Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

unable to focus

  • Please log in to reply
24 replies to this topic

#1 NotGalileo

NotGalileo

    Lift Off

  • -----
  • topic starter
  • Posts: 2
  • Joined: 16 Oct 2021

Posted 16 October 2021 - 06:11 AM

New to astronomy and telescopes.

Have acquired a new telescope: Saxon 767AZ with a number of lenses - 4, 12.5 & 25 and 3x Barlow.

 

Have used finderscope during the day 800m away - aligned main scope all good. (I thought).

 

First time out - black - nothing - finderscope crosshairs on the moon but nothing in the 'scope, just black.

 

Anyhow tried again after checking alignment (now a bit out) realigned (daytime) and got the moon in the crosshairs (yay!) and then still had to move the scope around to find the 'bright light' (moon).  Found the light but couldn't for the life of me focus it.  Tried various combinations of lenses and very finely attempted to focus but to no avail.

 

any suggestions would be most appreciated.

 

 


  • Sky Muse likes this

#2 kathyastro

kathyastro

    Soyuz

  • *****
  • Posts: 3,838
  • Joined: 23 Dec 2016
  • Loc: Nova Scotia

Posted 16 October 2021 - 06:31 AM

The first thing to do is to throw away the 3x barlow.  You can probably throw away the 4mm eyepiece, too.  You will only be able to use it in perfect conditions that happen maybe once every ten years.  You will never be able to get a clear view with either the barlow or the 4mm, because the magnification is too high.

 

The 12.5mm and 25mm eyepieces will work well enough.  When finding targets, start with the finder.  Then use the 25mm and centre the target in it.  Finally, use the 12,5mm and centre the target in it.  Then, check the alignment on the finder, and make sure that the cross-hairs are exactly on the target while it is still centred in the 12.5mm.

 

You should be able to focus easily with either the 25mm or the 12.5mm eyepiece.  Be sure to use the diagonal if one was supplied with the scope.  It will hold the eyepiece at the correct distance for focusing.


  • davelpg, SeaBee1, vtornado and 5 others like this

#3 NotGalileo

NotGalileo

    Lift Off

  • -----
  • topic starter
  • Posts: 2
  • Joined: 16 Oct 2021

Posted 16 October 2021 - 06:59 AM

Kathyastro, many thanks.  we will go back to square one and align during the day and try try again.  cheers and thanks again.



#4 belliott4488

belliott4488

    Ranger 4

  • *****
  • Posts: 388
  • Joined: 05 Oct 2020
  • Loc: MD, US

Posted 16 October 2021 - 08:42 AM

Kathyastro, many thanks.  we will go back to square one and align during the day and try try again.  cheers and thanks again.

Just to emphasize what kathyastro said, you'll do best if you correct your alignment at night when you're observing the moon, a bright star or planet, or something else in the sky. You can get close if you do it during the day - if you pick a target far enough away - but "infinitely far away" is best, since that's what you'll be using the finder for.


  • NotGalileo likes this

#5 SteveG

SteveG

    Voyager 1

  • *****
  • Posts: 10,542
  • Joined: 27 Sep 2006
  • Loc: Seattle, WA

Posted 16 October 2021 - 02:04 PM

Kathyastro, many thanks.  we will go back to square one and align during the day and try try again.  cheers and thanks again.

I’d be interested in seeing a picture of your scope and focuser.

 

I wouldn’t throw away the barlow just yet. Can you take a picture of it?



#6 JOEinCO

JOEinCO

    Apollo

  • *****
  • Posts: 1,377
  • Joined: 28 Sep 2017
  • Loc: Colorado Front Range

Posted 17 October 2021 - 03:45 AM

I wouldn’t throw away the barlow just yet. Can you take a picture of it?

I know where Steve is going with this....   biggrin.png



#7 Sky Muse

Sky Muse

    Cosmos

  • *****
  • Posts: 9,077
  • Joined: 26 Oct 2012
  • Loc: Mid-South, U.S.

Posted 17 October 2021 - 04:46 AM

New to astronomy and telescopes.

Have acquired a new telescope: Saxon 767AZ with a number of lenses - 4, 12.5 & 25 and 3x Barlow.

 

Have used finderscope during the day 800m away - aligned main scope all good. (I thought).

 

First time out - black - nothing - finderscope crosshairs on the moon but nothing in the 'scope, just black.

 

Anyhow tried again after checking alignment (now a bit out) realigned (daytime) and got the moon in the crosshairs (yay!) and then still had to move the scope around to find the 'bright light' (moon).  Found the light but couldn't for the life of me focus it.  Tried various combinations of lenses and very finely attempted to focus but to no avail.

 

any suggestions would be most appreciated.

You can't use that type of finder-scope successfully upon the kit's arrival.  In order for the finder-scope to retain its aligned position, you must shim the front of the holder, about 1/2" inward and all round...

 

accessories2.jpg

 

You can see the flocking, indicated by the yellow arrow, which is like thin felt, lining the front area just on the inside of the holder.  You can use thin, self-adhesive felt, or masking-tape even.  You want the finder-scope to fit snugly, tightly, there.  You then adjust the three thumb-screws at the rear to align the finder-scope with the telescope, and it will retain its alignment, perhaps indefinitely.  I would use the Moon to align the finder-scope with the telescope.  You should be able to align it quickly enough, once you shim the holder.  Aligning would be even better with a bright star.  The higher the power of the eyepiece, the more accurate the alignment, so use the 12.5mm.

 

You can most certainly make use of the 4mm(175x) eyepiece that came with the telescope, on occasion, particularly on the Moon, if your 76/700 Newtonian is well-collimated.  Don't throw the 4mm away, but do set the 3x-barlow aside in a drawer somewhere, within a ski-chalet on one of Saturn's outermost moons, for example.  In future, you can get a quality 2x-barlow, if desired.

 

Get some Plossl eyepieces, from Bintel, a 32mm(22x) perhaps, a 12mm(58x) and/or a 9mm(78x).  You can combine the 12mm with a quality 2x-barlow for a simulated 6mm(117x); a 9mm for a simulated 4.5mm(156x).

 

Let us know how you get along with all of that.  Keep up with it, and don't give up the ship.


  • SeaBee1 likes this

#8 SteveG

SteveG

    Voyager 1

  • *****
  • Posts: 10,542
  • Joined: 27 Sep 2006
  • Loc: Seattle, WA

Posted 17 October 2021 - 02:30 PM

I know where Steve is going with this....   biggrin.png

If his barlow is of decent quality, I can be used with the 25 mm, created an 8 mm eyepiece with long eye relief.


  • SeaBee1 likes this

#9 JOEinCO

JOEinCO

    Apollo

  • *****
  • Posts: 1,377
  • Joined: 28 Sep 2017
  • Loc: Colorado Front Range

Posted 18 October 2021 - 02:06 AM

I know where Steve is going with this....   biggrin.png

If his barlow is of decent quality, I can be used with the 25 mm, created an 8 mm eyepiece with long eye relief.

 

I was wrong. I thought Steve was going to see if it's one of the Barlows that you can unscrew the lens cell from, and attach directly to an eyepiece for a 1.5X effect. But the 3X Barlow that comes with the Saxon is not that type.

 

Nevermind.... crazy.gif 


  • SteveG likes this

#10 Sky Muse

Sky Muse

    Cosmos

  • *****
  • Posts: 9,077
  • Joined: 26 Oct 2012
  • Loc: Mid-South, U.S.

Posted 18 October 2021 - 02:41 AM

The 3x-barlow in question...

 

https://i.imgur.com/LVd4SJ8.jpg

 

...and bound for one of Saturn's moons.



#11 Sky Muse

Sky Muse

    Cosmos

  • *****
  • Posts: 9,077
  • Joined: 26 Oct 2012
  • Loc: Mid-South, U.S.

Posted 18 October 2021 - 02:53 AM

The first thing to do is to throw away the 3x barlow.  You can probably throw away the 4mm eyepiece, too.  You will only be able to use it in perfect conditions that happen maybe once every ten years.  You will never be able to get a clear view with either the barlow or the 4mm, because the magnification is too high.

 

The 12.5mm and 25mm eyepieces will work well enough.  When finding targets, start with the finder.  Then use the 25mm and centre the target in it.  Finally, use the 12,5mm and centre the target in it.  Then, check the alignment on the finder, and make sure that the cross-hairs are exactly on the target while it is still centred in the 12.5mm.

 

You should be able to focus easily with either the 25mm or the 12.5mm eyepiece.  Be sure to use the diagonal if one was supplied with the scope.  It will hold the eyepiece at the correct distance for focusing.

The Saxon 4mm SR(symmetrical-Ramsden)...

 

https://i.imgur.com/R1eApIp.jpg

 

...is the exact same as my Celestronica 4mm SR.  Both are manufactured, or sourced out, by Synta...

 

SR4mm3.jpg

 

That one came with my 127mm f/8 "Bird Jones" catadioptric, and I've learned to like it, a lot.  The Moon at 250x through said telescope and eyepiece...

 

https://i.imgur.com/bU9L0fg.jpg

 

During the live view, with the eye, it was eye-wateringly and jaw-droppingly sharp.


Edited by Sky Muse, 18 October 2021 - 02:57 AM.


#12 PatrickVt

PatrickVt

    Apollo

  • ****-
  • Posts: 1,039
  • Joined: 20 Apr 2018
  • Loc: Vermont, US

Posted 18 October 2021 - 07:42 AM

The Saxon 4mm SR(symmetrical-Ramsden)...

 

https://i.imgur.com/R1eApIp.jpg

 

...is the exact same as my Celestronica 4mm SR.  Both are manufactured, or sourced out, by Synta...

 

attachicon.gifSR4mm3.jpg

 

That one came with my 127mm f/8 "Bird Jones" catadioptric, and I've learned to like it, a lot.  The Moon at 250x through said telescope and eyepiece...

 

https://i.imgur.com/bU9L0fg.jpg

 

During the live view, with the eye, it was eye-wateringly and jaw-droppingly sharp.

 

And yet, completely useless to anyone who wears eyeglasses.  That tiny pinhole top eye lens and lack of sufficient eye relief renders this and most cheap kit eyepieces useless or, at the very least, extremely uncomfortable and difficult to use.  And then these beginners are turned off to backyard astronomy.

 

"According to the Vision Council of America, approximately 75% of adults use some sort of vision correction. About 64% of them wear eyeglasses, and about 11% wear contact lenses...".  Considering this, it makes absolutely no sense to package eyepieces in a beginners kit that only 36% of the public can use.  I really wish they would stop packaging this sort of useless junk in beginner kits.  We would see far fewer beginner problems in these forums if they marketed eyepieces that every beginner could use.  I suspect that most people just give up astronomy rather than come to places like here to ask questions (and I myself do know of a few people who had given up on astronomy years ago because of this). 

 

Here's an idea....  why not just package one cheap 15mm or 20mm 68 degree eyepiece with a moderately large top eye lens and sufficient eye relief for eyeglass use with each beginner kit?  If every beginner can actually use the lone kit eyepiece, perhaps they would be more inclined to get excited about astronomy and perhaps more likely to purchase more of a variety of eyepiece focal lengths.

 

Variety, magnification and even sharpness are completely irrelevant if the eyepiece can't be used at all by most of the population.  Even if only 25% of people needed eyeglasses, it still would not make sense to package this useless junk in a kit that is geared specifically toward every beginner in the hope of hooking them enough into a new hobby to spend more money on that hobby.  Even when I was a young kid before needing eyeglasses, I hated these tiny eyepieces.

 

Patrick


  • ShaulaB likes this

#13 kathyastro

kathyastro

    Soyuz

  • *****
  • Posts: 3,838
  • Joined: 23 Dec 2016
  • Loc: Nova Scotia

Posted 18 October 2021 - 08:01 AM

Here's an idea....  why not just package one cheap 15mm or 20mm 68 degree eyepiece with a moderately large top eye lens and sufficient eye relief for eyeglass use with each beginner kit?  If every beginner can actually use the lone kit eyepiece, perhaps they would be more inclined to get excited about astronomy and perhaps more likely to purchase more of a variety of eyepiece focal lengths.

The eyepieces packaged with department-store telescopes are not tools for facilitating views of the heavens.  They are marketing tools to encourage people to part with their cash.  Their sole purpose is to allow the vendor to claim "525x magnification" without running afoul of false-advertising laws.


  • ShaulaB, vtornado and RockyMtnRR like this

#14 PatrickVt

PatrickVt

    Apollo

  • ****-
  • Posts: 1,039
  • Joined: 20 Apr 2018
  • Loc: Vermont, US

Posted 18 October 2021 - 08:41 AM

The eyepieces packaged with department-store telescopes are not tools for facilitating views of the heavens.  They are marketing tools to encourage people to part with their cash.  Their sole purpose is to allow the vendor to claim "525x magnification" without running afoul of false-advertising laws.

 

I know what the marketing fools think is best but my research disagrees with their business plan.  They seem to be focused on inexperienced, unresearched impulse buys rather than growth and future/additional purchases.

 

Unfortunately, having asked all my family and friends of their experiences with these beginner telescope packages (none of them are astronomers today), most of those who attempted to get involved in backyard astronomy, whether for themselves or their kids or their own experiences as kids, couldn't see anything (like the original poster of this thread) and then simply gave up.

 

When asked why they gave up, the answers ranged from patience wore thin trying to get it to work, to figured this hobby wasn't for them, to they felt they got burned and refused to spend any more money on this activity.  These people were left with such a bad taste in their mouth that I can't even get any of these people interested in viewing through my good gear today.  They could be sitting 10 feet away from my telescope and they still refuse to be coaxed into taking a peek.  They are that turned off to this hobby.  This includes my son who had a brief run-in with a Bird-Jones piece of junk (it was a gift).   If more sales are the goal (it should be...  it is the purpose of marketing) and if you ask me, the marketing isn't working.  That initial sale is absolutely nothing compared to what the manufacturers can rake in with future purchases by excited customers and, right now with their current marketing plan, they are losing out on a lot of future purchases.

 

To the original poster, put the Barlow aside and use only the eyepieces with the highest numbers.  These will be the easiest eyepieces to use because these eyepieces provide the widest views.  Slowly rake that focuser all the way out while looking through the eyepiece.  When your view is very out-of-focus, you won't see a thing through the eyepiece so make sure you scroll through the whole range of the focuser while looking through the eyepiece when trying to find focus.  If it is a refractor telescope, make sure the diagonal is in the focuser and then put the eyepiece in the diagonal.  If necessary, find focus during the day on the most distant object you can see.  If it is a reflector telescope, there will be no diagonal so the eyepiece goes directly into the focuser.

 

Patrick


  • vtornado likes this

#15 Paul Sweeney

Paul Sweeney

    Viking 1

  • -----
  • Posts: 701
  • Joined: 19 Feb 2018
  • Loc: Heidelberg, Germany

Posted 18 October 2021 - 08:41 AM

Ditto the advice above about shimming the finder. I used scotch tape, but any tape will do. It has to be tight so that it doesn't slip out of position.

You also have to check that the finder base is very tightly attached to the tube. On mine there was a lot of space between the screw and the side of the hole in the finder's base. So it only took a minor bump to move the whole finder. I had to tighten mine quite a bit to keep it in place. You might also try two sided tape to help keep it from shifting.

#16 PatrickVt

PatrickVt

    Apollo

  • ****-
  • Posts: 1,039
  • Joined: 20 Apr 2018
  • Loc: Vermont, US

Posted 18 October 2021 - 08:44 AM

You can't use that type of finder-scope successfully upon the kit's arrival.  In order for the finder-scope to retain its aligned position, you must shim the front of the holder, about 1/2" inward and all round...

 

attachicon.gifaccessories2.jpg

 

You can see the flocking, indicated by the yellow arrow, which is like thin felt, lining the front area just on the inside of the holder.  You can use thin, self-adhesive felt, or masking-tape even.  You want the finder-scope to fit snugly, tightly, there.  You then adjust the three thumb-screws at the rear to align the finder-scope with the telescope, and it will retain its alignment, perhaps indefinitely.  I would use the Moon to align the finder-scope with the telescope.  You should be able to align it quickly enough, once you shim the holder.  Aligning would be even better with a bright star.  The higher the power of the eyepiece, the more accurate the alignment, so use the 12.5mm.

 

You can most certainly make use of the 4mm(175x) eyepiece that came with the telescope, on occasion, particularly on the Moon, if your 76/700 Newtonian is well-collimated.  Don't throw the 4mm away, but do set the 3x-barlow aside in a drawer somewhere, within a ski-chalet on one of Saturn's outermost moons, for example.  In future, you can get a quality 2x-barlow, if desired.

 

Get some Plossl eyepieces, from Bintel, a 32mm(22x) perhaps, a 12mm(58x) and/or a 9mm(78x).  You can combine the 12mm with a quality 2x-barlow for a simulated 6mm(117x); a 9mm for a simulated 4.5mm(156x).

 

Let us know how you get along with all of that.  Keep up with it, and don't give up the ship.

 

All of my straight-thru finder scopes that come with this type of bracket also come with a thin o-ring that is supposed to be in between the finder scope and the bracket.  I suppose that if you never installed that o-ring, then you would need to flock that bracket.

 

Patrick



#17 Sky Muse

Sky Muse

    Cosmos

  • *****
  • Posts: 9,077
  • Joined: 26 Oct 2012
  • Loc: Mid-South, U.S.

Posted 18 October 2021 - 12:06 PM

All of my straight-thru finder scopes that come with this type of bracket also come with a thin o-ring that is supposed to be in between the finder scope and the bracket.  I suppose that if you never installed that o-ring, then you would need to flock that bracket.

 

Patrick

That type of finder-scope/bracket has never come with an o-ring, not at that price-point...

 

finderscope.jpg

 

...nor is there a groove on the tube to accept one.



#18 Sky Muse

Sky Muse

    Cosmos

  • *****
  • Posts: 9,077
  • Joined: 26 Oct 2012
  • Loc: Mid-South, U.S.

Posted 18 October 2021 - 12:09 PM

And yet, completely useless to anyone who wears eyeglasses.  That tiny pinhole top eye lens and lack of sufficient eye relief renders this and most cheap kit eyepieces useless or, at the very least, extremely uncomfortable and difficult to use.  

 

Patrick

Ah, but that modern 4mm SR is an exception to the rule, I've found; quite adequate eye-relief, if you don't wear glasses, and a rather generous eye-lens diameter for a 4mm at that.



#19 PatrickVt

PatrickVt

    Apollo

  • ****-
  • Posts: 1,039
  • Joined: 20 Apr 2018
  • Loc: Vermont, US

Posted 18 October 2021 - 12:13 PM

The couple of Celestron 6x30 straight-thru finders that came with a couple of beginner scopes I've purchased had o-rings as well as grooves for the o-rings.  I didn't know there were variations out there with no o-rings nor grooves.  The o-ring and groove works perfectly fine.  I can't crane my neck for these tiny straight-thru finders but that is a different problem.

 

Patrick


  • SteveG likes this

#20 Sky Muse

Sky Muse

    Cosmos

  • *****
  • Posts: 9,077
  • Joined: 26 Oct 2012
  • Loc: Mid-South, U.S.

Posted 18 October 2021 - 12:28 PM

The couple of Celestron 6x30 straight-thru finders that came with a couple of beginner scopes I've purchased had o-rings as well as grooves for the o-rings.  I didn't know there were variations out there with no o-rings nor grooves.  The o-ring and groove works perfectly fine.  I can't crane my neck for these tiny straight-thru finders but that is a different problem.

 

Patrick

I'm afraid that those days are long gone.  I, too, have a 6x30, and it's grooved, with an o-ring.  It came with an 8" f/5 Parks Optical OTA, about eighteen years ago...

 

finis2.jpg

 

The Celestron bracket, I won via an eBay auction.  Both items were made in Japan.  They're older, as a result, unavailable, but you can still get Chinese clones of them...

 

https://www.telescop...2160/p/7210.uts

https://agenaastro.c...th-bracket.html

 

In so far as those plasticky, vending-machine type finder-scopes/brackets, I took my own 5x24 outdoors during the day, and was quite impressed with the view.  Bright and rather spacious it was.  


Edited by Sky Muse, 18 October 2021 - 12:29 PM.


#21 Sky Muse

Sky Muse

    Cosmos

  • *****
  • Posts: 9,077
  • Joined: 26 Oct 2012
  • Loc: Mid-South, U.S.

Posted 18 October 2021 - 12:57 PM

The OP's Saxon kit is the same as this Celestron "PowerSeeker" kit...

 

http://www.saxonopti...productid=10218

https://www.amazon.c...e/dp/B0002CTZB6

 

But Synta has discontinued the Celestron variant.  That Amazon seller is selling new old-stock, and marked up a bit at that.

 

Orion and Carson offer one as well, in teal, and red(smile.gif), respectively, for less.  I was wanting, desirous of the Carson, the RP-100, myself, but the sale expired at B&H Photo before I could "pull the trigger".

 

If it's done right, stiff springs and washers can be added to where the telescope joins the yoke, the mount, then to do away with the relatively useless slow-motion control...

 

kit2b.jpg

 

In the end, with these entry-level kits, all you're really after within one is the telescope.  It's the telescope, only and nothing else really, at these price-points.  If anything else within the kit seems suspect, replace it with better; simple.


Edited by Sky Muse, 18 October 2021 - 02:34 PM.


#22 PatrickVt

PatrickVt

    Apollo

  • ****-
  • Posts: 1,039
  • Joined: 20 Apr 2018
  • Loc: Vermont, US

Posted 18 October 2021 - 12:59 PM

Ah, but that modern 4mm SR is an exception to the rule, I've found; quite adequate eye-relief, if you don't wear glasses, and a rather generous eye-lens diameter for a 4mm at that.

 

LOL...  Okay, now I think you are just trying to be funny.  

 

What sort of eye relief does a modern 4mm SR eyepiece have?  Somewhere around 6-8mm?  I would not call that "adequate" eye relief by any stretch of the imagination.  I can just barely manage to get by when I mash my eyeglasses against the top lens of an eyepiece with around 15mm of eye relief...  I would call that "barely sufficient".  "Adequate" eye relief for me and the rest of the 64% who wear eyeglasses is in the 16mm+ range.

 

And, as far as the top eye lens of that 4mm or even any of the usual kit eyepieces being "rather generous"...  LOL  You really can't be serious.  In my photo, below, the far left eyepiece is the typical kit eyepiece in the 4-6mm range....  it is a pin-hole barely suitable for an infant.  The eyepiece that is second from the left is a cheap and adequate Starguider which I would call "adequate".  Next, moving right, is the GSO Plossl...  a little better.  I would say that "rather generous" would be the Baader on the far right.  For me and the remaining 64% who wear eyeglasses, this isn't even a close call.  

 

For the original poster who is having difficulty focusing...  There are a number of reasons you could be having difficulty but one reason could be the eyepieces or using the wrong eyepiece.  Forget about those eyepieces with a tiny top eye lens.  The eyepiece that is second from the left is a Starguider eyepiece that only costs around $15 (last time I purchased one anyway).  The next is a GSO Plossl...  those aren't all that pricy either.  Admittedly, the Baaders (far right) are in the $149-269 range so I wouldn't call them beginner eyepieces.  More comfortable eyepieces make everything about viewing easier and more pleasant.

 

And to Sky Muse...  thanks for the laugh!  :)

 

Patrick

Attached Thumbnails

  • DSC01623 oct21_web.JPG


#23 Sky Muse

Sky Muse

    Cosmos

  • *****
  • Posts: 9,077
  • Joined: 26 Oct 2012
  • Loc: Mid-South, U.S.

Posted 18 October 2021 - 01:27 PM

LOL...  Okay, now I think you are just trying to be funny.  

 

What sort of eye relief does a modern 4mm SR eyepiece have?  Somewhere around 6-8mm?  I would not call that "adequate" eye relief by any stretch of the imagination.  I can just barely manage to get by when I mash my eyeglasses against the top lens of an eyepiece with around 15mm of eye relief...  I would call that "barely sufficient".  "Adequate" eye relief for me and the rest of the 64% who wear eyeglasses is in the 16mm+ range.

 

And, as far as the top eye lens of that 4mm or even any of the usual kit eyepieces being "rather generous"...  LOL  You really can't be serious.  In my photo, below, the far left eyepiece is the typical kit eyepiece in the 4-6mm range....  it is a pin-hole barely suitable for an infant.  The eyepiece that is second from the left is a cheap and adequate Starguider which I would call "adequate".  Next, moving right, is the GSO Plossl...  a little better.  I would say that "rather generous" would be the Baader on the far right.  For me and the remaining 64% who wear eyeglasses, this isn't even a close call.  

 

For the original poster who is having difficulty focusing...  There are a number of reasons you could be having difficulty but one reason could be the eyepieces or using the wrong eyepiece.  Forget about those eyepieces with a tiny top eye lens.  The eyepiece that is second from the left is a Starguider eyepiece that only costs around $15 (last time I purchased one anyway).  The next is a GSO Plossl...  those aren't all that pricy either.  Admittedly, the Baaders (far right) are in the $149-269 range so I wouldn't call them beginner eyepieces.  More comfortable eyepieces make everything about viewing easier and more pleasant.

 

And to Sky Muse...  thanks for the laugh!  smile.gif

 

Patrick

Try one... https://www.aliexpre...0011320259080"}

 

lol.gif

 

I've ordered from that seller.  It would take a while to arrive, a month or so.  That way you wouldn't have to buy a kit. grin.gif  

 

The wearing of eyeglasses notwithstanding, the eye-lens and eye-relief is adequate, for a 4mm focal-length. False-colour is apparent at the edge of the view on occasion, but that's to be expected.  Then, it's not nearly as bad as these Meade kit items...

 

accessories3.jpg

 

The bottom of the barrel those are, stuck to it even; a grainy, lattice-like veil over everything, albeit subtle, but still.

 

The eye-relief of the 4mm is noticeably greater than that of my Vixen "NPL" 6mm Plossl.  The Vixen is tight, tight, and tighter still, but I have no real problems with it.  I do have to orient my eye just so in order to see the full view, and the view is well worth the extra work...

 

Vixen NPL 6mm3.jpg

 

Incidentally, the human eyeball is practically the same size, at 8 weeks, or 80 years, either.  In addition, I don't think that the OP has mentioned having to wear glasses whilst observing.   We've only seen two posts from them thus far.


Edited by Sky Muse, 18 October 2021 - 01:30 PM.


#24 Sky Muse

Sky Muse

    Cosmos

  • *****
  • Posts: 9,077
  • Joined: 26 Oct 2012
  • Loc: Mid-South, U.S.

Posted 18 October 2021 - 02:32 PM

To the OP, if desired, it is possible, and easy, to add an aftermarket finder-scope or red-dot finder to your telescope.  You simply remove the bracket's stud-assembly from the optical-tube, and install an aftermarket Vixen-type finder-shoe...

 

finder base1b.jpg

 

That way you can attach one of a plethora of finders sold in the online marketplace; for examples...

 

https://www.aliexpre...0024058968167"}

https://www.aliexpre...:"67304757872"}

 

Although, I've moved on from those one-thumbscrew shoes.  The two-thumbscrew shoes are more secure, and you shouldn't have to drill new holes into the optical-tube, but you will need somewhat short stainless-steel screws, flat/lock washers, and nuts...

 

https://www.aliexpre....6bce4c4dPGstmb

 

The manual that came with your kit mentions nothing about collimation.  This is the same kit, produced by Synta as well, and with collimation instructions within...

 

https://www.telescop...29579_05-17.pdf



#25 vtornado

vtornado

    Aurora

  • *****
  • Posts: 4,585
  • Joined: 22 Jan 2016
  • Loc: 42N 88W

Posted 18 October 2021 - 04:35 PM

Hello NotGalileo and welcome to CN

 

 

I see the accessories packed with this scope Huygens eyepieces probably plastic optics, the barlow is the all too familar barlow with plastic lenses.  

 

I have a warm place in my heart for value optics, (notice nothing that starts with T in my list) 

But this scope has serious issues.  Use what you have to get the scope generally working

Then replace the eyepieces and barlow.   They don't have to be top shelf but some ebay plossls

would be head and shoulders above what you have now.

 

I agree with Kath throw the barlow away.  Just looking though the lens of one, I can tell it is astigmatic.

 

A tip on focusing is that the focused image is always the smallest, It the big white circle moon is getting

bigger you are going the wrong way.  

 

If you get the moon in the main scope, then readjust the finder to match.  Be careful not to

bump the finder, they go off alignment easy.

 

Look at the moon, find Jupiter, and Saturn.  Once you have mastered the scope, you can

do a few low cost upgrades to get a much sharper view.

 

VT.

 

Regarding 4mm eyepieces.

Now I don't particularly care for 4mm eyepieces, however.

 

I wear glasses and have mild astigmatism.

Refractive errors can be fixed with the focuser.   (But you can share the view with a non-glasses user without refocusing).  With a 4mm eyepiece in a f9 telescope has an exit pupil of .44 this is so small that it will not bother an astigmatic eye.  The same goes for 4, 5 ... and others.  I see astigmatism with 25, and 32mm eyepieces. and

exit pupils exceeding 4.5 mm.

 

I have one 4mm plossl that is really sharp.  I take it out when seeing is good and I want to make sure

I'm getting the very best image possible.  Now excuse me while I go an peel it off my eye ball.


Edited by vtornado, 18 October 2021 - 04:38 PM.



CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics