ES 24mm 68 degree EP, one snag ....

[John]

I took delivery of an ES 24mm 68 degree eyepiece today. Very nice looking eyepiece, well made, lovely coatings, great value for money.

One snag though. I use a Baader 1.25" twist lock adapter on my Baader T2 Zeiss prism diagonal now which works brilliantly on all my other 1.25" eyepieces but simply won't grip the tapered barrel of the ES 24mm 68. Not tight at all. Very frustrating because I intended to use the eyepiece as my low power for my Tak FC-100 refractor which the Baader Zeiss diagonal / twist lock combo is otherwise absolutely ideal with.

Anyone else had a similar issue with tapered 1.25" barrels in these twist lock adapters ?

The barrel of the ES 24 68 is shaped like this BTW:

 

 

[Moonshane]

Bummer. How annoying

[Chris]

Hi John, sorry to hear about this. I used mine with a Takahashi Prism diagonal which was twist lock also, and it did take a number of twists to grip compared to my straight barrel EP's. It did grip after many twists though so just to clarify it's not gripping at all ! ? 

[John]

The 1.25" Baader twist lock works by applying upright bars against the eyepiece barrel. For eyepieces with a conventional undercut these ensure that you don't get those snags that the compression ring can cause. At maximum tension there is simply not enough grip to hold the eyepiece in place - presumably not enough of the tapered barrel of the ES is actually 1.25" diameter so there is not enough barrel for the tension bars to grip.

I suppose I could try applying some tape to the narrower section of the barrel

Not too much though otherwise it will not go smoothly into my other focusers

[John]

With the 1.25" dust cap having dropped off a couple of times from the barrel of the ES 24 68 I've been prompted to compare the barrel with my Delos and XW's and I think it's been machined just a touch undersized, which does not help the situation of course.

You would not notice this in a conventional compression ring fitting because you would just adjust the tightness a little more but the Baader 1.25" twist lock uses a very precise gripping mechanism so a very small difference in barrel diameter just makes the difference between a firm grip and very little grip.

Time to try some tape on the ES barrel I think ....

[Chris]

Sounds like the Baader twist lock is very different to the Tak twist lock which has a ring which tightens around eyepiece barrels concentrically.

I've got to agree that the taper is a bit annoying on the ES EP's, but I think the tape idea is a good one! Maybe just ad a bit at a time until it grips without getting in the way

I'll be interested to hear if the 'Blue Peter fix' works 

 

[Knighty2112]

How about carefully  wrapping some thin tape to the tapered part to see if it will grip better by taking some of the slope off the barrel maybe? Worth a try.  

[Knighty2112]

Ooops! See you suggested that yourself already!  

[John]

The 2" Baader twist lock uses the ring approach like the Tak. It's just the 1.25" one that uses the upright bars.

I've tried 1cm of tape all around the narrower part of the barrel and the situation is a little better (as Knighty2112 suggests) but I'm going to need thicker tape. I guess I will be able to sort this with some carefull use of tape but I have to say that I'm surprised that the ES 1.25" barrel is that much undersized

Edit: I've now tried a layer of tape around the widest part of the barrel and it works !. It also still fits OK into my other 1.25" adapters as well and is a much snugger fit, which I prefer.

Issue solved but I still find it a little odd that the original barrel was that much out

Thanks the suggestions folks !

[Paul73]

How annoying.

There was an issue with ES eyepiece barrels being machined slightly too small. But, I thought that the issue had been sorted and was contained mostly to the 2" barrels on nitrogen purged offerings.

Can you just swap the barrels with  an old unused eyepiece. Or, maybe ES will send you a new one.

Paul

[John]

Thanks for the suggestions Paul.

The field stop for the eyepiece is fitted into the 1.25" barrel so I'll need to stick with a specific ES 24 68 one if I replace it. I think the tape approach will work but I wan't to get some of that chrome auto tape I think so it looks less unsightly than the plain insulation tape I've been experimenting with.

Other than this, I can't wait to try the eyepiece

 

[Ruud]

There would be no tapered barrels if it were up to me. Tapered barrels are best when the eyepiece is held in place by the pressure of a screw (or two). But even then undercut barrels are better.

No barrel design seems perfect. I was hoping that the Morpheus barrel would be the ultimate solution (Baader's "Slip-Protect Safety Kerfs"), but they are only a marginal improvement over smooth barrels. (YMMV of course)

Congratulations, John, on finding a working solution.

 

[John]

Thanks Ruud

I'm not a fan of tapered barrels now either. The only other accessory that I have that has a tapered barrel is my Astro Physics 2" diagonal but on that the parallel section is 75% of the barrel length wheras with the ES approach it's just around 30% and not quite 1.25" even then.

But no worries, I'll get it sorted and then I'm sure the views with the eyepiece will help me forget this little issue

[Louis D]

Try aluminum foil tape.  Several folks on CN have had luck using it in this situation.

[John]

33 minutes ago, Louis D said:

Try aluminum foil tape.  Several folks on CN have had luck using it in this situation.

Yes, thats what I'm going to try next

[alan potts]

Not very good good John, it should be better from a big supplier like them. I tested the Meade version of this which we all believe to be pretty much the same and that hase a different barrel and I never recall a problem. I did find the outer field a little poor on my fastest scopes though, will be interesting to hear what you find with the ES version.

Alan

[Roy Challen]

The problem here is that there was never anything wrong with straight barrels (the only barrels I will have on my EPs now), it was with screw-only holders, or compression ring holders. So, manufacturers solved a problem that didn't exist, or that already had a solution (Baader Clicklock, Tak prism system etc.). There is no reasonable way that a straight-barrelled EP can fall out of either of these holders, so if the astro-manufacturers adopted them as a standard (not so difficult really), then there would be no need for these ridiculous shaped barrels.

I do seem to remember a thread last year (probably more than one) the subject of which was barrel design, in which I probably ranted as well. It's not reasonable that an eyepiece costing up to several hundred pounds should become more risky to use simply because the shape of the barrel actually makes it more risky, and forcing a bodge (yes, using tape, foil, whatever, is a bodge!). I wonder why astro EPs don't have the bayonet type fitting that is used on a lot of spotting scopes? That really would be more secure.

And....breath out!

[Ricochet]

For what it's worth I use this 1.25" Baader Clicklock, which has a ring rather than the bars, and it holds my 16mm and 24mm ES68's with no issue. 

[Moonshane]

It would indeed but John is using using a Baader prism which connects with a t2 fitting

I have have a have a big roll of foil tape John.  could bring to sgl or post foc

[John]

9 minutes ago, Moonshane said:

It would indeed but John is using using a Baader prism which connects with a t2 fitting

I have have a have a big roll of foil tape John.  could bring to sgl or post foc

Thanks Shane

I'll see if I can pick some up locally - it could be useful in a number of ways so worth having around. Meanwhile a wrap of insulation tape is doing the job.

If I get stuck I'll get back to you.

Thanks for all the feedback folks

[Ricochet]

1 hour ago, Moonshane said:

It would indeed but John is using using a Baader prism which connects with a t2 fitting

I have have a have a big roll of foil tape John.  could bring to sgl or post foc

It does actually have a T2 thread inside. However, there is 3mm of filter thread before that which looks like more than enough to stop the prism connecting.

[Moonshane]

Good to know thanks

[Highburymark]

John - there's also a cheap T2-1.25" adapter (made by telescop express) with a compression ring available from 365 which I use with the Zeiss - not really ideal to buy a new adapter for one EP, but worth considering if you get more eps with tapered barrels

[spaceboy]

You know what all this means though don't you John ??? A green and black panoptic is coming sooner than your wife was initially lead to believe  

[John]

11 minutes ago, spaceboy said:

You know what all this means though don't you John ??? A green and black panoptic is coming sooner than your wife was initially lead to believe  

I've been through the "wither a 24mm Panoptic" debate a few times in my head. I went for the ES 24 because this eyepiece is for use in F/9 apo refractors so I figured that the £200+ price difference would not be money well spent in terms of a performance return.

I really like the Baader 1.25" twist lock adapter in all other ways apart from how it handles the 1.25" barrel of this particular eyepiece. It's as tight as a nut with all my other 1.25" eyepieces.

BTW I have also now added a 2" Baader twist lock adapter to the drawtube of the Tak 100. It's the same unit that Highburymark has on his SCT except that it's got a 2" adapter on the end. The action of that is very nice.