Cosmic Geoff

42 minutes ago, Chrb1985 said:

My concerns are of course the mirrors and the corrector plate and im considering cutting 3hiles in the rear for vents with filters 12v and one in front, mabye som more holes to lighten the weight? And i plan dissasemble the whole thing and grease the threads and clean the inter thing inside with kirros and maby add some dark "tape" since i herad this is a smart thing to do whilst ut is already open. Please weigh in here.

If I were you, I would resist the temptation to do any of this.  In the photos the mirrors and corrector plate look okay, so my recommendation is to leave well alone.   The suggestion of cutting holes in the tube makes me shudder.  Unless it is very old, it should not need any re-greasing.  I have a C8 which I bought used and which must be over ten years old by now and it works fine.  No dismantling, no extra holes, no servicing. 

Re the 10/20/30 second exposures on the Seestar S50: My experience of doing EVAA with a 102mm refractor is that the longer the sub exposure time , the brighter the image, and  live-stacking more subs mainly reduces the noise.

With the Seestar, my initial impression on trying 10 and 20 second exposures on the same object was that the 20 sec version was brighter.  My provisional conclusion is that a lot of objects would benefit from using the longer exposure.  If one examines the raw 10 sec. subs, a lot of them require extreme stretching to make anything at all visible.

32 minutes ago, Elp said:

Was it down to the seeing or the tracking of the standard mount. The bundled mount is alt az so unless you're using a Hyperstar lens, long exposure DSO imaging is next to impossible, but EAA should be fine as long as the short exposures don't star trail. With an EQ mount F6.3 imaging and Hyperstar imaging is fine, but once you do the latter you'll very rarely image DSO any slower unless you want the resolution gain from the longer focal length.

C8 SE: The altitude control was not very good, with a tendency to overshoot.  Acceptable for visual use, but  it wasn't capable of doing more than keeping a planet on the cropped sensor with some use of the handset when taking a short video, while watching the laptop display.  As I noted above, a pain.  The CPC800 and EQ-5 Synscan perform far better.

With a f10 telescope, f6.3 reducer and a smaller sensor, the small-ish field of view that results mostly limits you to doing EAA of smaller objects like planetary nebulae or globular clusters, and you also need a decent mount that will track well for exposures of 20 secs or so.

I have a C8 SE, so can advise you that while it is good for visual use, it is not so good for imaging. You can do planetary imaging with it, as I did using a planetary camera (ASI 120 MC and then ASI224MC), and a used business laptop running Sharpcap on Windows, but the mount made it a bit of a pain and I later bought another scope with a more substantial mount, to use for planetary imaging.  (Note there is no need to use an Asiair or other fancy stuff).

As for EAA or deep space imaging, the deficiencies of the mount convinced me that it wasn't even worth trying.  If you want to do either, I recommend that you buy some other kit more suited to the purpose.   I have a 102mm f5 refractor and a EQ-5 Synscan mount that I use for EAA and some basic deep space imaging, along with a laptop and Sharpcap.  NINA and similar software suites are only advantageous for serious deep-space imaging. 

14 hours ago, Urumiko said:

I think I've got my eye on the The Celestron NexStar 130 SLT , which is a 130mm newtonian with larger aperture and is F/5. and seems reasonable build quality. Celestron also make a sony e-mount to T adapter for it. That said it is a little more than I intended to spend but I could afford it if its worth it.

This outfit would be a reasonable starter for visual use, but its utility for imaging is limited. The SLT tripod is on the wobbly side and the mount is alt-azimuth.

59 minutes ago, Elp said:

How does it cope with tracking at these exposures?

I couldn't see a difference between 10 sec and 20 sec exposure stacks of the same object & field, except that the 20 sec stack was brighter. 

On 10/01/2024 at 15:50, Elp said:

and the short 10s exposures are its main limiting factors,

It now has the option of 20sec and 30 sec exposures in the advanced settings.

Unless you buy a Seestar, serious imaging will require a four-figure bill for equipment and a steep learning curve for image processing and installing various bits of kit.

I suggest you buy Steve Richard's book "Making Every Photon Count" before buying anything related to imaging (other than the Seestar).

AFAIR your Astromaster does not have a good reputation, so best get a refund and see what FLO has to offer.

I have the ZWO  ASI120MC, the ASI224MC and the ASI462MC.  They all work, but the ASI462MC is the best of the three. Note that the ASI462MC is now discontinued.  ZWO frequently introduce newer and more capable cameras.   Note that you may also need an IR-cut filter, depending on which camera you buy.

Sharpcap includes polar alignment.

53 minutes ago, jweaver100 said:

The only problem is that it has a Security light.... Lets assume the S50 is stacking photos for a long period.. What would happen if the security light came on during one of the 'frames? Would the software recognize this and discard it... Or would it try to 'stack' it with the others affecting the quality?

With the recent software versions you get three versions of the stack : a processed image on your smartphone, a composite fits file on the S50, and (if you select the option) a set of fits files, one for each exposure.

The practical effect of this re your query is as follows: I imaged NGC2024 and found that the Iphone image had a pair of white lines across it - presumably an airplane track.  On investigation I found that the white lines appeared on only ONE sub out of about 200, and after deleting that one I processed the files with Deep Sky Stacker and Siril, to get a slightly enhanced image with no white lines.

You don't need an auto focuser. I don't use one.  Resist the temptation to buy unneccesary stuff which you will try once and then leave in the box.  Get some experience using the scope.

You need to focus Jupiter via the laptop screen - you can use software aids or just focus on the cloud bands (I do the latter).  It may not look sharp but just focus for maximum sharpness. Alternatively temporarily brighten the image and focus on a moon. 

Your flip mirror assembly should have a separate focus adjustment for the eyepiece. However it does not matter if the eyepiece view is out of focus as you are only using it to line up the scope with the planet.

In short, the eyepiece and the camera are NOT parfocal.

10 hours ago, jweaver100 said:

As I have a 3D printer, I have been making accessories ready for delivery... I have made a Bahtinov Mask and I am not actually clear what it does, or how its used on the S50? I believe its something to do with auto focus.. But how exactly would you use it on the S50 which has auto-focus?

The autofocus works fine without a Bahtinov mask.  I have not obtained or made any accessories for my S50, which I received in September. The only sensible accessories IMHO are a taller tripod, or alternatively a 3/8" spacer/adapter to mount it on a standard astro tripod.  And a reflective strip so you can see where the S50 is pointing in the dark.

Study this table carefully, after setting it for your position on Earth:

https://heavens-above.com/PlanetSummary.aspx?lat=51.993&lng=-0.7242&loc=Unnamed&alt=0&tz=GMT

I draw your attention to the angular size of Mars, and the time it is highest in the sky (meridian crossing).

What do you think is the likelihood of seeing anything of Mars with your telescope?

Compare with the view of Jupiter which you should be able to find any evening.

The Celestron f6.3 focal reducer is specifically intended for f10 SCTs, and may not work so well with a Maksutov.  See this thread here:

Skymax 127 Maksutov-Cassegrain with Focal Reducer - Cats & Casses - Cloudy Nights

"Try with what you've got" is a good policy, but you may get better results with a small imaging refractor.

I have the Startravel f5 102mm.  It has significant chromatic aberration, and I made little use of it till I found it worked well for EVAA (q.v.)

I would not recommend the EQ1 or EQ2 mounts - too wobbly.

5 minutes ago, Lung said:

No objection, just wondering whether I can simply swap out the tripod in the Astro-Fi bundle for something more sturdy if I find the included one too wobbly,.but keep the Goto mount and OTA.

As I just explained, you can't. The Astro Fi 127 tripod has a bowl-shaped head.

5 hours ago, Lung said:

I'm having a quick look at tripod options for the Celestron Astro Fi 127, but the base of the mount seems to rule out everything. Can anyone suggest a tripod that would work with the mount, or a modification that could sort it?

I am not clear what your objection is. If you buy this and decide you don't like the tripod, you will then have to buy a different mount and tripod and attach the OTA to it via the standard dovetail.

TBH the tripod does look on the flimsy side.  I am looking at an ebay photo for an Astro Fi 127 on offer for £547.*  It is common for the tripods of entry level kits to be on the wobbly side.  The tripod of my Celestron 127 SLT Mak was more wobbly than I would have liked, but I used it for a while.  (I also acquired another tripod head and made wooden legs for it, but that was a lot of work).

Unless you can identify a suitable mount that can be swapped onto a more substantial tripod later, you will have to resign yourself to either putting up with a tripod that may not be as rigid as you would like, or  buying an OTA and pairing it with a rigid mount and tripod, which if you go for a mount like the EQ-5 Synscan or the Celestron AVX, could cost you a lot of money.

*A potential for profit when the £300 offer expires? 🙂

You can do planetary and lunar imaging with a C8 SE, but it will be a pain because the mount is only suitable for visual use.

The 183C looks like overkill for planetary imaging (or solar),  and you will not manage much in the way of deep sky imaging unless you buy a more suitable mount, like the HEQ5, AVX or EQ6. You will probably also need some gear for autoguiding.

1 hour ago, GasGiant said:

Id like an allrounder, I guess.  But not only that, Im interested in learning about editing and stacking etc 

There is no such thing as an allrounder. 

If you buy a Seestar S50 you have the option of editing and stacking its output to your heart's content, or just using the image sent to your smartphone.

I suggest you invest in Steve Richards' book "Making Every Photon Count" before you reach for your credit card to buy any separates imaging gear.

22 hours ago, Lung said:

No love for the Astro Fi at such a low price? Poor little Celestron 😆

For £300?  Why is it so cheap?  Looks like you would be getting the same OTA as mine, plus a free mount.   Good OTA, basically the same as the Skywatcher 127 Mak.

I seem to recall the 6" SCT astro fi being offered at such  low price that one was effectively getting the OTA + a free mount.

20 minutes ago, Beardy30 said:

Hi , when connecting my zwo camera to the T2 adapter - to add a filter do I attach it to the end of the T2 adapter before placing into the diagonal? 

Yes, that will work.

It's up to you whether you swap the C6 SE for the C8 SE.  There will be some gain in performance, OTOH it's bigger and heavier, more load on the mount (it's the same mount).

I suggest that you stop fretting about eyepieces till you have used the scope for a while. As we have already pointed out, with a f10 scope, the choice of eyepiece is not critical.   There is no relationship between Bortle and seeing, vs magnification, other than that higher powers may get less use if the seeing is bad. 

Since you have the DX130AZ, I don't quite see what you would gain by swapping it for the DX5.  The DX5 has a more compact optical tube but is not obviously more portable.

SCTs are great scopes. They are more expensive than Newtonians because they are more difficult to manufacture.  They do have a narrower field of view, a fact which is trotted out every time SCTs or Maksutovs are mentioned, but the practical consequences of this are exaggerated.  Note that the other scope which 'everybody' tells beginners to buy, the 8" f6 Dobsonian, has roughly the same field of view as the DX5.

I should think that the DX 130 and the DX5 perform much the same on DSOs, if you set them up for the same magnification.  Which if you are observing from New York City means "not much to see".   Extended objects of low surface brightness, like galaxies cannot be seen well under light polluted urban skies.