Saturn Sunday night Brisbane

[carlstronomy (Carl)]

Hi there all, three images of Saturn taken tonight. All approx 300-400 frames through a 3x Barlow using Celestron Neximage camera. AVI's passed through AutoStakkert and then adjusted in Registax. I am only two weeks into this stuff so I am on steep learning curve, any help or criticism will be taken as it is meant to aid me to get better.

Thanks and clear skies.

[carlstronomy (Carl)]

Another image from the nights viewing which I think is a little better.

[Shiraz (Ray)]

that is a really good start Carl.

Your images show a bit of seeing blur which is probably due to the relatively slow framerate of the camera. next time out, try using the 2x Barlow with shorter exposure times to get around some of the seeing and stack with 1.5x drizzle, but you will really need a more capable camera in the longer term - that is the weak link in your equipment list. regards Ray

[carlstronomy (Carl)]

Ray,
Thanks for the feedback and adivce. I will certainly try your settings on my next outing which looks like by the skies over Brisbane and the current forecast may not be until next week. I agree my camera is very low end I was looking at maybe this camera DBK 21AU618.AS so if anyone has an opinion on this camera it would be greatly appreciated. Would it be much of a step up and will I get a much better image, as these are available for just under $500 here is brisbane.
Thanks
Carl

[Clayton]

Nice start Carl,
A seeing report will help, and also the amount of frames stacked/captured
300-400 frames is not many to capture of Saturn you should be capturing a minimum of 1800 with your camera in 6min or even double that.
The DBK is a fine camera

[Quark (Trevor)]

A good start Carl.

Planetary imaging is arguably the sternest test of any type of astrophotography, regarding collimation, focus & the relationship between the ambient temp and the temp of your primary mirror.

Working at very long F/L hi-lights any slight error that would go unnoticed under normal conditions ie; observing at the eyepiece or imaging at prime focus.

Personally, I go to extreme lengths with my collimation and control of my primary mirror temp.

I cannot overstate just how critical collimation is for planetary imaging.

I think the best advice I could give to you is to concentrate on the basics and learn by your mistakes and above all else, enjoy the experience.

Regards
Trevor

[carlstronomy (Carl)]

Originally Posted by Clayton

Nice start Carl,
A seeing report will help, and also the amount of frames stacked/captured
300-400 frames is not many to capture of Saturn you should be capturing a minimum of 1800 with your camera in 6min or even double that.
The DBK is a fine camera

Clayton, I did not think I had enough but thats all I can catch with my basic alignment. I will have to go to the next step on the dreaded drift alingment to produce exposures of that length. I knew it was only a matter of time before I had to try a more accurate alignment but I may as well learn.

Thanks

Carl

[carlstronomy (Carl)]

Originally Posted by Quark

A good start Carl.

Planetary imaging is arguably the sternest test of any type of astrophotography, regarding collimation, focus & the relationship between the ambient temp and the temp of your primary mirror.

Working at very long F/L hi-lights any slight error that would go unnoticed under normal conditions ie; observing at the eyepiece or imaging at prime focus.

Personally, I go to extreme lengths with my collimation and control of my primary mirror temp.

I cannot overstate just how critical collimation is for planetary imaging.

I think the best advice I could give to you is to concentrate on the basics and learn by your mistakes and above all else, enjoy the experience.

Regards
Trevor

Trever thank you I will answer you last first, yes enjoyment is a must after all it is a hobby. These pictures are better than my first so enjoyment levels are good as any progress and experience gained is good fun. Although this is a hard subject to learn it is the challange and possible results that have sucked me in.

Collimation is something that I think may be a little out still, the scope was probably 30% out when I started using it and a 2x barlow with a 9mm it was hard to see Saturn, it did blur. Now it is crystal clear with a 3x barlow, but I think I may still be around 5% out. Is it worth buying a collimation tool and if so which is the best for a SCT including value for money as a newbie, as there are many out there.

Temperature of the primary mirror is something I have not looked into as yet but I do try to get images prior to any due forming. Is there any articles out there on optimum temperature for photography I can read or do you have any advice.

Thank you for all your time a feedback

[Quark (Trevor)]

Hi again Carl, just noticed in your tag that you have a C 9.25. Many of the best planetary imagers started with this type of scope. I have seen stunning images produced with them.

Regarding the cooling, your primary needs to be within 1 degree C of ambient otherwise there will be turbulence in the boundary layer of air that is in contact with the mirror. At very long F/L you are not only magnifying the planet but also any turbulence within the atmosphere (jetstream & wind shear) along with any turbulence within the boundary layer of air in contact with your mirror. Adequate cool down time is critical along with some type of mechanical cooling, fans will help and in my Newt I have peltiers. I have info on my cooling system on my website but again, that is for a Newt.
Anthony Wesley aka Bird has excellent info on peltier cooling Newts on his website.

Regarding collimation for your SCT there are others here that that also use SCT's that should be able to help. With my Newt I use a Houghy Glatter laser & TuBlug, which becomes a barlowed laser along with a Cat's Eye Autocollimator, which is incredibly sensitive to the slightest misalignment. To get quality results with hi res planetary imaging having good collimation is not enough, it must be perfect.

It would also likely help if you did some research on the fine collimation of your SCT using defocused stars.

Another suggestion would be to start out with easier targets while you build up you knowlege base and experience level like maybe some craters on the Moon.

Cheers
Trevor

[Troy]

Nice images Carl.
Looks like you already have some good advice here. 8-)

[carlstronomy (Carl)]

Originally Posted by Troy

Nice images Carl.
Looks like you already have some good advice here. 8-)

Thanks Troy and yes the advice I have had here over the last couple of days has been awesome. Hopefully over coming weeks and months I can put some of this into practice and put up some better images.

Thanks to all for their time and efforts in helping.

[asimov (John)]

Hi Carl.

You can take every word of what Trevor & the other guys have said & stow it for later use. All true.

The only advice from me would be; if you are going to get into this, eventually upgrade that camera first.