Comparison of two budget 2" low power eyepieces

On Fri, 18 Jul 2003 11:45:00 -0400, "Stephen Paul"
wrote:

For me, the crap at the edge was just too much
of a distraction to be able to enjoy the center.

This is an issue of personal taste. Personally, I will accept some
crap at the edge for the advantage of less glass between me and the
object and generally more contrast. I think the Widescan III has
excellent contrast compared to the 6+ element lenses that are sharp to
the edge.

I use the 30mm Widescan III in my 100mm f6 achromat and the 4 deg view
of the NA nebula with a Lumicon 2" filter is sublime.

YMMV.

---
Michael McCulloch

On Fri, 18 Jul 2003 11:45:00 -0400, "Stephen Paul"
wrote:

"bwhiting" wrote in message
...
really Great Eyepiece with an 84 degree APOV....so don't bad-mouth
thoes 30 mm ultra-widescan eyepieces! No edge coma at all with f4.5
focal ratio.
Tom W

No coma, but a disgusting amount of astigmatism and curvature (in a fast
scope).

If we're talking about an F10 scope with negligable field curvature, then
the 30mm WS clones are a huge bargain.

I have no doubt that some people are willing to put up with the views in
this eyepiece in a fast scope, much the same as I am willing to put up with
the views in my Short Tube 80 (a fast, colorful achromat) to spare myself
the expense of an 80mm apochromat (for the time being).

However, I really do object to users giving the impression that this
eyepiece provides anything close to a useful 80+ degree afov in scopes below
F10. The reality is, at F5, it is at best a 60 degree eyepiece, with an
extra 10 degrees of crap along the perimeter. For me, the crap at the edge
was just too much of a distraction to be able to enjoy the center.


snip

Stephen, I begin to suspect that there is something wrong with your
version of this eyepeice.

Your description does NOT describe the views through my 10" f7.5 or
even my 15" F5 (with paracorr).

The last 20 degrees are far from useless. While you aren't going to
be doing planetary work with it, it's more than acceptable as frame on
DSO's, and does not matter a bit if you are looking for detection.

There is some astigmatism and field curvature, but it's hardly alone
in that respect. At these focal lengths, I often have to turn my head
to see what astigmatism is present in the eyepeice versus my own eyes.

And, while the edge is not perfect (the pan 35 *is* better), I'd
*hardly* call it crap. It's not pinpoint, but it's not huge seagulls
either. While I can't compare it at f5, going from memory, the edge
is comparable to the Pentax 40XL in my other scopes. That however was
a little more of a sudden degradation. The BW seems more gradual.

If you *must* have *exact* pinpoint sharpness across the entire field,
at f5, then yes, by all means go elsewhere. I'm not denying that.
However, the BW is a LOONNNGGGG way from crap. If you ignore the
price, it's a middle of the road (ok - maybe a nudge toward the high
end, but still pretty much smack in the middle of the bell curve). If
you take price into account, and many of us have to, IMO, it's a
standout.

Maybe I'm wrong here, but you seem to think that if it's not TeleVue
it's worthless (for a fast scope).

Believe me, I don't tend to "put up" with much. Outside of some UO
orthos, this is my first non-TeleVue eyepiece in years.

The worst issue I've seen with the eyepeice so far is the complete
lack of an acceptable eye shield - this gives rise to occasional
reflections off the neighbors yard light. But my 13 nagers (t6) have
the same issue. This is far more irritating than the edge of field
performance.

If I could get a 35 pano for $100 would I get rid of the BW?
Probably. Anyone want to sell me one for $100 so we can find out?

Tom T.

"Tom T." wrote in message
s.com...

Maybe I'm wrong here, but you seem to think that if it's not TeleVue
it's worthless (for a fast scope).


Well, that's not entirely true. It is however true, when discussing 68+
degrees of apparent field.

I am perfectly happy with the performance of my 18mm, 12.5mm and 7.5mm
Ultimas in the F5, but then they aren't being used in an application that
the design cannot handle. (I am, however, unhappy with the 30mm Ultima, as
it has too much curvature, and never seems to come sufficiently to focus
over a large enough portion of the field that it provides any useful
function.)

Subjectively, I don't like crap at the edge, and I don't mind saying so,
because others will be like me, I'm sure. Glossing over such performance
failures with soft language, is for salesmen, not for peer reviews. g

I would rather have a 50 degree afov that's sharp, than a huge field with
crap in it. I'm not dissing the WS, not really. If I had an F10 with a 2"
focuser, I'd be all over the WS. Deep light cones are where they excel, and
for the price they're a huge bargain, given that application.

It is not insignificant that almost everyone includes the reference to the
WS as a "finder" and "framing" eyepiece whenever they are discussed. I would
_never_ consider the 35mm or 24mm Pans "finder" or "framing" eyepieces. They
are for observing (whether 10% of the time or 100%), and that is where the
difference lies in the final analysis. Opinion has nothing to do with this.
My findings are a result of an objective evaluation of the 1rpd, the WSII,
the WSIII, and the 35mm Pan, with and without Paracorr in a 10" F5 Dob.

In the end I concluded that the wide fields afforded by fast scopes demand
better corrected eyepieces to appreciate maximum performance. With the more
simple design wide field eyepieces, a fast scope is going to screw up the
image. You just can't get around the optics.

I hope others don't take any of this personal. But it is an advisory posting
nonetheless, and therein lies its worth. If you have a fast scope, the
widescan design will have crap at the edge. Be advised. I'm not making it
up. It is fact. If you can accept that, then more power to you. The only
thing of a personal and subjective matter here, is that I cannot accept the
crap in an eyepiece purchase I made specifically for observing large fields
of view.

If I had a fast scope and wanted a "finder" eyepiece, I wouldn't hesitate to
buy a WS, but as a truly wide field eyepiece for observing using a fast
scope..., "yuck".

Peace,
Stephen Paul

Maybe I'm wrong here, but you seem to think that if it's not TeleVue
it's worthless (for a fast scope).


Well, that's not entirely true. It is however true, when discussing 68+
degrees of apparent field.

http://www.apm-telescopes.de/englisc...eyep/index.htm

I wonder if you have had the opportunity to look through some of the widefield
eyepieces by Zeiss, Nikon, Leica, Pentax etc. Personally I have not had this
opportunity but it does seem to me that that there are plenty of players in the
widefield eyepiece game and it would probably take quite a few years of serious
observing for you to really be able to support your claim.

If you have a fast scope, the
widescan design will have crap at the edge. Be advised. I'm not making it
up. It is fact. If you can accept that, then more power to you. The only
thing of a personal and subjective matter here, is that I cannot accept the
crap in an eyepiece purchase I made specifically for observing large fields
of view.

I am glad your realize the subjective nature of your evaluation. Others may
have different criteria and also may have different experiences with the
eyepieces than you, maybe you just were looking through a "bad one."

So, I will just say this, I am more likely to listen to what Tom says than you
because Tom discusses this stuff in objective neutral terms.

Jon Isaacs

Tom T wrote in response to me (Stephen Paul):
Maybe I'm wrong here, but you seem to think that if it's not TeleVue
it's worthless (for a fast scope).

To which I (Stephen Paul) responded:
Well, that's not entirely true. It is however true, when discussing 68+
degrees of apparent field.

To which Jon Isaacs jumped in with:

http://www.apm-telescopes.de/englisc...eyep/index.htm

I wonder if you have had the opportunity to look through some of the
widefield
eyepieces by Zeiss, Nikon, Leica, Pentax etc. Personally I have not had
this
opportunity but it does seem to me that that there are plenty of players
in the
widefield eyepiece game and it would probably take quite a few years of
serious
observing for you to really be able to support your claim.

Jon,
Please re-read Tom's comment, and my response. I was agreeing with him that
it indeed seems that I think if it's not a TV then its worthless for a fast
scope, but only with eyepieces at 68+ deg afov.

Up to that point, nobody was referring to TV's direct competitors. I'm sure
that Tom also meant TV "Class" eyepieces in his comment, but he'd have to
clarify that to be sure. That was the meaning I took. In any event, the
difference in premium eyepieces is meaningless here. We are discussing the
WS and the Panoptic.

I further wrote :

If you have a fast scope, the
widescan design will have crap at the edge. Be advised. I'm not making it
up. It is fact. If you can accept that, then more power to you. The only
thing of a personal and subjective matter here, is that I cannot accept
the
crap in an eyepiece purchase I made specifically for observing large
fields
of view.

I am glad your realize the subjective nature of your evaluation.

My evaluation was not subjective... the willingness to keep the eyepieces
based on that evaluation was subjective. There is however an omission of a
sort, and that is that I don't keep repeating that the evaluation was done
with an XT10 and a Paracorr, even though it is mentioned several times in my
responses on this subject. There are also some apparent errors in my final
conclusion, based on the reported experiences of others with _different_
scopes, but that in no way disqualifies the objectivity of my evaluation in
the XT10.

Others may
have different criteria and also may have different experiences with the
eyepieces than you, maybe you just were looking through a "bad one."

Which one are you refering to? The KK WideScan III, the KK WideScan II, or
the 1rpd ST80. All performed the same, and I wasn't the only one doing the
evaluation. More likely the difference in experiences posted here, is,
again, based on using scopes with different specifications.


So, I will just say this, I am more likely to listen to what Tom says than
you
because Tom discusses this stuff in objective neutral terms.

Well, you don't have to listen at all. You have a 10" F5. Do you have one of
the eyepieces in question? Please elaborate your experience in terms that
are as objectively accurate as is possible. Other than coming to a seemingly
incorrect conclusion that the the WS in _all_ fast scopes is crap compared
to an eyepiece that costs an additional $270, being objective in the
evaluation was never really in question. It being in question, was only the
opinion of others, who were not present at the evaluation.

I reiterate the complete result of my objective evaluation right here, right
now: in the XT10 the WideScans have crap in the outer 20 degrees of the
apparent field.

I will close with a quote from Florian's original post, with which I whole
heartedly concur, and a final comment:

"Both eyepieces [BW WS and Orion DV] in my f5 scope are quite poor off
center showing pretty bad images just half way from center to edge. Stars
around the edges were especially bad in the Ultrawide. "

I am not saying anything contradictory here, and it is not a singular
"opinion" but a consensus of objective evaluations by users of 10" F5 scopes
(and at least one 8" F6 user as well).

-Stephen Paul

Stephen,
you were right...I made a serious and conscious effort tonight
to check for coma/astigmatism, and in the low power 2 inch
widescans, about the outer 10% of the FOV is just that, crap. For the
higher power eyepieces,
it jumps to more like 20%; I never noticed it before...guess
with those extreme wide fields, my eye can only take in so much,
and most of the time, you are riveted to the object in the
center that you are viewing, so I just never noticed the extreme
outer edges of the FOV. Does it bother me...absolutely not.
But it was an interesting experiment tonight.
Because I had no idea that an f4.5 did that in the eyepieces.
And no, I still won't use a paracorr, because it doesn't bother
me.....I just don't look at it, because there is so much else
to look at. But I guess some people, and I can understand that,
it really bothers....but not me for some reason.
But thanks for the tip. You and Jan and David were right about
the coma/astigmatism...whatever it is. It's really there.
Clear Skies,
Tom W.





Stephen Paul wrote:
Tom T wrote in response to me (Stephen Paul):

Maybe I'm wrong here, but you seem to think that if it's not TeleVue
it's worthless (for a fast scope).


To which I (Stephen Paul) responded:

Well, that's not entirely true. It is however true, when discussing 68+
degrees of apparent field.


To which Jon Isaacs jumped in with:

http://www.apm-telescopes.de/englisc...eyep/index.htm

I wonder if you have had the opportunity to look through some of the

widefield

eyepieces by Zeiss, Nikon, Leica, Pentax etc. Personally I have not had

this

opportunity but it does seem to me that that there are plenty of players

in the

widefield eyepiece game and it would probably take quite a few years of

serious

observing for you to really be able to support your claim.


Jon,
Please re-read Tom's comment, and my response. I was agreeing with him that
it indeed seems that I think if it's not a TV then its worthless for a fast
scope, but only with eyepieces at 68+ deg afov.

Up to that point, nobody was referring to TV's direct competitors. I'm sure
that Tom also meant TV "Class" eyepieces in his comment, but he'd have to
clarify that to be sure. That was the meaning I took. In any event, the
difference in premium eyepieces is meaningless here. We are discussing the
WS and the Panoptic.

I further wrote :

If you have a fast scope, the
widescan design will have crap at the edge. Be advised. I'm not making it
up. It is fact. If you can accept that, then more power to you. The only
thing of a personal and subjective matter here, is that I cannot accept

the

crap in an eyepiece purchase I made specifically for observing large

fields

of view.

I am glad your realize the subjective nature of your evaluation.


My evaluation was not subjective... the willingness to keep the eyepieces
based on that evaluation was subjective. There is however an omission of a
sort, and that is that I don't keep repeating that the evaluation was done
with an XT10 and a Paracorr, even though it is mentioned several times in my
responses on this subject. There are also some apparent errors in my final
conclusion, based on the reported experiences of others with _different_
scopes, but that in no way disqualifies the objectivity of my evaluation in
the XT10.


Others may
have different criteria and also may have different experiences with the
eyepieces than you, maybe you just were looking through a "bad one."


Which one are you refering to? The KK WideScan III, the KK WideScan II, or
the 1rpd ST80. All performed the same, and I wasn't the only one doing the
evaluation. More likely the difference in experiences posted here, is,
again, based on using scopes with different specifications.


So, I will just say this, I am more likely to listen to what Tom says than

you

because Tom discusses this stuff in objective neutral terms.


Well, you don't have to listen at all. You have a 10" F5. Do you have one of
the eyepieces in question? Please elaborate your experience in terms that
are as objectively accurate as is possible. Other than coming to a seemingly
incorrect conclusion that the the WS in _all_ fast scopes is crap compared
to an eyepiece that costs an additional $270, being objective in the
evaluation was never really in question. It being in question, was only the
opinion of others, who were not present at the evaluation.

I reiterate the complete result of my objective evaluation right here, right
now: in the XT10 the WideScans have crap in the outer 20 degrees of the
apparent field.

I will close with a quote from Florian's original post, with which I whole
heartedly concur, and a final comment:

"Both eyepieces [BW WS and Orion DV] in my f5 scope are quite poor off
center showing pretty bad images just half way from center to edge. Stars
around the edges were especially bad in the Ultrawide. "

I am not saying anything contradictory here, and it is not a singular
"opinion" but a consensus of objective evaluations by users of 10" F5 scopes
(and at least one 8" F6 user as well).

-Stephen Paul

To which Jon Isaacs jumped in with:

I didn't jump in with anything, I have been posting to the this thread since
the original post. If you go to Google and look at the thread, you will
discover I was the first to respond to Florian's original post.

Jon,
Please re-read Tom's comment, and my response. I was agreeing with him that
it indeed seems that I think if it's not a TV then its worthless for a fast
scope, but only with eyepieces at 68+ deg afov.

I understood exactly that. If you went to the link I provided you would see
that several of the Nikon's, Pentax's and others have FOVs of greater than 68
degrees.

Up to that point, nobody was referring to TV's direct competitors. I'm sure
that Tom also meant TV "Class" eyepieces in his comment, but he'd have to
clarify that to be sure. That was the meaning I took.

That is not what was written. Tom's comment hit home with me. And then of
course you agreed with him.

In any event, the
difference in premium eyepieces is meaningless here. We are discussing the
WS and the Panoptic.

Actually that is what you wanted to discuss, the actual discussion was about
the BW-Optik and the Orion Deep View. For my part, I added a comparison
between the BW and the GTO Proxima 31mm 71 Degree FOV eyepiece, another budget
eyepiece. Tom then added the fact that he preferred the view of the BW-Optik
to the Panoptic in his F7.5 scope. This, I think, was difficult for you to
accept.

My evaluation was not subjective... the willingness to keep the eyepieces
based on that evaluation was subjective.

"Crap" is not a objective term, rather it is a slang word filled with negative
connotations.

Well, you don't have to listen at all. You have a 10" F5. Do you have one of
the eyepieces in question?

If you had read the entire thread, you should have seen what I wrote about a
comparison between the BW-Optik and the Proxima.

Please elaborate your experience in terms that are as objectively accurate as
is possible.

I have done this several times, at least once in this thread. Again here is
what I wrote in my response to the OP:
-----------
Florian wrote
I did a brief comparison of the BW-Optik 30mm Ultrawide with the Orion =
35mm DeepView last night in my Guan Sheng 10" f5 dob.

I wrote:

I have also had the opportunity to test two low end eyepieces in a GS 10 inch
F5 dob, the BW-Optik 30mm and the GTO Proxima 31mm 71 Degree eyepiece. I spent
quite a bit of time comparing these, looking at the same FOVs, moving the
bright stars to the edge, just looking at stuff.

Both are passable. Some views are really quite pleasing, some are rather
disappointing. I think the BW is sharper in the center but the edge problems
are worse.

Both eyepieces have noticeable edge distortion. The issue for me is whether
that edge distortion distracts me from the rest of the view. I find edge
performance of the GTO Proxima less distracting but certainly bright stars near
the edge of the FOV are pretty unpleasent to look at.

The FOV of these two eyepiece is quite similar, the BW-Optik is slightly larger
but at that point in this scope, the distortion is bad enough that it makes no
difference.

I have also tried both of them in my 12.5 inch F4.1 DOB. In this scope I can
only say both are quite horrid. Of course there is the nearly 8 mm exit pupil
and then there is the coma inharent in an F4 scope.

I would be interested in seeing how they looked through a Paracorr, might help
clean things up. I find most eyepieces look pretty decent in either scope when
used with a paracorr but my Paracorr is 1.25 inch....

The difference between either of these 2 eyepieces and my old Televue Widefield
24mm with or with Paracorr is large. By comparison with these two, the
Televue, with a FOV of about 63 degrees or so is sharp to the edge without the
Paracorr and with the Paracorr it is really quite sharp even near the edge by
any standards.

Overall, I think it is a tough call between these two eyepieces. The GTO is
better across the FOV but there is something that is not quite right about the
center, it does not seem to be truly sharp in the center. The BW-Optik is
quite sharp in the center but deteriorates quite quickly away from center.

Bottomline is that in a F5 scope, some views are really great, some are really,
ah, really ah... I will leave that to your imagination.

I think I have heard these are quite nice in an F10 scope so you SCT guys
finally have something to be happy about. g

----------------------
Other than coming to a seemingly
incorrect conclusion that the the WS in _all_ fast scopes is crap compared
to an eyepiece that costs an additional $270, being objective in the
evaluation was never really in question.

Again, "Crap" is not an objective evaluation of anything.

I also note that you use "crap" in two different contexts, in one it is
objective, ie "crap in the outer 20 degrees of the apparent field." As you
could see, I choose to describe the edge effects differently but agree with
your evaluation.

Your other use of "crap" is very subjective, you say the eyepiece is "crap"
when compared to a fancier eyepiece. As you should have noticed, I also
compared it to a TV eyepiece, I just pointed out the differences.

I am not saying anything contradictory here, and it is not a singular
"opinion" but a consensus of objective evaluations by users of 10" F5 scopes
(and at least one 8" F6 user as well).


You are saying two things, one is that there is "crap" in the outer 20 degrees,
which I think everyone agrees upon.

But whether this makes the eyepiece "crap" is a different issue and something
that is a personal decision for each user and is certainly not agreed upon.

I think it is important for this group to provide realistic evalutions of all
levels of equipment, from basic to the fancy. It is important to do this in a
way that is objective and provides the reader with a realistic understanding of
what they can expect without demeening someones possible choice.

Jon Isaacs

On Fri, 18 Jul 2003 15:39:49 -0400, "Stephen Paul"
wrote:

"Tom T." wrote in message
ws.com...

Maybe I'm wrong here, but you seem to think that if it's not TeleVue
it's worthless (for a fast scope).

snip

If I had a fast scope and wanted a "finder" eyepiece, I wouldn't hesitate to
buy a WS, but as a truly wide field eyepiece for observing using a fast
scope..., "yuck".

Peace,
Stephen Paul

Stephen,

I spent quite a bit of time on the veil w/ the 15" F5 and the BW last
night. "Observing" not "Finding".

It most certainly wasn't "yuck". More of a "Wow!"

Tom T.

On Sat, 19 Jul 2003 07:52:04 GMT, wrote:

I think some of the problems with low power eyepieces are in that fact
they produce large exit pupils and this possibly interacts with
problems with the observers eyes that are not seen in higher power
eyepieces.
-Rich


Good point Rich.

There is astigmatism present in the outer 25% or so of the eyepiece,
but - in my opinion it's not a huge amount.

I have a very slight astigmatism that shows up at exit pupils over
5mm, and when evaluating an eyepeice I have to be very careful to make
sure the abberations are showing up in the eyepeice - not in my eyes
themselves. I would suspect many people have this problem.

I do wonder if Stephen did a true side by side or if he's going from
memory.

Tom T.

On Fri, 18 Jul 2003 15:39:49 -0400, "Stephen Paul"
wrote:

"Tom T." wrote in message
ws.com...

Maybe I'm wrong here, but you seem to think that if it's not TeleVue
it's worthless (for a fast scope).


Well, that's not entirely true. It is however true, when discussing 68+
degrees of apparent field.


As Jon already said, that's not really the case even then. There are
several other decent wide field eyepeices. TV is not the only game in
town (although they are probably the most common).


I am perfectly happy with the performance of my 18mm, 12.5mm and 7.5mm
Ultimas in the F5, but then they aren't being used in an application that
the design cannot handle. (I am, however, unhappy with the 30mm Ultima, as
it has too much curvature, and never seems to come sufficiently to focus
over a large enough portion of the field that it provides any useful
function.)

Subjectively, I don't like crap at the edge, and I don't mind saying so,
because others will be like me, I'm sure. Glossing over such performance
failures with soft language, is for salesmen, not for peer reviews. g

Ok, let me approach this a little differently....

To me, *crap* is the subjective term. Moderate to slight astigmatism
over the last 15-20 degrees of the field coupled with a slight amount
of field curvature at f5 with the paracorr in place gives me a better
idea of performance than *crap*.

*Crap* is often a term I hear from salesmen who want me to buy a much
more expensive product that really isn't that much better.

I would rather have a 50 degree afov that's sharp, than a huge field with
crap in it. I'm not dissing the WS, not really. If I had an F10 with a 2"
focuser, I'd be all over the WS. Deep light cones are where they excel, and
for the price they're a huge bargain, given that application.

It is not insignificant that almost everyone includes the reference to the
WS as a "finder" and "framing" eyepiece whenever they are discussed. I would
_never_ consider the 35mm or 24mm Pans "finder" or "framing" eyepieces. They
are for observing (whether 10% of the time or 100%), and that is where the
difference lies in the final analysis. Opinion has nothing to do with this.

Again, Stephen, I guess we will just have to disagree. If I only use
an eyepeice 10% of the time, I don't want to sink that much money into
it - I'd rather have a larger scope, binoviewer, travel scope, etc...

Opinion has everything do do with it. IMO. g

As I said earlier, I had a blast with this eyepiece on the veil last
night in my 15" f5. Three separate observers (with varying levels of
experience) all agreed that it was a very nice eyepiece with
surprisingly good performance. No, it wasn't a pan 35 at the edge,
but it certainly wasn't crap. The word that seemed to fit better was
"Wow".

My findings are a result of an objective evaluation of the 1rpd, the WSII,
the WSIII, and the 35mm Pan, with and without Paracorr in a 10" F5 Dob.

Again, I don't see *crap* exactly as an objective term, and I have
done a side by side with the pano 35 (not without the paracorr tho).
I've owned a 40 pentax XL, and had opportunities to compare these to
the nagler 31. I've done this at multiple focal lengths, and would
ahve to agree that slower scopes are easier on eyepeices, but this
particular eyepiece performs acceptably *for me* at this focal length.

In the end I concluded that the wide fields afforded by fast scopes demand
better corrected eyepieces to appreciate maximum performance. With the more
simple design wide field eyepieces, a fast scope is going to screw up the
image. You just can't get around the optics.

I hope others don't take any of this personal. But it is an advisory posting
nonetheless, and therein lies its worth. If you have a fast scope, the
widescan design will have crap at the edge.

How about:

"Potential buyers should be aware that for this eyepiece (and most
simple wide field eyepeices) the edge performance will decrease as the
f ratio of the scope it's used in decreases.

The eyepiece exhibits a slight to moderate amount of astigmatism at
low powers and additionally, the field is not perfectly flat.

Most users report that edge performance is acceptable above f5, while
reports differ at f5 and below depending on user preferences.

Please note: A paracorr will correct for the coma inherent in the
scope, but you will still have to deal with the astigmatism."

IMO, The best way to judge any eyepiece is to use it yourself, in your
scopes at your site.

Be advised. I'm not making it
up.

And neither are the users who find the performance acceptable.

Clear Skies

Tom T.