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Too much eye relief on 7X26, or customizing the Customs ( a bit long, but with pics ) (1 Viewer)

Okay, so I just recieved the Elite Custom 7x26 for Xmas. I bought them online without trying , for these are quite uncommon here in France as retail. The first thing that struck me where how bright they are. Then I noticed some unpleasant eye-rolling effect, but I found I can deal with it. But what really disturbed me were some quick black-outs on each eyes, even with the IPD correctly set and the eyecups twisted up. I never had this problem with my old 10x42 monarch, neither with the 10x50 BOL custom I use for stargazing, and not even with my tiny Nikon Travelite 7x20. I got quite upset and was about to send them back, and add some cash to get a Monarch 7 8x30 instead.

Then I thought about how long I had been wanting these compact bins, and how good their overall quality was, and I decided to find a solution and keep them. Obviously, the distance between the top of the eyecups and the lens wasn't enough for me, even eyecups up. In other words, there's too much eye relief ! So I started customizing the Customs : I managed to add another eyecup on top of the stock ones to rise this distance a bit.

Rummaging in my drawers I found some spare eyecups for microscopes, in 33-34 mm diameter, one pair being thick and slightly winged, the other pair thinner and with larger wings. After some trials, I choose the latter, which are similar to the ones found online under the brand Baader ( see pics ).

As the outer diameter of the stock eyecups is 32 mm, there was some play when I added the winged ones around, and they added only 1 mm in height which wasn't enough. I remembered an old cyclist saying that goes " there's nothing an honest man cannot do with some old inner tube ". I cut two rings of an inner tube about 30 mm in diameter, and just a bit larger than the height of the raised eyecups. I fit them around the eyecups ( see pics ), then added the second winged eyecup around on top. It hit four birds with one stone : the bottom of the inner tube ring prevents the eyecup from twisting down, it wraps around the base and prevents the dust from getting into the eyecup mecanism, it tightens the winged cup around the stock one, and being a bit taller it gives me the extra height I need.

Result of my customizing the customs: higher eyecup so no more blackouts, and perfect sealing from side light. The only drawback is I have to fold the wings in order to put the bins back into their pouch. BTW I already had added some DIY leather wings to the eyecups of my BOL 10x50 (see pic ), with a very satisfying result : leather is softer than rubber on one's face ( although some people seem to be rubber lovers, but that's another story).

Please note another customization on the pics: I replaced the flimsy lanyard and its tiny metal rings by a good'old vintage Minolta camera laynnard with triangular clips. It feels a lot safer !

Voilà. Now I can truly enjoy these amazing bins. I just wanted to share this in case it might help somebody else. BTW, happy new year and may your days be multicoated.
 

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Okay, so I just recieved the Elite Custom 7x26 for Xmas. I bought them online without trying , for these are quite uncommon here in France as retail. The first thing that struck me where how bright they are. Then I noticed some unpleasant eye-rolling effect, but I found I can deal with it. But what really disturbed me were some quick black-outs on each eyes, even with the IPD correctly set and the eyecups twisted up. I never had this problem with my old 10x42 monarch, neither with the 10x50 BOL custom I use for stargazing, and not even with my tiny Nikon Travelite 7x20. I got quite upset and was about to send them back, and add some cash to get a Monarch 7 8x30 instead.

Then I thought about how long I had been wanting these compact bins, and how good their overall quality was, and I decided to find a solution and keep them. Obviously, the distance between the top of the eyecups and the lens wasn't enough for me, even eyecups up. In other words, there's too much eye relief ! So I started customizing the Customs : I managed to add another eyecup on top of the stock ones to rise this distance a bit.

Rummaging in my drawers I found some spare eyecups for microscopes, in 33-34 mm diameter, one pair being thick and slightly winged, the other pair thinner and with larger wings. After some trials, I choose the latter, which are similar to the ones found online under the brand Baader ( see pics ).

As the outer diameter of the stock eyecups is 32 mm, there was some play when I added the winged ones around, and they added only 1 mm in height which wasn't enough. I remembered an old cyclist saying that goes " there's nothing an honest man cannot do with some old inner tube ". I cut two rings of an inner tube about 30 mm in diameter, and just a bit larger than the height of the raised eyecups. I fit them around the eyecups ( see pics ), then added the second winged eyecup around on top. It hit four birds with one stone : the bottom of the inner tube ring prevents the eyecup from twisting down, it wraps around the base and prevents the dust from getting into the eyecup mecanism, it tightens the winged cup around the stock one, and being a bit taller it gives me the extra height I need.

Result of my customizing the customs: higher eyecup so no more blackouts, and perfect sealing from side light. The only drawback is I have to fold the wings in order to put the bins back into their pouch. BTW I already had added some DIY leather wings to the eyecups of my BOL 10x50 (see pic ), with a very satisfying result : leather is softer than rubber on one's face ( although some people seem to be rubber lovers, but that's another story).

Please note another customization on the pics: I replaced the flimsy lanyard and its tiny metal rings by a good'old vintage Minolta camera laynnard with triangular clips. It feels a lot safer !

Voilà. Now I can truly enjoy these amazing bins. I just wanted to share this in case it might help somebody else. BTW, happy new year and may your days be multicoated.

With eyecups up or down, if you don't have your eye at the f/l of the system, you will notice blackouts.

Bill
 
You're right, WJC. I could avoid blackouts by keeping my eyes at the right distance from the lens. But in my case, this distance was a bit longer than the height of the eyecups. So I could'nt apply them and rest them on my orbital area, I had to hold the bins a bit away from my face. Enlarging the eyecup and setting it higher enabled me to apply them tight.
 
The "forced eye relief/ blackout" issue is strongest for near-sighted eyes, without glasses on.
I use glasses with the Custom Compacts all the time, but my lenses are smaller so the
whole field shows up fine.

The best solution I've seen for the blackouts is the scheme used on Meoptas....they have a
3rd 'long' position. Otherwise, I tack on -5D Diopter lenses on a few pairs, just like Zeiss and Nikon
and Leica have for cameras and Televue has for telescopes. They make life a lot more
comfortable. They also shift the focuser into a more normal range so I can focus on infinity
without glasses, in several cases. You can choose concave-forward or concave-back to
find the best field response and neatly cancel out the spherical aberration.

It's all in the eyepiece design. Some never have blackouts, and the field is in focus
from inches away and just grows as you approach them. Old Kowa Prominars and Bushnell customs
are like that (Erfle and field-modified-Plossl design).

Others force the eye to a particular distance, like many Leupolds and Meoptas.
There is a field improvement, but it comes at that cost.

Many Nikons do not black out, so there is no actual focal 'location' for the eye
(after all, the virtual image is in fact at "infinity" for relaxed eyes), but the field shrinks
quickly).

Good to know you found the right spacing. Cutting a length of tubing can work great, too.

Larger Customs and some variants of the Compacts have precision-depth screw-up
eyecups.....awesome for this.
 
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Wings

Salut Christophe!

Many thanks for the idea of adding 'wings'!

I've now spent 10 minutes cutting 'Quickly detachable' sleeve-over wings from inner tube for fitting in bright sunlight conditions, and gratefully added them to my set of 'Make your own' binocular accessories.


J'envoies mes amitiés!

Stephen
 

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Okay, so I just recieved the Elite Custom 7x26 for Xmas. I bought them online without trying , for these are quite uncommon here in France as retail. The first thing that struck me where how bright they are. Then I noticed some unpleasant eye-rolling effect, but I found I can deal with it. But what really disturbed me were some quick black-outs on each eyes, even with the IPD correctly set and the eyecups twisted up. I never had this problem with my old 10x42 monarch, neither with the 10x50 BOL custom I use for stargazing, and not even with my tiny Nikon Travelite 7x20. I got quite upset and was about to send them back, and add some cash to get a Monarch 7 8x30 instead.

Then I thought about how long I had been wanting these compact bins, and how good their overall quality was, and I decided to find a solution and keep them. Obviously, the distance between the top of the eyecups and the lens wasn't enough for me, even eyecups up. In other words, there's too much eye relief ! So I started customizing the Customs : I managed to add another eyecup on top of the stock ones to rise this distance a bit.

Rummaging in my drawers I found some spare eyecups for microscopes, in 33-34 mm diameter, one pair being thick and slightly winged, the other pair thinner and with larger wings. After some trials, I choose the latter, which are similar to the ones found online under the brand Baader ( see pics ).

As the outer diameter of the stock eyecups is 32 mm, there was some play when I added the winged ones around, and they added only 1 mm in height which wasn't enough. I remembered an old cyclist saying that goes " there's nothing an honest man cannot do with some old inner tube ". I cut two rings of an inner tube about 30 mm in diameter, and just a bit larger than the height of the raised eyecups. I fit them around the eyecups ( see pics ), then added the second winged eyecup around on top. It hit four birds with one stone : the bottom of the inner tube ring prevents the eyecup from twisting down, it wraps around the base and prevents the dust from getting into the eyecup mecanism, it tightens the winged cup around the stock one, and being a bit taller it gives me the extra height I need.

Result of my customizing the customs: higher eyecup so no more blackouts, and perfect sealing from side light. The only drawback is I have to fold the wings in order to put the bins back into their pouch. BTW I already had added some DIY leather wings to the eyecups of my BOL 10x50 (see pic ), with a very satisfying result : leather is softer than rubber on one's face ( although some people seem to be rubber lovers, but that's another story).

Please note another customization on the pics: I replaced the flimsy lanyard and its tiny metal rings by a good'old vintage Minolta camera laynnard with triangular clips. It feels a lot safer !

Voilà. Now I can truly enjoy these amazing bins. I just wanted to share this in case it might help somebody else. BTW, happy new year and may your days be multicoated.
Th 7x26 Elite Custom has too much ER for a lot of people. It depends on how deep your orbital sockets are. I just returned mine. HaHa!
 
I have avoided rubber boots because of all the crumbled rubber and vinyl I see used,
but I'm realizing innertubes can be pre-treated, and even replaced later, so I should
try this on some bootless pairs I have. The little Customs I have are great with
eyeglasses, so I have no motive there...
 
Well for the moment I'm far sighted so adding -5D diopters won't apply to me, but eyeswise, things tend to change over time, and not in the good direction, so maybe one day....

About inner tube as a winged eyecup materiel : I tried this and wasn't satisfyied. First I had some trouble finding a tube that's 32 mm in diameter for the 7x26 customs, and a narrower one would of course shrink at the top. But if you can find one that fits the required diameter this is not a problem. More annoying : the wings tend to stay vertical. Using leather that's more supple, the wings will bend a bit sideways with use, making it more comfortable and allowing a better seal against light. That's why I just use inner tube as a sleeve between the stock cup and the added one.
Anyway, there are some aftermarket winged add-ons for eyecups, and the ones I'm using seem identical to the Baader brand. They give a perfect seal.

Opnuts, I don't understand what you're meaning by " inner tubes may be pre-treated". Do you mean one can give them a special shape or what ?
 
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Modding a Bushnell 7x26 compact: Inner tube sizes & Edge treatment

Christophe

Modding a Bushnell 7x26 compact: Inner tube sizes & Edge treatment

On the current model of the Bushnell 7x26, an inner tube for a 32mm (1.26in) section road bike tyre probably did also for me the 'stretching' job of locking the eyecup in the full-up position.

I can't remember what size inner tube I used, but I do have some gash tubes for road bikes.

I did the job in exactly the same way as you have done it.

In my set-up, I next sleeved over a doubled-over piece of inner tube (a mild stretching job) to give 1-2mm extra extension to the eyecap.

Again I can't remember what size inner tube I used, but it could have been a tube for a 1.5in (38.10mm) section mountain bike tyre.

To make the QD sleeve-over wings in my photo--unlike the first two jobs, not a 'stretching' job--I cut from Kenda inner tube marked as suitable for tyres sized:

'27.5x2.10/2.35 (650B)'

ie for 2.10-2.35in (53.34--59.69mm) section mountain bike tyres.

I haven't done a field trial yet (No sunshine!).

But if when I do the trial I find that the edges of the wings are uncomfortable for me, I shall put on my thinking cap, and canvass:
a) materials that I might bend over the edges of the wings to round them off
b) adhesives (eg rubber solution from my puncture repair kit) that might serve to stick the material to the rubber of the wings.

So far I have not found the naked edges to be uncomfortable.

However in response to your post, I did have a trial go at improving the edges with duct tape--its 'aggressive' adhesive stuck fine to the rubber--, but the new edges were no more comfortable than the bare rubber.


Stephen
 
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Risk of deterioration of type of rubber used in bicycle inner tubes

Optic_Nut

Risk of deterioration of type of rubber used in bicycle inner tubes

I have had some bicycle inner tubes in storage or used on a bike for 7 years. I have seen other people's inner tubes when the club that I belong to stops for them to replace a tube after they puncture. I have not yet, so far as I can recall, seen an inner tube where the rubber has deteriorated. Perhaps if someone leaves a bike unused out in their garden for 30 years--As some people do--the rubber will perish.

Bicycle tyres, on the other hand, are another matter!

Other people will have to answer how well the rubber that is used in inner tubes stands up, when used for non-bicycling purposes, to prolonged exposure to light. I don't use binoculars enough. Plus I live in cloudy Britain!

Stephen
 
By "pretreated", I mean wiping the innertube rubber with something like ArmorAll
to slow the surface aging. It may not matter, though: you could simply cut out
spare pairs and pack them in crimped foil.

The best add-on eyecups I have used were front end-caps or eyepiece sleeves from
scrapped 'parts' binoculars. If I had a little lathe I could make perfect eyecups...I am tempted.
Or maybe a molding scheme. There is a plastic that melts at 150F you can pour.
 
Oops!

Christophe

Oops!

I should have said also, perhaps most relevant to your last post, that so far I am happy with upright wings. It may be due to the specification of the rubber of the inner tube that I used. I do note from the figure '27', for a modern '27in', not '26in' wheel, in the description, that the tube is likely to be of recent manufacture. Unlikely to be of any special significance, but maybe ...


Stephen
 
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