Antares W70 eyepiece NOT as claimed

I received a pair of the so-called 14mm and 19mm Antares W70 1.25"
eyepieces. Initial study indicates are both only 66° AFOV not 70° as
was stated for these. I used several comparative telescope and
binocular eyepieces to get this information close vs. measuring the
field stop ring. The method used was for more definitive accuracy.

The W70 14mm eyepiece is exact same lens set design, top and bottom
retainers, and FL as the 15mm Skywatcher/Orion Expanse/etc. clones 66°
model. The only real difference noted is the obvious silver housing
variation and rubber grip ring. Also a color tint variation with
white paper test due slight coating and/or alternate glass variations.
I've seen same type thing with various label 102mm f'/5 Chinese
objectives lenses before.

As I said the lens set is exactly the same thing between the 14mm and
15mm models. This determined from direct comparison viewing the lens
curve/spacing under light source. The FL determined from object
comparison. I believe 15mm is to be a more accurate for FL measure.
The 19mm may actually be 20mm but that was not verified.

Coatings indicate 2 A-G surfaces on the "14mm" and 1 A-G surface on
the "19mm" as a bonified multicoating. The other surfaces probably
single layer or possibly marginal MC quality. When holding them up
and down against in-coming house window lighting I got impression my
Skywatcher 15mm was brighter for sensation to the eye than the Antares
14mm was.

Hoping this is found interesting or useful to other amateur
astronomers.

Clear skies,

Pete

In article , Pete Rasmussen
wrote:

I received a pair of the so-called 14mm and 19mm Antares W70 1.25"
eyepieces. Initial study indicates are both only 66° AFOV not 70° as
was stated for these. I used several comparative telescope and
binocular eyepieces to get this information close vs. measuring the
field stop ring. The method used was for more definitive accuracy.

The W70 14mm eyepiece is exact same lens set design, top and bottom
retainers, and FL as the 15mm Skywatcher/Orion Expanse/etc. clones 66°
model. The only real difference noted is the obvious silver housing
variation and rubber grip ring. Also a color tint variation with
white paper test due slight coating and/or alternate glass variations.
I've seen same type thing with various label 102mm f'/5 Chinese
objectives lenses before.

As I said the lens set is exactly the same thing between the 14mm and
15mm models. This determined from direct comparison viewing the lens
curve/spacing under light source. The FL determined from object
comparison. I believe 15mm is to be a more accurate for FL measure.
The 19mm may actually be 20mm but that was not verified.

Coatings indicate 2 A-G surfaces on the "14mm" and 1 A-G surface on
the "19mm" as a bonified multicoating. The other surfaces probably
single layer or possibly marginal MC quality. When holding them up
and down against in-coming house window lighting I got impression my
Skywatcher 15mm was brighter for sensation to the eye than the Antares
14mm was.

Hoping this is found interesting or useful to other amateur
astronomers.

Clear skies,

Pete

Hello Pete,

Did you purchase yours from Canada? Scopestuff (www.scopestuff.com)
sells these Antares W70 eyepieces. They also have a 25mm W70 eyepiece.
It sells for a higher price than the other four in the set (5.8, 8.6,
14 & 19mm) and it consists of 8 elements with (alleged) 70 degree afov
in a 1.25" eyepiece.

I also saw the 25mm Antares W70 advertised on the Canadian site
(http://islandeyepiece.com/Eyepieces/UwideSky.htm) along with the same
(I assume) other 4 eyepieces. However, on the Canadian site the prices
for all 5 eyepieces were the same - the 25mm did not cost more. I use
a binoviewer most of the time now, and am hesitating before buying a
pair. I have a 15mm Scopestuff pair and am pleased.

Linwood

Hi Folks,

I have just tried out the 14mm and 5.7mm Antares W70 eyepieces with a
102mm f5 refractor. I was not disappointed with the fov - they both
seemed to live up the the claim although I didn't measure anything. To
get an idea of how they performed I compared them as follows:

The 14mm against a Vixen 26mm plossl with an Antares 3 element x2 Barlow
and the 5.7mm against a Vixen 5mm LV.

The 14mm had about 50% of the central area pin sharp but outside that
there was a marked fall-off of sharpness which was attributable to
distortion.

The 5.7mm gave about 60% central sharpness and this time there was a
marked focus shift towards the edges.

When compared as described above the difference was simply that the two
Vixen lenses were sharp from edge to edge and the fov more or less
matched the central sharp portion of the W70s, although the 5.7mm was
definitely brighter than the LV.

That said, I have to admit that for me (strong astigmatism) the 5.7mm
was a pleasure to use and the loss of sharpness was not enough to
detract from using it on subjects such as Trapezium. In the end, they
were returned and I continue to save my money for Radians!

I will be interested to hear users' reports when used at f8+ where I
suspect they will perform well.

Clear skies to all.

--
Chris

The 14mm had about 50% of the central area pin sharp but outside that
there was a marked fall-off of sharpness which was attributable to
distortion.

Sounds like the Expanse Widefield 15mm...

The 5.7mm gave about 60% central sharpness and this time there was a
marked focus shift towards the edges.

Sounds like the 6mm Expanse 6mm...

Joe O'neil sells both the Antares and Synta widefields, he says the Antares
models are a noticeably better.

Wonder what he would say...

jon

On Sat, 01 Nov 2003 10:45:16 -0600, Linwood wrote:

Hello Linwood,

Did you purchase yours from Canada? Scopestuff (www.scopestuff.com)
sells these Antares W70 eyepieces. They also have a 25mm W70 eyepiece.
It sells for a higher price than the other four in the set (5.8, 8.6,
14 & 19mm) and it consists of 8 elements with (alleged) 70 degree afov
in a 1.25" eyepiece.

At the moment pending return of the two pairs of eyepieces I best not
say where I got mine. I certainly do like the dealer Ok though and
feel he is generally doing great things.

Yes, I've noted the price differences on the 25mm not sure why that
is. I also own the 15mm Skywatcher 66° as a pair and they are nice.
There isn't a hair of doubt in my knowledge that the W70 in 14mm is
the same thing as the 15mm and a person will be paying their extra
money _only_ for a superficial cosmetic change.

It would not surprise me now if each of the 4 shorter FL W70 are all
the same Chinese rebadge of the SuperWide 66° line.

I also saw the 25mm Antares W70 advertised on the Canadian site
(http://islandeyepiece.com/Eyepieces/UwideSky.htm) along with the same
(I assume) other 4 eyepieces. However, on the Canadian site the prices
for all 5 eyepieces were the same - the 25mm did not cost more. I use
a binoviewer most of the time now, and am hesitating before buying a
pair.

As it would seem there isn't much of anything else decent around 25mm
in WA 1.25". The closest I know of in the price range is the UO 24mm
Konig which has for years had excellent reviews.

Of other possible interest, I made and use a high viewing impact
custom modified 26mm reversed Kellner pair (60°) that I design adapted
to 1.25" from a commercial 2" barrel model. I'm sure most have seen
this model in series with 32m and 40mm before. They work Ok at f/6
and best f/7. The significant advantages are the minimum elements
(3) and real FMC coatings. They are super sharp and contrasty on axis
with great wide views. The best in these regards over anything else I
know of under $100 each. If a person wants a pair they should
probably best contact my astro-machinist (he was on Astromart). My
adapter plans are available to share with any amateurs without charge.

Pete

On Sat, 01 Nov 2003 11:51:39 -0600, Pete Rasmussen
wrote:


Yes, I've noted the price differences on the 25mm not sure why that
is. I also own the 15mm Skywatcher 66° as a pair and they are nice.
There isn't a hair of doubt in my knowledge that the W70 in 14mm is
the same thing as the 15mm and a person will be paying their extra
money _only_ for a superficial cosmetic change.
-snip-

Hi Pete;
First thing I did when I got a set of the W70s in stock is
compere them directly, side by side with the WA series from Synta. I
did notice a differnce there and then, swapping them out side by side.
I wonder if there are or have been changes to oen or the other.

The two are very, very similar to be sure, but i did think the
W70 was a bity better overall. Mind you, it's aobut $10 more each, so
it's liek comparoing the regular UO ortho tot he HD ortho - worth the
extra $10, but maybe no much more.

One thing about calling the W70 a copy of hte WA however -
something Glen Speers said to me once before "I learned the hard way
never to give any one factory all your specs for a single product.
next time, I'll split it up in two or three factories."

Not sure if that applies here, but makes you wonder, eh?
joe



http://www.oneilphoto.on.ca

On Sun, 02 Nov 2003 13:54:26 GMT, (Joseph
O'Neil) wrote:

Hi Joe,

First thing I did when I got a set of the W70s in stock is
compere them directly, side by side with the WA series from Synta. I
did notice a differnce there and then, swapping them out side by side.
I wonder if there are or have been changes to oen or the other.

The two are very, very similar to be sure, but i did think the
W70 was a bity better overall. Mind you, it's aobut $10 more each, so
it's liek comparoing the regular UO ortho tot he HD ortho - worth the
extra $10, but maybe no much more.

snip

I can't possibly imagine how you would find that to be true unless
there was something of a different eyepiece sold to you early on. I
bought mine last week as current stock, and, other than outside
cosmetics, the Antares 14mm W70 is *the same exact* set of lens
curves, lens spacings, lens diameters, coating matches on each and
every element, field stop diameter, apparent field of view, focal
length, eye relief, and retainer mechanisms as the Skywatcher 15mm
SuperWide...down to the last molecule. *The same exact* sky viewing
performance between significantly different labelled models is very
much assured!

The glaringly obvious set of provable facts certainly interest me
because I first and formost have the right of expectation to receive
something relative to what I pay for.

Perhaps Antares really does not fully intend the buyer to receive a
real 70° AFOV, different focal length, or brightness improved model
against the cheaper priced predecessor that wears the gold trimmed
black suit. Since it is ONLY an issue of silver vs. black attire,
that should ONLY BE the claim to change!

I suggest the game plan was for the buyer to pay for a sky *fantasy*.
In reality, that is apparently all this is about. I believe folks
should wake up and not accept being fooled. If something is stated in
writing one way and then proves out quite another, it very often means
there is underlying deception for each and every person that is drawn
in.

All I'm doing is voicing my opinion that I strongly prefer dealing
with the truth. Thank God I am able to clearly discern it some of the
time!

Clear skies (and opposing lies),

Pete

I
bought mine last week as current stock, and, other than outside
cosmetics, the Antares 14mm W70 is *the same exact* set of lens
curves, lens spacings, lens diameters, coating matches on each and
every element, field stop diameter, apparent field of view, focal length, eye
relief, and retainer mechanisms as the Skywatcher 15mm
SuperWide...down to the last molecule.

Sounds like you must have disassembled both eyepieces to get this much detail.

One interesting thing to note is that a 14mm 70 degree eyepiece and a 15 mm 66
degree eyepiece will have the same true field of view. This means to determine
the difference between these eyepieces without disassembly, one would have to
measure the focal length.

I am curious about the other Antares eyepieces, the approximately 9mm and the
20mm are 5 element, the 6 mm is 6 element. I was of the impression that the
Synta 20mm was 4 element, the Synta 9mm and 6 mm were 6 element...

jon

On 03 Nov 2003 19:56:22 GMT, (Jon Isaacs) wrote:

Sounds like you must have disassembled both eyepieces to get this much detail.

I didn't need take them apart. Careful external studies on my optics
bench were all that was required to determine or accurately
extrapolate the data list. This does include lens diameters but is
comparative based information. In a nut shell, the lens component
geometries themselves dictate there cannot be significant variation
allowed for beyond simple mfg. tolerances.

One interesting thing to note is that a 14mm 70 degree eyepiece and a 15 mm 66
degree eyepiece will have the same true field of view. This means to determine
the difference between these eyepieces without disassembly, one would have to
measure the focal length.

To determine FL well comparatively, all that was needed was to
correctly mount the two eyepieces (labelled 14mm and 15mm) and read an
illuminated scale through the glass. It could have been somewhat less
accurate if they had been different lens assemblies but they are the
same. There are also other ways like using a binoviewer to get this
kind of data. And do note the visual difference between a real 14mm
and 15mm FL eyepiece is very easy to see.

As mentioned earlier, I have a good hunch both measure about 15mm in
real terms. If there is enough interest shown here, I could go about
determining the TFL for the one.

Pete

To determine FL well comparatively, all that was needed was to
correctly mount the two eyepieces (labelled 14mm and 15mm) and read an
illuminated scale through the glass.

I wasn't doubting that you had measured the focal length.

Rather I was simply commenting that someone who happened to buy the thing could
measure the true field of view with a drift test and then compute the apparent
field of view using the claimed 14 mm focal length. This calculation would
produce the claimed 70 degree FOV.

As mentioned earlier, I have a good hunch both measure about 15mm in
real terms. If there is enough interest shown here, I could go about
determining the TFL for the one.



It would be interesting but I would probably be the only one interested.

So, how do you like these eyepieces in general? Do you have any others in the
series??

jon