gundog Posted April 18, 2008 Posted April 18, 2008 Hi, looking to purchase a video level meter for optimum setting up of camera focus, anyone got any suggestions which model is best, and do they work well "are they worth the spend". thanks in advance for your input.
djandysp Posted April 19, 2008 Posted April 19, 2008 Hi, looking to purchase a video level meter for optimum setting up of camera focus, anyone got any suggestions which model is best, and do they work well "are they worth the spend". thanks in advance for your input. Weve got one at the office and tp be honest unless we get major problems dont bother, what you could do with is a lens filter kit or a welders mask glass either will do for when you focus the camera as the focal point changes on a night and if you get it slightly out of focus in daylight it will be well out in darkness
satsuma01 Posted April 19, 2008 Posted April 19, 2008 Weve got one at the office and tp be honest unless we get major problems dont bother, what you could do with is a lens filter kit or a welders mask glass either will do for when you focus the camera as the focal point changes on a night and if you get it slightly out of focus in daylight it will be well out in darkness agreed i use a welders mask glass and find this the most useful and cost effective. "If you carry your childhood with you, you never become old. Why rush to end life when happiness is in the blissfulness of childhood innocence.""We all die, the goal isn't to live forever, the goal is to create something that will." 07475071344
nikko Posted April 19, 2008 Posted April 19, 2008 Hi, looking to purchase a video level meter for optimum setting up of camera focus, anyone got any suggestions which model is best, and do they work well "are they worth the spend". thanks in advance for your input. A focus meter is required for electronically correct focussing of cameras, not a video level meter. You can get the most popular kit from here. Neutral Density filters should be used to open the iris to pre-determined amounts, which in turn can be recorded on the commissioning document as a reference, NOT welding glass. Neutral Density means it will not affect the focal length of the lens whilst you set the lens up. I did once find a chap using his photochromic spectacles to set up back focus instead of neutral density filters. Sure enough, once back in the control room the picture was blurred. He, however thought it was spot on, which it was, so long as you shared his prescription! I went up into the attic...I found a Stradavarius & a Picasso. Unfortunately..... Stradavarius couldn't paint, and Picasso made a shocking fiddle. My Facebook page...http://www.facebook.com/home.php#/profile.php?id=1279556853&ref=name
arfur mo Posted April 19, 2008 Posted April 19, 2008 i have a focus meter bought from LJD, works ok but needs a still scene, if anything moves you have to start all over. you can use a scope but tbh i find it's better to pre-focus the camera before fitting using a similar distance it will be used over, i've got a polarising filter set which fits on the lens, expensive but indispensable for day night camera's imo regs alan If you think education is difficult, try being stupid!!!!
Doktor Jon Posted April 20, 2008 Posted April 20, 2008 Neutral Density means it will not affect the focal length of the lens whilst you set the lens up. To be strictly accurate, placing a light reducing filter material in the light path of the lens won't actually alter the 'focal length' of the lens (that being a product of the lens optical construction), but poor quality filter materials can slightly alter the 'back focus' point at which the image is normally brought into sharp focus on the imager. This little bit of nit picking doesn't really make much odds to anyone installing a camera, but I thought in the interests of accuracy, it might be worth mentioning Incidentally, I also subscribe to the two polarizer filters school of light reduction techniques. By providing what is effectively a variable ND filter arrangement, it's relatively easy for an installer to set the correct degree of filtration to suit the ambient lighting conditions.
nikko Posted April 20, 2008 Posted April 20, 2008 To be strictly accurate, placing a light reducing filter material in the light path of the lens won't actually alter the 'focal length' of the lens (that being a product of the lens optical construction), but poor quality filter materials can slightly alter the 'back focus' point at which the image is normally brought into sharp focus on the imager.This little bit of nit picking doesn't really make much odds to anyone installing a camera, but I thought in the interests of accuracy, it might be worth mentioning Incidentally, I also subscribe to the two polarizer filters school of light reduction techniques. By providing what is effectively a variable ND filter arrangement, it's relatively easy for an installer to set the correct degree of filtration to suit the ambient lighting conditions. Doktor Now that's what I call a comprehensive correction. I went up into the attic...I found a Stradavarius & a Picasso. Unfortunately..... Stradavarius couldn't paint, and Picasso made a shocking fiddle. My Facebook page...http://www.facebook.com/home.php#/profile.php?id=1279556853&ref=name
arfur mo Posted April 20, 2008 Posted April 20, 2008 To be strictly accurate, placing a light reducing filter material in the light path of the lens won't actually alter the 'focal length' of the lens (that being a product of the lens optical construction), but poor quality filter materials can slightly alter the 'back focus' point at which the image is normally brought into sharp focus on the imager.This little bit of nit picking doesn't really make much odds to anyone installing a camera, but I thought in the interests of accuracy, it might be worth mentioning Incidentally, I also subscribe to the two polarizer filters school of light reduction techniques. By providing what is effectively a variable ND filter arrangement, it's relatively easy for an installer to set the correct degree of filtration to suit the ambient lighting conditions. or if possible go back at night - then at least then you can see your test monitor properly regs alan If you think education is difficult, try being stupid!!!!
totalsec Posted April 20, 2008 Posted April 20, 2008 As mentioned before, best results by far is to set up at night, all my CCTV jobs with external cams include a night set up in the price. Do you Know a good local locksmith in your area if so please let me know as i might have some work for them. Thanks.
nikko Posted April 20, 2008 Posted April 20, 2008 As mentioned before, best results by far is to set up at night, all my CCTV jobs with external cams include a night set up in the price. Some of the places I work you wouldn't want to be at night! I went up into the attic...I found a Stradavarius & a Picasso. Unfortunately..... Stradavarius couldn't paint, and Picasso made a shocking fiddle. My Facebook page...http://www.facebook.com/home.php#/profile.php?id=1279556853&ref=name
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