Dust on your film scans

In my class I discuss 3 main downsides to digital camera film scanning your own negatives. The biggest one that impacts everyone's scan quality is dust. Let's talk about it!

Dust impacts your scan by falling on your negative, and sitting on the surface. When the negative is scanned, it's put over a light source, and the light passing through the negative is blocked where that dust is on your film. Since the light attempting to pass through the dust is completely blocked, it will come out as a dark splotch on the negative. When you convert it (invert the image), it will be white.

This dust will vary in intensity, shape, and size. Some will be hair squiggles, some will look like small dots. Here are some examples of dust found on my film scans I got back from the lab.

Dust is everywhere around us. Unless you're using a really high quality, professional level film lab where they have created an environment where absolutely no dust exists, you're going to see dust on your scans in some capacity. If you're developing film at home, the Photo Flo step can help reduce the dust that accumulates on your negatives while they're hanging to dry. (Note: Dust that accumulates on a negative while it's wet and stick is impossible to remove later when you go to scan it with just an airbrush or an antistatic cloth.) It also helps to diligently keep your workspace clean of dust. I like to just wipe my desk and scanning surfaces off with a slightly wet sponge before I go to scan them and it does make a huge difference.

A good lab should be working in a clean environment to minimize their dust. That should go without saying though is easier said than done; I know I've personally walked into filthy labs. They're probably using special antistatic gloves to handle your film, maybe they've got air blowers of canisters sitting around to get pesky little guys off the film. They also should be keeping the inside of their scanning machines clean through regular service. However, they have one extra secret ingredient for tackling dust: Digital Ice.*

I'm going to give a VERY basic explanation of Digital Ice, but if you want a technical discussion of it that doesn't make you totally turn your brain off like the Peanuts Teacher, watch this delightful video. Digital Ice is a dust and scratch removal feature in these lab scanners. The scanner passes a certain quality of light through the negative when in the scanner to identify aberrations sitting on the surface of a negative. Anything that creates dimension outside of the negative is then intelligently removed. This allows for it to remove dust while retaining a sharper image than using some global aberration removal algorithm in Photoshop that leaves the image a little soft. It does not work on true black and white film which is why you'll see a lot of labs say something like "dust is best effort" for their black and white offerings.

• Note: Some flatbed scanners also have Digital Ice.

Does digital camera film scanning lead to dustier scans?

I want to be clear, Digital Ice does not remove all dust from images. It does a great job but has technical limitations that prevent perfection from being achieved. I find people who start Digital Camera Scanning get hung up on dust removal on their negatives, even very small dust. Yet, they never closely evaluated their lab scans before. They're suddenly perseverating over an amount of dust that never bothered them before from their lab because they always just assumed perfection and were further divorced from the process.

That being said, digital camera scanning does not use Digital Ice. The film is exposed to open air and the environment, and it is prone to collecting dust if not thoughtfully prepared. It absolutely can turn out dustier scans than you've gotten from your lab before. Truthfully, this is a learning curve. You'll figure out what works best for you over time, but here are some of the things I do to reduce dust on my scans:

• Clean my workspace with a wet sponge or cloth periodically (I have two dogs, so this is a losing battle, but we're all just doing our best)
• Use an air canister on my light source prior to working with it
• If the film was developed at a lab, leaving it in the archival sleeves until I'm ready to scan it
• If I home developed the film, making sure the film is ABSOLUTELY DRY before touching or scanning it; any moisture attracts dust and it's impossible to wipe off without re-cleaning the negatives and letting them hang to dry
• I like to use my clean, dry fingers to "finger squeegee" the film prior to scanning it. This isn't a technical thing, but I find it keeps dust off my negatives better than gloves do.
• Having a clean, antistatic cloth to wipe the film off as needed

Spoiler alert: you will never get all the dust off your film before scanning it. I'm just going to take that potential pipe dream off the table right now for you. So, having some go-to methods for removing it in post is helpful.

I'm going to show you what I do in Lightroom to find and remove dust in the video below. There are other pieces of software/ plugins that suggest they can intelligently remove dust in post, faster (SRDx and IRDx being the main ones). They're not for me or my workflow. Definitely try them out, but I'm not going to give a deep-dive review on them since I don't like/ use them. Another thing to note is that often times the most dust you'll see is on the outer edges of the image, because it's closer to what's touching things and accumulating dust. Sometimes I just crop that out. Maybe not best practice, but again, something I do on occasion.