RE: [ETXASTRO] Still Cloudy - Can't test ETX-105 Yet
- View Source} It depends on if you are left-eyed or right-eyed.
} People who heavily prefer their right eye have always had a little more
} trouble with the ETX scopes and the Meade finders.
} Setting shorter eyepieces a little higher up in the eyepiece holder and
} securing them there with the set screw might help. Of course you will have
} to refocus the scope.
I really wouldn't recommend treating the eyepiece thumbscrew in that way.
The thumbscrew is very light weight and not meant to actually hold much
of anything. And the eyepiece tubes will likely get scratched and dented
if you overtighten it.
Also, the eyepiece probably won't be held in proper alignment.
A short collar around the eyepiece tube would be a better idea, I think.
- View SourceIn ETXASTRO@y..., "ngc5466" <ngc5466@y...> wrote:
>When I ordered the 2" length above, I asked about the other 1" they
>>By the way, I saw the posts about UO Optics, and I was wondering if
>>anyone has found a way to use the UO orthos with the ETX-105. The
>>finder seems to get in the way of using a short eyepiece. I suppose
>>if I dispense with that finder and replace it with a Rigel Quick
>>finder things would be different,
>I spent about two-and-a-half hours observing Jupiter, Saturn, and
>the Eskimo Nebula in Gemini. I did some experimenting with a UO
>12.5mm Ortho, and a Meade Research Grade 7mm Ortho. I also noticed
>what you have, and got out a Lumicon 4.5" extension tube. They have
>a shorter one (2 1/4") which I have decided to order tomorrow. It
>is $19.50, and I the part number is LAD12F.
list (LAD110) for $12. It just threads into the barrel of the
eyepiece, which is ok if you just have one or two eyepieces to outfit
Of course, the LAD12F is thread for filters which might be useful as
- View SourceTonight I just finished boring out and filter-threading three Lumicon LAD110
1.25" by 1" extension tubes so they could be used as full-aperture eyepiece
extension tubes with female filter threads too.
I can't for the life of me figure out why Lumicon made these with such a small
internal bore diameter and without a provision for filter attachments. As
shipped, they would block some of the light cone of any eyepiece about 16mm or
They came with a 0.670" center bore and I opened them up to 0.940" at the male
thread end and 1.098" at the filter end. I then threaded the filter end so it
could take 1.25" filters (1.115" by 40 TPI) or to allow extension tube stacking.
The whole purpose of this exercise was to give me some more eyepiece tube for
safety purposes after installing parfocal rings on a bunch of my miscellaneous
eyepieces. It sure would be nice if Scopetronix (parfocal ring supplier) also
made eyepiece extension tubes available for use with their parfocal rings.
And since I am already in a whiney mood, why do TeleVue eyepieces come with a
non-standard 0.5mm filter thread pitch? What's up with that?
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> They have [Lumicon] a shorter one (2 1/4") which I have decided<snip>
> to order tomorrow. It is $19.50, and I the part number is LAD12F.
> When I ordered the 2" length above, I asked about the other 1" they
> list (LAD110) for $12. It just threads into the barrel of the
> eyepiece, which is ok if you just have one or two eyepieces to
> outfit as such.
> Of course, the LAD12F is thread for filters which might be useful
> as well.
- View SourceI finally got a chance to test a scope last night, although it wasn't
the ETX-105. There were only sucker holes, and I knew that the clouds
would probably move in for good, so I tried out an Orion StarMax 127.
You're probably wondering why I would purchase a 5-inch StarMax when
I had already pluncked down the dough for an EXT-105, right? Well, my
folks surprised me for my 50th b-day with a $500 gift certificate for
Orion products. Since I already had everything I needed from Orion
that costs less than 400 dollars or so, I went ahead and picked up
Seeing wasn't very good, and the clouds moved back in before the
scope could cool properly, but it seemed to me that the ETX-105 may
have had better optics, both in terms of sharpness and contrast. (I
had the scope out for only about 50 minutes).
This was just my feeling because I was not able to make a direct
comparison between the scopes, at least not yet. Jupiter showed only
two bands clearly --not good. The Trapezium & vicinity didn't show
any more, and maybe less detail than the ETX-105 (as I recall).
However, at low power (64x), the stars of M35 were tack sharp.
About 2 months ago, I tested the optics of the ETX-105 that I had
originally received. I had to use it without motor drives because the
drives were faulty. Admitedly, the ETX was out longer on that
previous occasion, hence it had proper time to cool.
Can't wait for a real comparison test, but first we have to get what
amounts to a fully clear and steady night!
--- In ETXASTRO@y..., "ngc5466" <ngc5466@y...> wrote:
> Hello Lee,
> Please don't hate me for saying this, but I've had the 105 for a
> little over two weeks now and just came in from my fifth observing
> session with it. Tonight was cold, and clear, and steady.
> Leroy Guatney
> Aurora, Colorado
> ETX105/EC owner/operator