WO Star 71-II

I have one, unfortunately I havnt had a lot of time on it yet. But my observatory is now done and im getting heart nebula data as I type this!  Some things to keep in mind… The 2nd gen star71 DOES NOT fix the funky diffraction spikes the star71 gives. And it DOES NOT fix the Pentagon shaped mid-sized stars people get on the star71 1st gen either.

Most star71 users don't seem to mind these "issues" I call them "issues" because.. frankly that's what they are imo.  But let's face it… Do we have another 70mm option , or even a close option for less then $3-$4k? No.. we don't.

I've also ran into a discrepancy with the backfocus number WO is giving for the 2nd gen.. they say it's 71.3 mm from the Canon threads, but with my QHY10 in the train I can't achieve focus at all at 71mm, I have to go 63mm back from said canon(m4 threads.

This may not be much help to you! But figured id give the Info I have.

It's not temperature related at all from what I can tell. Also a CCD is always better than a non cooled DSLR, so anyone who upgrades from a dslr to a CCD will be -10 to -30 Celsius anyways.  Both the diffraction spikes and the Pentagon shaped stars are caused by the way the optics are mounted in the telescope (that's the reason direct from WO themselves)

If it was something easily fixed on this OTA, I'm sure they would have fixed it.  Maybe because the colder the temp the more constricted the optics are and that's why people are saying they see it more in cold temps? But again , my original star71-11 image was taken in the summer and it was 60-70 Fahrenheit outside and my mid sized stars still that slight Pentagon shape to them.  Most people don't upload full resolution images , so on some images on astrobin this may be hard to see.

Dan Kordella:
A fellow poster on CN has launched a mini-business 3D printing accessories for the Star 71. It's an aperture-step down combined with an extended dew-shield that also has a removable Bahtinov Mask. The "iron-cross" effect on stars is eliminated. I think with this you're probably no longer at f/4.9, but for me that's no big deal at all.Here's alink to his site.

I've seen this, good stuff, but .. not being at f4.9 is actually a very big deal. The fstop of this OTA is typically one of the two reasons people buy this scope (fstop, and focal length)

I wouldn't be surprised if an aperture step aggressive enough to take away the cosmetic star issues bumps this scope up to f6-7 (massive change)

Dan Kordella:
You lose about 5mm of aperture, which works out to about f/5.4. An aggressive aperture stop is really not needed, so that the "updated" version of this scope still has the iron-cross effect with stars is baffling.I think that's classic WO, though, they make stuff that is almost really great. Almost.

I guess I need more info, maybe I should contact him. I am wondering if this gets rid of both the iron cross and the pentagon shaped stars.  or just the iron cross issue.

I have some data I've collected with this setup, but I haven't gotten to processing it yet. I'll work on what I've got and post it so you can check it out. I honestly haven't seen pentagon shape stars, though.

Hoping this is allowed, but here's a link to full resolution QUICK process of heart nebula. (Please do not judge me on the processing of this 2 hours of data)

For the price of the scope I'm happy with the stars and the field.
Drop box link to heart nebula

I have an original Star 71, I don't have the pentagon shaped stars, never even heard of that and I have VERY minimal spikes too, I'm very happy with my WO and will never get rid of it. It is also my only refractor that I can use with OAG+Filter Wheel and the whole Shebang.

Tyler Jackson Welch:
Looking at others full resolution images, I think there's something very wrong with my star71-11....If you look at the stars in my image at the edges and corners.. they look completely out of collimation. And I'm not seeing this extreme issue with other star71 images ive looked at.  Does anyone have opinion on if this looks like a collimation issue or not?

Hi Tyler

I had three of the original WO Star 71s and all but one of them went back.  I can assure you that your image (Sadr) does not show anything like the issues I had in my other 2 Star 71s.  In fact they look OK to me.  It is very difficult to know for sure, however, with reduced size images.  Perhaps if you posted some 100% crops?  I'm not sure your Sadr was in good focus and, if I'm right, that would certainly amplify any issues.

The other thing I would suggest is that you look at images taken through the FSQ 85.  Examine the corners in a range of images taken with that scope.  You might get a surprise.

Steve

Just an update on this… I'm in contact with the retailer I purchased the star71-11 from. Hopefully grtting it returned and getting myself a stellarvue Sv80ST with reducer.. looking at photos… There no reason for me or anyone else to go with a star71. I wish I would have done more research before buying!! Bad news for the star71 is all over forums. Shame on me I guess.. and for those people who got one that actually works… Ur lucky.

I'm surprised to hear this much criticism of this scope.  I've been hoping to get one once I see a used deal on one, but now I wonder if buying one new would be the better choice.  If not, I suppose $1,400 for a SV80ST w/ reducer isn't so much worse than $1,100 for the Star71-II.  That is, assuming the SV80ST doesn't have similar complaints.

After owning one, seeing the reasons people put used ones up for sale, and looking closely at full resolution images from most star71s, I could never suggest this scope to anyone doing AP. I own a sv80 now, with reducer, have done lots of research on it and talked to the people who work at stellarvue in California, and I am very happy and confident in my new purchase. Even the build quality on the stellarvue is better, and they give u optical test results with each scope.  They do have an sv70 btw!

Samara:
Okay, do you guys think it's about time to stop with the product bashing? In case you didn't notice, this is a group for the owners of the WO Star71 that actually LOVE their scopes. I understand coming here to ask for suggestions, I think you already got your suggestion. For the ones that don't even own the scope anymore, I suggest leaving the group as it won't be any help to you anymore.Thank you!

My apologies then.  I hadn't understood that this was reserved for owners who love their scopes.  I will take your advice.