ETX-125EC USER FEEDBACK
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Last updated: 31 March 2003
This page is for user comments and information specific to the Meade ETX-125EC. Comments on accessories and feedback items appropriate to other ETX and DS models are posted on other pages. If you have any comments, suggestions, questions or answers to questions posed here, e-mail them to me and I'll post them. Please use an appropriate Subject Line on your message. Thanks.


Subject:	How to Tell a New ETX-125EC
Sent:	Monday, March 31, 2003 4:19:31
From:	tjstanton1953@yahoo.com (Tom Stanton)
Once you have determined that you have a new version of the ETX (I do --
Huzzah!) should you perform any of the modifications listed on the site?
Or does the new model obviate the need for them?
Mike here: I would not do any mods unless I absolutely know that there is something that needs to be improved. And yes, there are tips that can not be done on the newer models.
Subject:	RE: ETX/LX90
Sent:	Sunday, March 30, 2003 6:14:18
From:	mike@firthfamily.freeserve.co.uk (Mike Firth)
thanks for your great web site and the good advise..    Can you please,
please,  ask those guys at Meade to send deliveries to the UK!  I've
tried every supplier in the UK for THE LX90 and there does not appear to
be one in the country. Can you tell me where I can buy a Meade LX90 in
the UK. Signed a frustrated customer/astronomer
Many thanks
Regards
Mike Firth
Mike here: There are several UK dealers listed on the Astronomy Links page; check those.
Subject:	Collimation
Sent:	Wednesday, March 26, 2003 7:47:32
From:	studio.diluccio@libero.it (Luca)
luke from italy.

So finally last night i have tested my ETX 125 uhtc. ( seeing was very
good) First i have examined star in sharp focus well the airy disk
wasn't uniformly round throughout it's perimeter.

When i have defocused star the bull eye was a little skewed in one
direction.

As i have an Lx 10 8" uhtc i have tried to see jupiter. Well image of
jupiter was better in my lx 10 than in the 125 etx uhtc.

I have tested 8" to and i have suspect that 8" was not well collimated
too. But if me it is important this question: if my etx 125 uhtc is out
of collimation it is difficult to collimate it ?

Thanks . Luke
Mike here: Comparing a 5" to an 8" or 10" will show a definite difference in the two telescopes due to the difference in aperture and focal lengths. Certainly I don't see as much detail in my ETX-125EC as I do in my LXD55 8"SC. But it does sound like your ETX-125EC might be slightly out of collimation. However, attempting to correct that can actually make it MUCH worse if you are not extremely careful and patient. But if you want to try to attempt it (and personally I don't recommend it, especially if only slightly out of collimation), see the collimation articles on the Telescope Tech Tips page.
Subject:	Good 125 - odd Autostar problem
Sent:	Wednesday, March 26, 2003 6:17:11
From:	KlaraColli@aol.com
I just got my ETX-125EC.  It works great! Every GoTo object has been
almost centered in the 26mm eyepiece.

The one problem I am having is when I start off my viewing using
Tonight's Best and then try to do a GoTo from the Objects menu.  I have
experienced three different errors when attempting this.  They are the
telescope ignoring the object I selected and going to the next object in
Tonight's Best; Autostar indicating it is slewing to the selected
object, but the scope does not move; and Autostar saying that the
selected object is below the horizon when it is not.  I have not tried a
GoTo from the objects menu on a night that I have not used Tonight's
Best yet.  That will be my next test.  Is there a known problem with
switching between Tonight's Best and selecting from the Objects menus?

Everything else works great and meets or exceeds my expectations.
Mike here: Thanks for the report. I vaguely recall someone else reporting a problem when leaving a Tour (but I could be wrong); I don't recall what version that was with though. If you don't have 2.6Ed, you might want to download it from Meade's site.
Subject:	 RE: Meade ETX-125EC questions
Sent:	Tuesday, March 25, 2003 20:42:33
From:	erika@its-smartcalls.com (Erik Andersen)
I'm starting to think that someone wants me to find a different hobby.
This new 125EC has a bad motor, dead out of the box so now I have to
return this one as well. Very frustrating.... This will be my last
e-mail to you as I think I'm going to switch brands. I want to thank you
for your help, have a great week!

Thank you,
Erik Andersen
And:
Using a 26mm lens how much better can you view planets with the Meade
14" LX200 GPS telescope? Heck, I may just go the whole hog...

Thank you,
Erik Andersen
Mike here: Quite a lot better, depending upon the viewing conditions. Larger, brighter image with more details visible. Of course, that is assuming you actually take the time and effort to set it up. It is a MUCH larger telescope. Keep in mind that the best telescope is the one that gets used.

And:

Agreed, however I judge how much it will be used by my ability to
actually see things clearly. I don't see a carrying case for this scope
so perhaps I should meet in the middle and go with the 12" and carrying
case.

I guess I just expected too much from the 125.

I don't mind going through the motions regarding setup, whatever it
takes to view things properly!

Thank you,
Erik Andersen

Subject:	Meade ETX-125EC views
Sent:	Monday, March 24, 2003 10:18:34
From:	erika@its-smartcalls.com (Erik Andersen)
Last night at about 12:00am the sky was crystal clear. So for the first
time since I bought the 125 I had a good sky to try it on. Since I was
repairing my sisters 60mm Celestron (lost screws and such) I took hers
outside with me as well. I used hers as a spotting scope and much to my
surprise Jupiter looked crystal clear on it, very shocking indeed! I
pointed my scope to Jupiter and much to my surprise Jupiter had an aura
around it and the image looked weak, not as strong as on my sisters.

I thought maybe upper atmosphere clouds had rolled in and clouded the
view. Up I looked and not a cloud to be seen. I looked thru my sisters
$199.00 6 year old cleaned with Windex (?!?!?) telescope and hers is
clear as can be! So I tried mine again and sure enough, no matter how I
focused it, it just didn't look that good. I only have the 26mm lens
that came with it but surely that should be enough to put the 60mm
Celestron to shame? I've heard how excellent the optics are on the 125
and last night I just didn't see it.

Could something be wrong with my 125? What things can I check? The
lenses all look clean, the scope looks perfect.

Thank you,
Erik Andersen
Mike here: It sounds like you didn't give the ETX-125 time to cool down after taking it outside. It takes a lot longer for it to reach "thermal equilibrium" than the 60mm (was it a refractor?). For best results you need to let the temperature INSIDE the telescope cool down to the same temperature as the outside air. Than can take up to 20-30 per inch of aperture.

And:

I thought the very same thing so I left it outside for two hours and
tried again. Is this not long enough going by the 20-30 per inch you
mentioned? Today I contacted the place where I purchased the scope and
he asked me to take it in. He took it apart and found the main mirror
was not mounted properly and the focus knob wasn't functioning properly.
He felt it may have been dropped in shipping. He replaced it with
another one, this one seems much more solid (the first one felt loose)
so I've mounted it and it's covered waiting for this rain to end.

Yes the 60mm is a refractor, and now that I've used it I don't feel
guilty over not spending too much on it for her. It seems to do pretty
darn well!

Thank you for taking the time to help!

Thank you,
Erik Andersen
Mike here: Mismounted optics will certainly mess up the image! Glad the dealer took care of you.
Subject:	Req. Inf.
Sent:	Monday, March 24, 2003 1:02:41
From:	studio.diluccio@libero.it (Luca)
I am Luke from Italy, so i have updated my autostar with ver 26ed and
patch 26dd so now my autostar version display 26dd.

All is ok ! Very good.
Go to is Ok and all work very well.

But last night i have tried to test collimation of my etx 125 and i have
noted that is not very well collimated. Please Mike can you tell me is
if necessary collimate my etx ? Is difficult ?

Or is better that i don't touch ?
Please help me.
Thanks Mike. I will wait an answer.
Luke.
studio.diluccio@libero.it
Mike here: Glad the patch went OK. Thanks for the news. As to collimation, how did you test and what did you see?
Subject:	ETX
Sent:	Sunday, March 23, 2003 13:59:09
From:	mike@firthfamily.freeserve.co.uk (Mike Firth)
First of all thanks for a great web site.  I recently bought a copy of
your book on the ETX and I have to say it was a great help.  I have a
200mm Newtonian telescope at the present time but I would like to get
into astrophotography in a big way.  I'm torn between the Meade ETX 125
and the LX 90. In the UK we pay nearly double the US price, so I have to
be sure. Given my interest in digital photography I need your advise as
to which would be best for me.

Many thanks for your help on this one
Regards, Mike
Mike here: Since the LX90 has an 8" Schmidt-Cassegrain (same as the LXD55 8"SC that I have in addition to three ETX models), it would yield better images for most objects (you could compare the astrophotos on both my ETX Site and my LXD55 Site (http://www.weasner.com/lxd). However, the ETX-125EC can also yield some amazing photos, as can be seen on my ETX Site. One other factor might be that the LX90 mount is more stable than the ETX mounts.
Subject:	New ETX-125
Sent:	Saturday, March 22, 2003 13:35:09
From:	mlminto@cox.net (Michael L Minto)
I think your site is right on time; a dedicated site for such a popular
'scope is a great way to find out what one's equipment is capable of -
within a virtual community!  I just got my scope yesterday; I noticed
that when I raise and lower the OTA with the motors, the whole OTA moves
about 1/8 of an inch left (when lowering) and 1/8 inch right (when
raising).  Is this normal?  If so, why does it do this?

Thanks for any help,
 
Michael L Minto
Mike here: You could be seeing "torgue". There have been some reports of this in the past. If you are using the Autostar, be certain you have selected the right telescope model and mounting mode. Do a RESET, CALIBRATE, and TRAIN DRIVES before the first operation to ensure the telescope and Autostar are "matched".
Subject:	ETX125 question
Sent:	Wednesday, March 19, 2003 4:10:19
From:	Dubboy44@aol.com
What an excellent website you provide!! Thank you very much!

I am anxiously awaiting the arrival of my new ETX 125 from Woodland
Hills Camera & Telescopes in Calif. (now all I need is clear skies!
...Northern Michigan does not always like to cooperate)

I have been reading the information provided by Clay Sherrod on
mechanical fixes to enhance and improve the performance of the ETX. I
notice that his info is dated 2001. Do you know if Meade has done
anything since then to improve some of these problems? Or is it still
necessary to fine tune the scope? I will, of course, test the scope
before touching it, just wondered what to expect.

Thanks again for providing such a fine source of info!!

Sincerely,    Don Schwab
Mike here: I suspect that most users do not need to make any improvements. Yes, Meade has made some design changes from the original model ETX-125EC.
Subject:	ETX 125 - OTA removal
Sent:	Tuesday, March 18, 2003 1:55:09
From:	Iknowittoo@aol.com
I need to remove my OTA in order to carry out the necessary servicing to
correct for problems with DEC slippage etc..  My problem is this :- does
anyone know the exact size of the Allen key required to remove the four
bolts holding the OTA onto the two support arms?  I feel it is important
to use the correct size in order to prevent damage to these bolts, and
subsequent problems as a result.

Many thanks for such a great site.

Regards

Brian Burton
And from our resident hardware expert:
From:	drclay@arksky.org (Clay Sherrod)
That size is a Standard 7/64-inch.

With so many adjustments that can and should be made from time to time
on the ETX and other similar scopes, I highly recommend a full set of
standard measure Allen wrenches of good quality; the ones supplied with
accessories and with the telescopes are soft and sometimes lead to
stripping of hex heads, etc.  Stanley, Craftsman and other brands should
be considered as a set, and only cost a few dollars more than the
bargain store "cheapies."

Dr. Clay
Arkansas Sky Observatory
www.arksky.org
MPC/cbat Obs. H43 / Conway
MPC/cbat Obs. H41/ Petit Jean Mt.

Subject:	Meade ETX-125EC questions
Sent:	Monday, March 17, 2003 20:04:25
From:	erika@its-smartcalls.com (Erik Andersen)
Mr. Weasner,

I wanted to write and thank you for the review you posted of the 125 at
your website. I realize you wrote it awhile ago and I was wondering if
your feelings about the 125 still hold true. I just purchased a new 125,
884 deluxe tripod, carrying case and Autostar two days ago and finally
got a chance to see how it works tonight on the Moon and Jupiter. There
was significant haze but the Moon looked spectacular, Jupiter looked
fine as well, even thru the haze.

Meade has an offer for people who purchased this Telescope, the Meade
Plossl set cost $650.00 but now is $99.00, for a limited time only, of
course :-). Is this deal too good to be true? Here is the link to the
Meade Offer http://www.meade.com/promo.d/plosslpromo.html,  I was
going to avoid going accessory happy and keep it to a focuser (cable
type? From where?) the lens set, a 2x Barlow, a dew cap and a few
filters.

I would love to hear comments or suggestions as I am new to this and
could use all the advice people will give.

Thank you,

Erik Andersen
Mike here: Yes, I still like the ETX-125EC. And yes, the eyepiece deal is a good one; I got the set with my LXD55 8"SC.
Subject:	power supply for etx 125
Sent:	Monday, March 17, 2003 19:49:10
From:	ASiegel163@aol.com
Is the center post for the 12VDC external input for the telescope
sussposed to be    (+ )or (-). ? I have a 12VDC at 500MA power supply.
Is that sufficient to power the scope with the autostar and the electric
focuser?

Thanks for your reply.

Al
Mike here: As noted on the FAQ page, the center pin is positive. You'd be better off with 1.5A; otherwise you will likely get motor faults and other problems.

And:

Thanks for the quick response.

I had wanted to get a variable power supply with numerious voltage
outputs, so that I could use it for other purposes. I have access to a
7AH 12VDC batterys. I will connect a cable and use that power source.

Thanks

Al

Subject:	etx 125ec
Sent:	Monday, March 17, 2003 1:18:45
From:	trailcrawler@sbcglobal.net (James Kendrick)
I am looking to purchase my first telescope and am interested in the
etx-125ec.  However, I have read many negative reviews regarding "sloppy
drive gears," "Autostar not centering," "the scope being wobbly," and
other quality control related issues.  I have not been able to tell when
most of the reviews have been written, so they may have been written
about the "old" model.

My questions are:  Has the "new" model fixed most, if not all, of the
major complaints about the "old" model?  And, should the etx-125ec be a
rewarding scope for a first-time buyer/novice? Also, is the UHTC worth
paying an extra $200.  Or would it be better to move up to a different
(larger apature) scope?

Also, I have been considering the LX 90.  As a novice, would it be woth
the extra money to move up to the LX 90.  Lets assume that portability
is not an issue.

Thank you for your response.  I truly have enjoyed browsing through your
site.

James
Mike here: If portability and price is not an issue, then the LX90 8" is a super telescope. The views through the 8" will exceed the 5" ETX-125EC. And yes, I would suggest getting the UHTC. As to the ETX-125EC, it is still a fine telescope. The Autostar works and the mount is OK for the price. So, which telescope you'll be happiest with, only you can say.

And:

Thank you.  You have an AWESOME site.
And:
Right now I'm leaning toward the "Supercharged" 125.  Would you
recommend doing this right out of the box?  Or would it be best to use
the unit and see.  As a novice (this will be my first scope) I'm not
sure I'd ever know if it needed correction or not.  I'm afraid that I'd
settle for views that could be enhanced only because of a lack of
knowledge/viewing experience.

Please advise.

Thank you,

James
Mike here: The Supercharging is to address some mechnical improvements. You may or may not need those improvements, depending upon your expectations or usage. Optically, you'll have the same telescope either way. So, I'd recommend waiting and getting some experience with it. But if you decide to go with it upfront, you likely will like what's done.
Subject:	ETX-125EC,   Image shift 
Sent:	Saturday, March 15, 2003 12:24:51
From:	Flyfishinggo@aol.com
I'm looking for information on how to do the image shift adjustments. I
have too much image shift on my new ETX-125, the scope will be going
back for repair. For the future is this something that will frequent
need adjustment, and could we make this adjustments. Do you have
pictures  or articals of the main mirror move mechanism.

Thank You,
                                                                              John
Mike here: Image shift is a tricky thing to fix and could likely require re-collimating the telescope, also a tricky thing to attempt. See the Telescope Tech Tips page for image shift and collimation articles. Also see "Doc Greiner's ETX Info page" linked from the Telescope Tech Tips page.

And:

Thank You for the quick reply. More Info my etx-125 was sent in for
motor fault problems, it also had image problems.

When I received my scope, the motor fault and image problem were
resolved.

BUT, it came back to me with mirror shift. The scope did not have any
mirror shift when i t was sent in. I 'll be sending the scope back.
Would they be able to make adjustment or merely add grease to the baffel
tube, the addition of any grease would be only a temporary fix. Since I
now like the images, would I be able to keep my current  mirror and lens
system. The shfting of the mirror, is that cause by the fitting of the
baffel tube, and is the to grease to minmize the clearence.

Could the shifting mirror cause the intra, extra star pattern images to
now look good, when  it did not the at first.
Mike here: They should be able to fix the image shift. The original model ETX-125EC had a problem that would develop during shipment. Required some extra packing material.
Subject:	Hard Stops
Sent:	Thursday, March 13, 2003 13:34:48
From:	markp@waveworks.net (Mark P)
michal@tampabay.rr.com said:
>For some reason my Etx-125 has a turning field of 220 degrees or so.

This is exactly what happened to my ETX 125 just last month.  After a
year of faithful service it started hitting something that restricted
it's movement to less than 360 degrees.  It is now at Meade for warranty
repair.

Mark P

rockvile md us na terra soslys orionarm....... 

Subject:	ETX125 EC
Sent:	Monday, March 3, 2003 14:19:33
From:	harry.fleming@tesco.net (Harry Fleming)
Hi, I've been reading your feedback page and theres a lot of talk about
collimating.

I bought an etx125 some time ago OTA only and mounted it on a goto
mount. I didnt get any instruction book and mine is out of collimation
by the out of focus star test. Can any of your contributors tell me how
to go about collimating, I cant even see how to get the back box/flip
mirror off the thing.

Many thanks
Harry UK
Mike here: If you really want to try it, see the article "Collimating an ETX Mak" on the Telescope Tech Tips page. Word of caution: you can easily make it worse by trying to collimate the Cassegrain-Maksutov yourself. You will need a LOT of patience and time. Good luck. Let me know how it goes.
Subject:	ETX 125 new to me
Sent:	Sunday, March 2, 2003 6:44:50
From:	user@mydeskinthestudy.fsnet.co.uk (John BODSWORTH)
I was drooling over the scopes on ebay having been a part time sky
watcher with binoculars for many years, I clicked though to Meade's site
and though I really "need" one of these! So as a spur of the moment
thing I took the plunge and brought a second hand ETX 125 with some
extra's and a deluxe tripod from ebay. During the week that I anxiously
waited its arrival the British sky was unusually clear, I decided to
swat up so I would be able to start getting the best out of the scope
when it arrived. I found your site and was hooked.

Keen to get started the day my ETX arrived, which was in excellent
condition in original packaging. I set up in the back garden played with
it for terrestrial viewing to familiarise my self while I waited for
darkness. A cloudy night of course but I used it in manual mode between
the gaps in the cloud. Viewing a half moon, Saturn and Jupiter.
Satisfied with my new toy and the optical quality I retired to warm for
yet more reading, Star maps redshift and web pages.

A few days later I had an opportunity with a cold but clear night, after
reading the manual I tried to setup in polar mode, now I though this was
going to be simple as it says in the manual, just point the tripod leg
towards north set 51 degrees on the mount and start an easy align. No
need to be to fussy over this spend your time viewing not setting up
say's the book! Well I do not need to tell you how bad the goto was.
With the dec locked hard and the scope turned east and then started to
point to my feet! The clutch was slipping that badly.

So I have just completed as many of the tune up tips that I can from you
and the links to scopetronics. The biggest problem was that the dec lock
knob was on the floating [left-hand] side and the smooth knob with
setting circle on the dec lock side! The dec lock knob has been
tightened so much that it has stripped the brass bush from the plastic
OTA support. This was fixed with some epoxy, I have cleaned out both
clutches and adjusted the backlash, and reassembled with the knobs and
setting circle on the correct side. Retrained the motor's and wow what a
difference. At 9pm the cloud had gone and I setup following your home
position procedure for an alt/azi and an easy align [Meade's
documentation is very poor here] just a few minutes later and I try my
first goto on Jupiter absolutely spot on in the middle of FOV. I had a
glorious hour before the cloud came back I put it into sleep, inside for
a bite and a warm back outside after midnight and the cloud had gone as
quickly as it appeared but in its wake the dew had settled heavily, I
uncovered the scope for another glorious hour before I succumbed to the
cold.

So far I have spent my time with planets and the moon, I would like to
start looking for other galaxies ect, so I tried to look for M82 last
night but even though the goto is spot on I could not see anything that
I could recognise as a possibility. I chose M82 because it was virtually
vertical. I live between the city's of Sheffield and Doncaster and light
pollution is a major problem from my back garden upto about 30 degrees
alt, there is nothing. Am I right in assuming that I could not see M82
because of its magnitude? Which other Messer objects or galaxies should
I try and find in these conditions? If I travel out to a remote site how
easily can I expect to find spiral galaxies for example if I have a good
goto and no light pollution

Next on my fix list is to update Autostar as soon as I get the cable and
software, again following your tips. Thanks for an excellent site, can
anybody tell me how to convince or just con a woman into allowing me a
12" LX200GPS

John Bods
Mike here: Sounds like someone messed up the ETX but you corrected the problems. Good job! As to "faint fuzzy blobs", yes, you will need dark skies to be able to see reall faint objects. The problem isn't that they are faint (well, it is a major contributor), but that in light polluted skies the contrast is too low to see the faint fuzzy blob. Sometimes, the various types of light pollution filters can help but the best cure is DARK SKIES (one of the reasons that this ETX Site is a sponsor of the International Dark-Sky Association). You might want to look at the Messier catalog; see the SEDS Messier Database (linked on the Astronomy Links page). Remember that what you see won't look like the photos. Most galaxies and nebulae will appear faint, fuzzy, and with very little sharp. Yes, some galaxies will have some sharp visible (round, oblong) but don't expect to see spiral arms. M42, the Great Nebula in Orion is well positioned for viewing right now. From a reasonably dark site you can see a lot of detail.
Subject:	Question about seeing quality with my ETX125 
Sent:	Saturday, March 1, 2003 4:37:49
From:	Damhof@home.nl (Jan Damhof)
Well got my ETX125 a few weeks now, and I'm very happy with it. We had
some very clear skies in Holland the last two weeks so I was able to use
it on a regular basis.. The weather forecast says that this weekend will
be the end of the clear but cold weather. so the next sessions will
probably under warmer conditions. This is somehow what my Question is
about. Aldow I'm happy with my ETX there are two thing I'm not sure of.

I didn't managers to get a real sharp images of  the bright ( Double )
stars. I know that observing from my backyard in a light polluted area
doesn't do good for the sharpnes of an image ( heat from roofs etc. )
and so I had a try in the field an hour drive from my city and things
looked better ( especially galaxies ! ). But bright stars are still not
that sharp as I hoped to see. All other object look fine to me,
nebulas,galaxies ( faint but nice ! ), Jupiter ( in the field there were
short moments I could  really see lots of cloudbands, not all the time
but from time to time, this should say something about the seeing
conditons.)

It is just that the really bright stars were somehow still not what I
expected.. But, what can I expect ? I have no reference scope and have
not yet an feelling about the seeing and transparance quality of the
sky. So did I have bad seeing conditions ? There was this article from
Dr.Clay that in the winter months people starts to complain about there
scope, it this the case ? What can I expect in the spring and summer
months ? I also noticed (only for these bright stars ) when I focus the
best I can and look in the eyepiece, when I move my eye or head a little
the focus of that star seems to change a little. Is this normal or a
sign of bad quality eyepiece.

My second Q is about the finder scope. What qualilty can you expect from
this, because this the one thing I'm not impressed of.. when focusing
the finder scope, the stars in the center are ok ( if you move your eye,
focus will change somehow. )  but all star not within the center starts
to blur the more they are on the edge on de FOV.I only the center of the
FOV is somhow sharp. Is this normal with the ETX125 finderscope or
should the complete FOV be sharp ? Because I use this finderscope only
as a finder scope it's not a that big deal, it functions for what it is
worth.

For the rest, I'm a happy ETX user :)

thx,

Jan

http://members.home.nl/damhof/astro/
Mike here: First off, the finderscope is of low quality and images are not uniformly focused across its field of view. It is not intended to be a small telescope but an aid in aligning the telescope on the object you want to see. There are certainly higher quality finderscopes available but you would have to modify the mounting bracket or add a new one. As to seeing, etc, you might want to see the articles on Telescope Performance on the "Observational Guides/References" page. It sounds like your telescope/eyepiece is performing as it should. If you move your eye out of the central optical axis you can see the effect you describe; normally you should keep your eye on the optical axis. Letting the telescope reach "thermal equilibrium" with the outside air, which can take up to several hours depending upon the size of the telescope, its design, the temperature differential, etc, is required for best performance. As to the bright stars, you may be seeing the "airy disk", which is normal AND good. The disk is actually small concentric rings. If you look at a bright star and slowly unfocus the image you can see rings (a perfectly collimated telescope at thermal equilibrium will show the rings as concentric circles). But even when the star is in focus, bright stars should still show a small airy disk. Is this what you are seeing?

And:

If I slowly unfocus the image, I see the rings, they look somehow the
same in both focus directions  what I understand of it this should be a
good sign of quality. ( I find it had to say if they exact the same ) I
don't exactly know what you mean by an "Airy" disk. Is it like a
"heatwave" kind of movement of a star / disk ? I gone have a better look
the next time I've got a clear sky. It's hard to explane what it exactly
looked like, but what I remember of the last time a checked a bright
star was that it was very hard to determine when I had the best focus on
that star, and for my feeling never really had one, or a real disk with
rings.  But. I do get good focus on the rest like Jupiter, Saturn, open
star clusters ect. So maybe it's just me or the seeing conditions. Next
time I will try to take some pictures with my digi cam or webcam and
compare them with images is see on the net.
Mike here: When you move into and out of focus on both sides, having the rings be the same is a good thing. Don't worry if you are not noticing the "Airy Disks" on bright stars; you really have to have good seeing, a cooled-down telescope, and good eyes as well.

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