Starlight xpress or inova and guide scope for autoguiding advice

[Dave1964]

Hi all,

Finally down to my last couple of pieces of equipment to get for astrophotography for now .

I am after advice on which guide camera is better starlight xpress or the inova brands.

Also looking at Altair 60mm Miniguider with Autoguider Webcam focuser, tube rings, multi-purpose base

for a guide scope than opposed to piggy backing scopes.

Many thanks

Dave

[lensman57]

Hi all,

Finally down to my last couple of pieces of equipment to get for astrophotography for now .

I am after advice on which guide camera is better starlight xpress or the inova brands.

Also looking at Altair 60mm Miniguider with Autoguider Webcam focuser, tube rings, multi-purpose base

for a guide scope than opposed to piggy backing scopes.

Many thanks

Dave

The only Inova that has a chance to stand up to StarLight Xpress is the one with the 445 chip but I think it is an expensive camera for what it is. I am using an ASI 120 Mono at moment and it is a very sensitive camera with a guide port onboard, less costly than a Starlight Xpress but not really cheap either.

A.G

[Dave1964]

Hi A G,

Thanks for the info. I am struggling to understand auto guiding. What camera is desirable etc.

Then looking at the Altair astro mini guider, pondered the quesrion is it possible to put an autoguiding camera into the finder scope?

Many thanks

Dave

[PhotoGav]

Hi Dave,

I am at the beginning of the auto guide journey too. I have just purchased a QHY5-II camera with adapter to fit in the finder scope of my Skywatcher 80ED. It arrived yesterday thanks to great service from Bernard at Modern Astronomy and even better, it was a half clear night...

However, the Gods of New Equipment had their fun and by the time the scope was set up, the clouds rolled in, so no joy. It was also my daughter's 9th birthday party, so I felt slightly obliged to join in!

Later on, the sky was clear, so I set up the scope again and everyone oohed and aahed at the beauty of Jupiter, many seeing for the first time. I then set about preparing to test the guide setup. Of course, the clouds rolled in again. I swear I heard the Gods giggling...

So, it should be possible to use the finder as a guider. I will update you with my progress. I'm hoping that things will go further this evening!

[Dave1964]

Hi Gav,

That sounds really promising. Now I have mastered my new set I am intrigued by autoguiding and how it works.

More so as I am at the experimental stage of astrophotography and just enjoy experimenting.

Dave

[lensman57]

Hi A G,

Thanks for the info. I am struggling to understand auto guiding. What camera is desirable etc.

Then looking at the Altair astro mini guider, pondered the quesrion is it possible to put an autoguiding camera into the finder scope?

Many thanks

Dave

Hi Dave,

Auto guiding is at times like a dark art but it is not the evil that has been made up to be, I can see that you have the I-Optron mount, this mount is claimed to be able to track well into the 120s range unguided. I am sure that this is true but for this you ought to get your Polar alignment spot on, you'd have to do this for auto guiding anyhow . I have also read the polar scope in your mount is already centred to the axis of the mount at the factory so you should in theory be able to level your mount, point it to Polaris and do a proper polar aligment according to the mounts instructions and with a bit of luck you shoube able to do imaging up to 120s unguided without star trails provided that your imaging set up is 100% balanced for both the DEC and the RA . I would try this first before going on to guiding. I use PHD, GPUSB and my AsI 120 MM for auto guiding, the ASI has the ST4 guide port onboard but I don't use this, I connect the camera to the laptop, USB, the GPUSB to the laptop and the mounts guideport, and then the PHD software connects to the camera and the GPUSB .

Once PHD has aquired a guide star and locked on, it calibrates itself and then starts the guiding by keeping a lock on the guide star. As for the guide scope I have a dedicated 50mm guider, a 60 mm guider and an 80mm guide scope. They all work well with the camera. You could use a spare 50mm finder as a guider but you'd need an adaptor such the ones from Modern Astronomy  to connect the camera to the the guider and you also have to have a rigid mounting system for it, the usual finder bases are not suitable The Starlight is at the top of the sensitivity list but it is expensive and the 618 chip is a little on the small size, 1/4" format I think. There are other Planetary-guide cameras on offer too, the QHYLII has the same chip as the ASI and is very poular. Then there is  the QHY IMOGH  which has the same 618 chip as the Starlight but it has active cooling and can be used for some limited DSO imaging on the bright DSOs but I am not sure how well supported it is with guiding software such as PHD.  Hope this is of some help.

Regards,

A.G

[PhotoGav]

Well, despite the Met Office & BBC websites promising a clear night, The Gods are laughing again... I set everything up at dusk with a wonderful clear sky, but the clouds slowly accumulated and I eventually gave up hope and packed everything away again.

Hopefully soon...

My wish list is growing rapidly, with some kind of observatory / cover so that I can leave things set-up now at the top of the list!

Oh for a clear sky.

[lensman57]

Well, despite the Met Office & BBC websites promising a clear night, The Gods are laughing again... I set everything up at dusk with a wonderful clear sky, but the clouds slowly accumulated and I eventually gave up hope and packed everything away again.

Hopefully soon...

My wish list is growing rapidly, with some kind of observatory / cover so that I can leave things set-up now at the top of the list!

Oh for a clear sky.

Please Hush,

I have had nearly two hours of clear sky tonight, buI can see the clouds accumulating from the great North again, please keep them away for another hour till I collect my Ha data,

I repent for all my sins, again.

A.G

[PhotoGav]

You lucky thing! I hope it has stayed clear for you.

[lensman57]

You lucky thing! I hope it has stayed clear for you.

No it didn't, only 3 subs in Ha 900s eachatleast I managed a few Oiiis erlier on.

A.G

[Dave1964]

Morning all,

Alas the promise of th promise of 4 hours of clear night last diminished into 2 hours of intermittent cloud .

I really liked your in depth reply and I feel that upgrading from my originally goto mount has been the best thing I have done do far, yes totally agree the balancing is pretty easy to set up and leveling of the mount too. I have done polar alignment in less than 6 mins so far. However also done just a one star alignment amd with the little use of the mount due to weather has been very impressive. I had initially concerns that balancing both the DEC and RA would be off putting but far from it. Having the GPS is brilliant saves fumbling around with entering time and date and location etc.

I don't not fully understand the differences in the specs of the guide cameras as of yet and will need more research into them. Yet having starting imaging and seeing m45 Capella and Betelgeuse been pretty impressive so far. Also its fun experimenting in bulb mode different delays and setting to see what's possible. When my new laptop arrives I will be able to start on the joys of understanding stackimg.

I have a lot to learn as to what settings on the 60d is required for doing more complex things like m31 and understanding what object may or may not be visualalbe with the 80mm too.

Back to guiding, do you guys have to protect the laptop from dew too?

Ohh another possibility of two hours of clear nights tonight

Dave

[Dave1964]

Morning all,

Though we get the rare clear skies at night, it is hampered by the joys of all the neighbours security lights going on, oh to be out of town and into the countryside

Can you get light pollution filters for scopes themselves? I know you can for the cameras.

Dave

[frugal]

Can you get light pollution filters for scopes themselves? I know you can for the cameras.

I think you just get them as a 1.25" or 2" filter that screws into the ring that the camera is mounted onto. So you can use them for either visual or photography.

[lensman57]

Morning all,

Though we get the rare clear skies at night, it is hampered by the joys of all the neighbours security lights going on, oh to be out of town and into the countryside

Can you get light pollution filters for scopes themselves? I know you can for the cameras.

Dave

Hi Dave,

I have the same problem, my next door neighbour is actually a doctor's surgery now metamorphing into a mini medical center thanks to the encouragement of our government, all this in a cul de sac with 5 houses next to each other. As there will be drugs stored in the house they have had to put up 7 high intensity security lights that light up the area like the Old Trafford football ground. The use of the best LP filter on my OSC camera is mandatory, it is not necessary with narrow band as these filter almost everything else out. These are usually either 2" or 1.25" that will mount on to the nosepiece of the camera.

Regards,

A.G

[Dave1964]

Hi A G,

Thanks for the info that will be a worth while accessory.

Dave

[PhotoGav]

Quick update...

Finally, a clear sky. It's taken me ages to get it all set up, but the first results are in... 6 min sub just acquired, with the QHY5-II camera attached to the finder scope and guiding with PHD. Results - SPECTACULAR!!!!

Sorry, just a bit over excited!

Currently exposing a 12 min sub to see what happens!

[PhotoGav]

12 min sub is perfect... Now whacked it up to 20min...

The one major trouble I had with setting up was getting the stars in focus in PHD. I fiddled with adjusting the camera on the adapter and the adapter in the back of the finder, but to no avail. I finally resorted to reading the piece of paper that came with the camera and read the underlined sentence that advised that focus is obtained by unlocking and adjusting the front objective on the finder. Sure enough it is and once sharpish, PHD was a sinch.

So Dave, at the moment my advice is most definitely get that camera for the finder and get PHD auto-guiding!

My next mountain to climb... EQMOD.

[Dave1964]

Hi Gav,

Wow you got some really great shots of m31, I am now frantically waiting for clear nights as I was expecting such clarity from the 80mm.

I am certainly now in the process of sorting one out laptop arrive so I can put on stacking software and PHD.

Do you guys do bias before or after the shots? I hope I am right its black first, then lights finally white say a tshirt.

What is the recommend amount of shots you need of do for biasing?

Dave

[PhotoGav]

Thanks Dave. M31 became quite a labour of love and took three separate shooting sessions and hours of SGL / video / web research to get something that was acceptable. One heck of a learning process!

So far I have only done lights and darks. I know that I should do flats and bias frames and have experimented with taking them, using an ipad and an app called 'Color Softbox' that just displays a plain whole screen. I haven't used them in a project for real yet though.

It doesn't matter what order you shoot the different frames in, but you should shoot darks at the same temperature, give or take, as the lights and the flats need to be shot with the camera and everything in the same position as for the lights. I don't know how people can take flats before framing up the target as I fiddle around with the camera orientation to make the best framing once on my target.

So far I have tended to shoot lights first and then darks afterwards as you can never be certain what exposure time you are going to use. Also that way, you can take full advantage of a clear sky and then do the darks once it has clouded over!

As for numbers of frames: lights, as many as possible, darks, again as many as possible (I read/saw somewhere during my research that stacking apps work better with odd numbers of frames - don't know if that's true, but I stick to it just in case!), bias and flats, around 21-31, but don't know for certain, they are quick and easy to acquire though.

And then clear skies.... That seems to be the hardest bit of all at the moment!!!

Have fun.