Digital BW, The Print

Here's the procedure for making the LUT files in Silverfast: 

I've made them as positive image(Negative in SF), but you can 
also save them as a negative(Positive in SF) in the Main SF 
Dialog(the middle tab). This should rreally be done with definitive 
test negatives from 55PN, but this is a place to start. You'll also 
find that N+1, N-1 etc., mean differnt things with different files. 
You can have a high-key N+1, a regular mid-key N+1 and a low 
kwy N+1. The software will automatically compensate for these 
by changing the gray slider setting from 0 to a minus or plus 
setting. This can be done with both RGB files and Grayscale 
files. 

Because you only have one development for 55PN ( Normal), the 
contrast range will vary within the negative. Determine when you 
take the picture whether the scene is a Normal(5 Zones from III 
to VIII) an N+1(4 Zones) or N-1(6 Zones) and mark the packet. In 
Silverfast pull up the saved LUT and use the software as though 
it were your developer and you were using it to control the 
contrast. 

Scanning a Polaroid 55PN Negative
It is almost always better to scan a negative than a print. The 
resolution of a negative is often 10 times that of a print and 
enables it to be enlarged to greater magnifications.  The print 
resolution of 55PN is only 20-25 line pairs/mm whereas the 
negative is 160-180 line pairs/mm. In practical terms this means 
that the print can be enlarged only 2-2.5 times and the negative 
can be magnified 16 to 18 times.
 
Because 55 does not offer much in the way of traditional Zone 
System control, it is best to scan a negative that has full shadow 
detail and correct it in the scanning stage with SilverFast. 
Silverfast can be set up to process the "normal" Polaroid 55 
scan as N, N+1, N+2, or N-1. With the combination of 
preexposure to the film at the camera stage plus the scan 
correction, it might be possible to achieve an N-2. The new 
Polaroid SprintScan 45 Ultra Scanner comes bundled with the 
SilverFast software. Not only is this scanner easy to use, through 
its 3.9 density range and a 2500 dpi optical resolution the 45 
Ultra offers the ultimate quality in an affordable film scanner for 
4x5 photographers. It is possible to produce stunning 24x36 
B&W prints from Polaroid 55PN Negatives with the 
Piezography24 Pro 7000 Quadtone process using the 45Ultra. 
Silverfast is also available separately for a wide range of 
scanners from http://www.silverfast.com.

The SilverFast software is easy to learn and contains many 
user-adjusted controls that enable outstanding scans, nearly 
perfect, in fact, from the Polaroid 55PN negative. However, one 
needs to set up the N+1, N, and N-1 parameters. HereÕs how:
1. Load a 4x5 55PN normal range negative (Zones III-VII) into the 
scanner.
2. Open Photoshop 6 and go to File > Import > SilverFast.
3. In the Frame tab check 42-8bit grayscale, Unsharp Mask and 
Standard. YouÕll want a slight amount of Unsharp Mask to correct 
any scanning softness problems. Use the unsharp mask default 
setting or less. Set your desired resolution and set your scan 
size at 100%. Click Preview. Crop the image in the preview 
window. 
4. In the General tab chose Negative for the Neg/Pos window 
and a dialog box called Film Type and Exposure will appear 
below the main SilverFast dialog.
5. Choose Monochrome as your film type and adjust the 
brightness slider to read 50%.
6. Click Auto, let the scanner scan, then click apply. Save this 
setting as N, or Normal.
7. Repeat steps 2-6 using a negative that was taken under 
known N+1 conditions and save as N+1.
8. Repeat steps 2-6 using a negative that was taken under 
known N-1 conditions and save as N-1.
9. You may want to repeat this process for any other minus or 
plus development routines you have. When finished your 
scanner will be able to act as the developing stage of traditional 
B&W darkroom practice. 
10. Go back to the Frame tab and correct the histogram if 
necessary.
10. Scan. The positive image in Photoshop should be nearly 
perfect. 

An alternative solution( and a more favorable one as Photoshop 
adds more controls for 16 bit files) is to scan in 16 bit HDR 
mode(with the gamma setting at 3.00) and either go into 
SilverFast HDR and optimize the scan, or go directly into 
Photoshop and correct the scan with Curves and Levels and 
then drop down into 8 bit mode for printing.

George