Slide film scan does not look as great as the original

[Poisson Du Jour]

I was shooting on private property, half in error on my part. There were no trespassing signs although I thought I may have been trespassing. The scene was too pretty to pass up but couldn't wait to check it out after sunset. The owner chased me away just as I clicked the shutter then sent her husband to chew me out. I apologized and then emailed them an electronic copy after I scanned it to make amends. Frankly, I'm glad I didn't get shot

Oh...DEAR!

 

[markbarendt]

I haven't yet conducted these types of testing and I would appreciate seeing your setup and results on this.

No formal testing on my part, the ranges of these films have been well known for a long time. Slides show you exactly all the details they hold. The limits are the blacks and whites easily visible.

On the digital side and the negative film side there is typically ‘left over’ detail outside the range of a straight print positive.

Quick test to demonstrate this digitally, set your camera’s contrast setting as flat as possible, low contrast. When you import that photo into your computer you’ll probably find that you need to set the black and white points to make it look right. Everything outside the black and white points is the extra range you have in relation to a slide.

 

[Les Sarile]

No formal testing on my part, the ranges of these films have been well known for a long time.

I have made some informal observations and will move on to better qualify them formally. Unfortunately, long held premise about things don't mean it is so. For instance my results from Kodak E100 underexposed areas are in fact very good. Hopefully with it's return, I will be able to finalize testing.

 

[markbarendt]

I have made some informal observations and will move on to better qualify them formally. Unfortunately, long held premise about things don't mean it is so. For instance my results from Kodak E100 underexposed areas are in fact very good. Hopefully with it's return, I will be able to finalize testing.

So, when a slide is viewed in non-digital form (light box or projection) the only variable that allows seeing more shadow detail is increasing the luminance of the light source, that’s a global adjustment (unless you are making masks) and that global increase comes at a cost, it blows out some of the highlights and raises the mid-tones. This has always been the problem with slides.

When you scan a slide though the toe can then be played with ‘locally’ without blowing up the rest of the image. At that point you can tease out more shadow detail. Once you reach the black point on the film though, you are done, period.

In the digital world slides are akin to having a digital camera process the photos and save them as JPEGs. That process clips the data at the ‘after adjustment’ black and white point. Any extra data that was available is lost at that point. The finished black and white points are absolutes.

With negatives and raw digital data the positive we normally see rarely uses the full range of data the film/sensor catches. In this case though the ‘original’ data caught is still available, un-clipped. You get the opportunity to start over any time you want with data/detail that may actually be on the straight line and therefore ‘of higher quality and more easily used/manipulated.

 

[Mainecoonmaniac]

Don't transparencies hold more detail than a scanner can digitize? Never tried it, but I think you can do multiple scans for the highlights, middle tones and shadows then blend them in an HDR file.

 

[faberryman]

I think it is unrealistic to think a scan and print is going to look as good as a slide on a lightbox.

 

[Les Sarile]

So, when a slide is viewed in non-digital form (light box or projection) the only variable that allows seeing more shadow detail is increasing the luminance of the light source, that’s a global adjustment (unless you are making masks) and that global increase comes at a cost, it blows out some of the highlights and raises the mid-tones. This has always been the problem with slides.

That is the traditional assessment but we now have tools for more isolated adjustments.

 

[Les Sarile]

Don't transparencies hold more detail than a scanner can digitize? Never tried it, but I think you can do multiple scans for the highlights, middle tones and shadows then blend them in an HDR file.

That is what I have done to years old slides that I have and have been able to make much better adjustments. When I make more formal tests, I should be able to better quantify what I can achieve on slides much like I have done for negatives and b&w.

 

[markbarendt]

That is the traditional assessment but we now have tools for more isolated adjustments.

I suggested masks and digital fixes, what tools are you talking about?

 

[markbarendt]

That is what I have done to years old slides that I have and have been able to make much better adjustments. When I make more formal tests, I should be able to better quantify what I can achieve on slides much like I have done for negatives and b&w.

You can absolutely do it with slide film. It simply requires that A) you develop the slide film to a different contrast index, instead of 1.0 you need to get close 0.6 (essentially a huge pull/minus development) and B) you need to plan on adjusting the finished positive digitally to fix the final contrast.

The big problem is the color shift.

Les Sarile, these are actually just math problems. The manufacturers H&D curves for each film demonstrate the limits mathematically and show the range of usable exposure, I’d suggest you start there.

The numbers are well known, to change the numbers you have to change something significant.

 

[Kino]

Linear scans of Log materials are hard, if not impossible to create good a looking image. In the motion picture industry, we use Cineon .dpx log encoded files for both negative and positive materials to preserve the shadow detail. Linear encoded files waste over 1/2 of the dynamic range of the sensor, period. It's a pain in the butt to use log encoded files, because you then have to normalize them and then color correct them.
There is no simple solution to scanning film and getting a good image...

 

[markbarendt]

Linear scans of Log materials are hard, if not impossible to create good a looking image. In the motion picture industry, we use Cineon .dpx log encoded files for both negative and positive materials to preserve the shadow detail. Linear encoded files waste over 1/2 of the dynamic range of the sensor, period. It's a pain in the butt to use log encoded files, because you then have to normalize them and then color correct them.
There is no simple solution to scanning film and getting a good image...

Yep

 

[Poisson Du Jour]

There is no simple solution to scanning film and getting a good image.

There is. Understand the film's characteristics and expose the scene correctly. It does not need a PhD written about it.

 

[markbarendt]

There is. Understand the film's characteristics and expose the scene correctly. It does not need a PhD written about it.

That surely helps.

 

[Les Sarile]

Les Sarile, these are actually just math problems. The manufacturers H&D curves for each film demonstrate the limits mathematically and show the range of usable exposure, I’d suggest you start there.

The numbers are well known, to change the numbers you have to change something significant.

Sounds great now I will see how those numbers look in real life. No doubt film has been around a few but I suppose it's in my nature - having been a test engineer for a few decades now, to put numbers to the test and see how they add up.

 

[Les Sarile]

There is no simple solution to scanning film and getting a good image...

I am not sure if you mean this in the broadest sense or highly limited manner and/or that we just have very different skillsets and/or sensibilities.

 

[markbarendt]

Okay Les Sarile, here's the curve for Velvia. Direct from Fuji's mouth so to speak. http://www.fujifilm.com/products/professional_films/pdf/velvia_50_datasheet.pdf

The vertical lines I've drawn show roughly the range of usable exposure from the scene. One log equals 3 stops. The difference between my lines is about 1-2/3 log, or 5 stops.

The RGB lines diverge radically to the left of the "black' line. A divergence like that means a highly skewed color rendition compared with the rest of the photo where the RGB lines track together. This color relationship is at normal development. Changing development (push/pull) also skews the way the colors track so color shifts naturally follow development changes.

 

[Les Sarile]

The vertical lines I've drawn show roughly the range of usable exposure from the scene. One log equals 3 stops. The difference between my lines is about 1-2/3 log, or 5 stops.

Thanks for that but I am already familiar with that datasheet and all the others for films that I have used.

 

[philipus]

Back to the original post briefly, I'm not sure how that scan is a "bad" scan. Admittedly it's a small image file on shown through a forum's software over the internet but I think it looks quite OK. It would be nice to know more what is failing in the scan.

As for how I view my slides, I scan all my films and view the images on screens or on inkjet prints.

br
Philip

I have scanned my film with an Epson V700 and in the past a Nikon Coolscan 4000. The CS is sharper than the flatbed but they are both acceptable for a print. Then again a dSLR is more detailed than a CS. But the main thing I have with a slide is that it doesn't have the same impact as looking at the original slide.

I can see how one might appreciate b/w film or C41 film but with the original slide for me at least I see this slick, colourful, vivid, vibrant slide and the scan just doesn't look like that.

Like to know your views on this. How you do view your slides?

Cheers.

 

[Alan Edward Klein]

I find with Velvia 50, that when I post process, I start with white and black points or levels. By pulling in the range to the scanned range, 90% of the colors and exposure values seem to correct pretty well. I then tweak from there. I do not adjust any colors, contrast, or exposure until the level adjustment is done.

 

[Bob Carnie]

one only needs to google Fred Herzog Equinox gallery and look at scans of 1960 Kodachrome to see what quality can be achieved in a good operators hands.. Not sure who did them but they are quite fantastic.

 

[Mainecoonmaniac]

one only needs to google Fred Herzog Equinox gallery and look at scans of 1960 Kodachrome to see what quality can be achieved in a good operators hands.. Not sure who did them but they are quite fantastic.

Never saw the images, but I wonder if they're drum scanned? Drum scans uses photo multiplier tubes (PMT) , while most flatbed scanners use charged coupled devices (CCD). Do you have a drum scanner at your lab Bob?

 

[Bob Carnie]

Never saw the images, but I wonder if they're drum scanned? Drum scans uses photo multiplier tubes (PMT) , while most flatbed scanners use charged coupled devices (CCD). Do you have a drum scanner at your lab Bob?

I have an Imocan Flextight and a Creo Eversmart Supreme.

the images were most likely scanned by a very competent scanner operator... this is the most important feature, someone who knows colour, knows endpoints and knows when to sharpen and when not to sharpen... its a complicated dance. I have done much experimentation over the years of scanners and in the right hands all the top end scanners are equal.

 

[Mainecoonmaniac]

I have an Imocan Flextight and a Creo Eversmart Supreme.

the images were most likely scanned by a very competent scanner operator... this is the most important feature, someone who knows colour, knows endpoints and knows when to sharpen and when not to sharpen... its a complicated dance. I have done much experimentation over the years of scanners and in the right hands all the top end scanners are equal.

Scanners are like cameras. Requires a great operator. Without any real alternatives for printing slides, digital printing of transparencies is relying more on high-quality scans. Digital prints are only good as the digital image.

 

[MattKing]

The prints from those Fred Herzog (scanned) slides are truly marvelous. Bob Carnie is absolutely right.