Romanko
Member
Demosaicingfake mathematical wizardry
Demosaicingfake mathematical wizardry
Demosaicing
As I am sure everyone knows, part of the beauty of film is that every photosite has all three primaries in layers, and line scanners such as this are NOT Bayer, They have three scanner heads that are in rows of ONE color per head, one red, one blue
Welcome to Photrio @dwstudeman!
There's an interesting exploration of at least two different scanners (Epson V700/750 and Nikon 4000) in this pdf, which gets fairly technical and seems well-substantiated: http://dasch.rc.fas.harvard.edu/papers/Scannerevaluation1.pdf
Note that not all colors are actually collected at the same time for each spot on the film. Due to the distance between the CCD strips, each pixel will consist of several signal inputs acquired successively over multiple longitudinal steps. While this results in pixels that are indeed constructed from R, G and B signals (sometimes more than one, each), the fact that the sampling necessarily occurs in different moments introduces other problems.
There's always a tradeoff, somewhere.
Foveon X3 is one such sensor. Apparently, Sigma is busy prototyping a new incarnation of Foveon.until we can get a sensor with three color layers at each pixel
Note that not all colors are actually collected at the same time for each spot on the film. Due to the distance between the CCD strips, each pixel will consist of several signal inputs acquired successively over multiple longitudinal steps. While this results in pixels that are indeed constructed from R, G and B signals (sometimes more than one, each), the fact that the sampling necessarily occurs in different moments introduces other problems.
Not only at different moments, but also different positions. For a "standard" CCD linear sensor (3-line sensor with RGB filter) to get one line with all three R, G, B channels you have to take 3 readings and move film twice between readings. Results from staggered 6-line sensors like those in V700/V800 are obviously subject to even more interpretation. Not exactly "false math", but mechanical and electronic variation/imprecision.
Nikon Coolscan 8000/9000 have monochromatic (no RGB filter) 3-line CCD sensor and you can enable "fine" mode where three R, G, B readings are taken from the same line on the sensor and the film is not moved between readings.
Foveon would indeed be a perfect sensor, but Sigma (with Quattro) actually strayed away (slightly) form the original concept to keep up with CMOS sensors which are apparently perceived as good enough for general photography.
Welcome to Photrio @dwstudeman!
There's an interesting exploration of at least two different scanners (Epson V700/750 and Nikon 4000) in this pdf, which gets fairly technical and seems well-substantiated: http://dasch.rc.fas.harvard.edu/papers/Scannerevaluation1.pdf
Purportedly the PrimeFilm XA series does well with uncut rolls as far as flatness and focus.
Great scanner. Needs Silver fast for best results.
I purchased and returned when I found that it does not work with silverfast
So, this is a great scanner that requires Silverfast to work properly but you had to return it because it does not work with Silverfast, right?
Re software: I don't think that the developers at SilverFast would be collecting paychecks to create software that works for this device if only a few minor tweaks were sufficient to host this device. I agree that their form factors appear very similar (if not identical), but I ask why would PIE spend the resources to create a "new" device that offered no measurable advantage over what is already available, supported and used by customers? That said, the required software modifications might be minor compared to the potential return on investment if this scanner offers significant improvements over the previous model(s). (If I have a moment, I'll check the Vuescan website to see if this scanner is supported ....)
Re hardware: I use the XA version of this scanner and have no problems dependably scanning six-frame strips, but that might be dumb luck.
FWIW: I think that a reliable "lab" scanner that played well in the consumer marketplace would be an all-around win for the manufacturers and the software companies that supported this device and, most importantly, for the vast majority of film consumers.
You think wrong. SIlver fast is making it compatible.
Also compatibility with apple silicon and faster speed are not a small things.
I really dont see any difference with the XAs and the new coming XA Plus. They look identical to me, even in the specs. I wonder if the driver for this new scanner will work on the older XAs? And they havent seemed to solve the issue of getting each successive frame centered on the scan, without readjustment.
I had two XA Plus recently and they worked with Vuescan (Windows). They had other problems, but Vuescan compatibility was good.
John
I had two XA Plus recently and they worked with Vuescan (Windows). They had other problems, but Vuescan compatibility was good.
John
Silverfast gives me a lot better results the XAS.
The XAS is a different machine.
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