Alternative to a SW 150P-DS OTA

[Steve789]

In my quest to correct the coma from my images I've had to sell my old Skywatcher 150P with the 1.25" focuser as 1.25" coma correctors don't seem to exist and I was very short on back focus. So now the question is what to replace it with.

The replacement will be mounted on my HEQ5 and used with a DSLR and must be able to reach focus with a coma corrector. I've thought about going for an F4 scope but the general consensus seems to be that the necessity for accurate collimation isn't worth the hassle so I'll be looking for an F5. I'm not at all bothered about accessories and don't even need a finderscope. The scope will be used purely for imaging DSOs and I'm only considering reflectors as that's what I have experience with.

The most obvious and boring choice is to go for a new 150PDS and the skywatcher coma corrector but before I make an order I wondered if there is a better alternative in the same price range. I've read that the focuser on the 150PDS shifts when applying the locking screw and this concerns me somewhat. I don't want to add a focuser upgrade to the endless list of desirable items I already have in my head!

If anyone's got any alternatives I'd love to hear them, especially if you've been able to compare it against the 150PDS.

Thanks in advance

Steve

[nightfisher]

http://www.altairastro.com/product.php?productid=16588&cat=271&page=1

http://www.altairastro.com/product.php?productid=16420&cat=268&page=1

A couple of options for you, have to say i get tempted by the rc 150

[Steve789]

Thanks for the reply nightfisher. I have considered the Altair Astro 150-DS Newt' but have yet to read a review. I'd love to hear from someone who's tried it.

Regarding the rc 150 at F9 would that not be too slow for DSOs. Also the field of view is much smaller than the 150PDS. I would have thought this scope was more suitable for planetary and is more likely to be a replacement for my 127 Mak (correct me if I'm wrong). Its also a bit on the pricey side.

[nightfisher]

Thanks for the reply nightfisher. I have considered the Altair Astro 150-DS Newt' but have yet to read a review. I'd love to hear from someone who's tried it.

Regarding the rc 150 at F9 would that not be too slow for DSOs. Also the field of view is much smaller than the 150PDS. I would have thought this scope was more suitable for planetary and is more likely to be a replacement for my 127 Mak (correct me if I'm wrong). Its also a bit on the pricey side.

It seems the RC 150 is aimed at deep sky imaging, as to price compare it to a 150p ds and corrector could be about the same in long run, if you lived near by you could try my 150p ds out as i dont use it much nowadays

[Steve789]

One more thing, my old 150P had a skywatcher autofocuser http://www.firstlightoptics.com/astronomy-cables-leads-accessories/skywatcher-auto-focuser.html attached to it. Does anyone know if its possible to fit the same unit to the 10:1 dual speed Crayford focuser that's supplied with the 150Pds?

[nightfisher]

pretty sure it can be fitted to the p ds focuser but check first

[Thalestris24]

Hi

I've always been happy with my 150pds. Yes, the focus does shift when tightening the lock. I have a SW autofocuser fitted to mine so no need for the lock You might also consider the 130pds - smaller, lighter, shorter fl.

Louise

Edit: there is a YouTube vid for installing the autofocusser on the ED80 which has the same Crayford focuser

[Steve789]

Thanks for the info guys. That's good to hear about the autofocuser.

I did consider the 130pds because they're so cheap and people have been getting awesome results with them. To be honest I've been really happy with my 150P (apart from the coma) so will probably replace with like for like, unless someone can give me a good reason to go for something else.

[Uranium235]

Better the devil you know in your case

I've often fancied one of those CF newts from TS, but for what they are - they're pretty expensive.

[Thalestris24]

Thanks for the info guys. That's good to hear about the autofocuser.

I did consider the 130pds because they're so cheap and people have been getting awesome results with them. To be honest I've been really happy with my 150P (apart from the coma) so will probably replace with like for like, unless someone can give me a good reason to go for something else.

Hi

If you're happy with a 150 - no problem! I recently bought a 130pds but haven't got it up and running yet (my 150pds worked out the box and has never needed collimating (though it's more or less permanently set up so doesn't get moved around). I have a Baader MPCC on the 150pds but have ordered a GSO cc for the 130pds. It has a 70-75mm backfocus so should (hopefully!) allow use of a filter drawer with my modded 1100d

Louise