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P: Ability to invert negative scans to positives (color and black-and-white)

Forum|Forum|14 years ago
January 27, 2012
167 replies
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I would dearly like to see the Lightroom 4 Beta team implement an additional feature in the final release. That feature would be the ability to take a camera+macro lens image of a B&W negative -- essentially a camera-based scan of a negative -- and invert the negative image to a positive image at the beginning of the development process in such a way that the resulting sliders in the LR4 Develop Module would not operate in reverse. As I understand it, this capability exists in Photoshop, but I don't own Photoshop. I do own Photoshop Elements 9, but that program only supports an 8-bit workflow, not 16-bits per channel, and round-tripping between LR & PSE9 requires the reimportation of a TIFF file that is more than twice the size of my NEF RAW files. Since this programming wizardry already exists in Photoshop, I would think that it would be a relatively simple matter to transfer and adapt that code for LR4 -- but then, I'm not a programmer, so what do I know...

I've been digitizing 40-year-old Kodachrome slides from my Peace Corps days in Africa, using a 55mm Micro-Nikkor (macro) lens, coupled to a Nikon ES-1 Slide Copy Attachment, and even on a D300s body, I can get truly excellent results. I can't wait to continue that work using the pending 36 megapixel Nikon D800 body with an upgraded f/2.8 macro lens (mine is the old 55mm f/3.5 design). I really, REALLY want to be able to camera-scan my many B&W negatives without having to generate huge intermediate TIFF files.

You can respond to this request by emailing me, Jeff Kennedy Thanks, in advance, for taking the time to review and consider my request. I LOVE Lightroom 3, and from what I've seen, I'm going to love LR4 even more. I REALLY appreciate the effort that Adobe takes to solicit input from the photographic user community.

BTW, if the feature I request *can't* be implemented right away, could the LR support team provide detailed, interim instructions as to how to use the "backwards" sliders, and in what sequence? That would be very much appreciated. I'm sure many older LR users have considerable analog image collections that they would like to digitize, and doing so in-camera is both 1) of surprisingly high quality, 2) MUCH faster than using flatbed scanners and 3) of much higher quality and resolution than flatbed scan and MUCH cheaper than professional drum scans.

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Todd Shaner

Legend

Since Adobe is the developer and owner of the DNG specification it shouldn't be too difficult for them to implement a raw data invert function that doesn't also invert the LR controls. The primary issue is how to implement this capability AND maintain compatibility. Some more info here: http://dcptool.sourceforge.net/DCPFIles.html

The processing pipe
So, this is how, in vastly simplified form, you process your raw data in context of a DNG Camera Profile, assuming the Forward and Reduction Matrixes are not present (see the specification for more detail😞


    1.Linearize, rescale, do black level compensation, clip, etc.
    2.Derive interpolated ColorMatrix and HueSatDelta matrixes based on the color temperature.
    3.Get to an XYZ (absolute color space) via the interpolated ColorMatrix.
    4.Convert to HSV.
    5.Apply the interpolated HueSatDelta mapping table to get new colors.
    6.Convert back to XYZ.
    7.Do your exposure compensation, fill light, etc in whatever color space you want
    8.Convert to HSV, apply the LookTable and ToneCurve, convert back. Or, if I read the spec right, use the LookTable and the ToneCurve as the basis for your adjustment settings

johnrellis

Legend

"Also, you cannot auto white balance on the inverted negative. It seems like it should work, but the Adobe SDK on profiles said that the profiles are applied at the end of the image rendering process, so the white balance tool is still seeing the non-inverted image."

What if you did the inversion with the profile's HSV look table rather than the RGB LUT? The SDK documentation says that the HSV look table is applied earlier in the image pipeline, so maybe it's applied before any of the Develop settings. If so, then you could do white balancing and the sliders wouldn't be inverted?

I only have a fuzzy understanding of how one might create such HSV look tables in this instance, though.

Todd Shaner

Legend

Also, you cannot auto white balance on the inverted negative. It seems like it should work, but the Adobe SDK on profiles said that the profiles are applied at the end of the image rendering process, so the white balance tool is still seeing the non-inverted image.

Yet another reason for Adobe to do some additional work and fix both.

F

FeedbackCommunityMember

Inspiring

It’s great that the new profile structure opens another door for this task.

But in all other ways I no longer hold my breath for any implementation of inverting images (besides the curve trick we all use). Why?

After one year Adobe still hasn’t made LR compatible with HEIF / HEIC image format - the format produced by the most used camera on the planet (iPhone).

That should make clear how low on the scale a wish from a group as small as us here is.

If inverting is ever implemented, I’ll be happy. But I’ve stopped waiting a long time ago..

F

FeedbackCommunityMember

Inspiring

Todd,
Thanks for trying them out, but as I suspected, these profiles are specific to the negative scan process. I think you will find that the profiles produce much better and more consistent results if you create them yourself from your own negatives. After going through the process a couple of times, it is very quick and easy. And once created, those profiles will work for every roll of that film stock scanned under the same conditions.

Also, you cannot auto white balance on the inverted negative. It seems like it should work, but the Adobe SDK on profiles said that the profiles are applied at the end of the image rendering process, so the white balance tool is still seeing the non-inverted image.

Todd Shaner

Legend

Jeff, thanks for sharing this information. I was able to get a reasonable image rendering using your Portra 400 profiles with various color negative films. However, it required making some extreme Tone adjustments to remove excessive highllght and shadow clipping. Also the LR WB eyedropper doesn't work properly when clicked on neutral color areas. I had to adjust the WB controls manually. My film capture setup uses a 5500K color temperature Canon Speedlite and Canon 5D MKII and 600D cameras. Not sure if your profiles are camera model dependent, but if so that would explain what I'm seeing.
LUT based profiles are definitely a step in the right direction. Hopefully Adobe will also pick up the ball and implement a raw file invert function to fix the backwards control operation.

F

FeedbackCommunityMember

Inspiring

Here are a couple of sample profiles created using Portra400 outdoors. I am doubtful that these will work for someone else because I think the LUT will be dependent on your particular scanning setup, but it will be interesting to see what happens. For my test, I was able to use one of these 2 profiles to color correct about 90% of the images on 3 different rolls of film. The other images were under different enough lighting conditions, i.e., indoors and pre-dawn, that the profiles did not apply.

I have found that the negative MUST be white balanced under the Adobe Standard profile before applying the inversion profile. I use the unexposed frame outside the image for white balance.https://drive.google.com/open?id=1bSkl6lNTxeoXGAxEBEnMb4xWIzE3IRg2

Paste the XMP files into a folder in the location below, then restart Lightroom and they should appear in the Profiles Browser under the heading "Sample Film Negative Profiles".
Windows: C:\ProgramData\Adobe\CameraRaw\SettingsMac:/Library/Application Support/Adobe/CameraRaw/Settings

Todd Shaner

Legend

Jeff, can you post a share link to a few of your LUT based film profiles? This will allow others here using camera film capture (self included) to give them a quick try. Thank you!

F

FeedbackCommunityMember

Inspiring

With the 7.3 release of Lightroom Classic and addition of profiles, Adobe have almost given us the ability to invert negatives in Lightroom. We can create inversion and color correction LUTs in Photoshop then bring those into Lightroom as profiles for one-click inversion and color correction in Lightroom! The sliders still work backward, but no more messing with the Tone Curve.

http://www.cuchara.photography/blog/2018/5/one-click-inversion-of-color-film-negatives-in-lightroom

D

drtonyb

Legend

No good Johan!

Although inverting the tone curve does do the job of changing the negative into a positive, it is at best a 'kludge' to overcome a serious deficiency in Lightroom that has been requested by customers and ignored by Adobe for the past 6 years.

I can photograph a film negative with my macro lens and a slide copying attachment - works very well, producing a raw copy. Importing into Lightroom, I apply the negative tone curve to get a positive. Making a few more adjustments, being mindful of the reversing of some develop adjustments, I can get something that looks pretty reasonable.

Now I'd like to apply a preset to give the image a different look - oh crap! Only one tone curve can be applied, obviously, and now my negative tone curve has been obliterated, making my image a punchy negative. Not a good look!

This is why Lightroom needs a real NEGATIVE control, so that the develop adjustments aren't all screwed up and we can still apply presets as normal.

How hard is this? Has Adobe only got one programmer working on Lightroom who is completely overwhelmed by the volume of bugs and very good ideas being reported here.

Come on Adobe wake up. Six years is far too long for a very sound feature to be implemented in Lightroom. It's not difficult - just about every image editing tool has a NEGATIVE function! Why not Lightroom?

So sick of the Adobe ignoring its customers, but still taking our money and using us to test their sloppy programming, only to be mostly ignored when we report problems that should be fixed in a very short time frame. The silence from Adobe says it all - don't care as long as you mugs keep paying.

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