Using PWP to enhance scans from negs

[tonygamble]

I am embarking on the daunting task of scanning some of my ten years of negs into digital positives for web folders.

Wisely (I guess wisely) the Epson Scan software defaults to a flat positive. I am sure this is ideal as one can always add contrast and stretch the tonal range. Snag is an image that has nothing below 10 and nothing about 240, and is also slightly under exposed, does not make for an exciting image in a web browser.

I have been changing each one in the scanning software. It takes ages and there is no 'copy' facility.

It has just occured to me that the solution might be to allow Epson Scan to do all the positives in this default mode and then use the batch/widget facility in PWP to up the dynamic range. Does anyone feel like suggesting some settings in, say, the Grey dropdown, that would get me closeish to what I am aiming for?

I may need to come back for some help on widgets as it is ages since I used them - but learning them on the right adjustments will at least be more fun.

Tony

[ksinkel]

It would be easy to expand the dynamic range to full scale for each image using the workflow. To do so, use the Gray/Levels and Color widget and click its Full Range button. You can also add other widgets for further processing, possibly using the breakpoint feature if you want to customize settings for each image.

Kiril

[Dieter Mayr]

Tony,

If you can, scan them with 48 bit colour depth and best possible quality.
Scanning (especially a big bunch of pictures) is a boring, slow, and tedious process, so you only want to do it once and get the best out of your images, even though you might only need some web pictures now.
You would bite yourself you know where when you need to do the whole process again in a year because you need bigger images. (Have been there, done that ... )
As for processing, be careful to crop the images that you have no withe border from the prints or scanner around, this will screw up your Full Range adjustments and maybe color balace too.
As Kiril alrady suggested Full Range often does a good job, a S-curve to enhance contrast would be in my workflow, too, if needed a color balance widget, depends how well processed your images are, how old they are and the storing conditions.
Be prepared to have to lay hand on manually to the one or the other image, you will probably never get them all out as you wanted with a automated workflow.

[tonygamble]

Thanks Kiril and Dieter,

Oddly the Full Range does not make much, if any, difference to the flatness of the jpgs. Don't know why.

But I can stretch the slider to 10 or so either side. And I have done a batch with about 20 extra brightness. Probably not the optimum but I can experiment.

If I construct a worklow that exports to another folder I can revisit the really bad conversions.

I hear what you say Dieter but all I am doing is converting the prime events that I photographed on neg to digital files that people can browse on the web. The good photos have been converted a while ago. For example a Garden Party in 1995 is probably going to interest nobody but there might be the odd person who remembers it for a special reason - so all the shots will be there. It is a matter of creating an archive - nothing more. But, whilst the next 24 negs are plodding through the scanner I might as well use PWP to make them more viewable.

Thanks for the ideas.

Kiril - the built in help system is seemingly zero on the subject of Saving and Reloading Workflow files. When, if ever, you have a spare moment a para would have saved me half an hour of trial and error.......

[ksinkel]

Contrast is proportional to the slope of the brightness curve. Because of that, expanding the contrast to full scale will have only a small effect on contrast. However, it is still worth expanding the brightness range because doing so produces better blacks and cleaner highlights.

For more contrast you might follow Dieter suggestion and reshape the brightness curve to a slight 'S' shape. The S curve has a steeper slope in the center and thus increases contrast over most of the brightness range. (Of course this is at the expense of lowering the contrast in the shadows and highlights.) Frequently just a very mild reshaping is all that is required.

As far as workflow documentation is concerned, Workflow is designed to automate PW transformations. There is thus no separate documentation for most widgets -- they simply behave like their corresponding transformations. Files Save and Copy widgets and a few others are exceptions and therefore have separate documentation.

Kiril

[tonygamble]

Thanks Kiril,

Points taken.

My problem was how to save the actual workflow itself - and then find it again half an hour later when I had forgotten how I saved it.

I used the File box within the workflow - but I don't think you say that anywhere - or do you?

Tony

[ksinkel]

Saving the workflow is described as part of the description of the lower Workflow Pane of the Workflow window. However, I am glad you figured out how to do it.

Kiril

[tonygamble]

Contrast is proportional to the slope of the brightness curve. Because of that, expanding the contrast to full scale will have only a small effect on contrast.

Would not that increase the degree of the slope?

If you make the blacks blacker and the whites whiter then surely the contrast has to increase?

Sorry if I am dim. I have a lot to learn.

Tony

[ksinkel]

Increasing dynamic range does increase contrast. However if once you have adjusted the dynamic range to full scale, you still want to increase contrast further, you can do so by 'bending' the brightness curve into an S, as shown in the attached image. The S-curve allows you to steepen the central portion of the brightness curve without losing either your shadows or highlights, as you would if you pulled the dynamic range controls off-scale instead.

Kiril

[tonygamble]

losing either your shadows or highlights, as you would if you pulled the dynamic range controls off-scale instead.

Thanks, Kiril.

That is the point I was misunderstanding.

I'll re-run the untreated jpgs again this morning - the advantage of putting the results of my PWP widgets in another folder and not overwriting the originals.

Tony