Is there a device to see (measure) the view of Lenses?

[jjjjjjj 0]

Being fairly new to the CCTV field, I don't yet have the experience to go to a customers site and say, "You should get a camera with a x lens here and a camera with a x lens over there"

I don't know what lens type/size would look like from any given point.

It would be great if there was a camera or device that would show you what would be seen from a mounted point.

Any www links or general rules of thumb would be appreciated.

Thank you in advance.

[rory 0]

Hi,its called a view finder. Its almost become obselete with the introduction of Varifocal lenses, though it is still very useful.

 

Rory

[bryan1656 0]

The old fashion way is to do your own math.

 

Angle of view is a whole thing that makes my head hurt - maybe someone else will take a swing that is better at the cipherin'.

 

Here's what I use for basic lens selection - others may use something slightly different.

 

(value for CCD size) x Distance in feet

-------------------------------------------

(Width of desired target FOV)

 

values for ccd size

 

1/4 = 3.1

1/3 = 4.4

1/2 = 6.2

1 = 12.7

 

So, using a 1/3" CCD to get a 10 foot wide FOV for a camera 20 feet away, it would be 3.1 x 20 divided by 10. Then round to nerest focal length.

 

The other way is to use online lens calculators which will give you your specs based on CCD size, desired FOV, etc. (example below, not an endorsement or recommendation for the vendor.)

http://www.thermosight.com/LensCalculations.htm

 

You can also use a lens selector. I'd really like to get one of these, but I'll keep doing without for the time being. (Below is offered just as an example, not an endorsement or recommendation)

http://www.scdlink.com/shop/shopexd.asp?id=1628

 

 

I also want to get a program called LensCalc with looks like it offers some NICE features. Haven't gotten it yet, though as it's around $100 USD. (Again, just passing on the info. Not an endorsement or recommendation.)

http://www.cctvconsultant.co.uk/index.htm?http://www.cctvconsultant.co.uk/lenscalc/form.htm

 

HTH YMMV

[rory 0]

Anyway, no need for any lens calculators, just use one of these:

Ive never had to use a calculator except for my quotes

 

http://www.securityideasvar.com/index.asp?PageAction=VIEWPROD&ProdID=585

[Thomas 0]

I found a nice little palm program to do the lens caluations. pCAM it's called. You should be able to find it in google.

[DataAve 0]

Is there a device to see (measure) the view of Lenses?

Yep, an experienced Technician.

[bryan1656 0]

Holy binary code Bat Man!!!! a lens calculator for palm!!!!!

 

Thomas YOU ARE THE MAN!!!!!

 

I'll report back with a link if I can find it.

[bryan1656 0]

WOO HOO!! (Bow Chicka Bow-Bow!!)

 

pCAM

$15 Shareware!!

http://www.davideubank.com/

 

I'll have to wait till tomorrow to download and hotsynch it, but this looks like the Bee's Knees!!![/i]

[rory 0]

I still dont see the point ..

[AVCONSULTING 0]

Even with Vari-Focals this is a handy device to have and it makes you look more professional on a job walk.

 

http://www.cbcamerica.com/cctvprod/computar/access/access_pdf/VM300.PDF

 

http://www.cbcamerica.com/images/computar/access/VM300.jpg

[rory 0]

Even with Vari-Focals this is a handy device to have and it makes you look more professional on a job walk.

 

http://www.cbcamerica.com/cctvprod/computar/access/access_pdf/VM300.PDF

 

http://www.cbcamerica.com/images/computar/access/VM300.jpg

 

thats what i got Its all you ever need.

[VJD 0]

I use the VM300 too. Clients are always impressed when I pull it out during a walk through. Wait, that didn't sound right.

 

Another benefit is that you can show them exactly what the field of view will look like.

[rory 0]

yeah ..yah pull it out on a walkthrough huh!! LOL

 

Anyway, yeah it helps with identifying which lens you need, even if you are using a varifocal lens you will know what range you need.

[Integratek 0]

THOMAS !!!!!!

You are THE MAN indeed !!!

this is most useful piece of software i've found in last 10 years !!!

i'd even buy it !!!!

[Thomas 0]

I find it a bit easier to work with then the lens wheels.

[cctv_down_under 0]

yep ur almost the man Thomas, PM me a serial and then you are LOL...just kidding of course!!!

 

I will check it out, sounds interesting

[bryan1656 0]

I'll add that one of the handier things I use is a lightmeter. Mine is on old analog that I got used/cheap back when I did alot of still photography. It doesn't measure lux, only footcandles, so I have to do a conversion.

 

footcandles x 10.76 = lux

 

It's pretty handy for checking lighting conditions in various places, such as shadows, etc. - take some readings and do the math to come of with a scene average, high, and low.

 

I know it is probably a little overkill as far as most CCTV installs go, but I like it. Maybe it is just the old photographer in me.... I just like doing it

 

oh yeah... and a tape measure!

[qman 0]

WOW!!!!

 

ALL HAIL TO THOMAS!!!

 

[rory 0]

dont forget a good sharp machete for the ghetto areas .. or a gun if your in the US, we cant carry them 'ere mon

 

a couple empty bottles always good to have on hand too ..

[Thomas 0]

Okay, before the praise turns to anger, I have found one quirk of the software. It won't handle long ranges. So you can't figure 500mm lenses.

[rory 0]

it only works on Palm OS?? Do people still use those?

[Thomas 0]

Yep, my palm holds my address book and a few small apps. It's simple and it works.

[rory 0]

have you ever tried the PDA wrist watch ..?

[Thomas 0]

The Timex that synced up to a PC via screen flicker? Yep, still perfer my palm. My next watch will be this one: http://www.thinkgeek.com/gadgets/watches/5eec/

[rory 0]

No, not the Timex, I have one of them, plus I have the one that turns my alarm on and off etc.

 

Here are a couple: These arent exactly new but still neat:

 

Fossil PDA Watch

http://www.the-gadgeteer.com/fossil-pda-watches-review.html

http://wristpda.beiks.com/

 

Web Anywhere Watch:

http://www.webanywherewatch.com

 

Watch 2 way radios:

http://www.xactcommunication.com/Wristlinx-9/

 

Casio has some cool Databank Watches:

http://www.casio.com/index.cfm?fuseaction=products.section&catalog=Watches&section=DataBank

 

Not a watch but cool:

http://www.tiqit.com/prodoverview.shtml

 

And dis what I gots:

http://www.ademco.com/ademco/products/wireless/5804Watch.htm