Looking for a field of view monocular

[bike_rider 0]

I was kicking around the web a few days ago and I saw a device that helps you to know what lens length you need. You look through the device, zoom as far as you need and then read the scale on the outside. It would tell you what length lens you need, adjusted for sensor size.

 

Does anyone know who makes this and where I can find it?

 

Thanks.

[scorpion 0]

Are you an installer in the business?

Are you just a home owner who loves to tinker?

 

If you are a home owner who loves to tinker then I would say it is not worth the expense.

 

I paid about $250 for mine. I have done so many installs that I can tell what lens size I need without using this device.

 

I would rather take a 220X zoom camera, and hook it up to a monitor, and have the customer tell me what they want to see as we zoom in, and out.

 

I would buy this before I buy the lens selector.

 

In all honesty, I give the lens selector to the customer, and let them play around, and I am pretty close 9 out of ten times for what they wanted. When I am off it is usually the customer who missunderstands what they need.

 

Some people want to see the whole yard left, to right. A wide angle lens distorts the distance. There is no way you can watch your mailbox at the street, and get facial recognition with a wide angle lens at 50 feet.

 

We charge $100 to go out to a customers house to do a site survey. We give this value back when they buy a system. This covers our gas, and time. The lens selector helps in justifying the expense from the customers point of view.

______________________________________________________

 

To those that are reading this thread, and you are starting in the business go and buy a mini camera that is one inch by one inch. Now go and buy the various lens, 2.8mm 3.8mm, 4mm, 6mm, 9mm, and swap these back, and forth until you learn how these lens work.

 

Watch the video. The wider the picture, the further something at 20 feet will look farther away in the video.

 

A 6mm lens will not have this distortion, but you sacrifice the peripheral view.

 

9mm will get you close up on a sliding glass door if your customer is worried about young men sneaking in to meet your daughter!

[VJD 0]

Computar VM300

[rory 0]

Its useful but mostly for installers. Either way VJD posted the model. And scorp, I got mine foe free .. second hand

[bike_rider 0]

Thanks guys. That's the one.

 

I'm the neighborhood camera "expert". My neighborhood is taking a very proactive approach to fighting a growing crime problem. A couple of us already have systems and several more will probably add systems in the next few months. Nobody is likely to pay somebody to install a system for them, so this may help them avoid bad lens decisions.

[scorpion 0]

Get a 13 inch color tv with a composit input.

 

You can use a wall wart power supply, and an extension cord. You can use a premade cable plugged in to the tv, and you can run the wire to a camera. Now stand on a ladder, and point the camera in the direction that you are looking for. Looking at the TV, what you see is what you get. No guessing involved!

 

If you are using a TV that you have in your closet, and you are having problems getting the video from the yellow connector then try some of these tips here. Just scroll down to the TV part.

 

http://www.cctvforum.com/cms_view_article.php?aid=41

[rory 0]

cant see anything on a TV out in this sun

[bike_rider 0]

Thanks.

 

I'm just looking at all my options. I may just end up using my 100' tape measure and one of the many on line field-of-view calcs.