Increase lattitude for scanning

[Ronald M]

For several years now, I have been double processing raw files making one light and one dark file and merging them in photoshop layers with a luminosity mask. The procedure is outlined on the website, the lights right-digital darkroom tab- video tutorials- blended exposures. The beauty is this requires only one file, not like HDR where a series needs to be made.

I recently made a neg that was done under nasty conditions that just would not scan and pick up subtle detail in the darks and not blow out the highlights. I thought perhaps a double scan might work for situation.
I scanned one time for the highlights and a second for the shadows. Then layered them in photoshop with the darker scan on top, made a luminosity mask for the top layer which holds back the dark tones, blured the mask a few pixels with gausian blur, and flattened the image. Got an image that that picked up the whole range of the negative.

Alignment of the two scans is sometimes a problem. The trick is to change the blending mode of the top dark layer to difference and them move the image with the arrow keys so it all lines up when the screen goes darker, then change back to normal blend.

A luminosity mask is made by alt+ctrl+~ on windows, command+option+~ on the mac.

I suppose you could use the "Blend if" function sliders to blend in the highlits and block the shadows. Work with the top sliders and ose the option key on a mac to split the slider so there is not an abrupt transition.

Another hint is to open the two files and rename the layers one and two so you can stack and move them. Use the move tool, v, and hold down the shift key and they self allign as closely as two scans can go.

http://www.thelightsrightstudio.com/tutorials-video.htm

tutorial link

Give this a try next time you get a hark to scan negative.

 

[Brian Puccio]

Have you compared this (fairly manual process) to Vuescan's multi exposure option: http://www.hamrick.com/vuescan/html/vuesc28.htm#inputmultiexposure ?

 

[maddoc]

Thanks for that tutorial ! It sounds helpful and like not to much hassle with PS. I often face some difficult to scan negs and will give it a try.

Cheers,

Gabor

 

[sojournerphoto]

Another useful approach using Nikonscan is to increase the manual (analogue) gain in one colour channel (say blue) and reduce it in another (say red). Typically =1 and -1 is sufficient. This gives you a coloured output in rgb mode that you can blend using duplicate layers and layer masks. Simply create 2 new duplicate layers and use the channel mixer to convert each layer to greyscale from one colour channel. Then the green channel is your base image and you can use masks to pull information from the other layers to maintain highlight and shadow detail.

MIke

 

[robert blu]

Interesting infos for the ones who, like me, use an hybrid workflow. Thanks, I'll try it.
robert

 

[Ranchu]

Alignment of the two scans is sometimes a problem. The trick is to change the blending mode of the top dark layer to difference and them move the image with the arrow keys so it all lines up when the screen goes darker, then change back to normal blend.

That is very smart, thank you!

 

[stompyq]

Good information. Thanks. I use a similar 2 scan approch for dust and scratches on my neg.s. Once with and once without ICE.

 

[Mcary]

Alignment of the two scans is sometimes a problem.

http://www.thelightsrightstudio.com/tutorials-video.htm

If you're using using CS2 or a newer version of Photoshop here's a way to get your scans to to line-up perfectly.


Step 1 Open the scan you did for the shadows or the scan you did for the highlights which ever you prefer in Photoshop
Step 2 Go to Layers-Smart Object-Group into Smart Object.
Step 3 Go to Layers-Smart Object-New Smart Object via Copy
Step 4 Select the new layer then go to Layers-Smart Object-Replace contents. When the file open window appear select the version of the scan that you didn't open in step one.

There you have it two perfectly aligned scans/layers