AbsolutelyN

31 minutes ago, ddm4313 said:

Looking to get a coma corrector, but not sure which, there is this one https://www.firstlightoptics.com/coma-correctors/skywatcher-coma-corrector.html and have seen good reviews about it 

That's the one I use, does the job perfectly well for my 250pds. It's not been in stock for a long time but they come up second hand every now and then.  

Edit - I've never experienced any reflection issues or indeed any other issues. Bought second had for £105 couple of moths ago.  

22 minutes ago, CraigT82 said:

Interested to see this comparison but tifs of 50mb each is a bit large, not to mention my device won't open them! Could you convert jpeg and repost? 

Cheers

The moon is a bit bright for galaxies at the moment so I pointed the scope at a HA target as far away from the moon as possible from my view point. Unfortunately the Elephant's Trunk Nebula is still low in the sky so noisier that I would have liked.

6.3 hours with 250PDS and ZWO1600MM

https://www.astrobin.com/knu7vt/

2 minutes ago, callisto said:

That is lovely and crisp...very nice 👍

 

Mark

Thanks Mark. I was interested to see far I could sharpen it without it looking overdone. Always hard to judge and generally look at it next day and you conclude it is over sharp after all ...  

The moon is getting too bright for my (deepsky) liking but is always truly amazing when you take time to actually look at it.  250 frames with 250PDS and ZWO1600MM at about 7:30pm. 

M106 and surrounding galaxies. I was particularly drawn to the varying scales of all the galaxies, from big to barely visible. 5.5 hours with 250PDS and 1600MM. Taken 15th April 2021

We had our willow tree pollarded in April so I grabbed this quick picture before it sprouts back to life. When stood in the dark you could feel its presence behind you.  About 2hours of 30 second exposures stacked with Sony A7R3 and Sigma 14-24 2.8 lens. Taken 12th April 2021.

9 minutes ago, Neil27 said:

The biggest key to great customer support is whom you buy from. There are many dealers out there in the market place and getting the right one can make or break any purchase when the s**t hits the fan. Having dealt with FLO, RVO and Modern Astronomy recently I have no hesitation in recommending any of these.

Regarding your mount, there’s an old saying that I’m sure you may be familiar, always get more mount than you think you need, and the mount is the key to a stress free time in this hobby. If I was you I would seriously consider the CEM 120, it has the carrying capacity, a fair reputation from what I have seen both sides of the pond. Another option would be to wait for a suitable second hand mount, there have been instances of Mesu mounts for around 3.5k, AP mounts for a little more, even EQ8’s for around for around 1.5 to 1.8k if you want to ‘fettle’ it.

Happy hunting and good luck.

Thanks Neil. If buying new it will be with FLO as I know they will sort any issues. Good point on second hand. 

Does anyone have any experience of iOptron support? For instance I needed to replace main board on my AZEQ6 a couple of years ago and it was very quick and easy to get a replacement from OVL. Never had any dealings with iOptron and can't say I'm impressed with their website. 

2 hours ago, oymd said:

With such a LARGE and heavy scope like the 250PDS, I think you need to consider the moment arm as well.

It's not just that it's almost 15kgms, but due to it's diameter and length, it will act as a huge sail on a tiny boat.

I think that the CEM120 is the least you should consider.

And as the saying goes...there is no overkill mount...

It certainly does act as a sail but given calm conditions you can get very good results with it even with a light weight azeq6. Lots of great points here, it's now very clear CEM70 is not up to it and CEM120 is needed. I think I was a bit taken in with the 32kg and hope that there might be a cheaper option.  Clearly not. 

44 minutes ago, CedricTheBrave said:

I am in the same boat, currently with a NEQ6RPro and my new scope (which I always knew) is too big.

so I am deliberating on the CEM70 or the 120

So far I am erring on the 120 as the 70 will be on its limit for me.

so saving my pennies! (and waiting for stock)

also have to build my obsy first!! 

think I have gone mad

I dread to think when these things will be back in stock ... I guess it leaves lots of time to save up. 

33 minutes ago, david_taurus83 said:

I've not seen a CEM70 in the flesh but I did have an AZEQ6 and I would have lumped them together in the same weight class? Not sure you'll see the performance increase your looking for? I have the CEM25 and only have 6kg on it and balance is really critical. If its slightly out in Dec and RA it guides all wonky but get the balance just right and its great. I wouldn't like to try and balance a 250P on a CEM mount! The 120 might be better suited though. 

You're right, I guess I was hoping something more affordable existed 🙂 

2 minutes ago, vlaiv said:

I've looked at CGX-L when it came out - and for some reason I just did not warm up to it.

There is not much detail on how it performs (that I could find) - and to me, it looks more like 0.6" RMS mount than 0.3" RMS mount like iOptron CEM60/120.

Maybe it is just my imagination, but I classify mounts by their guide performance and CEM60/120 are 0.3" RMS class mounts. HEQ5/EQ6/EQ8 are 0.8" RMS (stock) or 0.6" RMS (modded). Mesu is 0.2" RMS range. I could be very much mistaken - but those are sort of figures that are in my mind when someone mentions those mounts.

For large aperture scopes it really is worth having mount at 0.3" RMS or below (of course - payload should be respected as well and it is always better to "overmount" then "undermount").

That's really interesting thanks. I was drawn to the EQ8 because I've used their support before which was ok but iOptron is totally new to me. Looks like it is the way to go for my budget.  

2 minutes ago, vlaiv said:

There is one more mount that is in the pipeline and looks very much like iOptron offerings.

Not sure when it will be available, nor if it's going to be good budget option.

https://www.primalucelab.com/world/equatorial/skywatcher-cq350-pro-synscan-mount.html

although it does say that it is CEM60 replacement - so not much better than CEM70.

Thanks that's interesting. Is it a daft question to ask if the Celestron CGX-L is in any way comparable to the other mounts in same price range?  

13 minutes ago, vlaiv said:

CEM120 or Mesu as higher end offering. Since Mesu is way out budget wise - then I guess CEM120?

Thanks, I infer from that the CM70 won't really cut it then. Better start saving. 

12 minutes ago, DaveS said:

Mesu?

Unfortunately way out of budget. I think they are in region of £6k and ideally I’m looking for half that.

My 250PSD is pushing my AZEQ6 mount to the limits and it often struggles to guide acceptably for even 2 mins so I'm looking at upgrading my mount. I'm trying to think long term as in I don't really want to have to buy another at a later date but I also don't want to spend a fortune on an overkill mount. 

It will be used with my 250mm Newtonian but in the future max weight scopes I can see it might need to handle could be a 300mm Newtonian or perhaps a RASA 11. 

The CEM70 seems to have a recommended weight for astrophotography of about  21kg (2/3rds of 31kg) which is fairly reasonable given with care you can push them a bit like I am currently doing. It won't be setup in an observatory but it will be semi-permanent so setup times for mount does not concern me as I only do it a couple of times a year. 

However my query is am I better simply saving and going for CEM120 or EQ8R? They are considerably more expensive so other than weight capability will they perform much better or is it diminishing returns?

Any thoughts really appreciated. 

M82 taken over the last two nights where I managed to get 9.6 hours altogether. Taken with the SkyWatcher 250PDS and ZWO1600MM. 

https://www.astrobin.com/yicme0/B/ 

That's amazing! Well done

4 minutes ago, Paul M said:

That's a very nice image. Sometimes images of M51 that have been processed to bring out the nebulosity can look quite overcooked. This one is very nice and natural; and the detail when I zoomed in was brilliant!

Much better than my recent attempt with my 250 PDS and ASI178 camera. I keep blaming the lackluster performance on the camera not being a good match to the scope. But I think it's the biological component of the imaging train where the problem lies   

Thanks. The 178 pairs very well with the 250pds but I've only used that on mars, might be tricky on deep sky. 

9 minutes ago, knobby said:

Really nice image 👍🏻

Was this 60 seconds RGB?

Any luminance ?

60 seconds per filter - probably 50% luminance. I find you don't really need that much colour. Did fine with just 20 mins blue the other day

4 hours ago, CraigT82 said:

Well the frames that made it were absolutely spot on! Your stars look perfect to my eye and there are so many faint little galaxies in the background that I haven't really noticed before and would probably just totally disappear with poorer tracking.

Just goes to show what a 'budget' mount and a 'budget' scope can do in the right hands!  👍👍👍

Tracking was at best 0.8, it really deserves a better mount. Quite amazing how sky quality makes a big difference too - images earlier in the week were so much easier to get the colour right, this one was awful to colour balance. 

4 minutes ago, CraigT82 said:

That's a real belter! Stunning when viewed full sized. What were the exposure lengths for this one? 

Thanks Craig. It's just 60 second exposures. The guiding just wasnt good enough to go any longer and out of two full nights about 50% of the frames had to be discarded due to either bad stars or haze. 

Cracking image Lee!

The sky has not been quite as transparent the last two nights so this one took two nights due to bad guiding and the colour was much more difficult. I've gone for a 16-9 crop because I wanted to keep in the little galaxy on the right but not sure if it quite balances. Best viewed bigger as the crop makes the galaxy quite small.

6 hours with 250-PDS and 1600MM. Full res on astrobin - https://www.astrobin.com/h1lzm3/ 

The revision attached show my very first attempt at this galaxy - by chance just happens to be 6 years ago to the day. EOS-M with a Vixen 80SF