liveinxs 0 Posted August 20, 2011 Has anyone ever tried or attempted to focus a camera at night, when it is dark, using a IR illuminator as a source of illumination, i was thinking that it might be much easier to focus a Black and White image as opposed to a Color image...as i believe a BnW image would appear much crisper at night... Share this post Link to post Share on other sites
liveinxs 0 Posted August 20, 2011 Here is a screen shot of one of my cameras, this camera was focused just as the sun was setting... i was thinking a little more fine tuning will greatly improve the image, not that its bad now... Share this post Link to post Share on other sites
rory 0 Posted August 20, 2011 Yes in fact I normally focus with light, low light, and if there is IR i fine tune it with IR in pitch dark, and go back and forth until it is perfect. I normally do that during the day in the garage so its a controlled lighting environment. At least for wide FOVs. But be careful as there can be focus shift even with the so called IR Optimized lenses. In fact even with the fixed lenses on cheap cameras you could get it nice and crisp in IR then its out of focus in color or bright light, and vice versa. And trust me, with some cameras it will always be a little blurry at night no matter what you do. Depends on the camera and lens Share this post Link to post Share on other sites
liveinxs 0 Posted August 20, 2011 Yes in fact I normally focus with light, low light, and if there is IR i fine tune it with IR in pitch dark, and go back and forth until it is perfect.I normally do that during the day in the garage so its a controlled lighting environment. At least for wide FOVs. But be careful as there can be focus shift even with the so called IR Optimized lenses. In fact even with the fixed lenses on cheap cameras you could get it nice and crisp in IR then its out of focus in color or bright light, and vice versa. And trust me, with some cameras it will always be a little blurry at night no matter what you do. Depends on the camera and lens well the cameras i am attempting to focus are the CNB VCM-24VFs.... would you know, if that camera would be a good candidate for night time focusing?.... Share this post Link to post Share on other sites
rory 0 Posted August 20, 2011 Ahh with them, under moderately low light (so you can see the monitor clearly, eg. cloudy or early evening) flip it from Auto Iris to Electronic Iris then focus, and then put it back to Auto Iris. Share this post Link to post Share on other sites
liveinxs 0 Posted August 21, 2011 Ahh with them, under moderately low light (so you can see the monitor clearly, eg. cloudy or early evening) flip it from Auto Iris to Electronic Iris then focus, and then put it back to Auto Iris. hey Rory, i just found a article that speaks of the Auto Iris, they recommend placing a shade 5 welders filter in front of the lens when focusing, is that similar to switching from Auto Iris to Electronic Iris , that you recommend.. here is the complete article: Have you ever wondered why Auto Iris cameras seem to go out of focus at night? Many installers have had to return to the job site at night and reset the focus of a camera to solve this problem. This can be costly to your company's pocket book and reputation. There is a solution to the problem that will enable you to set the cameras focus correctly every time, day or night. Let's examine what causes the Auto Iris camera to go out of focus when the lighting level changes, as it does day to night. All lenses and Auto Iris cameras exhibit this effect to a greater or lesser degree. THE CAUSES, DEPTH OF FIELD, WHAT IS IT? All lenses have a characteristic called Depth of Field. Depth of Field is a zone in front of the lens that is in focus. It is measured as the minimum distance and maximum distance from the lens where objects are in focus. All objects inside this minimum and maximum bracket zone will be in focus. The further away you go from this bracketed "in focus zone", either toward or away from the camera the more out of focus the objects become. THE PROBLEM WITH AUTO IRIS LENSES: The Auto Iris lens has a movable aperture inside the lens that controls the amount of light allowed to pass through it. This aperture also directly controls the Depth of Field of the lens. So an Auto Iris lens will have a variable Depth of Field depending on the amount of light entering the lens. This causes the minimum and maximum bracket zone of focus to change when the lighting level changes. During the day or in bright lighting conditions the Iris is closed down to a small opening, and the Depth of Field is quite large. So called Pin Hole cameras exhibit this effect where all objects in the scene are in focus. However with movable iris cameras at night or in low lighting conditions the Iris is open wide, this causes the Depth of Field to collapse down to a smaller minimum and maximum bracketed zone of focus. An object that was inside the zone of focus during the day can be outside the zone of focus at night. THE SOLUTION: One way to set up the camera to minimize the Depth of Field problem, is to adjust cameras focus at a time when the light level is at its lowest. This may not be convenient for your installers. The best way is to use a SHADE 5 FILTER PLATE also called a #5 welders glass filter. It is the filter plate that welders look through to protect their eyes during welding operations. When you have full daylight or bright lighting conditions the filter plate is placed over the cameras lens to simulate half lighting conditions. This filter plate costs only a few dollars and should be carried by installation personnel to every job site for use with Auto Iris lenses, especially those jobs using outdoor cameras. By using the filter plate to adjust the Auto Iris, you will be centering the control range of the Auto Iris system. This will give you optimum performance from your cameras Iris control system. Hand held focus meters such as the CM-1 Camera Master are also useful in determining the maximum focus of any scene. They are more accurate than large screen monitors and much easier to take up a ladder. They display the maximum focus numerically on an LCD type display. By eliminating the subjective nature of focus setting, you will insure that all cameras will be set to their maximum focus by any installer. An understanding of Depth of Field and the proper setting requirements for Auto Iris cameras will save you time and reduce the frustration of having to return to the job site to refocus cameras. Share this post Link to post Share on other sites
SEANHAWG 1 Posted August 21, 2011 I have heard the same thing. I think that basically gives the camera the nighttime effect which prevents you from having to focus the camera at night time. Share this post Link to post Share on other sites
rory 0 Posted August 21, 2011 Yes normally you either put a filter in front or even a piece of tinted glass, or do it under low light, basically thats to open the IRIS. Thats all fine and dandy but if its dark enough to see the monitor and edges of objects good enough to focus then the Iris is already probably opened up enough - plus thats where day night lenses come in, to prevent most of the focus shift. Biggest problem IMO is seeing the monitor clear enough in the daytime sun and trying to make out the objects clear enough - eg. bright sun, the edges of objects could be too full of glare to make out, again IMO with current cameras and lenses most of the time its blurry at night is because it was never focus crisp in the day to begin with due to too much sunlight and not being able to see the monitor and edges good enough; a little off focus in the day is ALOT off focus at night regardless of the focus shift. In any event with this camera I had the issue where there was a section staying out of focus at night and could not get there at night and had no tinted glass or filter, so in the middle of the day in bright sunlight even (though i could see the monitor as its under a low eave) I switched it to Electronic Iris and low and behold the blurry area appeared - focused it clear then switched it back to AI and its fine at night now. Wont work for every camera and every application, but it worked for this VBM-24VF (same as the VCM) Share this post Link to post Share on other sites
rory 0 Posted August 21, 2011 I have heard the same thing. I think that basically gives the camera the nighttime effect which prevents you from having to focus the camera at night time. They also say to manually open the Iris up but thats ridiculous under daylight sun as it would be whiteout and could not see any objects to focus - but could open it to the point that can still see. Share this post Link to post Share on other sites
liveinxs 0 Posted August 21, 2011 Yes normally you either put a filter in front or even a piece of tinted glass, or do it under low light, basically thats to open the IRIS. Thats all fine and dandy but if its dark enough to see the monitor and edges of objects good enough to focus then the Iris is already probably opened up enough - plus thats where day night lenses come in, to prevent most of the focus shift. Biggest problem IMO is seeing the monitor clear enough in the daytime sun and trying to make out the objects clear enough - eg. bright sun, the edges of objects could be too full of glare to make out, with current cameras and lenses most of the time its blurry at night is because it was never focus crisp in the day to begin with, a little off focus in the day is ALOT off focus at night. In any event with this camera I had the issue where there was a section staying out of focus at night and could not get there at night and had no tinted glass or filter, so in the middle of the day in bright sunlight even (though i could see the monitor as its under a low eave) I switched it to Electronic Iris and low and behold the blurry area appeared - focused it clear then switched it back to AI and its fine at night now. Wont work for every camera and every application, but it worked for this VBM-24VF (same as the VCM) well the article recommends a shade 5 filter, have you ever used specifically that shade... might be worth trying, i just ordered one, i will post my results, once i get the lens... Share this post Link to post Share on other sites
rory 0 Posted August 21, 2011 well the article recommends a shade 5 filter, have you ever used specifically that shade... might be worth trying, i just ordered one, i will post my results, once i get the lens... Yes and no, it was a professional lens filter that cost me a fortune at the time, but as I could not see the monitor the filter was useless. Many of these articles online are copied from outdated information, or by people that must live in an underground dwelling. Also, try standing at the top of a 12 foot ladder with one hand focusing the lens, one hand holding the filter in front of the camera, one invisible hand trying to hold onto the ladder incase you loose balance as the wind sways the ladder, and the other invisible hand trying to hold the monitor or manouver to see a monitor mounted on the ladder or arm while trying to do all of that ... makes you wonder if these folks that write these articles ever been out on a job site If this is a wide FOV and you have a big enough garage, then just go in there and focus it on some objects within 25', turn light down low (eg turn off light and let some light through a door), focus it like that, then double check the focus through the entire image (edges and center), and also with full light. Wide angle FOV so you can put it back up and be done with it. Share this post Link to post Share on other sites
liveinxs 0 Posted August 21, 2011 well the article recommends a shade 5 filter, have you ever used specifically that shade... might be worth trying, i just ordered one, i will post my results, once i get the lens... Yes, but as I could not see the monitor the filter was useless. Many of these articles online are copied from outdated information, or by people that must live in an underground dwelling. Also, try standing at the top of a 12 foot ladder with one hand focusing the lens, one hand holding the filter in front of the camera, one invisible hand trying to hold onto the ladder incase you loose balance as the wind sways the ladder, and the other invisible hand trying to hold the monitor or manouver to see a monitor mounted on the ladder or arm while trying to do all of that ... makes you wonder if these folks that write these articles ever been out on a job site well the article i reference is from the following site: http://www.fmsystems-inc.com/ as far as not having enough hands, you only need two, the way i see it is , hang LCD from gutter , one hang on filter and the other focusing camera, and a good old firemens leg lock on ladder, i did that dozens of times as a firefighter, swinging away with an axe...never had any stability issues...footing the ladder properly reduces any stability problems.... Share this post Link to post Share on other sites
liveinxs 0 Posted August 21, 2011 just in case your not familiar with the leg lock, its applied as in the following picture... Share this post Link to post Share on other sites
rory 0 Posted August 21, 2011 well the article i reference is from the following site: http://www.fmsystems-inc.com/ as far as not having enough hands, you only need two, the way i see it is , hang LCD from gutter , one hang on filter and the other focusing camera, and a good old firemens leg lock on ladder, i did that dozens of times as a firefighter, swinging away with an axe...never had any stability issues...footing the ladder properly reduces any stability problems.... Yes well to begin with they are trying to sell their $700 focus meter. Secondly, gutter and eaves dont exist with every camera install and when its nothing but a 10 foot drop to concrete below its hard to take those chances on such small paying jobs, especially when we are dealing with consumer ladders on unstable ground, not to mention heavy wind, bright sun, 100 degree temps and mosquitos carrying deadly viruses. Share this post Link to post Share on other sites
rory 0 Posted August 21, 2011 Thats great but then when the ladder tips over you are going straight down with it! BTW thats not the type of ladder I typically use, remember these arent being mounted more than 13' high in most cases. When I go up 25' its normally in a cage on a forklift. And imagine how much time is spent locking and unlocking your leg in as you go up down up down up down the ladder as we do when working with cameras ... ill try the leg lock on my 8' ladder though and see how it works out just in case your not familiar with the leg lock, its applied as in the following picture... Share this post Link to post Share on other sites
liveinxs 0 Posted August 21, 2011 Thats great but then when the ladder tips over you are going straight down with it! BTW thats not the type of ladder I typically use, remember these arent being mounted more than 13' high in most cases. When I go up 25' its normally in a cage on a forklift. just in case your not familiar with the leg lock, its applied as in the following picture... well in 22 years of firefighting, i have never had any issues with a ladder falling, if its footed properly, you could also tie it off at the top to alleviate any worries... 25' thats nothing, now 100' thats fun, especially when the wind blows your way, hold on..... Share this post Link to post Share on other sites
rory 0 Posted August 21, 2011 well in 22 years of firefighting, i have never had any issues with a ladder falling, if its footed properly, you could also tie it off at the top to alleviate any worries... 25' thats nothing, now 100' thats fun, especially when the wind blows your way, hold on..... do you use the same ladders we use? 100'? nah ill just hire you to mount the camera then Share this post Link to post Share on other sites
liveinxs 0 Posted August 26, 2011 well, i started to think about what Rory had said, about holding the Filter with one hand while trying to adjust the camera with the other hand, and not being able to stabilize yourself and keep yourself from falling off ladder, so i was set in finding a way to remove the holding of the lens from the equation... i had to figure a way to attach a 50mm shade 5 glass Filter lens to a focus sleeve that was approx 28mm, i knew i didn't want any screw type attachment or something heavy... this is what i came up with, first thing i did was to measure the size of the lens sleeve that had to be rotated to set focus, after have that i came up with the following homemade tool... i purchased 3 Rubber O-Rings and what is called a Lavatory Pop-Up Drain Gasket, the O-Rings provided a slightly snug fit to the focus sleeve and the Pop-Up Drain was the exact dimension of the Shade 5 Filter.. i then crazy glued the 3 O-Rings together in a pancake manner and then glued the O-Rings to the Pop-Up Drain, as seen it the photos, and then taped the Filter to the front of the Pop-Up Drain, i didn't glue it , in case i had to remove for cleaning... all the parts cost me 2.47.... after i was done , i test fitted it to the camera and it was a perfect fit... i did use it to focus one of the cameras as a test and it worked flawlessly... attached are the photos of the items and the completed filter adapter.... Share this post Link to post Share on other sites
