Precautionary Items

4.5 Precautionary Items

Observe the following precautions when operating the electronic shutter.

-The CCD for this camera uses the frame transfer method. At shutter speeds of 1/500, 1/1000, and 1/1500 second, the exposure period and the transfer period conflict with the readout period. There is black output from the line count, which conforms to the shutter speed; the image output fol- lows. Thus the lower part of the image output cannot be output onto the screen to the degree of the line count of the black output. Figure 4±5 shows what occurs. Table 4±1 lists the line counts for each shutter speed.

Figure 4±5. Exposure and Transfer Period Conflict With Readout Period

Screen

The line count conforming to the shutter speed outputs black

The lower part of the image cannot output to the extent of the line count conforming to the shutter speed.

Table 4±1. Line Table Corresponding to Shutter Speeds

Shutter Speed

MC-7890PIA

MC-780PIH

 

 

 

1/500

22

19

1/750

13

11

1/1000

6

3

1/1500

2

±

 

 

 

-Due to the circumstances noted above, during random shutter, when there is no shutter trigger input, the camera will be in continuous shutter mode. Consequently the bottom part of the image is not shown for shutter speeds of 1/500 through 1/1500 second. Images shot with random shutter have a full image output without the bottom part eliminated. Thus the image ap- pears to flicker because the positions shown on the monitor differ.

-When a timed exposure is made of over 1/60 second operating in VI mode, impurities on the CCD may become exaggerated. Also, due to the occur- rence of dark current, the image may be rough. The image quality of timed exposures is uncertain.

-Use non-interlace scanning when in random shutter and VI modes.

4-6

Using the Shutter Modes

Page 32
Image 32
Texas Instruments MC-780PIx manual Precautionary Items, ±1. Line Table Corresponding to Shutter Speeds