View Full Version : Trouble scanning chromes
I've just picked up a new Mikrotek i800 to scan my 4x5s (mostly chromes, a few negatives), and I can't seem to get the scan to even vaguely resemble what the chromes look like.
I'm very adept at Photoshop, so that's not the problem, and I can easily deal with color casts.
The problem is one of tone and dynamic range. Even scanning in 48-bit HDR with Silverfast or in 48-bit RGB mode in Scanwizard the scans are extremely flat and I can't seem to lift detail out of it. The slightest curve / level adjustments will blow out brighter midtones. Shadows are completely blocked and unsalvageable. For a scanner with a very high dynamic range (D of 4) I expect more than I'm getting.
I have a 4990. I found that scanning a well exposed b/w is easy, but it takes some experimentation to get a good scan from either a poorly exposed b/w or a trany. That is why I now mostly shoot color negs, Fuji 160S, which scan beautifully with Silverfast and give very saturated scans.
I found the best soln is to scan in RGB 48 bit, and carfully adjust the sliders. I usually do a couple of test scans at 1/4 of my desired resolution (faster), with different brightness and contrast settings. Once I find the correct setting, I go into the LAB colorspace to pump up the contrast and saturation. The resulting scans are quite good.
Bottom line, these consumer scanners don't do full justice to tranys. They do a great job with Fuji 160S though.
Try this first. Do a global reset of SF by deleting the preferences file. This will reestablish the defaults.
I'm definitely finding that the 48-bit HDR scan function in Silverfast is superior to the 48-bit scan function in Microtek Scanwizard; but Silverfast is a lot less easily manipulated at the same time. It came with my scanner, but I can't find a way to get access to its upgrades (for less than $500) -- and it doesn't support Digital ICE!! And Vuescan doesn't seem to support the Microtek i800 yet.
So now I'm dealing with a chrome with one area of sky that's not blown out, but I can't seem to scan it with any color left over. Any thoughts?
That seems very high for i800 upgrades. Email them.
No it does not support DI, never did and never will.
Did you try reseting the defaults as I described above?
Kirk is right, go to http://www.silverfast.com/pricing/en.html and you will see that the price for the i800 is $119 for teh full version of Ai which should solve your problems.
Ah, thanks, I'll look at those upgrades. The upgrade button that pops up when I open the bundled version doesn't take me to that page.
I haven't tried to restore the defaults yet.
This image is the quintessential example of what I'm having trouble with. The 'blown out' sky near the horizon and the very dark, nearly clipped shadows like on the bell tower, have lots of color and detail in the original chrome (which is beautiful). Even scanning in 48-bit mode with a linear tone curve hasn't helped.
The whole image looks pretty cyan. Are you calibrating your scanner with an ITT target? I would. It just looks off.
Try with this image going into curves, grabbing the middle eyedropper and clicking on some of the grey sunlit pavement in the cross street. Does that help the overall color balance at all?
The 'blown out' sky near the horizon and the very dark, nearly clipped shadows like on the bell tower, have lots of color and detail in the original chrome (which is beautiful). Even scanning in 48-bit mode with a linear tone curve hasn't helped.
CCD disease. The CCD array can't equal the dynamic range of the film. As you can see, the 4.0 Dmax claim is hype that doesn't live up to the reality of your chrome.
What can you do? A drum scanner could easily handle it. A professional flatbed like one of the Creo scanners might be able to do it. Consumer CCD scanners just don't have the capability yet.
Negative film has a Dmax considerably lower than chrome film. Your consumer CCD scanner should be able to handle this lower Dmax just fine. The software however may have problems with the orange contrast mask or with inverting the colors. Depends on the software. The added benefit of negative film is the increased dynamic range will let you capture subject brightness ranges (SBR) several stops larger than your chrome film can handle.
So, if you want to keep using your existing scanner, I suggest moving to negative film. Else, move to a better scanner. Sorry I can't be of more help.
This scan is well below the capabilities of this scanner. Indeed it is well below the capabilities of even much cheaper flatbeds.
Scanning color negs is a goog idea, I do that myself, but he needs to solve his immediate problems as he clearly wants to scan some of his existing chromes.
Dr, The technique I suggested above about setting the midtones, I tried it on that image and it did not help much. You need to do an ITT calibration I think.
I haven't calibrated the scanner -- it is way off, though. In fact I had a nice shot with Portra 160 NC of a golden beach that also looked cyan.
I've never calibrated my monitor, but for someone not professionally printing my monitor is as close as I need it. But my scanner could certainly use some calibration. How would I do (and what is) an ITT calibration?
It's just not worth my while for a drum scan or a >$1000 scanner as this is just a hobby. I'd rather spend the money on lenses. :)
Is it possible to scan the image separately for highlights and shadows?
Silverfast AI Studio has curve sliders that makes holding the highlights and shadow detail much easier.
There are curve sliders in the bundled version too, but the scan doesn't seem to 'read' the detail in the highlights and shadows. It seems to exaggerate the contrast, even when I set the whitepoint and blackpoint to 0% clipping, lift the shadows, and flatten the curve. In the original chrome of this image the extreme color gradient in the sky isn't nearly so obvious. By the same token my scans are really magnifying vignetting (which I'd think I shouldn't be getting if I'm using a 90mm super angulon xl on a 4x5 and with limited movements).
Kirkk is absolutely right. OTOH,it is impossible to tell where your workflow is going astray without knowing what you are doing step by step. My guess is that you are making some errors when you set the white and black points. FWIW, without seeing the original and without knowing the details of your wokflow and settings but accepting that the chrome is 'gorgeous' it definitely appears to me that the white and black points are mis-set and that there is an inappropraite curve in the instructions.
See my PM on our scanning workshops if it is of any interest.
Thanks so much for all the input.
Because I'm concerned about clipped highlights and nearly clipped shadows I'm setting my white and black points not to clip at all, i.e. at 0 and 255. I'm playing with different curves, but my best results have been from keeping the curve linear and decreasing the contrast slider. Then once in Photoshop I can use curves to reintroduce contrast.
At the same time, I'm really hoping for fidelity to the chrome, rather than trying to recreate it from a substandard scan.
Can't you make 2 scans (one fo the high values, another for the low values) and then overlay them in PS ?
If not, then next time, make 2 shots, and overlay them later in PS.
Or, do what Hollywood does: bring in a bunch of lighting equipment in a huge truck. Don't forget the donuts and coffee ;)
If you don't care to purchase a high-end scanner - just for this shot, and the occasional ones like it - then you can always just send it out to be scanned. The money you save will be your own, and in the future, you might learn to "just say no" to such a scene.
I might offer the comment that scanning is a learned skill. One can't expect to just lay a negative/transparency in the holder and get a great result. Find a well exposed film and experiment. Setting the scanner on auto may not get you a great scan (sometimes it does though).
Calibration of the screen and the scanner is a must first step. Calibrated workflow from input device (scanner/digital camera) to printer is essential to keep you from chasing your tail. I'm a fan of X-Rite's system. The key to a good scan is to get all the data intact, not clipping any channels. The output may not look great, but an editor (PS or Capture NX) can bring it to life.
I upgraded to Ai, and also purchased their IT8 calibration tool, which I have yet to put into action. The 48-bit non HDR option seems like it gives me the most flexibility. I also corrected a gamut mismatch (I was scanning in sRGB but my default colorspace in PS is ProPhoto), which probably explained the color shifts. Not a perfect scan, but not a perfect photo either.
Thanks for all your help again.
Paul I assume you mean you purchased an IT8 color target, correct?
Well, I believe the IT8 upgrade to Ai includes both a color target and film profiles (they seem to be all Kodak).
But after working for 2 hours or so, Ai just began to crash on startup and bring CS2 down with it, so I'll be spending tomorrow on the phone with their helpdesk. In short it hasn't worked for long enough for me to figure out how to use the features in the IT8 upgrade.
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