Depth of field

[Tony Cooper]

I need a new scanner, but I need one that will provide some depth of
field. I have a printer/scanner that works well enough with photos
and flat material, but I need one that will produce good scans of
objects like coins.

I can't figure out how to look at the specifications of a scanner and
pull out anything about depth of field. The ones available in the
stores near here are the Epson 4180 and Epson 3590. I'd rather buy
locally than off the web, but I'll go either way.

 

[CSM1]

I need a new scanner, but I need one that will provide some depth of
field. I have a printer/scanner that works well enough with photos
and flat material, but I need one that will produce good scans of
objects like coins.

I can't figure out how to look at the specifications of a scanner and
pull out anything about depth of field. The ones available in the
stores near here are the Epson 4180 and Epson 3590. I'd rather buy
locally than off the web, but I'll go either way.


--


Tony Cooper
Orlando, FL

They don't publish specs for Depth of Field. You have two choices of
scanners, A CIS and a CCD.

The Contact Image Sensor (CIS) has zero depth of field.

The CCD has a lens and some Depth of Field. How much DOF varies from scanner
to scanner. Coins are no problem for most CCD scanners that have a single
light source.

The Epson 3590 is a CCD, the 4180 is a CCD but not a current model. (The
store has old stock).

Epson USA web site for Scanners.
http://www.epson.com/cgi-bin/Store/ProductCategory.jsp?BV_UseBVCookie=yes&oid=-8172

 

[Tony Cooper]

They don't publish specs for Depth of Field. You have two choices of
scanners, A CIS and a CCD.

The Contact Image Sensor (CIS) has zero depth of field.

The CCD has a lens and some Depth of Field. How much DOF varies from scanner
to scanner. Coins are no problem for most CCD scanners that have a single
light source.

Trying to figure out which brand and model has the best depth of
field, though, is the problem.

 

[Norm Dresner]

I need a new scanner, but I need one that will provide some depth of
field. I have a printer/scanner that works well enough with photos
and flat material, but I need one that will produce good scans of
objects like coins.

FWIW, I've used my HP ScanJet 4570c to do scans of HO-scale model trains.
Depth of details runs about 1/8" to 3/16" and focus is no problem at all.
Exactly what this means for other scanners is probably problematic, but it
wasn't a particularly expensive scanner which was initially bought to scan
documents and a few 35mm slides and negatives.

Norm

 

[CSM1]

Trying to figure out which brand and model has the best depth of
field, though, is the problem.

Depth of field may vary among scanners of the same model.

DOF is a function to the focal distance of the lens and the aperture of the
lens. Just like it is in cameras.

This page is a good tutorial on Depth of Field:
http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/950/depth-of-field.html

 

[false_dmitrii]

I need a new scanner, but I need one that will provide some depth of
field. I have a printer/scanner that works well enough with photos
and flat material, but I need one that will produce good scans of
objects like coins.

I can't figure out how to look at the specifications of a scanner and
pull out anything about depth of field. The ones available in the
stores near here are the Epson 4180 and Epson 3590. I'd rather buy
locally than off the web, but I'll go either way.


--


Tony Cooper
Orlando, FL

The recent Epsons (4870 and on?) were noted for dropping any sort of
focus mechanism in favor of increased DOF, so as to capture both
on-the-glass reflectives and above-the-glass film. My 4870 had no
trouble resolving a coin or the bottom of my camera. My scanner's a
bit soft, though, although this might be by design too.

The photo-i.co.uk website often includes images of scanned 3d objects
in scanner reviews. Might be useful to you.

false_dmitrii