Scanning a transparency using EpsomScan: the input/output selection?

[l2oBiN]

For BW it quite logical, select the white and black points and then scan. However, for transparencies it apperas that each color has a selectable range. I have been looking at each histogram (red, green, blue) and seeing which contains the biggest range, then adjusting the combined levels to that range. While this seems to capture all the infoation, it often provides an undesirable exposur/look. Is this the right way to scan a transparency?

[Lenny Eiger]

It is really much more complicated than that. Both in b&w and color. You scan for the kind of print you want. You need to separate the tones so that they can be manipulated in photoshop... and the scan should be in range of the print you want to make... not necessarily matched, but in range.

Lenny

[l2oBiN]

Lenny, I would love to learn more. Could you point me to the right direction? Are there any tutorials or is there any literature on the web that would be helpful?

[Greg Lockrey]

Once you made a profile for the film type and printer-paper combination used, I would leave the adjustments post scanning in a program like Photoshop. I don't care what anybody says you can not calibrate LCD screens to be as accurate as the final output on paper if that's where your going. How your image will look on your screen will be different than mine. My work flow is: make the scan- sharpen in PS-make an 8x10 sample on paper and then tweak more in Photoshop. FWIW my business is copying artwork and making limited edition prints. So I have real world colors to match and not some subjective colors that I think look good. Don't make it harder than it is..... it ain't rocket science.

[Peter York]

It is really much more complicated than that. Both in b&w and color. You scan for the kind of print you want. You need to separate the tones so that they can be manipulated in photoshop... and the scan should be in range of the print you want to make... not necessarily matched, but in range.


AFAIK the only hardware-driven adjustments on an Epson, besides resolution, are the black and white points. All else is software driven, and many prefer to use Photoshop for these adjustments. A drum scanner is quite different.

The only reference to this that I have seen is Diallo's "Mastering Digital B&W." I think this is the least-known aspect of scanning workflow.

[Frank Petronio]

I generally treat my consumer level Epson and 35mm film scans as auto-raw input devices and often go with the auto-levels for film that isn't too wacky. Sometimes the highlights - white point can be moved over to hold more detail, sometimes I'll move the black point to open up the shadow... but beyond that, the Epson and Vue Scan software is so crude that there doesn't seem much point in fine-tuning it. And if you don't like the scan, do it over a few minutes later....

I haven't used a drum scanner since the G3 days so I don't know if the software has gotten better at previewing and pre-scan adjustments... but I remember the old Howtek and Leaf-Scan apps were nothing to get excited about either. It's just not going to get developed any further, we're stuck with small, crap previews and 1996 interfaces... it's a shame since Epson and Nikon must have milked their scanning software development costs a generation ago.

[Mark Stahlke]

AFAIK the only hardware-driven adjustments on an Epson, besides resolution, are the black and white points. All else is software driven, and many prefer to use Photoshop for these adjustments.
This brings to mind something I've often wondered about. When I scan in 16 bit mode on my 4990 with EPSON Scan is the hardware extracting 16 bits of data or is the software outputting a 16 bit file?

[Ken Lee]

This brings to mind something I've often wondered about. When I scan in 16 bit mode on my 4990 with EPSON Scan is the hardware extracting 16 bits of data or is the software outputting a 16 bit file?

Make an 8-bit and a 16-bit image, and compare the histograms in photoshop. If you are only getting 8 bits spread over 16, there should be gaps in the 16-bit histogram, like a hair comb. If the curve is smooth, then you are getting true 16-bits of data.

[l2oBiN]

I am also a little intrigued by how the hardware + Epsonscan works because if it's only the black and white points that are hardware limited, why does the gamma value play such an important role in determining the malleability of the scanned image? Is there any way tiger the "full raw data" from the scanner? This should shurely be the best file for post manipulation if it fallows the raw file format found in cameras?

[Lenny Eiger]

I haven't used a drum scanner since the G3 days so I don't know if the software has gotten better at previewing and pre-scan adjustments... but I remember the old Howtek and Leaf-Scan apps were nothing to get excited about either. It's just not going to get developed any further, we're stuck with small, crap previews and 1996 interfaces... it's a shame since Epson and Nikon must have milked their scanning software development costs a generation ago.

Frank,
Digital PhotoLab is quite good. You can preview down to the grain if you want. It's excellent at pre scan adjusting and adjusting the scanner's range so it scans with the pre-scan settings vs doing it afterwards.
Lenny

[Lenny Eiger]

Lenny, I would love to learn more. Could you point me to the right direction? Are there any tutorials or is there any literature on the web that would be helpful?

I think you're in the right place. There are a lot of folks here who use your scanner to good effect. I like many parts of Amadou's book as well, but I would say there is no definitive manual on how to scan. What you have to do is go find an expert and go thru their workflow with them. Most are very happy to share...

You are always welcome here, especially if you bring that little Wisner to trade... ;-)

Lenny

[l2oBiN]

Lenny your pm box is full!

[Lenny Eiger]

Lenny your pm box is full!

Fixed, thanks...

Lenny

[Wayne Crider]

Any thing like a HDR scan possibility?

[l2oBiN]

Any thing like a HDR scan possibility?

+1

[Ramiro Elena]

I spent some time at Ken Lee's site last night and found it extremely helpful. With the few tips he provides you should be able to get good scans and he precisely talks about input/output tweaking.
The green channel tip was great. I already knew about it but never thought to apply it on scanners.
You could work HDR scans by scanning the same image more than once. I think Broadbent does it.

[Ken Lee]

"Is this the right way to scan a transparency?"

Color films have a non-linear response to light in each channel. In other words, each color channel has its own curve, not just a straight line. Making matters more complex, these curves vary, depending on lighting conditions, film processing, etc. Over time, the dyes in color slides and negatives fade - and they do so according to yet another set of curves. So while it might be straightforward to calibrate a monitor or digital camera or scanner, it's more challenging to profile a film.

In the days of color film, professional printers (the people who ran the printing presses) knew how to mix their inks correctly to accommodate popular film stocks. Shooting color film today, it's very helpful to shoot a black/white/gray target (http://www.calumetphoto.com/eng/product/x_rite_colorchecker_3_step_gray_scale/mo2315) at each scene. (Even with digital, which has so-called "white balance" technology, it's still very helpful.) Opteka (http://opteka.com/optekapremiumreferencecolorandwhitebalancegreycardsetwithquick-releaseneckstrapfordigitalphotography.aspx) makes a small one that looks pretty affordable and portable.

Of course, a calibrated monitor is a must, and the paper+printer+ink has to be profiled, or it's a colossal waste of time and materials. See CHROMiX at www.chromix.com (http://www.chromix.com)

Scanning old color media, we have to approach each image separately. It's much easier if we can find a gray/black/white section of the subject, and let Photoshop do the heavy lifting. There are many free tutorials on the web, for which you can perform a search (http://www.google.com/search?q=Photoshop+color+management&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a) with your favorite search engine. There are many books on the subject, such as Real World Color Management (http://www.colorremedies.com/realworldcolor/).

Did I mention CHROMiX (http://www.chromix.com) ? :) Pat Herold (one of their staff) contributes here generously from time to time. They can steer you in the right direction and save you an eternity of frustration. As their name suggests, color is their... profession.

[l2oBiN]

In BW scanning, could someone please explain the gamma value? It seems to be extremely important in obtaining the maximum from the scan? is this a software based post scan application?

[Greg Lockrey]

http://www.underwaterphotography.com/PhotoShop/PhotoShop/help.html yes