(Last Updated On: January 10, 2020)
This is the Chapter 3: Television Cameras end chapter exercise in Basic Television – Grob TV as one of the Electronics Engineering topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Exam Questions in Electronics Engineering field, Electronics Books, Journals and other Electronics References.
Start Grob TV End Chapter Exercise 03
Answers are Underlined
- a. The lens inverts the optical image on the faceplate of the camera tube.
- b. The composite video signal includes the camera signal, signal and blanking.
- c. The standard composite video signal from a camera is 1 Vp-p with negative sync.
- a. The diameter of the vidicon image plate is about 2/3, 1 or 1.2 inch.
- b. The plumbicon camera tube uses a lead-oxide target plate.
- a. The signal variations are produced by the target plate.
- b. The photoconductive layer have less resistance with increasing light.
- c. The dark current is checked when the lens cap is on.
- d. Image lag is a problem of the target plate.
- a. The target of the Saticon is not constructed in the same way as that of the Plumbicon.
- b. The use of bias lighting in Saticon reduces the image lag.
- a. The typical target voltage is more than 50 V.
- b. Beam alignment is similar to centering of the electron beam.
- a. Dichroic mirrors are more efficient than optical filters for separating red, green, and blue light.
- b. Dynamic Shading corrects for optical effects in the light splitter.
- c. Static shading corrects for non-uniform dark currents.
- d. White balance is necessary for color cameras.
- a. The gamma required for the camera tube is 0.4545.
- b. Gamma correction is more important for color TV.
- c. White is stretched by the picture tube.
- a. The horizontal scanning with and the linearity affect the color video signal in single-tube color pick-up.
- a. The SEG can also be used as production switcher.
- b. CVBS means composite video, burst and sync.
- c. Commercial movie film is run at 24 film frames per second for TV.
- d. Gen-Lock is used to synchronize multiple cameras.
- a. A low f stop rating allow more light.
- b. The depth-of-field is improved with a higher f stop.
- c. To how many lux units is the illumination of 3 fc approximately equal? 30 lux
Fill in the blanks
1. Plumbicon is a camera tube that uses a lead oxide (PbO) for the photoconductive target plate.
2. Camera signal output without sync is called non-composite video.
3. A low-contrast picture in which white seems flat and lacking in detail suggests a low beam current.
4. A Plumbicon is a camera tube that has a minimum lag.
5. The part of the invisible spectrum where camera pickup tubes have the greatest output is the yellow-green.
6. Precise scanning size and linearity are most important in a single-tube color pickup.
7. Beam alignment magnets for the camera tube are adjusted while rocking which control the electrical focus.
8. Special effects and production switching are done by the SEG.
9. The gamma of the picture tube is 2.2.
10. If the camera cannot be placed far away enough to include everything in the scene, change the lens to one with a shorter focal length.
11. A typical value of vidicon dark current is 0.2 µA.
12. A lens has an 8-cm focal length and 4-cm diameter. Its f rating is 2.