Torch pattern at ??? distance?

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ray1377
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Joined: 05 Jul 2016, 02:28
Location: Across The Pond

Torch pattern at ??? distance?

Post by ray1377 » 10 Feb 2018, 03:41

Hi All
Hope this question isn't goofy or stupid.
Just been thinking lately about building my own handheld IR spotter and was curious if there is a way
to tell what your "field of view" would be with certain torches used in conjunction with certain cameras.
I would like to know how wide your beam would be in meters at say 100 meters distance?
I'm assuming from what I've read that 850nm would suit my airgun needs better than 940.
Could any of you suggest a camera/IR torch combo that would work well together at ranges out to at least 100 meters?
Would it be possible to make a spotter out of a vehicle back up camera and screen if it had the ability to see in IR?
I have seen lots of youtube video's on building homemade spotters but was curious what you fellows might suggest since
you seem to be the resident experts.
Thanks
Ray

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some bloke
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Joined: 27 Jan 2012, 16:14
Location: Cornwall or Leicester

Re: Torch pattern at ??? distance?

Post by some bloke » 10 Feb 2018, 12:25

Hi Ray - welcome to the forum.

Although a spotter lets in more light than a scope lets get to a camera sensor I doubt many on here would recomend you cheap out on a gash reversing camera thats going to rely on reversing lights to operate at night.

My advice is to build your spotter with the best foundations possible - An 'E700PUB12 - IR removed' camera costs more but is a very good invstment - from the SURE24 forum sponsors on top of the page - dunno about US suppliers. The extra quality performance will often allow you to use the spotter without an illuminator to be much more covert. I can't find a link to it on their website but here's their ebay item with the options already selected: https://www.ebay.co.uk/itm/NIGHT-VISION ... 2749.l2649

The torches we generally use have a zoom function if you twist the head, and three power modes if you half click the tail cap switch.
A ready to fit integrated torch build is going to need a lathe to cut and thread it so you might prefer to use a bolt on complete torch which simplifies the build but makes it top heavier.
A very capable torch from another forum sponsor is this one: http://www.nightvisionstore.co.uk/black ... 2x17313901

Most of those in the know will use a 50mm prime lens because the typical ebay cctv zoom lenses are a pain in the butt and require constant fiddling with every time you change the spotting range. Thus we mostly use F1.4 CINE/TV C mount lenses as linked to below.

https://www.ebay.co.uk/sch/i.html?_odkw ... +&_sacat=0

There are of course cheaper alternatives from China - I don't use them so can't recommend them - but you came to a place that generally uses the best that can be got from vendors that have an established reputation on here for a build that is going to perform extremely well. :angel:
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ray1377
Posts: 2
Joined: 05 Jul 2016, 02:28
Location: Across The Pond

Re: Torch pattern at ??? distance?

Post by ray1377 » 10 Feb 2018, 16:40

Thanks Bloke

I appreciate your input and honesty.
And yes, really no need in buying cheap and end up unsatisfied with the end results.
I notice most of your links are to UK ebay.
I wonder if I could do a US ebay search and find the same things? Or something comparable to them?
I understand about the adjustable focus and power of the torches you use.
The only thing that is still foggy to me is the lenses you speak of.
Will the 50mm lens fit directly to a 700 camera you suggested or will it need an adapter?
Thanks so much for your help.
Ray

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some bloke
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Joined: 27 Jan 2012, 16:14
Location: Cornwall or Leicester

Re: Torch pattern at ??? distance?

Post by some bloke » 10 Feb 2018, 17:13

ray1377 wrote:Thanks Bloke

I appreciate your input and honesty.
And yes, really no need in buying cheap and end up unsatisfied with the end results.
I notice most of your links are to UK ebay.
I wonder if I could do a US ebay search and find the same things? Or something comparable to them?
I understand about the adjustable focus and power of the torches you use.
The only thing that is still foggy to me is the lenses you speak of.
Will the 50mm lens fit directly to a 700 camera you suggested or will it need an adapter?
Thanks so much for your help.
Ray
There are M12 to C mount adaptors on ebay but I have no personal knowledge if they will get the back focus length you need, but they are not especially a durable mounting method.

The one's I KNOW will suit are custom made for me with very a solid fitting - here:
http://nightvisionforumuk.com/viewtopic ... rs#p146419

I'd be happy to post it to Clive from Night Vision Store for him to ship with his torch to you - and maybe he'd do the same with an E700 from sure24 if you asked him pretty please like. 8-) ( the torch being the biggest and heaviest item.
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