Transform the Prime HD eye cups (1 Viewer)

[Steve C]

This may hold little to no interest for eye glass wearers. I guess I’ve had a bit of cabin fever and some tinkeritis lately. I have been using my ZEN Prime HD quite a lot, and I had almost gotten used to the large size oculars, but after long use, they still chaffed at my nose a little bit. That’s OK as a trade off I suppose for the otherwise exemplary view.

Over the last several months, I had obtained three sets of winged eye guards for the Nikon EDG series binocular. One I got from ND Hunter and two from brownpelican1. Those I got from ND went back to Zen Ray with the 7x43 ED 3 to demonstrate a way to extend the eye relief. That left me with the two I got from brownpelican1. One of those works on the Eagle Optics 6.5x32 Raven I have and the other one was sitting alone in the drawer with some other miscellaneous binocular eye cup parts and accessories. So I got to thinking…

The large oculars of the ZEN Prime HD would not allow the Nikon accessories to fit on as they were made, as they did for the ED 3. So…and here is a disclaimer…I did this on my own free will and if you do the same and bork your eye cups, don’t blame me .

I took a Havalon knife, these are folding pocket knives with removable scalpel style …SHARP blades. Using as much care as I could, I literally skinned the outer rubber eye cup covers off the rest of the assembly. The exposed inner metal eye cup ring is about 42mm in diameter. The rubber outer covering on mine was glued down like it was meant to stay put and it presented some degree of difficulty, and caution to get them off. I remember seeing a post from somebody who has poorly glued eye cups, but did not find the post in a quick search.

Next twist the eye cup assembly all the way own. I got four (4) 40 mm OD 0-rings 2 mm thick. Roll two of these over each of the retracted metal eye cup assemblies and roll them to the bottom of the assembly, just above the rubber body armor. The EDG winged eye guard fits pretty tightly over the metal chassis of the eye cup assembly, and when fitted down to contact the top of the assembly. It just contacts the top of the two 0-rings. So positioned this gives an effective eye relief of 17 mm, which is perfect for my needs.

This simple little modification completely changes the dynamic of the facial ergonomics of this binocular. The EDG accessory has an outer diameter of some 4mm less than the stock Prime HD. The oversize issues are gone. The EDG guards are much softer against the eyes and the dual factor of size reduction and softer tactile feel against the face literally TRANSFORMS the HD ergonomics. The decrease diameter of the EDG shield, and the winged nature of its design eliminate the sometimes seen mirror reflection present showing off of the big ocular lenses. FOV does not, for me at least change.

So, Charles has a set of these and I have contacted him about this modification. I tend to think a similar accessory from ZR would have definite value. Right now the issue is finding the EDG winged eye guard. I have not found a way to buy them yet. But Nikon may sell them, but the Nikon parts department has not been good at answering the phone lately.

OK, pictures later I seem not to be able to find where they got downloaded to.

 

[Stet]

Interesting! Looking forward to the pics. Probably my only quibble about the Primes is the large eyecups. I've gotten used to them and they don't really bother me but if they could be made more comfortable, that would be a big plus in my opinion. Hope Charles is paying attention. I'm sure there have been some returns based just on the eyecups alone. It takes some time to acclimate to them and I'm sure some people aren't willing to take that time.

 

[stereotruckdriver]

I wasn't bothered by the eyecups even then i don't think i would of tried what Steve has done! Even powered up i'm not that steady! I no longer have them so the temptation to modify the eyecups won't be a problem! Still curious of the outcome! Bryce...

 

[Steve C]

OK, it turns out I have a driver malfunction with my digital camera, so they didn't download anywhere . I re-shot these with my cell phone, so I hope they turn out OK. I'm going to be replacing this laptop, so I'm not putting much effort into downloading drivers until that happens.

It should be pretty easy to see the obvious reduction in the size of the diameters of the distal end of the eye cups. I think ZR would be well served to have a slightly more "designed to fit the Prime" version of these, both an angled version like this, and a more traditional non angled style as well.

I will point out the obvious here just to be clear. This makes a static situation out of the eye cup adjustments, but so far, my sets of "other eyes" need no different adjustment than this. They are permanately extended with this method.

The photo on the right has the 0-rings covered with a section cut from a bicycle inner tube.

 

[ganymede]

Steve,

Great mod! I sure hope Charles will come out with a slightly more elegant solution

 

[Steve C]

Functional yes, elegant it is not. Kinda like me I guess .

I might add that the EDG eye cups fit very tightly over the exposed eye cup assembly, so far making gluing the things in place unnecessary

I will add a note that the diopter function remains unaffected.

 

[Stet]

The non adjustable eyecups will probably deter Charles from implementing it but I like the end result none the less. Definitely an option for those willing to tinker a bit.

I see your eyecups were glued down properly with a generous amount of glue which wasn't the case with mine. I also had one of my eyecups come off when removing the raingaurd and there was only a couple small spots of glue that was holding it on which didn't appear to be allowed to set properly.

 

[Steve C]

The non adjustable eyecups will probably deter Charles from implementing it but I like the end result none the less. Definitely an option for those willing to tinker a bit.

I see your eyecups were glued down properly with a generous amount of glue which wasn't the case with mine. I also had one of my eyecups come off when removing the raingaurd and there was only a couple small spots of glue that was holding it on which didn't appear to be allowed to set properly.

I don't think the non adjustable nature of this mod should deter implementation, but you have a point. It is just my opinion, but I think most people use the eye cups either all the way down (eye glass wearers) or all the way out (non eye glass wearers, and yes I know there are some who like some intermediate position). Again just my opinion, but I tend to think most binoculars don't get shared a lot, so I happen to think that a static eye cup will work fine unless you need it all the way down. I think that options are desirable and in my view this is a relatively simple, and I think ultimately fairly inexpensive option to fix the large eye cup issue for non eye glass wearers. Since the oculars contact the glasses and not the eyes, the ocular size maybe is less of an issue if you wear glasses. But surely this type of a fix will not appeal to everybody.

I guess it was your post I remembered about the eye cups being poorly glued. These did have more than needed. However a little contact cement or silicone based liquid gasket maker will fix them.

Another mod I tried was to place the 0-rings inside the standard eye cup, putting them ultimately just between the rubber cover and the metal chassis. This worked too, but left a lot of the metal chassis exposed and would have required a re-glue job and some 0-rings around the chassis underneath the modified rubber cover.

Edit to add:

It is possible to use this basic EDG modification with the stock rubber coverings too. Look at the photo with the EDG on one eye piece and the two 0-rings on the other. At this point the standard rubber can be used if one does not want the winged feature of the EDG shield. However, the diameter of the standard cover is too large, as they do taper ever so slightly. This requires the use of a piece of inner tube on the metal assembly then the standard cups can be fit over that. This does soften the feel of the eye cup against the eye and nose, but does nothing to decrease the distal diameter. You may feel the need to get out the contact cement if you go this way.

Right now I think two offerings would work. One is winged, the other is not, both should have the EDG style ocular covers (patent stuff allowing for this of course). Both are similar in weight and texture to the Nikon shields. Both should be made longer than necessary (5-6 mm) and the user could trim length by trimming off of the bottom of the accessories to match their needs. This would allow for enough space to not need the 0-rings to fill gaps. The EDG shields fit tightly enough that it takes some effort to remove them and thus re-gluing I don't think is an issue.