Interview Questions.

Q1. How Do I Back Focus A Camera Fitted With A Zoom Lens?

This can be performed by means of following these steps:

Set the lens to complete huge angle view.

Set the physical recognition of the lens to infinity (clockwise considered from the the front).

Aim the digicam at an object at least 30 Meters away.

Release the digital camera returned cognizance mechanism.

Adjust the returned cognizance to reap gold standard readability.

Zoom the lens in to full telephoto and awareness on a close-by object.

Keep this object in view as you slowly zoom out and if all is set efficiently it need to continue to be in consciousness (tune).

Secure the lower back attention mechanism.

Q2. Which Pan And Tilt Unit Should I Use?

The desire is huge and varied depending on the machine necessities. You may require Top mount, Side mount, 230V AC or 24V DC to call only a few.

TOP MOUNT:

Pro: Can match  IR lamps on the facet of the Pan/Tilt. These act as a counter balance enabling you to apply a lighter obligation Pan/Tilt head.

Pro: Compact length.

Con: Restricted tilt regularly -45 to zero depending on the housing geared up.

Con: Cannot be inverted.

SIDE MOUNT:

Pro: Can be inverted.

Pro: Often inexpensive.

Pro: Large tilt frequently +or- one hundred eighty

Con: Difficult to mount IR lamps.

Con: Generally big length.

Q3. What Is Video Termination?

This is the cease of line resistance of any CCTV system and this ought to be set to seventy five ohm. Should you come upon any double photograph or ghosting that is extra often than now not caused by two portions of equipment in collection both having the 75-ohm switch set on. Only the last piece of system need to be set at 75-ohm.

Q4. Can I Use I/r Lamps With Color Cameras?

The wer to this is a definitive NO. Color cameras are commonly equipped with an IR reduce clear out and could now not allow IR light in extra of 700Nm to skip ensuing in the digital camera appearing poorly in those circumstances.

Q5. What Type Of Illumination Can I Use With Color Cameras?

Only lighting fixtures in the seen wavelength need to be used with colour cameras. Tungsten Halogen is regularly the recommended source of lights.

Q6. What Are Osd Cameras?

OSD (On Screen Display) cameras have a menu gadget inside the digital camera assembly that may be accessed if you want to set capabilities inclusive of Iris ranges, AGC on/off and maximum functions of popular and superior cameras.

Q7. When Can I Use A Manual Iris Lens?

A popular rule of thumb is best to apply a MI lens in an inner application. This is because you are reliant on the digital circuitry of the digital camera compensating for mild modifications inside the scene and this isn't able to compensate to the same diploma as that of an Auto Iris lens.

Q8. What Is The Difference Between Auto Iris And Direct Drive Lenses?

An Auto Iris lens is one which routinely adjusts its iris for modifications in the scene lighting tiers. The motor that opens and closes the iris is pushed by using an Amplifier that approaches a small digital signal converting with the mild degree.

A Direct Drive 'DD' lens does now not have this Amplifier and might most effective operate with a digital camera equipped with one.

A digicam specification will indicate the to be had output options.

Q9. How Do I Back Focus A Camera Fitted With A Fixed Focal Length Lens?

This is executed via following 5 easy steps:

Set the bodily consciousness of the lens to infinity (clockwise from the front).

Aim the digicam on the issue to be considered.

Release the camera back consciousness mechanism.

Adjust the lower back focus to attain the quality viable photo.

Secure the cameras lower back attention mechanism.

Q10. What Size Monitor Should I Be Using?

The correct size display is depending on its use e.G. The number of pix to be displayed at any given time, the viewing distance and the to be had area.

Q11. How Can I Eliminate Ground Loop Faults?

This can be accomplished in a number of ways, the easiest of that is the set up of a Ground Loop Isolation Trformer. This is nice installed on the monitor or recording cease of the gadget.

Q12. How Do I Set Up A Camera And Lens For Use In Low Light Conditions And Or With Infra Red Lighting?

When putting the back cognizance of a Color camera for low mild conditions you must vicinity an ND1 (Neutral Density) filter out in the front of the lens. When setting the again recognition of a Mono digicam for low mild conditions you ought to vicinity an ND3 (Neutral Density) filter in front of the lens. When placing the lower back recognition of a Mono digicam geared up with I/R lights for low mild conditions you ought to vicinity an IRP (Infra- Red Pass) clear out in the front of the lens.

Q13. What Camera Housing Should I Use And At What Ip Rating?

Camera housings come in numerous styles and sizes. With regard to the correct IP rating protection, this will variety from dirt and water ingress. This system is ruled via a number of European and British standards.

IP55:

Protected towards dirt - constrained ingress.

Protection towards low-pressure jets of water from all guidelines - restricted ingress approved.

IP655:

Protection against low stress jets of water from all guidelines - constrained ingress Permitted.

Q14. How Do I Choose The Correct Camera For My Application?

This in preferred is a comparatively difficult choice. Many factors of the set up should be considered in order to achieve the proper overall performance that meets your requirements.

A high-resolution digicam ought to be taken into consideration where greater element of scene is needed. E.G. Color 460 TVL, Monochrome 570 TVL. Choosing a more sensitive digicam will improve duplicate in poorly lit regions. The sensitivity of a digital camera is indicated with the aid of the minimal quantity of mild so as for the digicam to provide a usable photograph. E.G. Color 1.Zero Lux at F1.@

A conventional digital camera produces a faded backdrop when an object is shot towards a shiny heritage. BLC (Back Light Compensation) will counter robust light assets maintaining photograph fine.

Concentrated light assets directed towards the camera (e.G. Car head lamps) can be inverted via an non-compulsory peak white inverter or an eclipse characteristic. This has the effect of bringing element to regions and making an object clear, that might otherwise be shadowed.

Q15. What Is The Difference Between Simplex And Duplex Multiplexers?

Video multiplexers are designed to allow recording of several cameras onto one recorder.

Simplex: 

A simplex machine is exceptional acceptable to packages in which recording simplest is the concern. Simplex machines cannot show multi display screen pix (i.E. Quad, 9 manner and 16 manner break up) at the same time as inside the file mode.

Duplex:

If an operator is tracking the system (i.E. Safety guard) then a duplex device is more appropriate. A duplex gadget can offer screen splits and user selectable pics with out affecting what is recorded onto the recorder. Should you use  recorders, it turns into feasible to record and playback concurrently.

Q16. Does The 'f' Stop Matter When Choosing A Lens?

Yes, lenses are generally distinctive as having a minimum and most 'f' forestall score; the 'f' forestall is a measure of how correctly the lens permits mild from the scene, to pass through the lens and onto the digital camera CCD sensor. The maximum aperture (while the lens is completely open), is the minimal 'f' forestall range and the minimal aperture, (simply before the lens absolutely closes) is the most 'f' prevent wide variety.

A low minimal 'f' stop wide variety me that the lens can bypass more light thru at some stage in dark situations, so as to produce higher pics at night time.

A high maximum 'f' stop quantity can be necessary wherein there's a high stage of light or mirrored image. This will prevent the camera ‘whiting out’.

Q17. Manual Or Auto Iris Lens?

The iris is the part of the lens that determines how plenty mild falls upon the camera CCD sensor.

The Manual Iris 'MI' lens has this constant on the time of set up. As the mild stages alternate within the scene, the lens can do nothing to prevent both too little or too much light getting into the camera. Virtually all cameras appoint an Automatic Electronic Shutter 'AES' to make amends for these versions when geared up with an MI lens. However they may be simplest able to address a noticeably small trade in light levels.

An MI lens should by no means be utilized in an external state of affairs, as the digital camera may be not able to cope with big changes in mild tiers. Use an Auto Iris ‘AI’ lens in this situation, or in which huge scene illumination modifications take vicinity.

The advent of recent sensor technology inclusive of PIXIM may also result in a alternate to this case within the future.

Q18. What's The Difference Between Hardware Compression And Software Compression?

Hardware Compression: Both Capturing Video Signal and Compressing Video Signal are executed through DSP chipset integrated on DVR Board. It doesn't need the pc's CPU to try this paintings. It's low cost of CPU and RAM assets. In this gadget the laptop CPU's mission cognizance on wering community request, streaming the video/audio to community and saving recorded records to nearby hard disk.

Software Compression: The DVR Board simplest seize video sign however doesn't compress it, it is the computer CPU and RAM to do this compression work. It's high price of CPU and RAM sources. In this machine the computer CPU and RAM are frequently overloaded. It is simpler to crash than hardware compression system.

Q19. What Is A Ground Loop?

An AC contemporary that can be produced in a cable. This is usually because of components of the device being fed from different electrical assets resulting in different earth potentials at every end. The end result is interference at the sign, typically within the form of dark bands across the screen and every now and then tearing within the top third of the image.

Q20. Do I Have To Use A Regulated Power Supply?

In wellknown the wer is yes. Most producers will recommend the use of such power substances as widespread with their device. You ought to always consult the manufacturer’s specs prior to the relationship of any strength supply.

Q21. What Is The Correct Level For A Video Picture?

The correct level is 1 volt top to top. This can simplest be correctly set either with an oscilloscope or with a video degree meter.

Q22. How Do I Connect An Auto Iris Lens To A Camera?

This is generally done by means of a easy plug-in connection to the rear or side of the camera. However you ought to continually seek advice from the applicable digicam guide.

Q23. How Do I Set Up An Auto Iris Lens?

An Auto Iris lens has  'pots' on the facet normally marked ALC (Automatic stage control) and LEVEL.

The ALC manage has settings of PEAK and AVERAGE (P+A).

The LEVEL manage has HIGH and LOW settings 'H+L'.

ALC:

The adjustment permits manage over any vibrant areas in the scene e.G. Solar reflection thru windows, avenue lighting etc. There are  settings PEAK and AVERAGE.

If set to PEAK, vivid areas inside the scene are taken under consideration more, decreasing the comparison inside the surrounding location. This lets in extra element to be seen in the shiny regions.

If set to AVERAGE the lens takes the intense regions less into account which generally causes over brightness or flare in these areas, however elevating the evaluation of the surrounding place.

LEVEL:

The handiest accurate way to set the VIDEO LEVEL is via the use of an oscilloscope, for maximum Engineers this is not an option.

A extra realistic technique is to apply a provider take a look at display and a camera that you know has been set up successfully to at least one volt top to top.

Put the video output from this examined digital camera into the check display and modify the assessment and brightness until you are happy with the picture. Mark the contrast and brightness controls so you can set them to this position again.

Set up each digital camera adjusting the ALC (as above) then adjusting the LEVEL to attain a photo similar to that accomplished with the take a look at digital camera. (Making sure that your check monitor is ready in your marked positions)

NB: On most zoom lenses the ALC adjustment is a speed manage for the Iris motor and is satisfactory left within the mid function. The Amplifiers on Auto Iris lenses are sensitive; so adjust the LEVEL and ALC with a proper trimming device in preference to an normal screwdriver, which could result in small voltages.

Q24. What Is The Maximum Distance I Can Run 12vdc When Powering A Camera?

This is a commonly asked question and there is no easy wer. Some producers may propose that their cameras can be run over (X) distance with (Y) cable. This but need to nonetheless be taken into consideration as a fashionable manual. Cable conductor size and installation course should also be taken into consideration. If you are unsure, we might recommend that you contact Technical Support for steering.

Q25. Why Do I Have A Clear Sharp Picture During The Day And It Is Out Of Focus At Night?

This is because of the intensity of area converting as the mild situations exchange and can be without problems conquer via following set approaches.