Scan for negative itself or color corrected file?

Discussion in 'Film and Processing' started by benjamin_kim|1, May 18, 2015.

  1. I usually scan films with color corrections. But I found out that if I just scan film negatives itself, it's much easier and better to do photoshop. Should I scan film negatives itself and then do photoshop for color correction?
     
  2. I don't think there is any "correct" answer. It depends on your scanner, the scanning software you use and your personal preferences. My scanners and software provide me with a reasonably close scan with color negatives and I finish up with Photoshop Elements.
    Al
     
  3. I use the school equipment which is Hasselblad scanner, the most expansive scanner. I don't get the right color from its own program so I start thinking and editing scanned files in photoshop without any color correction.
     
  4. As said. What works for you. Some prefer to scan in a native RAW. I prefer to try some corrections in the scanning stage then tweak in Post processing. Much depends on the film and scanner. The scanner you mentioned is expensive but not earth shattering. I mostly try to get a correct exposure to begin with but Stuff does happen.
    I find at times it is a mix between the 2 and nothing is perfect. Just remember that you are the artist and the final product the print is your work.
    I also know most don't print and are happy with just an image on the screen. You also though have to take into account the printer.
     
  5. To the OP, what did you mean by "just scan film negatives itself"? Save a scan with no adjustments, just as it turns out from the scanner auto settings ?

    In my opinion this is a fundamental mistake; and lack of basic comprehension of what the scanner do (please try to understand my critical comment in constructive light).

    By scanning a negative you literally take a second exposure of your original shot (you have a black chamber, a light source, a lens, and a registration sensor) - the information from analog to digital is not transformed in some other magical way. Therefore all care should apply to scanning as to shooting with film/digital camera. Saving a unadjusted non optimized scan is akin to shooting film and not taking care of exposure and focus with camera all on "Auto" ! It is a lottery: some shots might turn well while other not; Photoshop might save some but you will never have a file with the optimal information a properly adjusted/exposed scan has. Start to think of your scanner as a "digital camera and the RAW developing software all in one" (the scanning software serve precisely the analogous function of exposure controls and RAW development).

    Also, the term "RAW scan" is a misnomer, probably invented as a marketing obfuscation by the third-party software manufacturers. There are important differences between the RAW as produced by digital cameras and the files produced by scanners so scanner files not have the same latitude and malleability as native RAW.

    But RAW serve as a good illustration: making unadjusted scan is akin to exporting from the RAW developing software unadjusted "as it is" RAW file to TIFF to work with it in Photoshop. Hardly the optimal.
    Since all scanner software I have seen (KM, Epson, Vuescan, and SF) bear strong semblance to some of the adjustments in Photoshop mastering the scanner software should be an easy task compared to the first encounter with Photoshop.
    Hope the above helps.
     
  6. I think there's validity to the scanner "raw" file. Vuescan says:
    Hey: I've got this data from the scanner, would you like me to create a tiff file from it, with no messing around? Later on, you can "scan" from this file, do anything you like with it, any adjustments, within Vuescan. The results will be exactly the same as if you did this at the time of scan.
    Or, would you like me to process the data, with whatever you currently think is the best way to do it, and discard the raw info?
     
  7. Agree with Mendel. Seems a valid description of raw to me. I agree with the others. It doesn't really matter: whatever you find easier. Personally, I use Vuescan to get the image reasonably correct before going to Photoshop, but this is not the way everyone does it, although I think it easier this way and requires less experimentation.
     
  8. An advantage with the Vuescan tiff format "raw" too: you can crop, rotate, and "spot" it, ie: deal with any dust and scratches. As long as it doesn't include infrared data, the cleaning channel. And you can apply Vuescan's cleaning to the raw file. It's a mixed-bag though.
    The file's appearance if opened in Photoshop is extremely dark. But in PS you can set up a gamma 1.0 Proof Viewing Mode, and toggle it on/off with a hotkey, helps a lot.
     
  9. Re: RAW.
    I shall not rely on the word of interested parties like producers of commercial software. There are at least three fundamental differences between the RAW file format as used in digital cameras, and the "RAW" files from some scanner software.
    RAW as output from digital cameras is,
    1. Non demosaiced and non interpolated.
    2. Does not have ascribed a standard colour space.
    3. For the above reasons true RAW files are not visible in ordinary software.
    None of the above apply to files from scanners. Scanner software usually output TIFF as a high quality format; or as an alternative (worse) some proprietary format that cannot be read by any third party software. On the contrary TIFF is universal and visible in pretty much every image software on the market.

    I truly fall to understand this misplaced fixation with RAW files, and the insistence that some scanner software output "RAW". So what?
    RAW files are a true curse in the digital realm because the format in non standardized and proprietary to every manufacturer; and every camera from the same manufacturer uses a different RAW format... true madness... and crying out loud for some strong competition laws!
    As for the big latitude in processing RAW this "feature" is the result of the nature of the sensors used in digital cameras, which are not the same with scanner sensors. Sensors in digital cameras (with the exception of Foveon) register only a fraction of each colour, and the missing information is created during the RAW data processing. This is the reason why different software often render dramatically different results. On the contrary TIFF files from scanners contain all data and ascribed colour space, and naturally are less flexible compared to RAW.
     
  10. Scan to make sure you get all of the color and tonal values. To maximize information in the file try this: when making the
    scan drag the black and white clipping end points in the histogram to just barely beyond the ends of the "mountain range"
    in the histogram and save the scanned image as a 16 bit per channeL TIFF in the Pro Photo RGB working space.

    Then do your tone and color corrections in Photoshop.
     
  11. I've done it various ways but have settled on the method described by Ellis above. Except I use Lightroom instead of Photoshop for the post processing. Good luck.
     
  12. Ditto the other posters. The color negative auto-corrects work good sometimes, and sometimes not. Once it's baked into the output file, you can't go back. Unless you use the Vuescan .dng format, if you use that program. There are advantages there. I just scan negatives as a positive, which in some programs (like mine) is the only way to utilize an IT8 calibration. I do use the levels adjust (or black/white points in some programs) to make sure the scanner is parsing the usable dynamic range as much as possible. Reverse the negative, crop in PS or whatever, and save. Then you can make adjusts on copies, layers, etc. non-destructively to the original file. FWIW, I started doing it this way partly because my abilities to use PS and/or Lightroom and/or PaintShopPro improve over the years. So, now and again I want to use a file, and if I cringe at what I did a few years ago, I can just do it again.

    One suggestion might be to try outputting a corrected file to best way you can get it to look, and then also an unmodified one. Pull them both up and see if you can do it manual better/worse, etc.
     
  13. As I mentioned, I do adjust the levels prior to the scan but I'm not convinced that matters. I believe those adjustments are made by the scanner after the scan. So the "parsing" of the usable dynamic range is really just an adjustment after the collection of data along the 0-255 for the full range of the scanner and then the level is adjusted and the "mountain range" bits are just expanded to 0-255. The scanner can only provide data to the extent its dMax's capability.
    What I've noticed is that auto adjust scan looks exactly the same as scanning flat and post-scan adjusting levels in Photoshop Elements. Also, if you pre-scan, you can flip from a flat scan look to auto adjusted look in the pre-scan routine which tells me that adjustments appear to be post scan.
    If these are the cases than you might as well scan completely flat and reserve ALL adjustment to post processing. The other advantage is you don't have to re-scan if you think you some how can get better results in the future.
     
  14. Hasselblad scanners can save scans in their proprietary file format, which I think is called 3F (flexible file format).This is what some
    people refer to as "RAW". Once a negative is scanned as a 3F file, then unlimited manipulation can be made using the scanning
    software, but the original 3F file is not destroyed. Maybe this is what the OP meant?
     
  15. Non destroyable files are another venture I believe. Many Scanners and software allow that not just Hasselblad.
     
  16. Not to start an argument, but some of the statements posted above are plain wrong and thus misleading.

    Corrections done in the scanning software are applied at the moment of the scan, not after the scan as some claim. For reference check this Epson file where on page 10 the adjustments are explicitly termed as "pre-scanning".
    https://files.support.epson.com/pdf/exp16_/exp16_ts.pdf
    I compared the scanner adjustments to camera controls; other knowledgeable in analog printing compare scanning to optical printing and for a good reason. By adjusting Exposure, Histogram and Curves in the scanning software one alters for how long each colour channel is exposed by the sensor; other adjustments are most likely done on the level of the A/D conversion. In consequence an adjusted scan and a Linear scan in most scenarios do not contain the same data - the optimized scan will have redistributed tonal values across the range and good contrast while the Linear scan will contain poor information in the weak channel(-s) if there is/are such. Once the scan is made and saved - no matter in what format - it has finite information and any manipulation in Photoshop will be degrading (even rotating the file in PS involves computation and interpolation).
    If some are still unconvinced try the following: shot with a daylight film (or digital) a city scene at night without a light-balancing filter (80A in this case) and adjust the white balance in post; and shot the same scene with the filter (digital set to Daylight WB). With a filter when the three colour channels are equalized prior the capture the histogram is much more even, the dynamic range is greater, the noise is less, and the colours natural. The two files will not be the same no matter the post processing involved. The same apply to adjustments before- and post-scanning.
    As for the some scanner software "RAW" format I came across this instructive citation of Ed Hamrick (VueScan) - basically he says that his "RAW" is plain TIFF.
    "The reason Adobe Camera RAW doesn't read TIFF files is because there's
    no reason for it to do this. The whole point of Adobe Camera RAW is to take
    images from a color filter array (i.e. one color per pixel) and interpolate this
    into a three colors per pixel data source.

    Scanners already produce 3 colors per pixel and VueScan's raw files have
    3 colors per pixel.

    The people at Adobe could read VueScan's raw files with about 5 minutes
    work, and the files are just normal TIFF files that they could easily read. The
    reason they don't do this is because it would be a complete waste of time - the
    VueScan raw files are already 3 colors per pixel."
     

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