Home
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

Most Accurate Color Negative to Positive conversion method
View previous topic :: View next topic  


PostPosted: Fri May 23, 2014 2:35 pm    Post subject: Most Accurate Color Negative to Positive conversion method Reply with quote

What's the best way of converting color negative to color positive in photoshop while retaining accurate color rendition?

When i try inverting colors (either Image>Adjustment>Invert command or Curves Adjustment layer) i get bluish tint, skin tones appear all whacky, pale-ish, not natural. There should be a better way to get natural results.


PostPosted: Fri May 23, 2014 2:52 pm    Post subject: Reply with quote

Well if there was an easy answer there would be no need to use a film scanner. I assume you photographed the neg with a digital camera.


PostPosted: Fri May 23, 2014 3:00 pm    Post subject: Reply with quote

Excalibur wrote:
Well if there was an easy answer there would be no need to use a film scanner. I assume you photographed the neg with a digital camera.


Yup. Bellows with slide duplicator.


PostPosted: Fri May 23, 2014 3:17 pm    Post subject: Reply with quote

Jvg wrote:
Excalibur wrote:
Well if there was an easy answer there would be no need to use a film scanner. I assume you photographed the neg with a digital camera.


Yup. Bellows with slide duplicator.


well you're in luck as there are threads here where members have used a DSLR for "scanning" negs and have achieved very good results.


PostPosted: Fri May 23, 2014 3:32 pm    Post subject: Reply with quote

Excalibur wrote:
members have used a DSLR for "scanning" negs and have achieved very good results.


I am hoping for that Very Happy


PostPosted: Fri May 23, 2014 11:29 pm    Post subject: Reply with quote

I can do it now but its a steep learning curve. I copy the negs with a bit of the border included. Open photoshop, select adjust levels, click on the right hand dropper and sample the border colour. The image changes colour. Select invert and you are almost there. I use colour balance to tweak it.

It sounds simple but takes a bit of time to get used to it.

Importantly you must have your camera set to the right colour balance depending on the light source. Do not rely on auto white balance because the orange mask buggers it up. I've not read this bit of advice anywhere I had to discover it myself.


PostPosted: Tue May 27, 2014 1:57 pm    Post subject: Reply with quote

philslizzy wrote:
I can do it now but its a steep learning curve. I copy the negs with a bit of the border included. Open photoshop, select adjust levels, click on the right hand dropper and sample the border colour. The image changes colour. Select invert and you are almost there. I use colour balance to tweak it.

It sounds simple but takes a bit of time to get used to it.

Importantly you must have your camera set to the right colour balance depending on the light source. Do not rely on auto white balance because the orange mask buggers it up. I've not read this bit of advice anywhere I had to discover it myself.


I use cheap LED light source with diffuser by sunpack, and have it set right behind the film. White balance is set to 6300K. It gives pretty good, steady light which lets me use fast shutter speeds even at F8 (ISO 100).

In any case, i followed your instructions, sampled film border for level adjustment, and once inverted i still got heavy blue cast on entire image.


PostPosted: Tue May 27, 2014 2:41 pm    Post subject: Reply with quote

Jvg wrote:
In any case, i followed your instructions, sampled film border for level adjustment, and once inverted i still got heavy blue cast on entire image.


I don't have photoshop so don't really understand the instruction but sounds like you still have the orange mask left because inverted it turns blue?


PostPosted: Tue May 27, 2014 3:23 pm    Post subject: Reply with quote

virtual photographer http://www.optikvervelabs.com/ has a stand alone version that does this conversion, I've liked the results in the past, plus you have some other image options while you're doing so. And it is Free!


PostPosted: Tue May 27, 2014 4:31 pm    Post subject: Reply with quote

kansalliskala wrote:

I don't have photoshop so don't really understand the instruction but sounds like you still have the orange mask left because inverted it turns blue?


looks like it. I'll play with it some more and see what i can come up with.

Nesster wrote:
virtual photographer http://www.optikvervelabs.com/ has a stand alone version that does this conversion, I've liked the results in the past, plus you have some other image options while you're doing so. And it is Free!


downloaded both PS plugin and stand alone program from their website. stand alone program returns whole bunch of error messages, can't navigate into folders, can't open images - pretty much error basket.

plug in - won't even register under photoshop. tried installing it into its own folder and copying that folder into 32bit and 64bit plug in folders for PS. no luck.


PostPosted: Tue May 27, 2014 5:39 pm    Post subject: Reply with quote

OK, i think i have figured it out.

Leaving some frame border advice by philslizzy stands true, and here is step by step:

1 - open the color negative scan in PS.

2 - convert the background into layer and duplicate it.

3 - with the Eyedropper Tool sample the frame border (important)

4 - with duplicated layer selected, menu Image>Adjustment>Levels, and in levels window click on Eyedropper Tool with minus sign in it (when mouse over "Sample in image to set white point" and sample frame border from scan. Do not click OK button yet (important).

5 - Select each color channel (red, green, blue) individually and adjust brackets to beginning and end of the color curve. Now click OK.

6 - Invert the layer.

7 - if blue tint still exist (and it does in my case), create blank new layer and with color sampled in step 3, click on Paint Bucket tool and fill in the new layer with that color.

8 - change layers blending mode to Overlay with Opacity to your taste (60-80% worked fine for me).

9 - crop the image to exclude frame borders.

10 - create new Levels adjustment layer and adjust brackets individually for each color channel (or you may click on Auto adjustment).

11 - all done, time to grab a beer and celebrate. Very Happy


PostPosted: Tue Mar 03, 2015 2:32 pm    Post subject: Reply with quote

Here's a link to a related article (contains a link to a downloadable pdf) at Luminous Landscape.

http://luminous-landscape.com/scannerless-digital-capture-and-processing-of-negative-film-photographs/

I have been scanning 35mm and 6x6 negatives with with a light table and a Nex-7 mounted on a tripod, using a C/Y Makro Planar 100/2.8.

Previously I've opened the raw files with RawTherapee, set white balance according to the unexposed part of the film, inverted and fiddled with curves until (more or less) satisfied with the results. However, the method described in the article utilising MakeTIFF and Silverfast software is so much easier and quicker that I really don't think I'll be returning to processing my negatives with RawTherapee anytime soon.