Question about Fuji minilab prints

Yes, I know that; judging from their specs, the CCD array is 1 pixel* wide x
5,000 pixels long (across the scanning direction). My nagging question is how
*long* (in inches, mm, fractions of nautical miles, whatever) is this 5,000
pixel array? I'm still interested in finding what the scanning resolution (in
pixels per _____) is of the SP-2000.

* "1 pixel" meaning 1 logical R/G/B pixel, so physically 3 pixels, one for
each color.

 

I hasten to correct my own post: I don't know for sure if the CCD is only 1
(logical, 3 physical) pixels wide: it may not be. But it doesn't matter, since
we know what the other dimension (the 5,000 pixel one) is.

By the way, keep in mind that this scanner is apparently capable of handling
6cm film, so it may be (read: probably is) wider than 36mnm. Which makes a big
difference in the resolution of the device.

 

Length of imaging sensor has not to be (dont know if that the right english
expression) the same length of the object!
Your cameras film is not as large as the photographed object.

Today some flatbed scanners has an CMOS as long as the scannes area width,
but there also scanners with 35 mm long CCD!
Scanners = some kind of camera.


How depends the resolution of a scan (through an optics!) from the witdh of
the CCD?

If the CCD (with 5000 Pixels) is, only for example, 24 mm long. The optics
is zoomed so that the 24 mm from the film (the smaller side from 24*36)
fits the 24 mm of the CCD properly - 1:1.
The scanning resolution is then: 5000 Pixel / 24mm * 25,4 mm/inch = 5291
ppi (pixel/inch).

If the CCD (with 5000 Pixel) is, for the second example, 48 mm long. The
scanner optics is zoomed that the 24 mm from the film (the smaller side)
fits properly (!) on the 48 mm of the CCD!! - 1:2 or 2:1
Which scanning resolution do we have?
Ok, 5000 Pixel / 24 mm (from the scannned Area on the film!) * 25,4 mm /
inch = 5291 ppi.

Only if you intrested in the sensors original resolution, the length of the
sensor is important. With the resolution of the sensor you can calculate
how big the sensors are, and from this information you maybe can tell
someting about noise.
But for the scanned resolution I see no need for this information. OK, I
assume, that the optics is zoomed if you change your film format.
If that not, then the 5000 Pixels are used for ~ 56 mm film. the resolution
is then 2267 ppi. In this case (optics wihout any fitting of the scanned
area) this resolution is for 120, 135 and APS the same. I dont think Fuji
Frontier is working that way.

Hope it helps
Markus

 

May I add one small point: note how scanners (and scanning backs) give (or
should give) _two_ different resolution figures - one for the X and one
for the Y dimension. Photographers might find that a rather daunting
change - resolution is higher in one dimension? How wierd! But true.

 

Lets say x is the direction of the movement - normal fladbed scanners ~ 30
cm, y is the direction of the CCD / CMOS ~ 22 cm.
Resolution x depends from the smallest steps of the scan slegde and the
dimensions of the CCD.
Resolution y depends from the dimension of the pixels on the CCD and the
optics.

By the way: Normal photographic optics have also two different resolutions
(or more precise: MTF) - tangential and sagittal.
For example look at a MTF of a ZEISS lens (www.zeiss.com).

Markus

 

A Frontier 350 operator explained me that he always makes the final print at
300 DPI. I can assure you his prints look absolutely fabulous...
The negative is scanned with a resolution calculated in function of the
print size; if you make a 5" x 7" print you need an enlargement of 5 x hence
the scan is made at 1500 DPI. For smaller prints the initial scan has a
lower res.

Jan Tieghem

 

I don't know where you get this information: if from an operator, it's
possible they were misinformed.

The printer (3-color laser) *always* prints at 300 dpi; the operator has no
control over this aspect of Frontier operation.

Don't know if they have control over the scan resolution, but as stated above,
the scanning CCD has 5,000 pixels, so scans are made at something
significantly higher than 1500 dpi.