DARC DIY Night Vision focusing trick:

You ever had to change your focus when using NVG’s to see something close up then re-focus so you could continue? It’s a hassle and you never really get re-focused unless you are able to take your time.

Here’s a neat, and inexpensive trick you can do to your NVG’s that will allow you to stay ‘far’ focused yet be able to see things up close. This DIY fix helps out when moving around (CQB stuff), walking over uneven terrain and/or operating a vehicle. It’s not perfect, but it does help your depth perception tremendously because you can see better at varying distances.

Basically, you want to control the amount of “light” coming in the front of your objective lens. The larger the hole the more blurred your near image will be when focused at a distance.

Here’s the early version, made from tape.
Cost is pretty much free.99 if you have a roll of tape or a friends you can steal from.





Four pieces of small tape placed over the objective with a small opening in the center then an outside wrap to keep the four smaller pieces in place. Be sure not to over tape or you won’t be able to adjust your objective.
This system was cheap and easy to do but didn’t leave you with many options and wasn’t very durable. Heat, wind, dust and humidity would take its toll on the tape. Also, if you went into a dark space and needed to “open” it up in a hurry, you were stuck with what you had at the moment.

Another old school method was to use the rubber objective lens covers.
Most NVG’s come with the cover so I would say this is pretty much free too unless you are OCD. In which case, you will spend a lot of time trimming the hole to make it perfect.



These were fairly durable and you can remove them if you needed more light to get in. You can inadvertently create little tears in the rubber when making these and they get worse over time (adhesive around the hole helps). The rubber objective covers also get routinely lost or damaged (especially with the hole in it).  I found that it is hard to make them matching/even in size and not a very ‘clean/neat’ opening but I am also arts & crafts challenged.

The cheap bastard method…
Find a plastic bottle cap that is the right size or cut out some wax impregnated cardboard. Make the size hole you want and tape the functional, yet tawdry home made device onto your night vision.



The McGyver-Butler Creek covers technique.
These normally cost around $9 each plus you will need the devices to make the hole. These are great because the top covers can be flipped out of the way if you are in a really dark spot and need the additional light collection. If you are running BNVD-G’s, PVS-14’s or one that uses compatible accessories, you will need the 1.485”/37.7mm (09A EYE) Butler Creek flip up objective covers.



These were made with a knife, hammer, small nail and a 5.56mm/7.62mm round. Make a small notch where you want the hole with your knife. Open the cover and drive the nail through the cover from the front then remove the nail. Push the bullet into the hole until you reach the desired diameter. Shave off the excess plastic on the inside (makes a cone) so it doesn’t rub against and damage the objective lens.



You can also make the desired hole out of out fired 5.56mm or 7.62mm brass. Just hold onto the primer end with a Leatherman and heat up the opening until warm; then punch a hole in the plastic cover. *How you hold and handle the brass makes a huge difference. You want to apply constant, even pressure as you melt through the plastic.

This set (pictured below) was made with a knife, dremmel tool, cordless drill and some sand paper. Make a small notch with your knife. Align the dremmel drill and punch a hole in the cover from the front. Pick the size bit you want based on the desired aperture. Put the bit head onto the hole, turn on the drill and punch out the rest. Lightly sand away any burrs on the inside.



*I recommend you start with a 5mm diameter hole (centered) and then increase size from there if desired. I wouldn’t go more than 8mm. I found that I really like the 5.5mm size if I’m going to be looking at things up close up a lot, make dynamic movements or driving but it’s ambient light sensitive/dependent. A 7 to 8mm diameter gives me the most operational latitude if I’m just a sled dog in the stack. I have a 5mm and a 7mm pair that goes everywhere with my NVG’s. The 5mm’s are the ones that stay on it. Finding the right diameter sized aperture is a very personal thing due to various biological differences, how you wear your NVG’s, mounts, gas masks, eye pro and your most common use.



**Focus your NVG’s and then put on the cover. Put the cover on so it does not obscure your controls, your IR illuminator and or your peripheral vision. I found that I prefer them to open up and a little angled out. The most convenient is for them to flip down but then you will be blocking your under NVG view, which I do not recommend.



The tier .5-007-ninja covers…
These are made by Phokus Research and called the Hoplite. I assume that some smart guy saw and/or used the old home made designs down range and decided to make them. These bad boys have the flip-up, factory made dust cover with different inserts so the user can chose the aperture size AND it has a built in polycarbonate sacrificial lens. The improvements and use-ability are cool but it comes at a price.

The Hoplites are definitely the Ferrari of the bunch. Here’s a link for more information:
http://phokusresearch.com/products/hoplite/

If you have any questions or would like me to email you a PDF on this, just shoot me a PM, email
< [email protected]  > or find us on FB < https://www.facebook.com/pages/DARC/132176453462424 >

Thanks,
Rich
www.darc1.com

Thanks for the questions and the interest.
These covers go on the objective lens not the ocular.
Here's a picture of them mounted for clarity:

No Thanks! I will wait till the $500.00 per lens comes out from some enterprising young person and labeled the "QCB Tactical NVG Optical Enhancement Device" or "QCBTNVGOED"!

LOL

Dude, you could always recycle those sheep skin condoms... I heard they already had holes in them so you are half way there already.

LOL.... True!!!

Neat! Thanks!!!!

Hey Rich,

Good to see ya' here. I was just checking out some NV gear down at the COLA warrior. First time I had ever messed around with NVG and it was a blast.

Give a shout if your around next week and I'll spring for lunch.

Deal

@ shooters101  

Wait no further.. LMFAO http://phokusresearch.com/

I like this method better, its not $500.00/each LOL!

@MRF

Good post =D

So...anyone tried it out yet?

Tag. I'm going to try this.

I haven't done it yet, but I will.  I have an Anvis project that I am using Butler Creek caps on.

I bought a Butler Creek cap to try out on my 14s.  I'll give it a shot tonight.  I like the idea, doubles as a good way to protect the objective as a bonus.

Bear with me, 'cause I'm not the smartest feller, but how does this not cut down on the field of view?

theory on how this works is similar to that of pinhole cameras....



look either here on the theory of operation of a pinhole lens



http://en.wikipedia.org/wiki/Camera_lens





or this link, the first part is a bit more technical, but it it has some pictures that helps make it a bit easier to understand



http://web.phys.ksu.edu/papers/2008/pinhole-glasses-tpt.pdf
 

Little tips and tricks like this are awesome. I did the same thing to my surefire to help with unwanted white light discharges.

I'm surprised your 14's aren't the same. Are they different manufacturer's?