Vuescan Color Frustration

[bongeiste]

I recently decided to start using film again and have run into some problems

with Vuescan. I had this problem earlier and simply reverted to an earlier

version of Vuescan, but I'm using a new computer (old computer died), so I don't

have the earlier version available.

 

Basically, I'm running into a problem which has been mentioned before where the

software seems to be taking into account the borders of the frame which throws

the colors of the picture completely off. The solution to this problem, from

what I've read, is to lock the exposure and film base color of the film before

scanning. I've tried this, however, and have run into several problems. First,

I've tried to preview a blank frame about half a dozen times. Most of the time,

the frame has come out black, but sometimes it comes out a pinkish color. I

checked the Vuescan "Help" and it says that when scanning color negative film,

the user should choose a frame that would scan as completely black. I'm

guessing, then, that when the scanner scans a blank frame and the result is

pink, there's something wrong. I've also first previewed the image, cropped it

and then previewed it again to find that the previewed image has gone from black

to pink.

 

I've also tried previewing the image, cropping the image in Vuescan to exclude

the borders of the frame, rescanning (preview), locking exposure, rescanning

(preview), and then locking the film color base. When I scan images, however, I

get the same problem. I've found that sometimes unchecking the "Lock film base

color" box helps a bit. What seems to work the best is to uncheck everything,

reduce the area that is scanned to exclude the edges of the frame and then scan.

This is a less than ideal solution as the cropped area isn't in the same

location on each frame (the film doesn't match up to exactly where the scanner

thinks it is on each and every frame) and I would rather have the entire frame

scanned so that I can crop the image in Photoshop.

 

Has anybody else had this problem and not had the Advanced Workflow solution

work? As much as I used to like Vuescan, I'm considering other software that

might not have this problem/quirk. Does anybody have suggestions on other

software to consider (besides Silverfast)? Am I doing something completely

wrong?

[peter_langfelder]

I think you should try again. For color negative, do this: uncheck all "lock" settings. Calibrate scanner. Preview a piece of clear leader - the whole frame need not be clear, in fact things may work more intuitively if it isn't. Click "lock exposure". Preview again, click "lock film base color". At this point (unless you select "white balance: none"), if you previewed a piece of film that is completely clear, the preview will appear pink(ish) and the scan histogram will span the whole range of values - that is normal, vuescan will by default choose the black/white points such that the histogram will span the whole range. Try selecting "white balance: none" in the Color tab to get rid of the (overcorrecting) behaviour. Irrespective of what your preview looks like, the film base color is selected correctly and locked in. At this point it doesn't matter at all whether the frame borders are selected or not - they let in less light than the emulsion, so the emulsion will be used for base color calculation.

 

<p>You can now preview a frame with a normal image in it. If you want to lock white balance and brightness, click "lock image color" after you previewed the frame. You can adjust the black and white points for all three primary colors with image color locked and the changes <b>should</b> be applied to all subsequent scans. I write should because there appears to be a bug in the UI that does not apply the changes to previews, which is quite annoying (I contacted Ed Hamrick about it several times, to no avail).

 

<p>If you want to adjust color balance for each frame separately, you can leave "lock image color" unchecked and work with the standard white balance settings.

 

<p>If you want to be able to scan the borders (i.e., film carrier), I strongly recommend choosing a reference frame and doing the above "lock image color" on it. If the image color is already messed up by borders, select a small part of the image, then carefully select most of the image but leave borders out (small changes of cropping will not trigger recalculation of colors, but large changes will - that's why you need to select a small area, then enlarge to a big one). Also note that there is a setting in the "Prefs" tab (IIRC) that allows you to specify a buffer at the borders that will be ignored for color calculations - you can use this to make sure the borders are never included in the calculation.

 

<p>Lastly, my preferred and recommended method of scanning negatives is to scan the leader, lock exposure and base color, then scan all frames into raw files. After I'm done with the physical scanning, turn the scanner off and restart vuescan; read in the raw scan of the clear leader to lock film base color, preview all image scans, select one with neutral grey, lock color on that, save settings, quit and restart vuescan (this because of the above mentioned bug), preview everything again (now the color lock has been applied to all previews), adjust colors and scan from raw to tiff. This way my scans have a correct base color, consistent (though perhaps not best) white balance and are extremely easy to touch up in your favorite image editor.

 

<p>There some more tricks I use, such as adjusting the base color manually to get more neutral and contrasty shadows, but I'd recommend getting the above the work first.

 

<p>Hope that helps.

[Robert_Lai]

I've just started to use vuescan with my Nikon Coolscan 5000, and I did find the lock exposure/lock film base color process somewhat intimidating at first. However, now that I've scanned several rolls of color negative film with it, it's a godsend. Unfortunately, the instructions on page 22 of the manual aren't exactly clear on what you need to do.<p>You want a clear film base to calibrate with. The ideal area is the clear section of the leader of film between the (black) light struck portion and the first image frame. If you don't have the leader handy (just in front of image 1), then the area in between image frames will do. Before you insert film into the scanner, uncheck the "Lock exposure" box. Also, check the "Multi-exposure" box, and I usually set the batch scan setting to "Off", and the multi-scan setting to 8.<p>Now, insert the film, and hit the preview button. Vuescan will obtain previews of the first image on the strip of negative. With "Lock exposure" unchecked, you will see black in the areas where the negative is transparent film base. Adjust the cropping until you see that everything in the crop box is in the black area.<p>The manual doesn't say this, but at this point I hit "Preview" again. Vuescan will adjust the exposure until the black crop area now looks beige/pink. You can look at the histogram (Curve/BW) to verify that the curves are close to zero luminance values, i.e. hitting the left side of the curve. At this point, check the "Lock Exposure" box. Ignore the fact that the black area now looks pinky-beige.<p>Hit preview again, and now "Lock film base color" becomes visible. Check this box. At this point, you can "Save options" and save all of your options under a name suitable for your film type, e.g. Kodak Gold 100.<p>Now, I change the batch scanning setting to "All", and generate previews of all of the frames on the strip. If auto crop/auto rotation don't get it right, then you may adjust these manually for each frame on the film strip. You can also adjust the focus point for every frame individually. If you don't want to scan all of the frames, then set batch to "List", and in the box underneath just give the frame numbers that you want scanned. For example, if I want frames 1, and then 3 to 6 inclusive to be scanned, you may type in 1,3-6.<p>The resulting scans don't have a gamma curve applied to them, and they usually look too dark and flat. Don't worry. Import them into your image editor, and they tune up very easily.

[bongeiste]

Thanks for the answers, guys. I'll try your suggestions and see what happens.

[steven_clark]

Have you tried upping your buffer percentage under the crop tab?

[mendel_leisk]

Steven beat me to it: upping your buffer percentage to around 15% will instruct Vuescan to ingore that percent of the edge. I believe it used to default to 15%, but it might have been revised to default to 0%. 0% is good only if you're dealing with raw files that are already cropped. Otherwise, and as long as there is a black surround on your images, you *need* to raise this percentage.

 

BTW, I've more or less given up on Vuescan for color negative film, and instead just scan as a slide with my scanner's OEM software, *only* ensuring nothing is clipping, and then invert and adjust through auto levels and a constrast enhancing curve in Photoshop. I might give it another try but I've found Vuescan very frustrating: color casts the norm, at least with my scanner.

[roger_smith4]

Vuescan can do color negatives very consistently with film base color and exposure locked. I prefer to do all color correction from there in Photoshop.

 

I find it much quicker than using my Canon OEM software- others with better software like Nikon may benefit less.

[william_norfleet]

From Peter's answer: "Lastly, my preferred and recommended method of scanning negatives is to scan the leader, lock exposure and base color, then scan all frames into raw files." Does locking the base color do anything during scanning into raw files? I thought such files contain the straight CCD output, unmanipulated in any way (most importantly, by any of the settings in the "Color" tab). Locking the exposure makes sense, but I'm not so sure about base color.

 

The nitty-gritty details of how VueScan processes color don't seem to be terribly well documented. I've done lots of trial-and-error, but I'm still never completely sure what's going on!