All great information & advice thankyou Gentlemen...
I'll probably go for some shots through the refractor next time out, just to see if it was the camera rotating or not...
Just have to wait for the next clear night.. which could be a while according to current forecasts
Slowly, slowly I will get there... especially with the assistance of all the experience found on this forum.
Cheers
Quote:
Originally Posted by raymo
Make sure that your R.A. and Dec clutches on the mount are securely tightened.
raymo
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Quote:
Originally Posted by mynameiscd
Hi Carlton,
Like Raymo and Peter say.....Patience grasshopper.....
PA is vital. I was pretty rough with my PA for a while and also my scope wasnt quite square with my mount so my alignment was always a bit out. I'd do a visual and then a drift and it was out so I'd go back to a visual alignment not realizing it was out a bit so I'd start to get stretched stars.
Then it dawned on me it's not the scope that needs alignment it's the mount!!
It helps if the scope is spot on with the mount and that's why a drift alignment works because it picks up errors with the mount.
Also a bahtinov is a must. The screen on my 450d is tiny and without a mask there's no way I could get focus. I also got an app on my phone that I can conect my camera to my phone and with a bigger screen focus is easier.
At the moment im getting 2 minute unguided subs and only getting coma so I must be doing somthing right.
http://www.iceinspace.com.au/forum/s...d.php?t=174169
Is was getting frustrated for a while until I went back to basics and stated learning from the Masters....
Now im trying to learn processing and thats another hurdle but with the years of expertise on this site and people willing to help it makes it so much easier
PS Have you tried nightscapes yet.
They're pretty easy and you get not too bad results.
They kept me going when all i was getting was washed out stripey stars!!
http://www.iceinspace.com.au/forum/s...d.php?t=167819
Cheers
Andy |
Quote:
Originally Posted by xelasnave
Hi Calton
May I suggest for starters do this.
Mount your camera direct to the mount...take away your counter weigths add jury rig something small ..tape on something☺
During the day line the cameramm up with the polar axis by looking to see that what is centered in your polar scope is what is centered in your camera with the mount in home position. At night have the mount pointing South as best you can.
At night dont switch on your mount as we dont want any tracking. Set iso to 100 choose bulb. We want a shot off the CSP☺
Take a long exposure of say 10 minutes (sit and catch your breath).
At the end look at your photo and you will have many arcs of star trails. Adjust the mount to get the trails centered.
Repeat until the center of your trails is in the center of your photo.
This should be pretty close to get you started. I do this for my widefields and is all I did until I got the pole master and even with pole master I do this to bring the stars into frame needed to use polemaster (I cant see squat thru the polar scope and so this gets me there).
I notice that even before I use pole master I have gotten pretty close.
For starters dont worry about your goto if you want to get something...
I dont use it cause I dont have trouble finding objects with just the guide scope.
Anyways I think this will get you a decent polar alignment for a wide field.
Next and most important remember to reset ISO☺ so easy to forget.
Now start the mount tracking and select a region to photograph.
Focus as best you can and take a test shot of say 10 seconds and ask if focus could be better. This will horrify camera lovers but I stick some blue tac on the lens body to hold it from moving..check focus again to make sure nothing moved..blow up your test shot and check focus is as good as it can be...take say a 60 second capture and check it blown up..if trails reduce it to 30 seconds..check again..reduce exposure until trails are negligable.
When happy take as many subs as you can...20 minutes worth at least maybe do an hours worth...put the lens cap on and take darks while you pack up or have a coffee...as many as you can but at least 20 ..whatever.
Do another batch at a little higher exposur maybe but dont overstep your limit.
This way you will get a decent result and get a handle on the overall process.
Look at your results and delete anything that does not look ok..no need to be to harse but drop the ones that had a cloud or a plane.
Stack in Deep Sky Stacker and get to know your way around it..select the opion to stack say 85% or 90% and play with the various settings on your final result...if that is the only software you have else dont play with the settings and process in Startools...have a play with whatever result in Gimp. It has a levels feature and a brightness contrast feature which is handy for starting out.
If you have photo shop even better as it has a dodge and burnbfeature that enables broghtning or darkening specific areas which I find really handy.
Both Deepsky Stacker and Gimp are free downloads and not trial versions.
Startools provide a trial version but I would not bother first up.
The polar may be off but if you can get decent stars with 30 seconds the mount not being absolutely perfect in PA you have a built in dither☺ and together with many subs and darks should manage noise and hot pixels.
This proceedure is the very basic but it will get you there...if you notice drift in a particular direction you can do a small adjustment on the mount mid stream...at least think to yourself..now the stars are drifting North so what should I do..do it a quarter turn and note the result in the next ten frames...I think doing this helps to get a feel for how to polar align...I have found even using pole master my stars drift a little North which I think is a refraction of atmosphere factor..my point is you think about what is going on...also balance of counter weights is often an issue...the mount can be perfectly balanced but the thing travels too fast West or hangs East until you move the counter weights to destroy your perfect balance.
Also I cant recall what camera lens you have but start with the lowest F/L in your kit..18 if you have it and take a batch and progressively increase your focal length...that way you get a feel for where the lens works well..an 70/200 may have a sweet spot at 100 for example...so in the future you know that your 70/200 lens really for your astro purposes a 100 mm lens☺.
And a good wide field is very satisfying but not as easy as it seems.
Now if you can get that down after you have got something to process introduce the goto but after you have your first batch...
Avoid your long fl scope in my view until you really know what you are doing and able to understand drift and balance etc...
Like the bass start simple...a solid simple beat is better than a complex beat that is not in time☺ do it good slow and slowly increase pace with practice and repetition.
Also I suspect you may need something in the way of dew hoods...there is a material like a wet suit or mouse mats which work really well for a camera lens even a small refractor...dew can sneek up on you so always keep an eye on your lens.
So that my 2 cents worth...hope you can use something there...and the star trail circle thing is a nice photo to have in ones collection even if you dont like the idea of finding PA that way.
Alex
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Quote:
Originally Posted by xelasnave
If you want to use a scope you can still go the star trail way and it will be better of course.
Alex
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