HELP!: How to calibrate VueScan?

[hassiman]

Hi,

I have a Nikon CoolScan 9000 and I was wondering if anyone could walk me through using a 35mm iT8 calibration target ( which I got from Silverfast) to calibrate VueScan for this Scanner?

I have read the documentation... but Neither the VueScan software GUI or the DOC are very user friendly.:confused:

[Ken Lee]

Where do you live ? A phone call might be easier than hours of typing.

[Leonard Evens]

Since Ken offered to talk you through it, I will let him do it. But i do have some general advice.

First, you have to use a camera target which you should be very careful to set up when photographing. Make sure the camera and the target are perfectly level and parallel to each other so the image is square on. When setting the cropping area in preview, you use the area inside the lines. That should be pretty clear because vuescan provides you with a grid to use in aligning the image properly.

Second, you have to read the instructions VERY carefully. If you do that, it works just as the documentation says it does. I even managed to use it to profile my Epson 3200 scanning Portra 160, which is a color negative film. The general wisdom is that you can't profile color negative film, but Vuescan managed to do it.

Third, you should understand what vuescan does with the profile. Under the Color tab, you set the information about the profile, but you also set the output space. Vuescan uses the profile to scan. It also uses the output color space profile to determine which RGB values it puts in the output file. (My advice is to use SRGB unless you have a strong reason to do other wise and you thoroughly understand enough about color management to know what you are doing!) By default no profile is embedded in the output file, but under the Output tab, you can specify that a profile be embedded in the output file. That profile will be the profile for the output color space, not the film profile. Your photoeditor, e.g. Photoshop or in my case Gimp, will never see the film profile used by the scanner. If you read up on color management, you will find that there are other ways of handling all this, so this can be very confusing. In my opinion, vuescan does exactly the right thing, but it can be confusing.

Finally, there was a bug which was present in vuescan which prevented it from producing a profile in certain circumstances when you already had a profile and wanted to create a new one. The circumstances were somewhat special, so you may not run into it. Also, Ed is aware of it and may have already fixed it. But if, in the process of learning how to do it, you end up wanting to replace an earlier profile with a newer one, and you find vuescan not doing anything when you tell it to make the profile---it shouldn't take long and it gives you a message when done--- you would be well advised to remove the vuescan.ini file from the relevant directory and start from scratch.

[konakoa]

I've had a lot of trouble trying to figure out IT-8 myself. It never worked no matter what I did. I came up with something a little different: I photograph a X-rite color checker card on film, scan the film, sample the colors of the card in photoshop, then use the color balance function in photoshop to cancel out my scanner's color bias. The corections put in the color balance box are recorded as an action, and I can apply it to every scan brought up in photoshop thereafter. Works perfectly for me.

I've done this for all the color films I use. Each film has its own set of corrections. All I have to do is photograph the Xrite and I have a color target to sample and make corrections from.