Wish: Adjustment-induced data loss indicators!

[Carson Wilson]

I wish SilverFast had an easy way of telling me when a curve adjustment was resulting in a lot of lost data. I think PhotoShop does this by allowing you to turn all of the pixels that will turn to white or black on your output device to a contrasting color.

The idea is to make it easy to detect posterization or flattening in the preview window, or through an alarm of some sort. This would reduce the trial-and-error that occurs with difficult images. Often it's difficult to see posterization in the preview window, or even full-screen, and I don't notice it until it shows up in my prints.

I should think that SilverFast could help us by calculating mathematically the ratio of lost to existing color range that will occur as the result of an adjustment and somehow displaying this to the user. Perhaps even a "loss meter" of some kind would help.

Any thoughts?

[ianders1]

Carson,

That's a cool idea, but I wonder how it would work. The problem is that the prescan is low-res, so Silverfast doesn't see the actual pixels of the scan, and second of all, since it's a prescan, it's not actual pixels that it's looking at, like PhotoShop does.

Maybe they could implement something that would show when you made highlights and shadows white and black respectively in the prescan window.

This would be a very valuable tool for getting the maximum dynamic range without losing important detail, and let's see if the talent at Silverfast could incorporate something like this.

-Ian A.

[Guest]

On 2001-12-28 18:30, Carson Wilson wrote:
I wish SilverFast had an easy way of telling me when a curve adjustment was resulting in a lot of lost data. I think PhotoShop does this by allowing you to turn all of the pixels that will turn to white or black on your output device to a contrasting color.

Nope - Photoshop has a clipping display in levels that shows when you have began clipping image data. Push too far and you loose the data. This functuion is NOT available in Curves.

You can use the white and black point tool (left side of preview screen belwo what looks like a trash can) to find the lightest and darkes pixels. If you push the white or black to max or min the whole area will turn black. You should try it and I think you will realise it is better than you think. If only a few pixels turn black then you do NOT have a problem. You can also see on the levels histogram display where those pixels are. You can use the Alt key in the Levels Histogram to see how the data spreads after correction. If you experiment with SilverFast tools you'll realise that there is a lot more to this toy than a simple scanner interface. I'm all for new features and improvments on the old but add more features and SilverFast will begin to creek. Lets fix the bugs before we implement features that already exist, albeit in a different form.

The idea is to make it easy to detect posterization or flattening in the preview window, or through an alarm of some sort. This would reduce the trial-and-error that occurs with difficult images. Often it's difficult to see posterization in the preview window, or even full-screen, and I don't notice it until it shows up in my prints.

Since Silverfast is working on the high bit data from yor scanner there should be no problem. You can also increase the resolution of the prescan display by changing it to 2X, 4X etc. in the Option>General tab. more detail in the prescan - No Problem! Again the tools exist you just haven't found them

I should think that SilverFast could help us by calculating mathematically the ratio of lost to existing color range that will occur as the result of an adjustment and somehow displaying this to the user. Perhaps even a "loss meter" of some kind would help.

Any thoughts?

I don't know what this means and I don't know how it would tell me anything my eyes don't already!

I'm not being nasty or awkward but I really do think a lot of these requests for features have little benefit over those we already have.

Ian

[ilyons]

The above message was posted by Ian Lyons and not Anon!!

[ilyons]

Carson,

I'm not sure if my words pointed you in the right direction or just made you search out the shotgun (just in case; I'm hiding in a steel box). Nevertheless, you and lot of other folk seem not to clear on how extensive the existing features in SilverFast are. I have written up the following tutorial as help. It simply shows what I "tried" to describe in my earlier post. There are a few more examples I want to include but cannot figure how to capture what is in effect a dynmaic screen capture. As soon as I figure this part out I'll include the screenshots.

Note the dynamic screenshots have now been included!


The tutorial can be found at the following location http://www.computer-darkroom.com/sf5-negafix/edit.htm

Ian





<font size=-1>[ This Message was edited by: ilyons on 2001-12-30 20:59 ]</font>