L/H or Level Adjustment:
The L/H level is a gain adjustment on the back of a security camera. It should be used to adjust the camera for the best acceptable brightness. This is normally only an issue in a situation where the CCTV camera’s power cable’s length has reached a point where the voltage to the camera has dropped off due to resistance in the cable. This is a very touchy control, and if you set it towards the low setting the camera could lose power and go completely out. This will not damage the camera, just adjust back towards a high setting and it should come back online.
We tested this in our shop with an auto iris lens on the camera. Whenever we made changes to the setting we would see changes in the image quality but could not see anything definitive as to what it was doing. Our senior installer says whenever we made a change the auto iris would try to correct it which follows what the manufacturer says about the setting. We later tested this with a manual iris and saw small differences in the brightness of the image. Our senior installer says he has used this in the field and the only time he has seen it make any difference is when security cameras are ran 200’ or more from their power source.
#1 by CSH on October 22, 2009 - 5:15 am
Thanks
#2 by Jeff D on October 22, 2009 - 7:43 am
I can’t help but notice the other switches on this camera. Could you guys explain what these do?
#3 by joeltjen on October 22, 2009 - 10:59 am
We are continuously updating our CCTV Glossary Category to include as many detailed explanations of CCTV adjustments and products as possible.
We will hopefully soon be transferring this to an actual glossary page, also, so please keep an eye out for more info in latter posts.
#4 by Todd on October 22, 2009 - 2:49 pm
Good to see decent descriptions of tiny, (otherwise) cryptically labeled switches and dials like these.
#5 by Jimmy on October 23, 2009 - 11:24 am
Your blog is very help I wil use it for more help in the future. Keep up the good work and thanks for adding stuff all the time.
Thank you apexcctv.com you guy have been a big help.
#6 by JimBob on October 23, 2009 - 5:11 pm
Thanks for all the information you give here on your blog. It is very helpful to those of us that are just learning about CCTV systems!
#7 by Sameer on October 23, 2009 - 5:24 pm
I have known this L/H to be the lens iris adjustment. It comes in handy when trying to maximize the lens capabilities. Thank you for the mention to this.