Dan13

Great stuff!

5 minutes ago, vlaiv said:

I think that you are looking at it the wrong way: Scope might cost £170 for visual - but it costs £310 for AP (CC price included).

Evostar 72 costs £270 for visual, but £455 for AP - you need to add the price of field flattener.

There are scopes that you can use "as is" - without additional optics - and yes, you can get one cheap - but it is another level of imaging in terms of resolution and imaging process  - something like this:

https://www.firstlightoptics.com/ioptron-telescopes/ioptron-photron-6-ritchey-chretien-telescope.html

Then there are scopes that are not as cheap - and don't need additional optics, but still keep you in the "ballpark" of 130PDS - something like this:

https://explorescientificusa.com/products/152-maksutov-newtonian

Thank you Vlaiv, i agree with you and i think now im being very impulsive due to not finding what i wanted!  im going to stick with the 130pds and grab the CC im in talks with now. many thanks

7 minutes ago, jambouk said:

Impressive aberration; I can see why you want to get a corrector. Maybe put a wanted advert on astrobuysellUK and see if you can get one for £80.

it is indeed isnt it. Ive done just that and im currently speaking to a chap now ref one. he advises that the SW one no longer reducers to x.09 and is just plug and play. I've just checked this on rother valley and they say the same...so maybe after all this time SW actually took note of all the backlash they got for it and took the reducing part away from the CC?

M51 last week with the 130pds 

7 minutes ago, Peter Drew said:

A coma corrector could be used on subsequent telescopes, a one off purchase.     🙂

thats a very valid point

9 minutes ago, jambouk said:

I’m not sure what you’ve read about cutting things... I would have thought you stuff the corrector in and it either helps reduce coma or it doesn’t. Show us one of your images with coma.

The SW CC apparently needs you to cut a few mm off the focuser tube so it doesn't protrude into the mirrors view..

this is a single light frame at 240 secs of M51- converted to PNG from CR2

4 minutes ago, andrew s said:

Ok toss a coin, heads refractor tailes coma corrector. Don't  go with the result but your emotional response to it.

Regards Andrew 

good idea!!

4 minutes ago, jambouk said:

I find refractors easier to work with personally, than reflectors, so if someone was starting afresh I’d say go for a refractor. But I suspect there is little difference. A short tube refractor will probably have a shorter focal length and wider field of view, which if adding in a reduced/flattener on top will give an even wider FoV - if this is important. Horses for courses.

 

Food for thought appreciate it. Im sure if there was a plug and play CC for the 130pds id just get that but where i read you need to "cut this" "cut that" and weird reflections after installation etc its just really put me off..

1 minute ago, andrew s said:

Might you need a field flattner for the refractor ? Do you want a drop in aperture? 

Regards Andrew 

 

i would yep, i guess it was really do i spend on the 130pds or buy and spend on a refractor, will my results be that different that i seen the monetary gain from it. think im being impulsive , that tied in with the dilemma of a coma corrector has just stumped me....

Just now, jambouk said:

For most short tube refractors you’d need a field flattener which probably costs as much as a coma corrector...

James

Just been looking at that James, thinking to 130pds may still be the best bet. Im not opposed to upgrading further to say a William optics zenith or something alike but im really not sure its going to give me a world of difference in results and fell im being impulsive

Hi, Im after some advice as im a bit torn on what to do. I currently image with a 130pds and a HEQ5 pro. My imaging is starting to come along and im in love with the hobby. To better my imaging i would like to resolve the coma im getting in my images at the far edges.

Now theres countless threads on how bad the SW CC is and to go with the Baader one etc, believe me its all ive done the last few days  

My issue is that although the 130pds is a fantastic scope and i adore it, im not sure i want to pay £140 for a part for it when the entire OTA cost only £170 itself. Im wandering would i benefit from using the money and say buy a 72ed or an 80ed refractor and keep the 130 for visual??

Am i being silly and should i just get the CC or should i go the refractor route, or another route if theres any other suggestions?

many thanks for any help it would be greatly appreciated.

Dan 

Ah ha! I've just seen it's not the length of the SW Cc itself that the issue it's that it also reduces down to x.9 so you have to wind the focusser all the way down to within 7mm which then protrudes into the aight of the mirror, hence why people took a hacksaw to the fuccuser tube 🤣

7 minutes ago, Stub Mandrel said:

Not sure about this, it's far shorter than the tube.

A lot of people shorten the focuser tube though.

Ok thank you. 

Yes I've seen a fair few in this forum advising it but not sure if the one I linked above is a newer version as this seems pretty small. 

1 minute ago, TheCounter said:

Here you go:

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p6706_TS-Optics-NEWTON-Koma-Korrektor-1-0x-GPU-Superflat-4-Element---2--Anschluss.html

That's a recommendation from a few colleagues.

Thank you! 

Quick question, I see a lot of threads saying the SW CC is to long for the focusser but the one linked below seems pretty small to me? 

https://www.rothervalleyoptics.co.uk/skywatcher-2-coma-corrector.html

58 minutes ago, TheCounter said:

I had the MPCC too, but I switched it for a GPU (TS Superflat GPU).

First light is tonight. I'll report back as soon as I have some results.

What I can say for sure, it fits so much better into the focuser tube, without any play or tilt. I always had issues with the MPCC not fitting correctly or tilting.

Thabk you. Results would be great from tonight. Do you have a link for the product please?

Hi, when played solving in APT it gives you the circle in the centre of the screen, I guess to replicate the telescope. 

Can you change it to replicate your camera sensor like you can in cartes seen below? 

1 hour ago, spillage said:

I use the baader one and I can agree it is fussy about spacing. I found that starting at the recommended spacing and then just adding/removing a few mm will clearly see which direction you need to move it and then you can do you fine adjustment. I remember that the recommended spacing was not correct for mine and I think I need to add some extra.

(still not 100% happy with the results but maybe due to movement in the train as it have been moved about or just tracking.)

Thabk you spillage. That's food for thought. You had any experience with the SW one?

19 minutes ago, Stub Mandrel said:

Plenty of folks. Consensus seems to be that the Baader has better control of reflections of very bright stars, but is fussy about spacing - the Skywatcher is fit and forget.

Ah ok thanks stub. I only looked at this opposed to the SW one as I've read theres problem with the focus tube protruding into the scope chamber with it? 

10 minutes ago, MarkAR said:

Very well done, super image.

Thank you Mark appriciate it. I'm getting there. 

not sure if im in the wrong place to post this but has anyone used this with the 130pds? 

https://www.rothervalleyoptics.co.uk/baader-mpcc-multi-purpose-coma-corrector-mark-iii.html

1 minute ago, Ouroboros said:

Lovely image. It is a very beautiful galaxy isn't it? 

Its beautiful @Ouroboros im not long in to the hobby and have really struggled with the galaxy images but things are starting to click, and seeing the real beauty in them now  thank you for your kind comment.

Really happy with the colour and detail i pinched out of this one

Skywatcher 130pds

HEQ5 pro

Zwo asi 120 mm-s / Zwo mini scope 30mm f/4

Cannon 600d

55 x 240 secs

Software.

APT

PHD2

Sharp cap for PA

Dithering  through APT

Pixinsight for all stacking and post processing

Thank you! This was invaluable at midnight in the freezing cold trying to plate solve M51! 

Worked a treat good job, excellent info.

Any pointers on dithering within NINA? I've read mixed opinions on movement in terms of pixel settings. Some have said 3 pixels some say 10?

I'd like a smaller wait time while dithering so something around 10 secs ish would be good.

I'd be looking to image about 40 frames, would you think every other sub or every sub.

Many thanks 

20 minutes ago, david_taurus83 said:

Your guiding is good. Dont concentrate too much on what the graph looks like. You will have good nights and bad  nights. Look at the stars in the subs.

Thank you David. Stars look good, so I'm happy atm. I will change the exposure rate just to see but other then that by the looks of it , it could be a if not broke dont fix it sort of thing