Watec 902h Behind Scope - Picture Very Grainy Beyond 100yds

Show and tell for your homebrew nv projects. DIY 'Stickies' here too.
LancsNinja
Posts: 10
Joined: 07 Apr 2013, 16:01
Location: Lancashire

Watec 902h Behind Scope - Picture Very Grainy Beyond 100yds

Post by LancsNinja » 06 May 2013, 21:00

Hi Guys,

Help! - I need some advice please...

The Setup:
I have built a watec 902 h rig that mounts onto my scope with the camera sat about 95mm behind the scope. I put the camera there because that is where the scope manual says the exit pupil is.

I have a nice IR Illuminator (IRI) from Sika Stag, and that can be zoomed from a wide circle down to a very tight square.

These pictures with the rig on my .223 foxing rifle, show the set up:

http://s1195.photobucket.com/user/Lancs ... sort=3&o=0

http://s1195.photobucket.com/user/Lancs ... sort=3&o=1

I have fitted a 16mm lens to the Watec, which I bought from http://www.ebay.com/itm/221194261762

I spent quite a while aligning the camera to the scope and got that done in daylight, so I think the alignment is not too bad, because in daylight I get a very clear picture on the screen, with clear cross-hairs.

The Problem:
When used in total darkness, the picture on the screen is very clear out to 100yds, but at 160yds it is so grainy that you can make out a cow, but would have no chance of making out enough detail to see/shoot a fox/rabbit. I have tried different combinations of scope zoom, IRI zoom, and IRI dimmer, but nothing I have yet found will stop the picture being grainy beyond 100 yds.

I am a complete novice on the camera (and wouldn't have been able to put this lot together without all the good work you guys have already done). I have searched but not found anything that may help me fine tune the camera settings, because I don't think there is any issue with IR alignment, I can see that by setting my scope to a wider angle, the tight circle or even tighter square when the IRI is fully zoomed is clearly visible with the cross-hairs in the centre of the bright zone. So I am thinking I have an issue with the camera. I noticed on another post that the advice was to have the watec about 40mm from the scope - so maybe I have made a mistake by mounting it at the exit pupil distance. I have read a little on this forum about a few of the camera settings, which I don't understand, and don't know how to change any camera settings.

I have the ability to swap parts with the spotter to diagnose if that helps. The spotter I built is using another Watec 902h and this lens from Stock Optics, http://www.stockoptics.com/cctv-lenses/vf-mi.html with the same IRI is giving excellent clear visibility out to 500-600yds. Here is the spotter: http://s1195.photobucket.com/user/Lancs ... sort=3&o=1

So any suggestions on how to improve the image beyond 100yds would be very much appreciated.

Thanks,

Graham

User avatar
Marky610
Posts: 3505
Joined: 12 Jul 2012, 15:10
Location: Mid Suffolk
Contact:

Re: Watec 902h Behind Scope - Picture Very Grainy Beyond 100

Post by Marky610 » 06 May 2013, 21:12

From your first pic I can see the problem straight off...................your illuminator isn't plugged in :mrgreen:

Sorry bud, more serous now ;)



95mm is a long way back bud, mines more like 40mm.

Get the camera in your hands and move it in and out from the scope until you find the right spot. The edge of the scope should look like a nice crisp circle. Also you need to focus your crosshairs at night as ir light has a different wavelength so your focus will change.

Also have you switched your camera to low gain? Gives a much clearer picture, inside the back cover is a tiny white switch, should be in the down position (IIRC, if not someone will correct me),
Land Rovers, who would be daft enough to own one?

LancsNinja
Posts: 10
Joined: 07 Apr 2013, 16:01
Location: Lancashire

Re: Watec 902h Behind Scope - Picture Very Grainy Beyond 100

Post by LancsNinja » 07 May 2013, 08:44

Marky,

Thanks very much for the quick reply and suggestions. :thumbup:

I have checked both the camera on the spotter and the camera on the scope add-on, and both were set to high gain mode with the switch in the up position. I have set them both to low gain (lower position) - assuming the spotter needs to be on low gain also - if that is wrong can someone please let me know.

I will give them a more thorough test tonight at longer range, but I had a quick peek in the early hours with the add-on rig, and the image seemed to be a lot clearer - with a lot less grainy effect. I also took your advice to fine tune the cross-hair focus using the IRI in the dark - that has sharpened up too.

I have made up a packer to mount the camera on so it will have the correct distance below my aluminium support frame in case I need to slide that forwards in my hands to reduce the distance from the back of the scope eyepiece. I will have a look at that tomorrow if the high to low gain change has not completely solved it in the tests tonight.

I intend to set the rifle up on bipod and rear butt support at darkness tonight on top of the foxing vehicle with a view out to 300 yds to fine tune any settings - like scope zoom, IRI zoom and dimmer control.

More feedback to follow tomorrow after testing tonight.

Thanks a bunch Marky... :thumbup:

2-dead-in-the-air
Posts: 69
Joined: 07 May 2012, 20:56
Location: Chippenham, Wiltshire

Re: Watec 902h Behind Scope - Picture Very Grainy Beyond 100

Post by 2-dead-in-the-air » 07 May 2013, 10:14

LancsNinja wrote:Hi Guys,

Help! - I need some advice please...

The Setup:
I have built a watec 902 h rig that mounts onto my scope with the camera sat about 95mm behind the scope. I put the camera there because that is where the scope manual says the exit pupil is.

I have a nice IR Illuminator (IRI) from Sika Stag, and that can be zoomed from a wide circle down to a very tight square.

These pictures with the rig on my .223 foxing rifle, show the set up:

http://s1195.photobucket.com/user/Lancs ... sort=3&o=0

http://s1195.photobucket.com/user/Lancs ... sort=3&o=1

I have fitted a 16mm lens to the Watec, which I bought from http://www.ebay.com/itm/221194261762

I spent quite a while aligning the camera to the scope and got that done in daylight, so I think the alignment is not too bad, because in daylight I get a very clear picture on the screen, with clear cross-hairs.

The Problem:
When used in total darkness, the picture on the screen is very clear out to 100yds, but at 160yds it is so grainy that you can make out a cow, but would have no chance of making out enough detail to see/shoot a fox/rabbit. I have tried different combinations of scope zoom, IRI zoom, and IRI dimmer, but nothing I have yet found will stop the picture being grainy beyond 100 yds.

I am a complete novice on the camera (and wouldn't have been able to put this lot together without all the good work you guys have already done). I have searched but not found anything that may help me fine tune the camera settings, because I don't think there is any issue with IR alignment, I can see that by setting my scope to a wider angle, the tight circle or even tighter square when the IRI is fully zoomed is clearly visible with the cross-hairs in the centre of the bright zone. So I am thinking I have an issue with the camera. I noticed on another post that the advice was to have the watec about 40mm from the scope - so maybe I have made a mistake by mounting it at the exit pupil distance. I have read a little on this forum about a few of the camera settings, which I don't understand, and don't know how to change any camera settings.

I have the ability to swap parts with the spotter to diagnose if that helps. The spotter I built is using another Watec 902h and this lens from Stock Optics, http://www.stockoptics.com/cctv-lenses/vf-mi.html with the same IRI is giving excellent clear visibility out to 500-600yds. Here is the spotter: http://s1195.photobucket.com/user/Lancs ... sort=3&o=1

So any suggestions on how to improve the image beyond 100yds would be very much appreciated.

Thanks,

Graham
Which lens are you using from Stock Optics on your spotter ?

poppy mae
Posts: 1287
Joined: 19 Aug 2012, 21:21
Location: Wirral Chesire

Re: Watec 902h Behind Scope - Picture Very Grainy Beyond 100

Post by poppy mae » 07 May 2013, 13:41

With the setting in low the picture will be a lot better,but you will start to loose picture range if using your mag on the scope,depending on what ir your using,ideal for fac air and rimmy distances in the low setting,but prefer on hi,if using any great distance....just my preferences......

User avatar
Marky610
Posts: 3505
Joined: 12 Jul 2012, 15:10
Location: Mid Suffolk
Contact:

Re: Watec 902h Behind Scope - Picture Very Grainy Beyond 100

Post by Marky610 » 07 May 2013, 14:50

poppy mae wrote:With the setting in low the picture will be a lot better,but you will start to loose picture range if using your mag on the scope,depending on what ir your using,ideal for fac air and rimmy distances in the low setting,but prefer on hi,if using any great distance....just my preferences......
He's using 66mm lamp, we all get 300 yards using the same combination (a part from the scope)
Land Rovers, who would be daft enough to own one?

LancsNinja
Posts: 10
Joined: 07 Apr 2013, 16:01
Location: Lancashire

Re: Watec 902h Behind Scope - Picture Very Grainy Beyond 100

Post by LancsNinja » 07 May 2013, 17:26

Thanks for the suggestions and questions guys - much appreciated keep em rolling in... :thumbup:

2-dead-in-the-air - I am using the following lens on my spotter - as recommended elsewhere in this forum. Part code: VF-MI-5100 spec: 5-100mm Vari Focal, Manual Iris CCTV link: http://www.stockoptics.com/cctv-lenses/vf-mi.html . It produces a very clear image to a very long range, and can be zoomed to suit your needs, wide or narrow field of view.

More feedback to follow after tests tonight....

Thanks guys

Graham

2-dead-in-the-air
Posts: 69
Joined: 07 May 2012, 20:56
Location: Chippenham, Wiltshire

Re: Watec 902h Behind Scope - Picture Very Grainy Beyond 100

Post by 2-dead-in-the-air » 07 May 2013, 18:38

Thanks for info Graham on lens, I cant seem to find info or details for the Sika Stag IR, looks good.

User avatar
Marky610
Posts: 3505
Joined: 12 Jul 2012, 15:10
Location: Mid Suffolk
Contact:

Re: Watec 902h Behind Scope - Picture Very Grainy Beyond 100

Post by Marky610 » 07 May 2013, 18:46

2-dead-in-the-air wrote:Thanks for info Graham on lens, I cant seem to find info or details for the Sika Stag IR, looks good.
His email addy is in my siggy bud ;)
Land Rovers, who would be daft enough to own one?

2-dead-in-the-air
Posts: 69
Joined: 07 May 2012, 20:56
Location: Chippenham, Wiltshire

Re: Watec 902h Behind Scope - Picture Very Grainy Beyond 100

Post by 2-dead-in-the-air » 07 May 2013, 19:24

Thanks Marky610, any details on here ?

Post Reply