Supercalifragilisticexpialidocious EP : 10 mm 70° 2" LER weighing in at only 2.735 pounds

[Bivanus]

Ok , so it's THAT season , the hollydays are over , job is back with a vengeance, the sky is rather overcast , what is one to do ? Well, some suck on their EP's some find other ways to improove them.

I happen to find at a good price a 3X ES telextender. Been looking for a 3X Barlow/Teleextender for some time without great succes for my DSLR fun so I pounced on it. Well...there is a catch...it's the 2" version, a Wholly Hand Grenade in its own right. But wait ! I also happen to have a 2in EP - the APM UFF 30mm ! And look - not a lot of info about how it barlows...I wonder why....MAAAAAYBE because the unwholly combo weights more than even the 92° series and is longer than the 110° series ? NONSENSE ! Let the fun begin ! And since we're at it let's also adapt it for a bit of projection AP ! What can posibly go wrong...😅  

 

[Mr Spock]

x200 in the 12" 

[Astronomist]

Here's my sensible, compact 14mm 82°... only weighs about 1.1kg. 

[Louis D]

Why stop there?  Plug the assembly into a coma corrector next.  I've done that.  It becomes hard to reach the Dob tube to move it because I'm sitting so far back from the side of the scope. 😄

[Don Pensack]

like this:

 

[Louis D]

Yep, more or less.  Just substitute a GSO ED 2x Barlow with TV PBI for the Paracorr so there is one more layer of thumbscrews.  And it does indeed become unwieldy trying to locate the right one(s) in the dark.

[Ags]

Spelers WALER zoom behind a nice long Barlow.

[Bivanus]

4 minutes ago, Ags said:

Spelers WALER zoom behind a nice long Barlow.

Interestgly enough it was an offer for this zoom on a Canadian site some weeks ago when I was still there. Is it good ?

[Ags]

I have only used the fixed focal length Speers WALERs and they are very good.

[Don Pensack]

1 hour ago, Bivanus said:

Interestgly enough it was an offer for this zoom on a Canadian site some weeks ago when I was still there. Is it good ?

Bear in mind, it is not a zoom in the traditional sense.  It is a variable focal length eyepiece, and substantial refocusing is needed every time you change the focal length.

[Bivanus]

Aha , that explains it 😂

[Louis D]

10 hours ago, Bivanus said:

Interestgly enough it was an offer for this zoom on a Canadian site some weeks ago when I was still there. Is it good ?

Very good.  The Speers-Waler 5-8mm varifocal compares favorably with Pentax XW and XL eyepieces at matching focal lengths, just wider.  However, eye relief is tight compared to actual long eye relief eyepieces like the XLs and XWs, so not so good for eyeglass wearers with strong astigmatism.  Focal length for focal length, I preferred it to the Svbony 3-8mm zoom over the 5mm to 8mm range mainly because of the vastly increased dwell time between nudges, and more usable eye relief when not wearing eyeglasses at small exit pupils.  The main things the Svbony excelled at were small size and near pafocality across its range.

You can look at this review for comparison ruler images of the Speers-Waler and others in its range:

[Bivanus]

OK , so , finaly tonight I was able to have a look at the moon as it breaked the clouds a bit. 

The view was good for the conditions, the detail was a bit washed out due to the clouds but still clearly visible in glorious play of shades. As expected a tad on the heavy side , had to really tighten the mount 

Also managed to take a picture thru the APM UFF30 , as expected a tad of blue fringe on the bright side , but again not bad especially with me on my knees bearly reaching the focuser wheel 😄

I vow that I shall get the wholly 500mm M48 extender and try doing a pic with the telextender on ...or maybe just try doing Jupiter 

[Louis D]

Are you taking images using eyepiece projection rather than afocal projection?  It looks like you may be running into issues with a curved projected focal plane from the eyepiece.  Try using afocal projection with a 50mm prime lens on the DSLR, coupling the eyepiece to the lens's filter threads with step rings, to see if you get better results across the field of view.  Make sure to leave the lens aperture wide open to avoid vignetting.  You can pick up a used Olympus Zuiko 50mm f/1.8 with an OM T-adapter for a reasonable price these days.  I use them for this and other afocal photography duties on Canon DSLRs.