will stack images for deep sky objects
registax v5 (people don't seem to recommend v6) is great for stacking planetary images / video files. i'll admit to struggling with this software as it's quite daunting to begin with. again, this is free.
sat24.com will give radar weather images so you can see what the current and forecast cloud cover is like
xcweather.co.uk is another great weather site that is uncannily accurate.

you'll need to check to see if the ETX90 will take the weight of an SLR hanging off of the back of it. a quick scout around the astro forums should give you the answer, or just try it and see

it'll be good to see the scope getting used again!

[devilgas]

Re: twinkle twinkle little star

ha. the joys of both typing at the same time