Televue Delite adjustable sliding eyeguard

[Surfer Chris]

Just wondering if anybody else also finds that their Televue adjustable eyeguard slips when removing or replacing the caps? 

Being able to adjust the eyeguard height is a great feature, but with the 4mm Delite I have, I find that even if I tighten the locking collar as tight as I dare (without feeling like I might damage something), when I go to replace the caps after use, I end up shifting the eyeguard position slightly. So every time I use, I have to re-set the position. This sounds like a trivial thing, but if you have tightened the collar as hard as possible on the previous use, it is quite annoying.

I like the eyepiece in every other aspect (well apart from undercuts too I guess!!!), so I wanted to find a solution to this slightly irritating issue. By unscrewing the eyeguard, it was fairly apparent the issue was related to the internal split compression ring that is squeezed down onto the body of the eyepiece when tightening the locking collar.

In the image below, the right hand compression ring (with the split) is the one supplied with the eyepiece. This looks to be injection moulded using a hard & rigid plastic. The problem to me appeared to be that the co-efficient of friction offered by this material was too low, and so, even when the collar is tightened as much as sensibly possible, the low friction material of the ring would still allow movement over the ultra smooth anodised eyepiece body.

So as a test, I decided to get a couple of custom rings made using a hard Nitrile rubber material instead. The left hand ring in the photo below is one of my custom rings. My cross sectional profile is purposefully slightly different to the Televue supplied ring (with longer angled faces on the ends for a more evenly distributed radial compression from the mating features inside the eyepiece). 

Anyway - just tried out one of my custom Nitrile rings in the eyepiece and it works a treat. I can now lock the collar and the eyeguard will not budge.

So good to know I have an option to overcome this slipping eyeguard issue should I purchase more of the Delites - which I was hoping to do. Although saying that I do have 4.5, 6.5, 9, & 12.5 Morpheus coming today to try out in the FC100-DC I purchased earlier in the year. So will see how I get on with those first maybe - before purchasing any more Delites.

I would be interested to hear if anybody else has found this same issue with the eyeguards though, and whether anybody else has found an alternative solution?

 

[Louis D]

I wonder if the problem is simply that the gap in the original isn't large enough.  The two ends meet before maximum pressure has been achieved.  I've heard of this being an issue with locking collets on binoviewers.  Simply snip out a bit of material and put it back in to see if matters improve.

[Surfer Chris]

Thanks for the suggestion Louis. I don't recall checking this - but I am sure I must have. 

To be sure I just slid the supplied ring over the relevant diameter on the body, and I am left with a gap that measures 2.5mm (see image below), so it's definitely not a case that the ends of the ring can meet. There is absolutely no 'give' in that ring when fitted onto that diameter - so it is not going to collapse inwards significantly enough to close that gap any noticeable amount. I think it simply a case of the ring material being too hard and slippery to provide sufficient friction.

I only bought the scope in February (my first set proper scope), so have been slowly trying out a few eyepieces. This is my first Televue EP with an adjustable eyeguard...so I don't know if what I have is a typical user experience? I am guessing so.

I do like the Delite eyepiece though - am thinking that I might end up with a 4, 5 & 7mm to go with the Morpheus EP's that have just arrived today.

[Don Pensack]

I agree totally, but the problem isn't the aluminum collet, it's the lower eyepiece cap.

They're made far too tight and are difficult to remove and install.

I replaced all of mine with looser-fitting translucent plastic caps and the eyeguard doesn't move when installing or removing the cap.

[Ricochet]

Mine are the same. Optically they are excellent eyepieces, but the mechanically they are awful. The sliding section doesn't lock, the rubber eyecup is uncomfortable, the undercuts catch on everything and are so deep that the collets on my cheap binoviewer can't even grip the eyepieces, and the choice of a painted metal as the exterior surface allows radiative cooling making the eye lens prone to dewing. 

[John]

Is the design the same as that used with the Delos ?

I have a couple of Delos and the mechanism works really well and is rock solid once tightened. I've not used a Delite though.

 

[HollyHound]

4 hours ago, Don Pensack said:

I agree totally, but the problem isn't the aluminum collet, it's the lower eyepiece cap.

They're made far too tight and are difficult to remove and install.

I replaced all of mine with looser-fitting translucent plastic caps and the eyeguard doesn't move when installing or removing the cap.

I had exactly the same issue and solved it the same way as Don… using the looser (usually translucent) end caps solved it… the internal ridge lines on these caps allow air in and so less (or no) suction occurs when pulling them off 👍

[NGC 1502]

This problem is worrying on otherwise great eyepieces. I’m a fan of the discontinued TeleVue Radians. The clickstop eyeguard was often criticised for being too loose, but easily fixed by dismantling and reducing the diameter of the internal spring.

It’s a mystery to me why TV have persisted with sliding eyeguards. A well engineered screw operated eyeguard is the simple solution. Pentax XW and XL are good examples of this.

Good that the Delite problem can be sorted with end caps that fit a bit looser.

Ed.

[Surfer Chris]

The caps supplied with mine did seem a little on the tight side at first, but actually they have loosened up a little with use. I would actually say they are a not far off perfect now on my sample. But I still kept knocking the eyeguard position out, which on my sample definitely isn't helped by the lack of friction provided by the split compression ring. With the replacement nitrile ring that I have installed - I am able to lock it rock solid now.

I was considering having a look at the Delos John, but decided they probably have a similar mechanism to the Delite (which put me off trying them). As a cheaper alternative to the Delos, I decided to give the Morpheus a go instead. 

It does sound like my Delite is not an isolated case though with others experiencing the same issue with the adjustable eyeguard not locking solid. I will probably still look to get the 5mm and 7mm Delite as I do like the everything else on the eyepiece (apart from the undercuts). I think I will just get a few more of the custom made nitrile rings ordered, as they were only a few £'s each. 

[NGC 1502]

2 hours ago, Surfer Chris said:

I’ve sorted the undercut problem with hard plastic tape. Dymo tape for label making is ideal. On the eyepieces I’ve used that on the undercut was just a fraction deeper than the tape. This worked fine, no snagging job done. Regular electricians tape is too soft.

Ed.

Edited June 18, 2021 by NGC 1502

[KP82]

Not a fan of this sliding up/down eyeguard design of my Delos either. I'd much prefer the twist up/down type of the Pentax XW or the basic simple rubber fold down type on the ES and Morpheus.

[scarp15]

Yes sometimes replacing the caps in-between use there is slippage, yet personally this does not bother me at all because when that eyepiece is required again, a simple twist action adjustment and you very quickly regain that comfortable eye placement, in which Delos and DeLite eyepieces are renowned for lovely enhanced relaxed observing. I agree with the comments above that the lower cap can be a bit tight (perhaps until worn in), although I like this as less likely to drop off and lose and ensures no moisture etc gets trapped in. Holding steady either the upper or lower eyepiece body helps a bit when replacing the cap. When the eyepieces are ready to be stored away, I always retract the barrel before going back in the eyepiece case.

[John]

I own a couple of Delos and 4 Pentax XW's. On balance I prefer the twist up and down eyecup approach that the XW's take but I don't have that sliding issue with the Delos at all. Once locked in the position that suits me best (longest extension) they are locked solid and I've never experienced any movement. I've just taken my 17.3 and 14mm Delos out of their case and tried to move the eyecup assembly and there is no movement at all even with some force being used - until I loosen the tension and then it slides smoothly again.

I leave all my eyepieces that have adjustable eyecups in the position that I observe with them when they are in storage. I wonder if I was extending retracting the Delos eyecup regularly during use or before putting them away, if the tension might loosen over time ?. I'm not going to experiment to find out though !

 

[laudropb]

I have never had this problem with my Delites. Eyepiece position locks tight and no slippage. I also like the tight fit of the lower caps. Much less likely to let moisture in during storage.

[Surfer Chris]

Seems to be a little variability in opinion - maybe different materials used on the compression rings for different batches or a change of material on newer EP's?

The Delite does seem to have very easy eye placement, slightly easier and more relaxed than the Morpheus. Morpheus obviously good for the wider FOV though. I think I will still look to order a 5mm Delite soon, so will be interesting to see how that compares mechanically to my 4mm Delite.

[Highburymark]

I don’t have any problems with the Delite design either. If the lower caps are a little tight, they are easy enough to remove by holding the barrel with two fingers and pulling off the cap with the other hand.

[scarp15]

Worth noting to that Delos and DeLite eyepieces are conveniently parfocal, no faffing with refocusing. It could be that the extent of locking tension, applied amongst users might vary a little and that maybe on a damp night, moisture could form on the sliding part. Perhaps Delos might be a little more manageable at applying tensioning pressure, due to the chunkier barrel for gripping when twisting.  

1 hour ago, Surfer Chris said:

Seems to be a little variability in opinion - maybe different materials used on the compression rings for different batches or a change of material on newer EP's?

The Delite does seem to have very easy eye placement, slightly easier and more relaxed than the Morpheus. Morpheus obviously good for the wider FOV though. I think I will still look to order a 5mm Delite soon, so will be interesting to see how that compares mechanically to my 4mm Delite.

Definitely, I use both 4mm and 5mm DeLite, along with 7mm and 18.2mm. It is complementary to the 4mm and 7mm.  The 62 degree field of view is enhanced with comfortably seeing the field stop. 

[John]

2 hours ago, scarp15 said:

Worth noting to that Delos and DeLite eyepieces are conveniently parfocal, no faffing with refocusing....

 

Apart from the 17.3mm and 14mm Delos which reach focus around 8mm further inwards.

 

[BGazing]

On 17/06/2021 at 19:39, Don Pensack said:

I agree totally, but the problem isn't the aluminum collet, it's the lower eyepiece cap.

They're made far too tight and are difficult to remove and install.

I replaced all of mine with looser-fitting translucent plastic caps and the eyeguard doesn't move when installing or removing the cap.

Bingo, it is removing the lower caps on a Delite or Delos that pulls the whole thing up.

[Louis D]

1 hour ago, BGazing said:

Bingo, it is removing the lower caps on a Delite or Delos that pulls the whole thing up.

I always keep my 10mm Delos cup all the way down and have never experienced this.  Perhaps because I bought it around 2011 when it first came out, they were using a different lower cap back then?  I'll have to check how tight mine is the next chance I get.

[Don Pensack]

On 17/06/2021 at 14:14, Ricochet said:

Mine are the same. Optically they are excellent eyepieces, but the mechanically they are awful. The sliding section doesn't lock, the rubber eyecup is uncomfortable, the undercuts catch on everything and are so deep that the collets on my cheap binoviewer can't even grip the eyepieces, and the choice of a painted metal as the exterior surface allows radiative cooling making the eye lens prone to dewing. 

Painted metal?

The outer surfaces are:

--chrome plated lower barrel

--black anodized upper barrel

If you are referring to the iris in the sliding eyeguard, the upper surface is black-anodized aluminum.

If the eyeguard is used raised at all, even one notch, it acts like a dew shield for the upper lens, not to mention a light trap to reduce peripheral light scatter.

I own all 9 focal lengths and the eyeguards lock tightly in place, so "doesn't lock in place" just isn't true.  You just not be tightening them sufficiently.

I do note you cannot lock them using only one hand.  One hand has to hold the lower section while the other hand tightens the top.

The bottom caps, though, are just way too tight and even with a pinhole in them, they still are very difficult to remove.  I recommend replacing them with something else--anything else.

We are in agreement about undercuts, though they are of the recent beveled edges, so catch a lot less.

[Don Pensack]

On 18/06/2021 at 02:02, NGC 1502 said:

I’ve sorted the undercut problem with hard plastic tape. Dymo tape for label making is ideal. On the eyepieces I’ve used that on the undercut was just a fraction deeper than the tape. This worked fine, no snagging job done. Regular electricians tape is too soft.

Ed.

I used copper tape, which also works great--it's thin enough you need a couple wraps but it serves the same function and makes removal and installation a lot easier.

[Don Pensack]

23 hours ago, Louis D said:

I always keep my 10mm Delos cup all the way down and have never experienced this.  Perhaps because I bought it around 2011 when it first came out, they were using a different lower cap back then?  I'll have to check how tight mine is the next chance I get.

The Delites have a different lower cap in black that fits the barrel very tightly.  Too tight, in my opinion.

There is an answer I could have used, in retrospect--simply using some light sandpaper on the interior surface of the caps--it would have taken me only seconds per eyepiece--but I didn't thin of it at the time.