Using film's dynamic range from scans

[NLewis]

Good BW film like TMax100 has about 15 stops of usable dynamic range. My V700 scanner has a reported Dmax of 4.2, which is fourteen stops. Possibly this could be extended by multi pass scanning as is offered in recent updates of Silverfast.

In the traditional darkroom, this extended dynamic range could be accessed by "burning" part of the print, allowing the brightest parts of the image (densest parts of the negative) to gradually lower their values to the desired range. For example, Zone 10 on the negative would be lowered to Zone 7 on the print. This was a common method especially for landscapes, where this darkroom method was used to balance exposure in land and sky, instead of the ND grads that were used with transparency film.

I would like to understand better how to capture this extended dynamic range during the scanning process, in some sort of HDR file for example, and then access it with some technique similar to "burning" (reducing exposure) via software like Aperture.

Let me know how you fellows do this sort of thing.

 

[Michalm]

scan as positive

scan as positive

Scanning film as positive is the best option, I'm setting scanner up as follows : : positive scan, gamma 1, 16 bit .This will allow u to capture the most of the film's dynamic range . You will recieve negative image which can be converted using the following workflow:http://sites.google.com/site/negfix/howto

 

[Pete B]

I've downloaded negfix a couple of times and I just can not work out how it is supposed to be used. Can you explain further how you use it (with out referring to the website as that seems to be designed for computer literates).
Pete

 

[mdarnton]

That the film can capture a subject spanning 15 stops does not mean that the image on the film will encompass 15 stops.

I "scan" my B&W film with my Nikon D300, which has a range of around 9 stops, but with the camera set to normal contrast, my [full range] negs give a histogram that only takes up about 1/2 of the possible span, and consequently if there's a problem, it's of too low contrast in the scan, not too high.

Transparency film has a contrast range much greater than any neg you're going to put in your scanner--that's why scanners need the Dmax, not for your B&W negs.

 

[craygc]

B&W film usually only presents a dynamic range of around 2.0; as mdarnton mentioned, this is very different from the brightness range that has been compressed on to the film itself

 

[ChrisN]

Don't forget that you can do the multi-pass thing yourself - make two or three scans at different exposure levels, capturing detail in both the highlights and the shadows, then blend them in photoshop.

 

[Michalm]

negfix8

negfix8

I couldn't explain it better then the link does itself.If u follow the steps on it you will be fine.What seems to be the problem exactly Pete?The only advantage of Negix8 is that it is removing orange mask very of the colour film nicely- it works as well with B&W negatives but is not that much required.