Thanks for all of the replies! I will have another try sans filmic.
Calibration targets… these slides are not ‘high end’ photos - many are less bad than the test shot but we are not talking about National Geographic material here. I have looked into calibration targets in the past and concluded that their cost is beyond what these photos justify.
Is digitising with a DSLR a good idea? I’m sure that all of the reasons why not are valid but in my own experience… I’ve tried three different scanners over the past 10 or so years with my slides and all have produced poor results even after a lot of effort on figuring out settings and post processing. The most recent was an OpticFilm 8200 something or other. Fine in terms of resolution but it never coped with the shadow areas on my Kodachromes and for that reason it could not reproduce what I could see just by looking at the slide. The DSLR digs more detail out of the shadows and with less noise than the scanner so that’s why I’m putting my effort in that direction now. For some slides I have already had results that I am very happy with… but green grass and red pullovers don’t feature heavily in those.
I’ve seen differing reports about the dynamic range of Kodachrome. I don’t know the definite answer. I do know that I have the option of bracketing my exposures and doing an HDR stack. I’ve tried HDR on some more tricky slides with good results. I’ve also found that some slides that I thought would need HDR have actually worked fine with just a single exposure. In fact I struggle to get the optimum exposure in a single attempt so bracketed exposures tend to happen whether needed for HDR or not.
I’ll have a look at that preset but quite often my search results for Kodachrome turn up styles/presets etc which aim to apply a Kodachrome ‘look’ to the output of modern digital cameras. I already have the ‘look’. I want to get it digitised, hopefully without making it worse.
My overall impression from reading this thread is that it doesn’t need to be so complicated. I do DSLR scanning regularly and professionally, with excellent results. I use RawTherapee, not darktable, but the same principles will apply. This procedure below is for continuous light such as an LED light panel.
You need some slides that are “perfect” in that the color balance is dead on and they don’t need any adjustment to improve them. They should have good skin tones, some neutral grays, and a mix of other colors. They should also be sharp so you can recognize any issues with your focus, alignment or lens. They must be exposed perfectly.
Shoot a custom white balance on just the light source, with the slide removed. Read the camera manual to figure out how to do this. For example, my Nikons are only able to do a white balance shooting through the viewfinder, not on live view. Use this WB for shooting the slides or negatives.
This should be done at the lense’s sharpest aperture, say around f8 for most macro lenses. Set the ISO to base, often 100.
Put the slide in the holder and get the focus and size.
Remove the slide and shoot a blank, stopping down about 2 - 3 stops so the histogram is roughly centred on the camera’s LCD. The histogram should narrow column, indicating that the exposure across the frame is about the same. If the histogram spreads out at the bottom it means the exposure is uneven across the frame. You can see this clearly by shooting one with the the lens wide open, say f2.8, which will often show darkening toward the corners. A shot at f8 will show a much more even exposure.
Some of your slides will probably be a bit over or underexposed. Leave the aperture around f8, but adjust the shutter speed to make exposure corrections.
This shot is digitized from a Fujichrome 35mm slide, using two different LED panels as the light source. One panel has a good CRI and is about 5500 K. The other is a cheap Huion which is about 9300 K. In each case I set a camera custom WB to the panel and made no further color adjustments. Personally, I can’t tell the difference. This is a good test slide as it has skin tones, grays, whites and a variety of other colors.
Duplicated the image, compressed the history back to the default modules.
Played with colour balance to push green into the mid tones. Looked promising but a green tint was appearing in places where it wasn’t wanted
Turned on a parametric mask. I haven’t used these before so not sure what all of the sliders do but by trial and error with the preview mask I ended up with… Input L 0-49, Input C 13-100, Input H 37-123
added local contrast with default settings.
Other than boosting the greens I have not touched the saturation of the other colours.
Plenty of scope for more fine tuning (e.g. I’m not looking at the slide today) but I think this way shows promise…
Thanks for your thoughts. Your results with the two different light sources are very interesting. My two sources are not so far from each other temperature-wise but so far (other than the required white balance temp) I have not seen a difference in the results. The Solux lamp is preferable for a couple of more practical reasons - it is less bulky than the projector and it doesn’t have the same annoying tendency to produce a focussed image of dust onto the opal screen.
I only have the one (home made) light box so that’s busy previewing slides.
I’d like to be able to keep a constant white balance because it would be one fewer step in the workflow but so far that has not worked for me. I’ll have another try.
I’ll keep looking for a perfect slide. It may take some time
The colours in your images are not what Kodachrome looks like!
In my opinion, there is only one way to achieve good and authentic colours for Kodachrome slides, that is a calibration with an IT8-target: Shoot an IT8-target on Kodachrome material with the same illumination used for digitizing the slides, create the ICC-profile e.g. with Argyll and embed this profile into your images.
Caveat is, that these targets are rare and expensive!
Yes, you definitely need a better slide to establish your baseline color. I also notice that your image is soft on the right side, possibly out of focus due to an alignment issue. Are you using a mirror for alignment? A couple years ago I started a thread here about a DIY copy stand for digitizing film which you might find useful. Since then I’ve modified the system a bit, using a Benro GD3WH geared head and eliminating the Super Clamp. For a light source, a lot of people now are using a Raleno video light, which I’m considering getting myself. DIY copy stand for DSLR scanning
I think that is rather pessimistic. I’ve already had results on other slides that I am very happy with - a big improvement on results for the same slides from the OpticFilm scanner.
No, it’s the original slide that’s the problem. I think there was something wrong with my uncle’s camera because I see the same issue in other slides from the same camera. I’ve checked by messing with the focus while zooming in on the blurry areas in tethered live view. Ironically I’d always assumed that his kit was better and that he produced better photos. Most of my own shots are from my first 35mm camera which was hardly perfect (but not this bad). I have some later slides from my own Minolta XGM but I have not dug those out of their drawer yet.
I have an Ektachrome 35mm IT-8 target but rarely use it, as I get good results from setting my camera white balance to the light source. The scan needs to look good, and nobody is going to quibble about whether a piece of wood in the photo is R217 G167 B58 or R220 G166 B58. You can get excellent, professional quality scans without an IT-8 target.
no, it is my experience, and that of others. And, most importantly, it is just physics. You cannot ignore the spectral sensitivity of your detector in combination with the spectrum of the illumination not being standard.
Just a quote from the excellent book by Giorgianni & Madden (2008):
An RGB scanner will produce accurate CIE
colorimetric values, based on a particular light
source, only when used with a transform that is
specifically designed for the particular medium
being scanned.
In your case, replace “scanner” by “DSLR”. The principle is the same.
You can get better results with a dedicated scanner but that is only practical if you need maximum quality and have the time to do the scans. DSLR scanning is a proven technique, just keep it simple:
Take an empty shot against the light source to read your white balance.
Then pick a slide with heavy overexposed parts - or if you still have it - frame an empty slide from the overexposed leader of the film. That will give you the correction to get white - if you want to neutralize the whites of your film.
Same can be done for the blacks if you want.
Mind: the look of almost any film depends on neither black nor white being neutral grey but having a strong tint.
But turn off pretty much every tool in your RAW editor and start from there.
Once you have a setting you like it should work with pretty much every slide you have.
Wavelengths of light are physics, colour science… may be physics but with a huge slice of human perception to muddy the waters. Whether I’m happy or frustrated with my results… not physics.
A good point. I had not thought about the inherent tint of the film itself. From memory my leaders are black though… such as they are after I’d tried by best to get 37 or 38 exposures onto the film I’ll keep an eye out for major overexposure to check the whites. I need to check the ‘reject’ boxes. Dark areas are not in short supply.
Back in the day when most scanning was done by service bureaus charging hundreds of dollars per drum scan, the goal was to match the original transparency as closely as possible. Then, when the client complained about a scan having a slight color cast, the service bureau would point out that the original film also had that color cast, and they did their job by making a good match to the flawed original.
These days, with DSLR or mirrorless scanning, my goal is not to exactly match a flawed original, but to make the necessary corrections to improve it. Was the slide underexposed? Then I’ll increase the exposure time when digitizing. Was the slide taken in open shade resulting in an ugly blue cast? Then I’ll adjust the color temperature in RawTherapee. I don’t need an IT-8 target so I can get an exact match for a flawed slide. Instead I’ll use my own judgement, and a well-calibrated monitor, to get the image looking good to my eye.
Keep it simple. Set your camera’s white balance to the light source for a baseline, and make adjustments based on the individual slide.
I bought PacificImage Electronics many years ago, along with SilverFast SE Plus 9 :: LaserSoft Imaging. They have most if not all color profiles for film emulsions and scanners, and support multi-exposure HDR scan along with infra-red dust removal. Scanning is not exactly fast, but there is a lot less fiddling around than trying to hack your DSLR and fight everything at once.
I guess we are all a product of our experiences. My experience is that in 2013 I had my wife spend what is for us a considerable sum of money on a dedicated film scanner (with bundled Lasersoft) for my birthday. I thought it was going to be ‘the answer’. It wasn’t.
After 106 scans I concluded that I just wasn’t getting the shadow detail from many of my slides. Stretching the dark areas in post processing quickly produced a nasty reddish purplish ‘mud’ of noise. Admittedly some were underexposed but some just had a lot of dynamic range. I had a second try in 2018 and spent more time adjusting the exposure settings but it made very little difference - the scans got brighter but also more noisy. My conclusion about the scanner was that it just wasn’t able to cope with the density of the dark parts of Kodachrome slides and no amount of calibration or post processing was going to fix that. As I understand it this experience is not unique to me - the dark parts of Kodachrome are very dense but that does not mean that they don’t contain detail.
So for me the film scanner has been an expensive learning experience. Maybe there are scanners out there that can cope better with Kodachrome but I don’t intend to spend more money in that direction.
On a more positive note I discovered Darktable during my second attempt to improve the scanner output and I have not regretted that discovery at all.
I think it was when googling the issue with scanning Kodachrome shadows that I found some articles about using a DSLR to digitise slides. I already own a DSLR (a present for a significant birthday) so I saw no harm in trying it. My initial attempts with a secondhand bellows and my 1980s Minolta lenses on some slides with difficult shadows went well so now I have put together a better setup using an 80mm enlarger lens (secondhand again). Neither the bellows nor the lens has involved a great deal of expense and no birthday credits have been used in the process.
So, I understand what you are saying but please understand that there are financial reasons and past failures which have sent me down this route. I have had some good results already but it’s not ‘job done’ for every kind of image. I have also learned a lot more about image processing from your writing and videos while doing it so thank you for that.
I digitized this transparency about 5 years ago, before I was using the camera WB method. Still came out okay by eyeballing the color. Kodachrome 3x4 inch transparency from 1946, taken by my father. One of the wonderful things about Kodachrome is how well it keeps its color over so many years.
Nice! I’ve been sorting through my slides today. I’m fairly sure there are no film stars hiding in my collection.
My earliest (inherited) ones go back to around 1965. Most look OK but a few films have suffered - maybe from age or maybe they were not processed quickly enough after exposure. A few others have not been kept away from daylight and have suffered in that way. Most look usable though, excepting camera and operator errors and some really pointless subjects.
My experience is different. I’ve had numerous film scanners with the most recent being the Minolta Dimage Multi Scan Pro, which is an excellent scanner. After starting DSLR scanning I realized that the DSLR scans were not only faster, but more detailed and with better color. Part of the advantage was being able to manipulate those beautiful Nikon .NEF files with great software such as RawTherapee, compared to scanning software (Vuescan) that felt like it was stuck in 1995. I could even get rid of chromatic aberration that was in the original transparency. I sold the Minolta, at a profit, and haven’t looked back. Since I’ve been a professional photographer for a while, I’ve also been able to compare my current DSLR scans to drum scans that were done earlier, and they’re at least as good.
Any scanning workflow, whether using a scanner or DSLR, has a learning curve, and you get better with time and experience.
I know DSLR scanning is the new kid on the block but I agree with @anon41087856 here in that you’re compounding problems doing it that way. I’ve never understood the appeal vs a dedicated piece of hardware like a scanner that is properly calibrated and setup.
I’ve had OK success with my Epson Perfection scanners over the years (works with Linux and VueScan, a nice bonus) doing 35/645 scans. Before that I used the NIkon scanner in the school’s media lab but I honestly didn’t like the results as much as I did the Epson after some calibration. Could be the software or lab build they had on those Macs. Either way, I’m happy with the results from the V600/V700.
Mamiya 645 1000s with Portra 160 from my Epson with some adjustments made in GIMP.
Hm, what prevents you from editing the scanner output in the software of your choice? I am using vuescan to capture a “raw” tiff file, which can easily be processed in e.g. darktable.
I am going to test the camera “scanning” method in future though, since there are film formats that do not fit into my scanner. However, if you do own a scanner and the software is the only issue, maybe you can give some details why it does not work for you and maybe we can help solving the issue …
