Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login

Log In

A valid email is required.
Password is required.
Site Notices
Page / 16
Link Posted: 3/30/2012 9:14:01 PM EDT
Originally Posted By Sturmgewehr-58:
Won't win any contest, bit it's functional.
I still have to add the illuminator when it arrives and give the case a couple coats of paint.

http://i563.photobucket.com/albums/ss75/ALOrihuela/0330121748.jpg


Looks great man, good job!
Link Posted: 3/31/2012 12:12:55 AM EDT
b_rogers, would love to see that pic of yours mounted on a helmet.

David, thanks very much for the explanation. I'm just wondering if anyone can build something that is somewhere close in size/weight to a PVS14 that the military is using. Sounds like a MX10160A tube would be as close as anyone could get.
Link Posted: 3/31/2012 1:57:33 AM EDT
Originally Posted By jb2c:
b_rogers, would love to see that pic of yours mounted on a helmet.

David, thanks very much for the explanation. I'm just wondering if anyone can build something that is somewhere close in size/weight to a PVS14 that the military is using. Sounds like a MX10160A tube would be as close as anyone could get.



Still had the 3x on there, can't walk around with that on..
Link Posted: 3/31/2012 2:00:54 AM EDT
Good news! I came home to a call tag for a package from the UK. The only one I'm expecting is this one, so Saturday morning I'll hustle down there and have my tubes!
Link Posted: 4/2/2012 2:24:20 AM EDT
Originally Posted By b_rogers:
Originally Posted By jb2c:
b_rogers, would love to see that pic of yours mounted on a helmet.

David, thanks very much for the explanation. I'm just wondering if anyone can build something that is somewhere close in size/weight to a PVS14 that the military is using. Sounds like a MX10160A tube would be as close as anyone could get.



Still had the 3x on there, can't walk around with that on..
http://i42.photobucket.com/albums/e344/b_rogers/IMG_3023.jpg



Thanks b-rogers! Now that looks alot more like it. Not sure what you mean when you say 'with the 3x, you can't walk around with that.' Is this not the picture you had wanted to find? To me, this looks similiar in size to the PVS-14. Would definitely be interested in building up one of these. Or convincing someone on the thread that has more technical ability than I do to build one! How does it perform compared to the cascade design being generally discussed in this thread??

Link Posted: 4/2/2012 5:13:10 PM EDT
I just ordered three sub-$10 teleconverters for Nikon; I'm going to gut them for the flanges so I can mount a Nikon camera on one end and Nikon glass on the other end. The teleconverters should arrive by this time, next week.
Link Posted: 4/2/2012 7:05:04 PM EDT

Originally Posted By RyJones:
I just ordered three sub-$10 teleconverters for Nikon; I'm going to gut them for the flanges so I can mount a Nikon camera on one end and Nikon glass on the other end. The teleconverters should arrive by this time, next week.

Ahh, an intensified camera... A nice project :)

But you'll need to include a relay lens as well - something worth considering - or the camera won't be able to focus.

Because the screen from the tube is like a piece of "glowing paper" it's like taking a picture of that piece of paper, really closely up. You'll still need a lens on the camera - either a simple relay lens or a macro lens.

Regards
David
Link Posted: 4/2/2012 8:36:58 PM EDT
[Last Edit: 4/3/2012 1:24:46 AM EDT by RyJones]
Thanks.
Link Posted: 4/5/2012 11:59:46 PM EDT
Absolutely BAD ASS I'm going to attempt this... Thanks for posting this David...
Link Posted: 4/6/2012 3:53:39 PM EDT

Originally Posted By SteelTalon:
Absolutely BAD ASS I'm going to attempt this... Thanks for posting this David...

Yeah, I've always wanted to build my own NVD but never knew the tubes were available for a homemade device.
I built my own a week after reading David's post. Awesome project, thanks a lot David.
Link Posted: 4/7/2012 9:51:59 PM EDT
Finally managed to take some pictures outdoors. Took a walk around the golf course tonight.

I just held my cell phone camera up to the eyepiece, so the actual view is much better than the pic shows.

Link Posted: 4/7/2012 10:41:14 PM EDT
Originally Posted By jb2c:
Originally Posted By b_rogers:
Originally Posted By jb2c:
b_rogers, would love to see that pic of yours mounted on a helmet.

David, thanks very much for the explanation. I'm just wondering if anyone can build something that is somewhere close in size/weight to a PVS14 that the military is using. Sounds like a MX10160A tube would be as close as anyone could get.



Still had the 3x on there, can't walk around with that on..
http://i42.photobucket.com/albums/e344/b_rogers/IMG_3023.jpg



Thanks b-rogers! Now that looks alot more like it. Not sure what you mean when you say 'with the 3x, you can't walk around with that.' Is this not the picture you had wanted to find? To me, this looks similiar in size to the PVS-14. Would definitely be interested in building up one of these. Or convincing someone on the thread that has more technical ability than I do to build one! How does it perform compared to the cascade design being generally discussed in this thread??



Yep, 3x on there, and not the right pic

I would have to say similar overall performance, David has both, he can probably give a more authoritative answer
Link Posted: 4/8/2012 12:09:31 AM EDT

Originally Posted By Sturmgewehr-58:
Finally managed to take some pictures outdoors. Took a walk around the golf course tonight.

I just held my cell phone camera up to the eyepiece, so the actual view is much better than the pic shows.
http://i563.photobucket.com/albums/ss75/ALOrihuela/GolfCourseAtNight.jpg

Quite a reasonable pic I thought... Nice :)

It looks like the golf course is pretty dark though. That makes for really good conditions under which to evaluate the NV gear :)

Regards
David
Link Posted: 4/8/2012 12:12:47 AM EDT

Originally Posted By b_rogers:
Originally Posted By jb2c:
Originally Posted By b_rogers:
Originally Posted By jb2c:
b_rogers, would love to see that pic of yours mounted on a helmet.

David, thanks very much for the explanation. I'm just wondering if anyone can build something that is somewhere close in size/weight to a PVS14 that the military is using. Sounds like a MX10160A tube would be as close as anyone could get.



Still had the 3x on there, can't walk around with that on..
http://i42.photobucket.com/albums/e344/b_rogers/IMG_3023.jpg



Thanks b-rogers! Now that looks alot more like it. Not sure what you mean when you say 'with the 3x, you can't walk around with that.' Is this not the picture you had wanted to find? To me, this looks similiar in size to the PVS-14. Would definitely be interested in building up one of these. Or convincing someone on the thread that has more technical ability than I do to build one! How does it perform compared to the cascade design being generally discussed in this thread??



Yep, 3x on there, and not the right pic

I would have to say similar overall performance, David has both, he can probably give a more authoritative answer

Well, the P8079HP tube has about 100,000 gain and better overall resolution while the MX9916 would have 30,000 or less so the P8079HP would give a much sharper, brighter and more detailed image.

But the MX9916 is small enough to be worn on a helmet which makes it far more practical.

If offered two scopes, I'd go for the MX9916 at twice the price, simply because the size and weight difference makes it worthwhile. You can navigate with a MX9916. You can only really spot with a P8079HP based system.

Regards
David

Link Posted: 4/8/2012 6:21:57 AM EDT
[Last Edit: 4/8/2012 8:08:20 AM EDT by RaptorFuel]
I'm still trying to figure out what kind of epoxy to try to create an adapter with. I haven't had any luck sourcing it locally I need to order some online. Anyone have suggestions on what kind to try? I'm going to also try that jb weld stick.
Link Posted: 4/8/2012 9:28:47 AM EDT
[Last Edit: 4/8/2012 1:06:40 PM EDT by RaptorFuel]
Found a stick of JB Weld and its curing right now. Fingers crossed.


ETA: Its dry and works but I need to sand it down to move the rear element closer to the sensor because Its not close enough to focus more than 20 ft. Saving that for tomorrow.
Link Posted: 4/9/2012 2:14:36 AM EDT
[Last Edit: 4/9/2012 2:43:49 AM EDT by RyJones]
Well, I made a flangeish thing - Wikipedia said the flange distance for an F mount lens is 46.5 mm (1 7/8 inch), so I stacked up laser cut 3mm birch ply to reach the vicinity of 1 7/8". I have more work to do - I have flanges on the way from KEH - but I was able to hand-hold the thing together, adjust the iris and focus, and see stuff in a really dark room, in focus, on the ocular. Pretty cool. Can't wait for the rest of the parts from KEH to show up so I can strap on the Nikon and get to work.

Also, why do I keep getting shocked?
Link Posted: 4/9/2012 9:39:56 AM EDT
[Last Edit: 4/9/2012 9:40:54 AM EDT by cj7hawk]


Originally Posted By RyJones:
Well, I made a flangeish thing - Wikipedia said the flange distance for an F mount lens is 46.5 mm (1 7/8 inch), so I stacked up laser cut 3mm birch ply to reach the vicinity of 1 7/8". I have more work to do - I have flanges on the way from KEH - but I was able to hand-hold the thing together, adjust the iris and focus, and see stuff in a really dark room, in focus, on the ocular. Pretty cool. Can't wait for the rest of the parts from KEH to show up so I can strap on the Nikon and get to work.

Nice work ! :) You're nearly there - and I'd love to see pics of your flange when done.

Remember, if you can focus close up but not to infinity, it means the lens can't get close enough to the photocathode and you might need to sand one of those 3mm birch ply boards down.

Also, remember to seal them from moisture - any warping would cause infinity focus issues.

Originally Posted By RyJones:
Also, why do I keep getting shocked?

It might be the 45,000 volts or so of electricity inside the tube you're holding...

Seriously, there is a LOT of voltage in there. Even induced static electricity is going to give you a shock - though I've never had a very big one.

But it does highlight that it's important to properly seal it - Also, the 45,000 volts is relative to the ground, so not being grounded or having your hand next to the front of the tube helps too :)

Regards
David
Link Posted: 4/9/2012 2:49:20 PM EDT
It was suggested that I should stick a 10-100k ohm resistor between power and ground in order to bleed off built up voltage - I plan on doing this on the unused pole of a SPDT switch, wise?
Link Posted: 4/9/2012 7:32:02 PM EDT
[Last Edit: 4/9/2012 7:32:32 PM EDT by cj7hawk]

Originally Posted By RyJones:
It was suggested that I should stick a 10-100k ohm resistor between power and ground in order to bleed off built up voltage - I plan on doing this on the unused pole of a SPDT switch, wise?

That won't do anything unfortunately - the voltage is within the tube itself.

-though you could put it into a metal housing or run some foil under tape the length of the tube - and leave it a little shy of the viewing screen.

Regards
David
Link Posted: 4/13/2012 11:43:38 PM EDT
Took a few more pics tonight, wish I had a better camera though. A zoom lens for this would really be great too.

Sprinklers on the golf course at 11pm. It was really dark, but there was enough city light reflecting off low clouds that I closed the aperture some.


A pic of mail armor in my bedroom, with IR light for illumination.

Link Posted: 4/14/2012 7:41:26 PM EDT
Nice pics :) Thank you again.

The pics highlight the only real flaw of the older tube technology - many earlier designs had a fair bit of distortion around the edges. Otherwise the gain and clarity of the image are exceptional and really challenge Gen3 technology. Especially on darker nights.

Cascade tubes were great tubes and the "upgrade" from Gen3 was also another cascade technology but cost and complexity as well as suitable function from Gen3 have made it obsolete.

But these home-made works still make excellent spotters - they were originally intended for rifle use but are too heavy for that IMO. Still, stick them on a tripod and give it to your spotter and they are great.

Regards
David
Link Posted: 4/15/2012 3:43:56 PM EDT
Arrggghhhh.....

I need an eyepiece, but know nothing about optics!

Can someone just give me a link?

Can't really search ebay 'cause I don't know what I'm searching for...

I would pay extra for a VARO eyepiece if I could find one

Thanks!
Link Posted: 4/15/2012 4:00:20 PM EDT
Originally Posted By Gurn:
Arrggghhhh.....

I need an eyepiece, but know nothing about optics!

Can someone just give me a link?

Can't really search ebay 'cause I don't know what I'm searching for...

I would pay extra for a VARO eyepiece if I could find one

Thanks!


I just used this
Link Posted: 4/15/2012 4:09:13 PM EDT
Originally Posted By Sturmgewehr-58:
Originally Posted By Gurn:
Arrggghhhh.....

I need an eyepiece, but know nothing about optics!

Can someone just give me a link?

Can't really search ebay 'cause I don't know what I'm searching for...

I would pay extra for a VARO eyepiece if I could find one

Thanks!


I just used this


I found I didn't need one - the image is focused on the back screen. Am I doing it wrong?
Link Posted: 4/15/2012 4:44:04 PM EDT
That screen is a bit small, no? I'd strain my eye trying to stare at that little picture.
Link Posted: 4/15/2012 5:26:07 PM EDT
Originally Posted By Sturmgewehr-58:
That screen is a bit small, no? I'd strain my eye trying to stare at that little picture.


true.
Link Posted: 4/15/2012 5:57:29 PM EDT
Someone here suggested a Plossl lens/eyepiece and they are amazing for abt $20.

Link Posted: 4/15/2012 7:18:06 PM EDT
Yes, the Plossl lens works great, but if you use a Plossl or even a Loupe, you will need a focussing mechanism. I just used two threaded pipe adapters and cut them to size, so that the eyepiece turned one thread and the other I fixed to the scope.

Anyway, the correct eyepiece.

But only in a group of 7... So better to split this up amongst a few people. They are VERY good lenses.

There are some camera loupes with adjustable focus as well that can be cut down to fit -

If anyone does get a plossl lens, remember that you have to cut it down with a hacksaw to get close enough to the focal plane to use one. They can't be used out of the box because the focal plane is within the tube.

Regards
David
Link Posted: 4/15/2012 9:29:02 PM EDT
Originally Posted By cj7hawk:
Yes, the Plossl lens works great, but if you use a Plossl or even a Loupe, you will need a focussing mechanism. I just used two threaded pipe adapters and cut them to size, so that the eyepiece turned one thread and the other I fixed to the scope.

Anyway, the correct eyepiece.

But only in a group of 7... So better to split this up amongst a few people. They are VERY good lenses.

There are some camera loupes with adjustable focus as well that can be cut down to fit -

If anyone does get a plossl lens, remember that you have to cut it down with a hacksaw to get close enough to the focal plane to use one. They can't be used out of the box because the focal plane is within the tube.

Regards
David


The Varo eyepieces are great. Just a reminder, they were MADE to fit the HP8079 tube, and mate up with the silicone shock absorbing ridges on the end for a tight seal.

However, the condition of the eyepieces will be a bit rough. There might be some foxing/oxidization on the optics, and quite a bit of Israeli desert sand/dust in them that might need cleaning. The good news though is even if the optics are a bit beat up, as long as they adjust properly (and you put them back together in the right order) you'll be focusing through or past any damage, as long as it's not too significant, and it won't really matter.
Link Posted: 4/15/2012 9:45:14 PM EDT
This place is great for optics, reticles all kinds of oddball stuff.

www.surplusshed.com
Link Posted: 4/16/2012 6:36:54 PM EDT
[Last Edit: 4/17/2012 1:37:09 PM EDT by Sturmgewehr-58]
Got my 200mW IR laser I planned to use as an illuminator in today.

It was listed as 780nM, the module itself is labeled 635-660nM, hardly infrared. Oh well, I guess being visible will make it easier for me to keep from blinding myself.

I just got my new lens in too, Can't wait to play with it this weekend.

Link Posted: 4/18/2012 11:38:54 PM EDT
I just ordered two tubes from Starlight NV UK, and Julian was very helpful in answering my questions. Just in case anyone reading this thread is deciding which place to order from, on Anchor Supplies' website it mentions that they guarantee that the tubes are free of blemishes and that they are tested and verified to be in working order. I emailed Julian, and he stated that Starlight NV UK also offers these guarantees. He also mentioned that the 80gbp tube is the new old stock, model 8079hp. It doesn't explicitly say on the website, and I thought I would save somebody from having to send an email.

I did also have a few questions:

1. b_rogers, in another thread about PVS-2 scopes, you mentioned this, "Make sure the PVS2 has a green ring on the eyepiece. This keeps any radiation from reaching your eye. The US tubes usually don't emit, but better safe then sorry." Are there any such concerns with this type of tube? I think it was decided in that thread that this was mainly a concern with 1st generation Russian sights, but I thought I would double check. The thread in question is here: http://www.ar15.com/forums/t_3_123/521778_AN_PVS_2_Starlight_Scope.html

2. My second question is, a PVS-2 eyepiece would work just as well as the VARO eyepieces without any further modification, and attach to the tube, correct? They look identical to my untrained eye. cj7hawk, I saw your post on www.nightvisionforums.com, and my impression from that thread was that the PVS-2 eyepiece would be a good fit, but I just wanted to be sure as they are a little pricey.

Thanks again for posting this thread, I am really excited to get started!
Link Posted: 4/19/2012 12:27:26 AM EDT
[Last Edit: 4/19/2012 12:28:22 AM EDT by b_rogers]
Originally Posted By conBLACK:
I just ordered two tubes from Starlight NV UK, and Julian was very helpful in answering my questions. Just in case anyone reading this thread is deciding which place to order from, on Anchor Supplies' website it mentions that they guarantee that the tubes are free of blemishes and that they are tested and verified to be in working order. I emailed Julian, and he stated that Starlight NV UK also offers these guarantees. He also mentioned that the 80gbp tube is the new old stock, model 8079hp. It doesn't explicitly say on the website, and I thought I would save somebody from having to send an email.

I did also have a few questions:

1. b_rogers, in another thread about PVS-2 scopes, you mentioned this, "Make sure the PVS2 has a green ring on the eyepiece. This keeps any radiation from reaching your eye. The US tubes usually don't emit, but better safe then sorry." Are there any such concerns with this type of tube? I think it was decided in that thread that this was mainly a concern with 1st generation Russian sights, but I thought I would double check. The thread in question is here: http://www.ar15.com/forums/t_3_123/521778_AN_PVS_2_Starlight_Scope.html

2. My second question is, a PVS-2 eyepiece would work just as well as the VARO eyepieces without any further modification, and attach to the tube, correct? They look identical to my untrained eye. cj7hawk, I saw your post on www.nightvisionforums.com, and my impression from that thread was that the PVS-2 eyepiece would be a good fit, but I just wanted to be sure as they are a little pricey.

Thanks again for posting this thread, I am really excited to get started!



I don't think there are documented problems with it, but I did notice that a lot of the PVS2 "refurb" scopes had them. Probably just a "in case" kind of thing.

The VARO eyepieces i believe are actually pvs2 eyepieces, same thing.


Looking good there Sturm!
Link Posted: 4/19/2012 12:57:39 AM EDT

Originally Posted By cj7hawk:

As for lens quality, the actual image quality of the lens is a big deal and something to consider. A cheaper lens will not keep the entire far field in focus at the same time and despite tube limitations, you will lose 80% of the image if your lens is crappy - something that does not bother people who only have a focal plane of around 5mm - These tubes have a focal plane of around 25mm and more than 16mm is very useable and not all that distorted.



I bought a Canon TV lens 11-70mm f1.4
I lets plenty of light through, the focus is fine, and the zoom is pretty nice. Unfortunately the image circle is terribly small and the image on the output screen is about the size of a dime.
Link Posted: 4/19/2012 1:01:38 AM EDT
[Last Edit: 4/19/2012 1:10:04 AM EDT by RyJones]
Originally Posted By Sturmgewehr-58:

Originally Posted By cj7hawk:

As for lens quality, the actual image quality of the lens is a big deal and something to consider. A cheaper lens will not keep the entire far field in focus at the same time and despite tube limitations, you will lose 80% of the image if your lens is crappy - something that does not bother people who only have a focal plane of around 5mm - These tubes have a focal plane of around 25mm and more than 16mm is very useable and not all that distorted.



I bought a Canon TV lens 11-70mm f1.4
I lets plenty of light through, the focus is fine, and the zoom is pretty nice. Unfortunately the image circle is terribly small and the image on the output screen is about the size of a dime.


If it's a EF mount, it has a focal plane of 44mm - do you have the lens at the right distace? the 44mm is from the inside of the bayonet groove.

Looks like it's a C mount, which is 0.6900 inches.
Link Posted: 4/19/2012 1:22:46 AM EDT

Originally Posted By RyJones:

If it's a EF mount, it has a focal plane of 44mm - do you have the lens at the right distace? the 44mm is from the inside of the bayonet groove.

Looks like it's a C mount, which is 0.6900 inches.

Yep, it's a C mount.
I already had a 55mm C mount lens I used to set the distance. The TV lens can only focus between 50-70mm, so no wide-angle views.
I tried playing with the distance and the image circle didn't seem to get any larger. Apparently the camera this lens was made for has a tiny sensor.

Oh well, it's not noticeable how small the viewable image is when viewing through the eyepiece, and at least I have some magnification.
Link Posted: 4/21/2012 10:56:05 PM EDT
[Last Edit: 4/22/2012 12:23:23 AM EDT by Zoomies]
Got my tube in, cleaned up the ground contact, and the sucker fired right up! I made little girl noises when it did, too.

My dad, who is big into photography, is letting me "borrow" a 58mm Minolta F/ 1.4 lens. Now I just need to figure out how to mount it. The easiest (and cheapest) way I can think of is to get my hands on a toasted Minolta camera body and pull the lens mount.

I'm thinking about 3" PVC for the housing, shimming the intensifier, and probably tearing apart a cheap Wally world scope for my eye piece. As far as these Varo eyepieces, does anyone know what the designation for the scope these are actually intended for is? PVS-2, PVS-4, PAS-2? I ask because I have a decent surplus store local, I might be able to narrow things down if I know the right questions to ask.

Gotta say that I am stupid excited about this project.

ETA: Is it normal for these tubes to make a high-pitched whine and/ or a crackling noise? The crackling noise I could chalk up to an iffy connection on the front ring, but the whIne worries me.
Link Posted: 4/22/2012 1:57:31 AM EDT
[Last Edit: 4/22/2012 2:11:31 AM EDT by Gurn]
Thanks all for the help with this project...it's been a lot of fun

I, so far, have gone with a 50mm c-mount f1.3 lens and the "loupe" eyepiece...have a pvs-2 eyepiece on order.

Just wanted to give anyone who has been thinking of doing this, and is on the fence, some comparisons.

I took these pictures with my iphone, so I apologize for the quality...

This is my old Zenit moonlight Gen 1 scope

http://i1267.photobucket.com/albums/jj560/gurnio737/IMG_12453.jpg?t=1335073508

And here is my homebrew cascade scope

http://i1267.photobucket.com/albums/jj560/gurnio737/IMG_12432.jpg?t=1335073508

Lastly, my TNVC gen 3 night enforcer.

http://i1267.photobucket.com/albums/jj560/gurnio737/IMG_12342.jpg?t=1335073508


All pics were starlight, no moon, rural setting with a small porch lamp about 75 yards away...the pole is 50 yards away.

Hope it helps!




Oh, and one more...

http://i1267.photobucket.com/albums/jj560/gurnio737/IMG_12522.jpg


ETA: One question,...are there any places to buy an old PVS-2 housing, and can I just stick everything in there
instead of building a housing?

Thanks again!


Link Posted: 4/22/2012 10:35:49 AM EDT

Originally Posted By Gurn:
Thanks all for the help with this project...it's been a lot of fun


Wow! Nice pics... It looks like the Cascade has a better contrast than the Gen3 too! At least at that light level. Fantastic work on it all!

Regards
David.
Link Posted: 4/22/2012 12:57:03 PM EDT
Those pics are really great Gurn. After looking at them I do have a question though. I've been trying to decide which kind of lens to use for my project, and I would like to get a field of view like in the third pic, of your gen 3 unit, vs a narrower, "zoomed" looking field of view. Is there a specific type of lens I should look for? I have been trying to educate myself on what different types of lenses, but I'm not sure I have a firm grasp on what exactly I am looking for. From what I have found, a lower "mm" value would provide a wider field of view, is that correct?
Link Posted: 4/22/2012 1:19:49 PM EDT
[Last Edit: 4/22/2012 1:28:02 PM EDT by Gurn]
Yeah, good question, conblack...

I used this lens
for the objective...

I'm using this lens for the ocular until I get my VARO lens

As I understand it, a 50mm lens should be 1:1 magnification, but I think my ocular (rear) lens magnifies the picture on the back screen a bit.

Maybe someone who understands optics better than me can give a better answer, but it is quite a bit more magnified than my PVS-14, and less
than the PVS-14 with 3x afocal lens on.

Hope it helps!

BTW, the focus and clarity are significantly better to the eye on both units...It's really hard to take a picture through an eyepiece at night with an iphone!


Link Posted: 4/22/2012 2:19:06 PM EDT
[Last Edit: 4/22/2012 2:20:34 PM EDT by EXPY37]
A Plosel [spelling?] eyepiece is abt $20 on ebay and altho they don't have an adjustment built in [you can order an eyepiece housing] the brightness and size of the pupil dia is outstanding for the price.

It's sort of like looking thru an Acog.

Thanks to the poster who suggested this lens.

Link Posted: 4/22/2012 3:47:05 PM EDT
[Last Edit: 4/22/2012 3:50:06 PM EDT by b_rogers]
Originally Posted By Gurn:
Yeah, good question, conblack...

I used this lens
for the objective...

I'm using this lens for the ocular until I get my VARO lens

As I understand it, a 50mm lens should be 1:1 magnification, but I think my ocular (rear) lens magnifies the picture on the back screen a bit.

Maybe someone who understands optics better than me can give a better answer, but it is quite a bit more magnified than my PVS-14, and less
than the PVS-14 with 3x afocal lens on.

Hope it helps!

BTW, the focus and clarity are significantly better to the eye on both units...It's really hard to take a picture through an eyepiece at night with an iphone!





Thats a good objective lens you got.
25mm = 1x
50mm= 2x
75mm=3x
Link Posted: 4/22/2012 3:49:03 PM EDT
Originally Posted By conBLACK:
Those pics are really great Gurn. After looking at them I do have a question though. I've been trying to decide which kind of lens to use for my project, and I would like to get a field of view like in the third pic, of your gen 3 unit, vs a narrower, "zoomed" looking field of view. Is there a specific type of lens I should look for? I have been trying to educate myself on what different types of lenses, but I'm not sure I have a firm grasp on what exactly I am looking for. From what I have found, a lower "mm" value would provide a wider field of view, is that correct?


Generally thats the rule, but there are wide view lenses too, I have 50mm wide view that has just a little more FOV.
Link Posted: 4/23/2012 1:44:56 PM EDT
The smaller the focal length of the lens ( in mm ) the wider the field of view.

Zoom is a ratio between the objective lens focal length and the ocular lens focal length. Eg, If you have a 25mm ocular then a 25 mm objective lens will produce 1:1 zoom. A 50mm will produce 2:1 zoom and so on.

If you use a 50mm ocular, then a 50mm objective will only provide 1:1 zoom.

Field of view is based on the size of the screen and the focal length of the lens. The tangent of half of the field of view is equal to the screen radius divided by the focal length of the lens.

Regards
David
Link Posted: 4/23/2012 4:25:56 PM EDT
Just out of curiosity, how are you guys mounting to the ground terminal? I was thinking of soldering some kind of connector to it, but figured I'd probably melt the rubber before I got a good connection. Thanks for all the help, I've learned a lot on this project!
Link Posted: 4/23/2012 5:25:55 PM EDT
Originally Posted By Zoomies:
Just out of curiosity, how are you guys mounting to the ground terminal? I was thinking of soldering some kind of connector to it, but figured I'd probably melt the rubber before I got a good connection. Thanks for all the help, I've learned a lot on this project!


I just pushed the wire under the rubber and put a drop of solder on the metal to hold it in place.
Some electric tape around the tube keeps the wire from pulling out.
Link Posted: 4/23/2012 6:39:39 PM EDT
Anyone know the actual thread pitch of that positive terminal screw hole?

Link Posted: 4/23/2012 9:48:02 PM EDT
It's #3-48, metric. 1/4" long will sit tight to the threaded hole.
Page / 16
Top Top