Should I send my shiny new telescope back?

[vulkan]

Hi everyone, this is my first post on Stargazers lounge but I have been lurking around here for a while and have been thorougly inspired to empty my wallet on new toys.

I recently purchased a William Optics GTF-102 and have been vvery impressed with the fit and finish of the scope, problem is some weird things happen when I look at bright stars.

Out of focus I get the diffraction and concentric interference patterns i'm led to believe are a good thing, as the star gets smaller and closer to focus however another bright ring crops up and I get what looks like a pinpoint star surrounded by a bright halo.

Any further on the focus and the whole lot starts to blur.

Despite some frantic googling I cant find anything similar, so is this normal? should I, in fact send my shiny new telescope back?

i have attached a pic of the Pleiades taken with my DSLR to show you what I mean.

http://www.flickr.com/photos/nicksshaw/10028228266/

Thanks in advance,

[Ant]

That is not normal.

What does it look like visually? Is it the same?

What else do you have in the imaging train? Any reducers, FF, filters, diagonals? etc.

Cheers

Ant

[Naemeth]

Send it back, it looks like a fault in the optics. At the very least they should be able to test it an diagnose the problem (and pay for it to be fixed), but it may actually be cheaper to send you a new scope.

Hope you get it sorted .

[ollypenrice]

Certainly not right. It does need to go back.

Olly

[John]

If that photo is the closest the scope will get to focus then something is very wrong. You should have pinpoint stars with perhaps a single thin diffraction ring around the brighter ones. Like this:

[johnrt]

Ooooh, that looks bad, not at all what you would expect. Contact your dealer with that picture and ask for an exchange!!

[NGC 1502]

Hi and welcome to SGL.    If that image is the closest you can get to focus, something is definitely wrong.

Are you saying that when used visually (with an eyepiece in the focuser) you get a similar result ?

The image looks like proper focus has simply not been achieved, and adjusting the focuser should be all that's needed.

Any decent supplier will sort it.

Hope you get a good resolution of the problem, your new refractor should be very nice indeed.

Regards, Ed,

[ronin]

That image just looks plain weird. Cannot think of any optical error that would give something like that. Wonder if someone had it before you and managed to be it in a very humid place and there is now water between the lens. Did it come from th US, as not aware of anyone having easy access to GTF-102's in the UK and some parts of the US are very humid, 98%-100%.

The other area is the flattener that is part of that scope, and I would be more suspect of a problem around there as you seem to have star images with something around the image and the flattener is fairly close to the focal plane.

Whatever it's not nice.

[spaceboy]

While I agree with the others it looks like good reason to get the scope back in the post and requesting a replacement I can't help but ask the question..........Did you notice if the objective had any condensation/ fogging on it? It is more often the case of bringing a scope in to the warm from the cold than vice versa but I'm assuming fogged up optics might give a similar halo effect around brighter stars?

[haitch]

I'm not expert but to me it looks like you've got an in focus(ish - must be hard to know how near focus you are with that) star with a reflection of an out of focus star's diffraction rings overlaid as though you are getting a nasty reflection somewhere close to the focus point and it is as though it is further off centred from the focussed image the further you are from the centre of the field

I don't think it alters the fact it needs to go back - possibly the flattener is dislodged? 

[vulkan]

Wow!

Thanks for the responses guys, I did check for condensation on the objective and the scope had cooled down for around an hour before I used it, the views where the same through an eyepiece as well as the camera too.

After speaking with the supplier today we came to the conclusion that the field flattener may have been installed in reverse (having to unscrew the focusser and flattener from the tube was a bit scary) but after reversing it my daylight images look miles better.

Just need to wait for some clear skies to check it out again on stars.

fingers crossed, and thanks again for all the help

[Davey-T]

The WO GTF 102 is primarily designed as an astrograph, I did look into purchasing one but read reports on CN of them not being able to bring some eyepieces to focus when using a 2" diagonal, also a bit slow for astrophotograpy and not able to fit a focal

reducer as it's built in, not bad scope for the price though.

Dave

[Herbig]

Oooh, that must have been very dissapointing, hope you have it sorted now.

[vulkan]

Hopefully I will be able to post a nice clear image soon, keeping my fingers crossed for some clear skies to test it with the flattener (hopefully) in the right way round.

[ronin]

If it all works as well as expected now, the question is who was playing with the internals before it came to you?

Never read of this on the CN site and a number there have the GTF-102, so I doubt it was at the WO assembly stage.

[LukeSkywatcher]

Has this issue been resolved? It really was/is the strangest thing ive seen. A focusing issue no doubt (stating the obvious here).

[Donkeiller]

I have not had a good experience with WO scopes.

Save yourself time and money.

Return it and get your money back.

Then buy a different make of  scope.

[vulkan]

Hi all,

The skies cleared enough tonight for me to test out the scope again, it was definitely the flattener that was installed backwards. www.flickr.com/photos/nicksshaw/10108804123/ here's another shot of the pleiades, much better

I spent the last 4 hours going from interesting object to interesting object, then jupiter came up and I was absolutely bowled over by the crystal clear image, I could clearly see banding on jupiter and several moons.

Such a relief to have it working.

Thank you all for your help, I seriously thought it was just me being a dummy.

Now I'm off to get some sleep

[ronin]

In some respects thanks for asking and putting up the question and images, then following through. If someone comes along with a similar instance then it may be possible to suggest the cause of the problem and so a solution to someone else.

Still think it is odd that the flattener became reversed however.

Makes me think some one wanted more back focus and thought if they moved the flattener out then they may get it. So unscrewed it and it fell out.

[haitch]

Yep,

Sounds like you got sent a customer return to me. My guess is someone did as Ronin said then realising their [removed word] up returned it keeping quiet about the issue. Then it managed to get sent back out without being thoroughly checked over optically. Not good in any case :/

Sent from my iPhone using Tapatalk - now Free

[Herbig]

Goat it had a happy ending. Did you get the flattened replaced?

[vulkan]

I didnt need to get it replaced, I just unscrewed the flattener from the focuser and the rest of the tube, flipped it over and screwed it back in.

and ever since then it has been cloudy. im thinking of flipping it back again so at least you guys can have clear skies