127mm ED Triplet for $1199 at VTI Optics

[casstony]

Originally Posted by MortonH

Wonder if it was someone here?

Yup
They must be still building it though - I ordered on the 14th and it's still marked 'Awaiting shipment'. I expect it will be of similar quality to previous samples, but it's nice to have an Australian warranty if there happens to be a significant optical defect (aside from a little blue fringing which appears normal for this objective).

[MortonH]

Nice one, Tony. Hope it doesn't take too long to arrive!

[Astro_Bot]

Originally Posted by casstony

(aside from a little blue fringing which appears normal for this objective).

Would a minus violet filter take care of that or would it require something more substantial?

[casstony]

The slightly out of focus blue wavelengths would only be an issue for imaging; I've read that imagers adjust the focus slightly towards blue to avoid fringing around bright stars and I guess it's not a problem for mono imaging.

[cometcatcher (Kevin)]

But... blue fringing is the very thing I want to get away from, since I will be using it for photography.

[Larryp (Laurie)]

I have the 102mm North Group triplet, and it doesn't show any blue fringing-in fact it shows no colour error at all!

[MortonH]

Colour error increases with aperture, all other things being equal. Maybe 127mm is the point where it becomes visible with this particular lens, but also possible is that there is some variability in how the lenses are put together in the cell, which means some are better than others. Clearly you have a good one, Laurie!

[Larryp (Laurie)]

Originally Posted by MortonH

Colour error increases with aperture, all other things being equal. Maybe 127mm is the point where it becomes visible with this particular lens, but also possible is that there is some variability in how the lenses are put together in the cell, which means some are better than others. Clearly you have a good one, Laurie!

Yeah-very happy with mine!

[casstony]

My 127 has shipped. I'll give a report on the scope once it arrives. I'm not an imager but I've got a DSLR I can put on the back to image something bright and see if there's a blue fringe. We're moving house over Xmas so I probably won't get to test the scope until the new year.

[casstony]

The 127 arrived yesterday and I managed to get a look through it last night in poor conditions. The optics look decent with no glaring faults (checked for astigmatism, decentering, zones, spherical aberration). The test certificate supplied with the scope claims a smooth 1/4 wave peak to valley and that fits with what I see (ie. uniform, concentric, well defined out of focus rings with some difference in brightness between inside and outside focus).

Jupiter showed about the detail I'd expect at 100x with no visible chromatic aberration. A bright star had to be carefully focused to avoid a blue fringe which fits with what others have reported with these scopes (ie. blue doesn't come to quite the same focus as the other wavelengths).

The case is of good quality and makes a handy bench to sit the scope on, but there was a lot of black dust from the foam on the optical tube and the tube was not in a plastic bag. The metal lens cap was not screwed onto the objective and there are finger prints on the lens. The rings were not square to the handle/dovetail and there are several scratches through the paint. Some packing foam between the tube and dew shield was doubled over making the shield very difficult to remove initially. The 10:1 focuser was not properly attached to the focuser body.

After fixing all of the little niggles I'm left with a reasonable quality scope with some scratches in the paint. I'm curious to hear what condition other 127's have arrived in if others have ordered. I'll do another optical check at higher mag when conditions allow.

On another note my new backyard is a lot darker after shifting house this week - no streetlights shining into the yard and no neighbours lights even though we're in town and no heavy industry in the area.

[MortonH]

I ordered another eyepiece from VTI yesterday and they mentioned that they have received another two orders for this scope. It will be interesting to see if they have the same issues as yours.

VTI also mentioned that they do their own QC check on the eyepieces before shipping to customers, but obviously they can't do any checks on these scopes as they are shipped direct from the manufacturer. Have to say I'd be a bit disappointed with these issues, even for the price. The scope should be clean, properly assembled and carefully packed.

Did you manage to square off the rings to the dovetail or is something out of alignment?

[casstony]

Originally Posted by MortonH

Have to say I'd be a bit disappointed with these issues, even for the price. The scope should be clean, properly assembled and carefully packed.

Did you manage to square off the rings to the dovetail or is something out of alignment?

The issues are disappointing and demonstrate a general lack of care. The rings were easy to fix by loosening the bolts - an extra 5 seconds and they could have been properly assembled in the first place, perhaps avoiding the scratches on the tube.

[MortonH]

Do you reckon the excess blue from the lens might also be due to a lack of care in aligning the elements? Or just from the design and/or type of glass used?

From older posts about North Group scopes I'm guessing that most people consider the lens to be quite good and it's simply the assembly of the complete telescope that is a bit haphazard. They might as well sell all the components as a DIY kit!

[casstony]

I think the blue is just part of the design Morton. It's only a small amount and some people will notice while others will consider it a full apo, but it's not as good as the top tier apochromats and priced accordingly. Some blue fringe will show up on the brightest objects when imaging unless you adjust slightly away from best focus - again that's going to bother some folks and not others.

[MortonH]

Useful info, Tony. What about the focuser? In the past a lot of people said it should be replaced asap. Wonder if the design has been improved at all?

[Profiler (Profiler)]

I am certainly not defending poor assembly/QC nor wanting to be seen advocating these refractors but just for some broader context concerning a 127mm refractor that is clearly not an achro for $1,200 with some of the top shelf brands

Televue NP-127is - $7,599 (note this is actually a Nag/Petzvel Quad element design - not a triplet)

Takahashi TOA-130NS - $6,961
Takahashi TOA-130NFB - $8,647

Please note that both of the Tak's are strictly OTA only - so the price is for the OTA and absolutely nothing else presumably packed in two authentic made in Japan super high quality cardboard boxes
No case, rings, diagonal, finderscope or bracket etc

Televue do however kindly toss in their own very nice hard case but once again their price is OTA only so no diagonal, rings or finder of any description for the modest sum of $7.6k.

Somewhere between these two extremes of HiOptics and Tak/Televue are the likes of WO with their commensurate prices - I think a WO FLT132 is about $5.5k these days.

[MortonH]

Some good points, Profiler. If you expect TV or Tak quality for $1200 then obviously you're going to be disappointed. But it's interesting if you compare to other scopes of 'similar' size/price. For example, Andrews has the Skywatcher achro 120mm for $799, while the Black Diamond 120ED doublet is $2299. So the price of the HiOptic really is close to that of a comparable size achromat.

I hope someone in Sydney gets one as I'd love to compare it to my Stellarvue 110ED, a very well corrected doublet.

[casstony]

Originally Posted by MortonH

Useful info, Tony. What about the focuser? In the past a lot of people said it should be replaced asap. Wonder if the design has been improved at all?

I think the design is the same as the earlier scopes and the focuser isn't great, the main issue being that it doesn't hold the diagonal securely - if the diagonal moves, collimation goes out. Somewhere I saw a focuser tune up for this scope and the focuser can be made to work well enough.
EDIT: I later found that the TV diagonal I used did not work well with the focuser compression ring whereas a WO style bevelled diagonal nosepiece is held securely.

[RobC (Rob)]

I purchased both an ED80 amd ED127 ( carbon fibre ) from the North group in July this year, with their updated focusers, Cannot detect any blue wavelength problems with 5 or 10 minute exposures and the focusers work like a dream with my Cannon 60D. I switch between the two for imaging and guiding.

So I am very happy with mine.

[MortonH]

Originally Posted by RobC

I purchased both an ED80 amd ED127 ( carbon fibre ) from the North group in July this year, with their updated focusers, Cannot detect any blue wavelength problems with 5 or 10 minute exposures and the focusers work like a dream with my Cannon 60D. I switch between the two for imaging and guiding.

So I am very happy with mine.

They used to offer two focuser options - one for visual only and the other for astrophotography. Is that still the case? And if so did you go with the astrophotography version?