Nikon COOLSCAN V ED - AF (Autofocus) operation

VRA53801-R.3609.A
- M10 ･ -
LS-50
・IA-20(S)
The inner motor of IA advances frames, and the image is obtained through scanning by the body
(scanner). The scanner scans with the mechanical block unit moving backward and forward, but
as for frames that were scanned only with its moving forward, the reversal process is performed
by the driver software.
Resolution: 90dpi (Pitch 44)
Averaging: ON（8-pixel average in the main scanning direction)
AF position: is set when outputting thumbnail or set to the latest AF address in the past
(224 address when AF is not performed)
Thumbnail can be automatically performed by detecting the insertion of lms.
2.16 AF
The scanning range is 3.75-mm in total (set value), covering 2-mm downwards and 1.75mm
upwards from the alignment reference position.
When the AF scan is performed, the maximum position of contrast is calculated at a designated
point. Then, comparing with data near the designated point, the maximum position is decided.
If the contrast cannot be calculated, it is retried by changing the illumination LED of AF.
The illumination LED of AF should be No.1:B / No. 2:I / No. 3:G or R.
To prevent wrong focus on borderlines of images, it should be conrmed that the max. and min.
values of contrast meet the following condition:
（Max. value － Min. value） ＜ 1920（14 bits）
If the above condition is not met or the contrast cannot be calculated, it is retried by moving the
CCD in sub-scanning direction.
In case of AF manual, the position can be selected arbitrarily. (default: center of frame of lms)
2. 17 Default focus address
When performing the main scan without AF, the focus address should be the latest address in the
past.
After initialization/replacement of adapter, if the scan is performed without even one AF, the focus
address should be the xed value of each adapter（including thumbnail scan of SA and IA.）
MA-21：132 MA-21+FH-3：197 MA-21+FH-G1：150 MA-21+FH-A1：153
SA-21：192 IA-20(S)：224
The focus address, when WB or SD is measured, should be the xed value of each adapter.
MA-21：186 SA-21：323 IA-20(S)：323
2. 18 Detection of insertion/removal of lms in use of MA-21
The CCD detects the insertion/removal of lms in/from MA-21.
The CCD signal is checked by G-LED once per 1 second.