Celestron Nexstar 6 SE on standard mount

[roelb]

Hello,

I'm considering buying a ATIK Infinity camera.

My mainly goal isn't to go in complicated/expensive astrophotography but to extend my visual observing and to better document the observations.

Since I become older, long time observation at the eyepiece becomes more difficult.

Therefore I think dat Video Astronomy (EAA) is a good way to go.


My equipment is rather simple:
Celestron Nexstar 6 SE with the standard Celestron mount.
A f/5 focal reducer. I don't have the expensive Hyperstar.

On YouTube I have found following videos:
https://www.youtube....h?v=JheW2PHKwcY
mono camera on a Celestron Nexstar SE 6 with f/7
https://www.youtube....h?v=28nuK8X6xbw
colour camera on a Celestron C11 + Hyperstar (f/2 ?)
https://www.youtube....h?v=dg-KGJr8J-o
mono camera on a Celestron Nexstar SE 6 with f/7
https://www.youtube....h?v=R4MLUBa8ZDk
Current Software Compatibility

And also some other user videos/images, but always with bigger telescopes.

Before deciding to purchase the ATIK Infinity, I have some questions:

First question: how good will be the results with the colour camera on my Celestron Nexstar 6 SE,
   without a Hyperstar and using a f/5 focal reducer?
   I cannot find a video to show that. This is important to me, to decide which version mono or colour I have to choose.

   I presume that the exposure time for a colour sensor must be higher to achieve comparable details on the images
   as with the mono.
   But this requires perhaps a more accurate drive (spur gears versus worm gears like the Celestron Evolution series)?
   Will the software compensate enough to achieve reasonable results?
   So, in other words, will my Celestron Nexstar 6 SE be accurate enough to use a colour camera without a Hyperstar?
(I do my observations in rather good, dark environments)

Second question: do have someone a (downloadable) recorded session (if possible both mono/colour)?
   So I’m able to replay and evaluate the different software settings.
   (I have downloaded and installed the version 1.2 BETA Infinity capturing software),

Thanks in advance for some advice from present users.

Roland
roelb@skynet.be

[Howie]

Hi Rowland,

I have stuffed disks in back and neck and hence have done video (Mallincam) live-observing, ZWO camera live-observing and DSLR live-observing for quite a while. I use a light'ish weight equatorial mount, however ... in the past when in less pain, I did also use my 12" GoTo AltAz dob. Bit bigger than a 6SE, but ... you do realise the youtube vid done by Atik for the Infinity Color version test video was done using a 6SE on the std single fork mount! So I dont think you will have any issues. Google that test, its on YouTube. There is one test on the mono and one of the color so it should answer your questions.

For what its worth here's my tips on electronic assisted observing ...

1. Exposure times for Alt/Az mounts varies for different targets depending of their diff ALT/AZ coords. Stuff at the equator flies up in the E to W direction but little N-S. Stuff at the poles goes slower but more zig zag in ALT/AZ as it tracks around the circles of rotation. So in some areas of the sky you can only shoot for 5 seconds before you get star rotation and in other ares much more than that. How long you can shoot in each area of the sky depends on your latitude. The book Astronomy on the Go - Using short exposures (strongly suggest you buy that if this is a direction you wish to go) and google searches in general on this topic will bring up websites where folk have grabbed those tables and posted them up. IE there are tables for latitude 10 degrees, 20 degrees, 30 and so on. If you are at latitude 25 you just interpolate between the one for 20 and the one for 30 degrees latitude. The general rule which you see around on the web is 20 seconds. So if your google searches find nothing ... then 20 seconds is the go to start with. Experience will then allow you to tweak as you gain it.

2. Re gear slop/accuracy on the 6SE ... like I said ... the Atik inifinity test done by Atik was a std 6SE mount and 6SE OTA. However, if you are in doubt of your mount due its age or maybe you just have niggles that yours doesnt track well or something ... do a test run. If near an astro club someone there will have a DSLR and T ring to test with. If not near an astro club, then do you have a DSLR or such like camera. Just get a T ring and you can test it out. See point 4 below.

3. General camera tip ... Dont balance the OTA and camera to within an inch of its life as it will wobble on its balance point for sure! Make it slightly off balance like camera end heavy which is usually they way the 6SE or any SCT is anyway. Then gravity will keep one side of the gear teeth in contact all the time. It wont overbalance and teeter across the tooth gap to the other side of the gear teeth.

4. To test your mounts tracking abilities ... Do as precise a 2 or 3 star alignment as you can and then turn on sidereal tracking.  Take 10 shots at 5 secs, 10 at 10 secs, 10 at 15 secs and so on all the way to 60 seconds. Look at each shot in each series. You will find that there is some point where the central star appears oblong/trailed/blurred in more than half the shots, but still quite sharp in the other half. I'd stop at that point and use that setting as your mounts max. Dont worry about star rotation in the non central stars at this point, as you are only worried about the central star which shouldnt rotate, to see if your gears n stuff can track that central point for long enough to get reasonable results. If you find you can only get 5 good subs out of 10 when doing 15 sec shots on your 6SE ... well thats what you should use as your max exp time. Can you get good live-in-field-at-night "views" at 15 secs? You sure can!

5. Mono or colour ... IMHO for live-observing in-field it's all about do you want to see nebs in color and the star color temperature or not? That's what you have to think about. Remember you are aiming for in field adjustments on the fly with limited screen real estate on your laptop to ... observe ... and maybe save the odd image or two when you tweak up a keeper! You aren't trying to win the NASA photo of the day. If you were CCD imaging / true astrophotography then you'd want all the pixels to be dedicated to picking up light signals then you'd go mono, but then you'd also go a totally different route for your mount and OTA and dollar wise!

6. Speaking of dollars ... If you already own a Canon / Nikon / Sony DSLR or mirrorless you could get a T ring for it and start now without purchasing an Infinity. (Sorry Atik I know this is your forum It is great experience and if you already own it a cheap starting point and it works! Use the usb cable which came with the camera to connect it to the pc with the supplied software that came with the camera. I like Canons as the live view feature allows you to focus by looking at the image zoomed in the live view window right there in-real-time on the laptop. My old Nikon doesnt have live view and for it I snap a series of 2 sec ISO1600 shots of a reasonably bright (but not the brightest) star and use a bahtinov mask tweaking the focus with each shot until i see the spikes in the right place. So still do-able without live view! BTW you can crank up to ISO12800 (or whatever your camera will go to) for 3 secs to glimpse color and thus centre nebs and galaxies really quickly, then turn back to iso1600 (generally) for the main shots.

Over to you. Best wishes on your quest.

Ooops one more thing. Software. For live viewing with the DSLR and ZWO's I use their camera control software and I downloaded the free DSS software and the free AstroToaster software with which you can setup a seamless workflow in-field. Photos are auto saved via your DSLR camera capture software/usb cable/eye-fi card into a folder on the pc which AstroToaster auto monitors. You just sit and watch the AstroToaster preview window and see it counting up the stacks eg 1 of 5, 2 of 5, 3 of 5 etc and just tweak the color in the image on the fly using the black point, white point, brightness etc from seeing the first shot right through to the final shot. In the background unbeknownst to you, AstroToaster has used the DSS engine to derotate (!yes it derotates!), stacks, applies darks (if you use them - I dont as I use in-camera noise reduction). It works very well. Note it does not have a histogram like the Infinity software ... only a slider for blackpoint and whitepoint. But heck, seriously, if the image looks too bright you really dont need a histo to tell you that! Just raise the blackpoint until you get a dark grey (not pitch black which clips data!) background. So it's NOT as seamless as using the Atik Infinity software, but still quite acceptable IMHO. And cheap if you already own a dslr/mirrorless

cheers
Howie

[roelb]

Hello Howie,

Thanks a lot for your detailed/extensive reply.

An imported point to clarify: I don't have a DSLR camera.
In fact, until now I don't have any astrophotography equipment, except a focal reducer.

The YouTube videos I have seen from ATIK:
- with a mono camera done with a Celestron Nexstar 6 SE like mine: https://www.youtube.com/watch?v=JheW2PHKwcY
- with a colour camera done with a Celestron C11 with Hyperstar: https://www.youtube.com/watch?v=28nuK8X6xbw
So, I didn't find a test with the colour camera on the Celestron Nexstar 6 SE.

My standard Celestron mount is 2 years old, in very good condition.
But of course not as good as the Celestron Evolution mount with worm gears.

Your tip, not to balance the OTA so he can wobble, is very useful. I never thought about it.
On the other hand, I have never done that, even with heavier wide angle eyepieces.

Re. mono/colour. Since I want to have more pleasure observing the small Messier and Caldwell objects,
I thought a mono camera will be more suited because of the higher resolution.
I have all the "Deep-Sky Companions" from Stephan James O'Meara.
And the "The Secret Deep" and "Hidden Treasures" shows a lot of other NGC objects, worth to observe.
I also like to read some background information on the objects I try to observe.
Documenting my observation logs with an image would be satisfactory.
Nice colour images can be seen enough in glossy books and on the internet.

So these are some considerations to take into account.

Thanks a lot for your extensive response.

Kind regards.
Roland

[Howie]

Apologies Rowland, I am retired and it seems my memory and reading comprehension has retired too.  . The mono was demo'd on the 6SE and you are correct, the color was on the larger rig 11" hyperstar.

Have you decided yet which way you are going? I would love to see your results and hear how you are finding it.

Howie

[roelb]

Hello Howie,

Thanks replying. You've seen in the glass sphere...
Today, I just ordered my new "astro toys":
- Celestron Nexstar Evolution 8"
- Celestron Starsense (to save time for imaging and have a improved goto accuracy)
- Flexible dew shield
- Starlight Xpress Lodestar X2 mono (more sensitive then Infinity and thus smaller exposure times, avoiding field rotation)
- Celestron f/6.3 focal reducer/corrector (to obtain larger TFOV)
I'm planning to sell my Nexstar 6SE to offset the costs.
I do have also a SE5 tube (without mount, but with the original tripod with wedge), which I can use for bigger FOV DSO's.
I have tried to make a balance between: a better mount and a cheaper camera (but with higher sensitivity for smaller DSO's)
So, I think that I can plunge into EAA.
I planning to post my first trials on "Cloudy Night". I follow this forum since about 2.5 years.
I have already learned a lot from their threads.

So, again thanks for your valued comments and, because this a Infinity forum, perhaps I "see " again on Cloudy Nights or
another forum?

Kind regards.

PS: I'm also retired...

[Howie]

Have fun Rowland! Those evolutions are nice mounts. Maybe you've seen Mega-Bob / mega256 on CN. Yesterday I saw on his youtube channel his evolution mount with (tada) a colour Infinity! The video was just put up - it only shows as one day old when I just had another look at it today, so yesterday I must have viewed it when only an hour old!

Anyhow, I look forward to hearing how you go and will look for you on CN. One things for sure, and that's if you want to use cameras to see stuff and occasionally record a still shot of what we saw on the night, there's quite a few good options now. With competition we get progress, so its a good time.

For me, I think I will still keep saving for the Infinity. I like color, the (high) number of pixels, the sensor size suits my kit and I like the look of the software. Just wish the share market hadn't collapsed as being retired I ain't got any other income source!

Catch you on CN

Howie

[roelb]

Hello Howie,

For the record: my CN username: roelb

See you on CN!