Clarkey

NGC7129 in Cephus. Approximately 13 hours of HaLRGB data over two nights from early October. Seeing was not as good as I would like. ASI1600MM pro and Stella Lyra RC8, processed in PI. Not too unhappy with the result, but the background is still a bit noisy. Probably pushed the data a little too hard to get the nebula detail.

Constructive criticism and comment welcome.

16 hours ago, CCD-Freak said:

F2.8 speed is where it is at

I do still like the look of the Sharpstar- in particular using mono and filters. Feedback from FLO seems to be that most of the earlier issues with the primary mirror.

Blimey, that must have been some gust to do that. Have you checked your focuser alignment? It might be a simple job of realigning? (Far from my area of expertise, but I would check that first).

You won't need anything, but a dual band filter will allow you to image HOO with a colour sensor. Also, helps if imaging during a full moon.

You don't say what mount you are using. At the end of the day, it's the most important part of the set up.

With my ZWO camera it came with the correct spacers to give the 55mm back focus required. As far as I know this it still the case.

Unfortunately, I sold my ED80 which I have come to regret. It is a great all-rounder for visual and imaging.

Assuming your 0.85 reducer is the standard SW flattener/ reducer, it with readily combine with your image train.

Also, the 294 is known to be a bit temperamental with flats, so the 533 I'd probably a better option.

Those are some cracking images - I love the 3D look.

I have tried to image the Wizard a couple of times, but I have failed dismally to do it justice. Even with long integration, it never quite looks right.

You have got further than I did. I did 2 nights last winter from my bortle 6 garden and ended up binning all the data. It was just too noisy to be any use. Not sure you'll get much from SE London!

I think the Samyang 135mm lens recommended by @Elp is a good shout. This will work with a standard star tracker or mount. You might want to consider modifying your DSLR so it will pick up H-alpha signal much better than unmodified. (There are filters that can be put back into the camera so it can be used for terrestrial use without messing up the white balance). The 72ED is a reasonable scope to image with but you are getting towards the need for guiding. It might be worth you looking at the AZGTi owners thread on here. There are plenty of people using this set up (modified for EQ use) and getting good results.

My first image processed 100% in PI. I still struggle with the interface - but it is starting to make slightly more sense to me now. I still find Affinity easier to work with, but I'll get there eventually.....

Imaged using my trusty ASI1600MM pro in LRGB on a StellaLyra RC8 reduced to F6. Taken over 2 nights last week, with a total integration time of just over 14 hours. Stars are a little mis-shaped so I think I need to do a little bit of collimation.

Critical comment and review welcome.

I think for capture only a pretty basic laptop will be fine. I have a very basic one (with usb3 and SSD) and it is more than adequate. However, if you are looking to process as well then it's worth getting something better. I process on a separate desktop PC as the specs are much better for the price.

3 hours ago, billy86 said:

kinda wish FLO offered finance

No! No! No! Through no fault of there own (other than selling astro kit) FLO have managed to make me a poor person. Finance would make me bankrupt🤣

I think everyone feels that this year has been pretty poor in the UK. Mine has been pretty awful until the last couple of weeks when I did get 4 clear nights.

I just hope this is a 'glitch' and not a sign of things to come.....

You can get m42 adaptors for 0.75 to 1.0 pitch. I think I ordered some from fleabay. Also, if you search online you should be able to get the back focus for your lens. If you get a variable adjuster it will give you some wriggle room.

This is the one FLO sells with the ST80 as a guiding package:

Astro Essentials 1.25" to T / M42 Thread 65mm Focus Extension Tube | First Light Optics

You can add an extra M42 extension which will allow you to rack the focuser in a bit and make it more stable.

20 hours ago, Rico said:

Only issue with it, is that if you want to get the most out of it for astrophotography, you need to invest in a better draw focuser

You might be lucky. I had a good one and the stock focuser was OK for imaging - but they are a bit hit and miss. I did have to file the draw tube and adjust the settings, but it was OK.

Yes, you will need an extension of some sort. I use the ST80 as a guide scope and it needs a lot more back-focus than the focuser allows. From memory you need something like 70mm extra.

The RCA ports are 12v pwm outputs whereas the USB few bands are 5v, so I suspect they will be overloaded. You could get a 12v usb port to do the job with a bit of DIY. The other option is a 12v powered usb power hub and put an RCA plug on it.

Much as I find Pixinsight a right PITA, I have started using it - mainly for the Russell Croman tools. Also, I do believe if I ever get proficient it will give the best results. However, if I was ever to design a user interface it would be the opposite of PI. I did use Astro Pixel Processor and Affinity photo for some time (Affinity is a cheaper version of Photoshop but very similar functionality). Even with PI, I still use Affinity after to get the image looking more how I want. I suspect this is more to do with lack of ability in PI, rather than the software itself. If you want quick and easy results, give Startools a go with the free trial version. Personally, I don't like what it does to stars - but just going through using all the defaults will give you an acceptable image.

Personally, I would keep the ED80 and get another scope to complement it. I sold mine and I have somewhat regretted it since. They are good for both visual and a starter scope for imaging. Maybe add a Mak or SCT for planetary imaging / viewing and you would have a reasonable pair of scopes for general viewing and imaging.

@ollypenriceand @gorann - I see what you mean about the square stars. Just checked out some images on Astrobin.

From all the above information, it looks like the general advice is towards the RASA. I have contacted FLO regarding the mirror issue and it would appear to be a limited number of poor examples. I will have quite a bit of time to think about it - the new ones are not expected until Dec / Jan. Having read lots of threads on here and CN, there seem to be fans and supporters of both options. However, as there is a knowledgeable crowd on SGL regarding the foibles of the RASA - best stick with what YOU know. I will undoubtedly be back with more questions in the new year. (SWMBO permitting of course)...

10 hours ago, gorann said:

but that the smaller stars are squares and not round

Probably a dumb question, but why? The only reason I can see it due to the resolution, but that would be the same on any 400mm scope.

Thanks for the replies - really useful information. 

1 hour ago, fwm891 said:

. If you chose a camera like the ASi533 with a 6.5mm back focus then you will have the option of fitting a filter drawer and use various filters with your RASA. If you chose a camera with a 17.5mm back focus you can’t fit a filter drawer and you are limited to finding a way of attaching individual filters and fitting them to the camera before you attach the camera to the RASA each time. Changing filters and realigning the camera being somewhat awkward!

This is a bit of an issue. I was unaware there was no space with the longer back-focus. I have an IMX571 Risingcam so this could be a problem.

1 hour ago, Elp said:

The alternative option would be the Edge HD 8 and Hyperstar,

I think the overall cost rules this out - I had looked at it. Also, I already have a RC so I do not really need a longer FL

41 minutes ago, ollypenrice said:

Obviously a dew magnet? Certainly not

Good to know. I assumed given it had the front plate it would attract dew, but this is clearly not the case. Also, as @Elp says, there is the option of the Celestron dew heater - I assumed these only fitted the SCT's.

From the replies above, the general consensus seems to be the RASA is the better option. I was aware that the 8" version was out of supply for months, but I was unaware that this was a QC problem. I have noticed that FLO are now showing them as in stock soon which is the first time in months. I just hope the 'poor' mirrors are obvious and I don't spend ages trying to fix the unfixable.

1 minute ago, saac said:

I also think people hang on to these scopes, haven't seen many for sale second hand

No - I think you are right.  Much as I would like an 11" scope, my budget won't stretch to that.

Now I just need to get my 'financial planner' to give me the go-ahead. (Some grovelling may be needed🤣)

Due to the very limited times that I can image, I am seriously considering one of the two scopes above to allow much higher data collection rates. In terms of FL, both are pretty similar at 400 and 420mm respectively. The RASA is quicker at f2 compared with f2.8 for the Sharpstar. Obviously, one is a dew magnet and the other gives diffraction spikes. The Sharpstar also claims to work with a full frame sensor which is much larger than the RASA, it can also work with a mono camera (if you can afford the filters).

However, what I would really like is some real world experiences. I know the RASA can be difficult to set up, with tilt being an issue and similarly high-speed Newtonians can be tricky to collimate. I also know the early HNT scopes had issues with the mirrors moving - but I believe this has been fixed. For anyone who owns or has used either of these scopes, I would like some opinions.

Thanks in advance,

Ian

25 minutes ago, alacant said:

two per month if we're lucky

In a typical month I am lucky to get this many days imaging. I do not even look at the seeing / moon - just do what I can, when I can.

Having said this, my RC8 is reduced and binned to give 1.5"/pixel and the only other longer focal length scope I have is 800mm. So in reality I do not do any 'high resolution' imaging.

It's a nice looking cluster - sharp stars and natural looking colours.👍