Scanning negatives and transparencies with a DSLR

As you say, IR cleaning doesn’t work for silver-based B&W films, but it would still be very useful for colour films. When I have a bit more time I’ll read your other thread in more detail and try to follow the steps with a colour scan. Thanks.

Chris, do you know if the IR channel would show defects on both sides of the film, or would it require two IR shots, one on each side?

I cannot observe any difference on if the film is lying upside down or not (I had several scanned upside down by accident since for old film it is often not easy to detect the emulsion side correctly), so I would conclude that it shows defects on both sides. As far as I understand it is a transmitted light technique. But this is only out of experience, I did not do a direct comparison.

Wouldn’t the IR filter in the DSLR interfere with that?

I am not sure. Interfere, of course, but it may be nevertheless feasible, tt may depend a little on the actual frequency and on the power of the infrared light source.

There are “screw-on” filters sold that block visible light to allow for pure infrared exposure (marketed as “infrared filter”) which give the impression that the cameras do not entirely block parts of the infrared spectrum. For the application of film scanning, doing the infrared exposure at much higher iso values may be feasible to account for losses due to attenuated infrared spectrum. And/Or to use more power at the emitter. Furthermore, one would not have to use the entire dynamic range of the sensor, since the goal is a b/w mask anyway. To get a reasonable feeling, tests are required, and since I do not own everything which is required to do it myself, I try to collect indicators that allow for better understanding of the whole topic.

Thanks for showing your setup, it was quite similar to mine :slight_smile: I only used an Artograph LightPad as my light source, and my camera was hooked up to my pc for tethered shooting. I used DigiCamControl, which has a really nice ‘focus’ functionality that helped a lot in setting the focus just right. This was especially useful when the slides had been slightly damaged or wrinkled.

Still a question: how did you take multiple shots of the same slide? Your setup looks quite immobile.

I’ve only done a bit with tethering, mostly with Entangle, but should try DigiKam for that as well. Have you compared the two?

The film holder I showed in the photos is only for 35mm and there’s no reason to shoot multiple shots as even 24 mp exceeds the useful information in the slide. For medium and large format film I can move the holders around to get multiple shots. But even that 35mm film holder can move around easily.

I’ve been experimenting with light pads as well. While they are very convenient I’m finding two issues. First, my copy stand is not as sturdy as some, such as the Manfrotto. This means there is slight vibration which makes the images not quite as sharp as they are with the flash. Second, with one of the LED panels, the CRI (colour rendering index) is not that great, resulting in slight shifts of some colours. I have a better light pad on loan from the store and it seems more accurate for colour, but there’s still the sharpness issue. With ISO 100 and f8 on the lens, the shutter speed is 1/15 second, which is the worst shutter speed for vibration. I have an LED video light which is much brighter and gives me 1/250 second, thus sharper images. Still working on this as the light panels are more convenient.

1 Like

I believe all the tethered shooting options use gphoto2 as the backend, so they should all be fairly similar. I was happy with Engtangle and thought it was a nice solution.

I, too, have a similar setup (with a lightpad). Didn’t yet think about the vibrations, good point. I shoot color slides with bracketing (Magic Lantern) and merge them with HDRMerge.

Best,
Flössie

Flössie, just wondering if you’re shooting these raw. I’m shooting raw, processing in Rawtherapee and I really don’t think I have any clipping of highlights or shadows when carefully compared to the original 35mm slides or other film types. The dynamic range of the raw files is much greater than that of slide film.

Scott, I somewhere read it was 14 EV for slides, and my Canon isn’t a DR beast. I used Magic Lantern auto-bracketing and it produced three to five shots each 2 EV apart. But I usually throw away the brightest one(s). So basically two shots usually do. And it could well be, that one was enough, maybe I was overcautious…

Ah, and yes: I shoot raw, I must confess. :wink:

Flössie, I’ve noticed a significant improvement in both shadow and highlight detail when I started using a DSLR for scanning instead of a scanner, with the same slides or negatives. For instance, when zooming into dark shadows, slides I scanned with other scanners such as the Minolta Dimage Multi Scan Pro with Vuescan show noise and posterisation. The D800 scans are very clean in the same areas, with smooth transitions between the dark tones.

Similarly, I re-scanned some medium and large-format B&W negatives with the D800. The improvement in dark areas of the final image (light areas of the negative) is striking when compared to scans I did on an Epson 4990 with Vuescan. I don’t know whether this an issue with the scanner hardware, Vuescan software, or the setting I was using with Vuescan.

Do you have any experience with color negatives? I bought a KB12/80B filter for not clipping the red channel too early but had troubles getting good colors back in RawTherapee. I showed one example to @Morgan_Hardwood and he suspected the filter for my problems. Maybe I’ll give it another try without the filter this year if time permits. BTW, I also use the Sigma 70 2.8 EX for the job.

I don’t have a lot of colour negs, but have experimented with some. I’ve been able to get decent results in Rawtherapee by inverting, getting a white balance off of the orange mask between frames, then adjusting the colour temperature and tint. That profile can be saved for other negs from the same film type. It’s much more difficult for my dad’s colour negs as they are badly faded. Sometimes I just convert them to B&W. Fortunately he didn’t shoot too many colour negs, at least in material that’s important. I’ll post an example of one of mine.

This is scanned from a 6x7 Fuji colour neg. Cropped for the privacy of the models. Shot with a Nikon D7100 and processed in Rawtherapee.

2 Likes

Very nice! I’ll sure try without the filter.

I’ve also done tests with processing the Nikon .NEF files with Vuescan. It works fine, but I’m able to get better colour by processing the same files with Rawtherapee.

This is a great effort to do all these cloning and healing. I have lots of negatives that were stained. Have lots of trouble to remove it.

I’m interested in this topic as my parents did a lot of ice tours when they were young. So we find great information here.

It would be great if you would work together to create an article for pixls.us with all the information how to create a setup for taking photos of film negatives. Using rawtherapee invert or darktable negadocotor would be antoher topic :slight_smile:

1 Like

Andreas, I covered some of my setup in this thread. DIY copy stand for DSLR scanning

Also, this thread has good info about the RawTherapee film negative tool, which I found very useful.

Pat David and I are discussing an article.

2 Likes