My wife bought me a Plustek OpticFilm 8200i SE scanner for Christmas. She had heard me lament the long scan times I was experiencing with my otherwise acceptable Minolta Scan Dual II and decided to help a film photographer out.
I scanned a strip in the Plustek from each of the last five rolls of film I shot. Holy cow, is the Plustek blazing fast compared to the Scan Dual II!
My Plustek came with SilverFast scanning software, but I didn’t install or use it. I used to use it with my old Epson flatbed and found it to be so cumbersome as to be unpleasant. I just stuck with VueScan, which recognized the Plustek instantly.
I scanned strips of Fomapan 200, T-Max 100, Kodak Max 400, Fujicolor 200, and 50-year-expired GAF 125, aka Ansco Versapan. I’ll share a scan from each roll here from the Plustek, and for black and white a scan from the Scan Dual II, and for color a scan from the lab’s scanner. The Plustek scan is always first in each pair.
This is just a quick comparison. All photos were Photoshopped to my liking at the time of scanning, and my liking does vary over time.
If you’d like to pixel peep, click any image to see it on Flickr, where you can see it at full scan size.
First, a frame I shot in my Pentax ME SE with my 50mm f/1.7 SMC Pentax-M lens on Fomapan 200 @ EI 125, developed in Ilford ID-11 stock. Right away, you can see that the Plustek captures more of the frame than the Scan Dual, as the Scan Dual scan was not cropped.
Nikon N90s, 50mm f/1.8D AF Nikkor, GAF 125 (Ansco Versapan) x-7/72, HC-110 B 6 minutes. These are hard to distinguish from each other at blog size. Both scanners did a great job of cutting through the base fog of this very expired film.
Nikon N70, 28-80 mm f//3.5-5.6D AF Nikkor, Kodak Max 400. The lab scan is warmer with more contrast. I could probably have Photoshopped my scan to get exactly the lab scan’s warmer look. But I’m not sure which look I like better.
Nikon N70, 28-80/3.5-5.6D AF Nikkor, Kodak TMax 100, HC110 B. Other than a slight difference in the crop, these are hard to distinguish from each other.
Kodak VR35 K12, Fujifilm Fujicolor 200. Once again the lab scan has stronger contrast. The colors are much more alike than in the previous color comparison. The Plustek yielded a more turquoisey hue in the vehicle than the lab did.
So far I’m happy with the Plustek. It does fine work with black and white, and yields scans much larger than the older Scan Dual — 7200 dpi vs. 2820 dpi. I didn’t use my Scan Dual for color film much as I didn’t like the look right off the scanner. The Plustek does a better job with color and now gives me the option to have my lab only develop my color film so I can scan it myself.
This is the first guest post ever on Down the Road. Reader P wrote such an excellent comment on how to understand dots per inch and pixels per inch in scanning and printing that, with his permission and a little editing, I’ve turned it into this post. Thanks, P, for demystifying PPI and DPI!
Pixels per inch (PPI) and dots per inch (DPI) are challenging to understand in large part because the Internet is littered with outright wrong information about what these things are. Also, plenty of people use the terms improperly.
For the sake of brevity, parts of the following discussion are oversimplified. The purpose is not to explain everything, but rather to eliminate a lot of the confusion surrounding these terms by establishing a foundational understanding what PPI and DPI are, and what they are not. Doing a deep dive into every technical aspect, of every technology, of every possible situation where these terms might be used, in order to be 100% accurate and technically correct in every possible way, would defeat the purpose entirely as it would no doubt add to the confusion instead of alleviating it.
PPI has to do with screens: monitors, televisions, cell phones, tablets, and so on. It is merely a measurement of how densely packed the physical pixels are on a display — the pixel density. This in turn tells you how much physical screen real estate a given digital image will take up when viewed at 100%. PPI is simply the ratio of the screen’s native resolution, a×b pixels, to the screen’s linear physical dimensions, x×y inches.
Horizontal PPI is a pixels/x inches = a/x PPI. Vertical PPI is b pixels/y inches = b/y PPI. These days most screens use square pixels — pixel height and width are the same, so there’s no need for separate horizontal and vertical PPI values. We just say a monitor or screen is such-and-such PPI, a single value, because it’s the same horizontally and vertically.
The closer you are to a screen, the greater the PPI needs to be to provide an image of acceptable quality. For example, a big-screen LCD TV offers far fewer PPI than your cell phone.
Understanding DPI in print
Screen PPI and print DPI are similar in concept, but they are not the same thing. However, people use them interchangeably and it causes confusion. Instead of being the density of pixels on a display, DPI is the density of dots laid down on a physical medium such as paper to form a physical image.
The closer you are to a print, the greater the print DPI needs to be to provide an image of acceptable quality. For example, the DPI of a billboard advertisement is far less than that of your 4×6 vacation photos.
Understanding DPI in optical scanning
In scanning, DPI measures the scanner’s resolution. Look at it as the number of dots per inch the scanner can allegedly resolve when scanning a given piece of film. Let’s say a scanner has a maximum optical scanning resolution rating of 3600 DPI. This means that for each linear inch of film, the scanner is capable of resolving 3600 dots of information — allegedly, as the true, effective resolution will be less, a topic outside the scope of this discussion. These individual dots of information captured become individual pixels in the output digital image, the “scan.”
For square medium format negatives (1:1 aspect ratio), which are 56mm square, the calculation is:
3600 dots/inch × 56 mm × (1 inch / 25.4 mm) = 7937 dots
In other words, you get a scan of 7937×7937 pixels.
For 35mm negatives (3:2 aspect ratio), which are 36x24mm, the calculations are:
Horizontal: 3600 dots/inch × 36 mm × (1 inch / 25.4 mm) = 5102 dots Vertical: 3600 dots/inch × 24 mm × (1 inch / 25.4 mm) = 3402 dots
That’s a scan of 5102×3402 pixels.
Going from scanner DPI, to screen PPI, to print DPI
In print, dot density matters, combined with the pixel resolution of the digital image that’s being printed, along with the image’s overall quality or the amount of information and detail it contains. Pixel density, which is not the same thing as the pixel resolution of a digital image, applies only to screens. The term DPI as it relates to the optical resolution of a scanner and the density of dots on a physical print are not the same thing. The former is a measurement of how much information the scanner can resolve while digitizing a piece of film, while the latter is a measurement of how densely packed the dots are that form the image in a print.
That said, when printing from a digital image the number of dots per inch (DPI) the printer lays down is related to the pixel resolution (a×b pixels) of that digital image. In simplified terms, due to differences in various printer technologies and how each one lays down dots on a physical substrate such as paper (which is also beyond the scope of this discussion), if there aren’t enough pixels in the original image to match at least 1:1 the number of dots that need to be printed at a given DPI and physical print size combination, then the digital image will have to be upscaled to a higher pixel resolution to match the printer’s DPI and print dimensions. This is a problem, as it means interpolation will occur, artifacts are likely to present themselves, and image quality will be greatly diminished. If an image is already lacking in pixel resolution or resolved image detail, you can’t do anything to salvage it. You can’t create detail that didn’t exist in the first place.
Advice for scanning
As stated previously, a scanner’s actual effective optical resolution is less than the rated value. For flatbeds, it’s much, much less.
For a typical flatbed scanner, I’d scan everything at a DPI that provides scans that are at least 4 times the pixel resolution (total area — 2 times the length and width = 4 times total area) of what I want my final output resolution to be.
For square, medium-format images, if I want my final files to be 2500×2500 pixels, I’d scan them at no less than 2400 DPI as 16-bits-per-color/channel TIFFs (i.e. 48-bits-per-pixel for color images, and 16-bit-per-pixel for greyscale). I would then do all of my levels editing, dust/scratch spotting, cropping, and so on at that original large resolution, but not yet sharpen anything. I’d save these as my “master” images, again as 16-bpc TIFFs. Then, I’d resize them to 2500×2500 pixels using the Lanczos-3 method, and finally use unsharp masking to sharpen them to my liking. That would be my final image for output, for sharing online, which I’d save as JPEGs.
I’d follow the same practice for 35mm. So, if I want my final 35mm images to be 3000×2000 pixels, I’d scan at no less than 4400 DPI, and then follow the same procedure as I did for medium format, cropping 3:2 instead of 1:1.
I’ve been unhappy with the 35mm scans my Canon CanoScan 9000F Mark II produces. They lack sharpness and shadow detail. I’ve done everything I can figure out in VueScan to make them better.
I’ve complained about this before, and reader P paid sharp attention. He contacted me recently to recommend a dedicated 35mm scanner he found used for a good price, refurbished, at KEH. I bought it straightaway.
It’s the Minolta DiMAGE Scan Dual II, which was manufactured in about 2003. This scanner’s maximum output is 2,820 DPI, yielding images of roughly 3680×2580 pixels. That’s nearly 10 megapixels, which is enough for anything I do with my images.
When it arrived, I quickly scanned a negative strip from a roll of Ilford Delta 400 I shot in my Olympus XA in December to make sure the scanner functioned. It did, but my scans weren’t sharp. So I tried again later with the same strip, digging into the manual and into VueScan’s settings to get focus right. I got very good sharpness that time.
I’m going to show you all four frames from both scanners. In each pair, the Scan Dual II scans are first and the CanoScan 9000F scans are second. I’ve tweaked both in Photoshop to my liking, within the limits of the scan — but the ScanDual scans didn’t need very much help. They are far better than the CanoScan scans, especially in contrast and sharpness. The contrast is apparent right off, but you need to see these scans at full size to appreciate the sharpness difference. To do that, click to see them on Flickr and then click them there to see them larger.
Even though the Minolta is 17 years old and relies on a USB 1.0 interface, I got scans faster than I ever do from the Canon. This is in part because VueScan was able to accurately detect frames in the Minolta, and it can’t in the Canon for some reason. I have to painstakingly select each frame before scanning.
The Minolta scans are far sharper than the Canon scans straight off the scanner. No amount of Photoshopping can make the Canon scans look sharp, while a tiny bit of unsharp masking makes the Minolta scans look great.
This scanner’s native software doesn’t work with Windows 10. Fortunately, VueScan recognized this scanner instantly and was ready in seconds to make scans from it.
I kept going, this time with a strip of color film. This is Fujifilm Superia X-tra 400, shot in my Olympus OM-2n using the 50mm f/3.5 Olympus Zuiko MC Auto-Macro lens. I sent this film to Fulltone Photo for developing and scanning. My scans from the Scan Dual II are first, and Fulltone’s scans are second. I adjusted VueScan’s settings as best I could but still got rather cool scans. So I adjusted white balance and a few other settings on them in Photoshop.
The Scan Dual II scans are not far better than the Fulltone scans. I rather prefer the color Fulltone delivered — but it could be that after all these years I’m just used to the color a lab’s Noritsu scanner delivers. Now that I’m looking at these again, the ScanDual scans might have a slight magenta cast, and removing it might help. Yet these scans are acceptable for the day I might choose to develop color film at home, or wish to rescan an old color negative.
I knew I could cut costs even more by scanning the slides myself, but could I get scans as sharp and colorful as Fulltone’s? Also, Fulltone’s scans are smallish at 1024 pixels square. I can easily get more pixels from my Canon CanoScan 9000F Mark II.
I tried it on a couple frames. I thought I’d show you my scans and the Fulltone scans to see what you think. My scans are at least 5100 pixels square — I select each frame by hand in VueScan, so the pixel dimensions vary slightly frame to frame. I shrank them to 1200×1200 for this comparison. WordPress shrinks them further to fit the blog template. I edited them all in Photoshop to my liking — nothing too invasive, mostly stuff like color temperature and exposure.
My scans are first, Fulltone’s are second.
Fulltone managed to bring out far better shadow detail than I could get from the CanoScan, VueScan, and Photoshop flow I use. Their scans look slightly sharper than mine.
But the Fulltone scans have a green cast that I couldn’t entirely erase, a cast that isn’t present on the slide. My scanner captured color that looks a little truer to the actual slide. Also, I was able to capture more of the frame than Fulltone did.
I don’t think there’s a clear winner here. Both Fulltone’s and my scans are fine. It’s a roll-by-roll judgment call whether saving $5 in scanning charges is worth the couple hours I’d spend scanning the roll myself. But when I want scans with large pixel dimensions, it’s very good to know that my existing scanning setup produces good results.
I thought it was a shame I hadn’t shot my Nikon F2AS in a long time, so I put some film through it recently. The meter led me to shutter speeds that seemed slow for the full-sun conditions, out of line with Sunny 16.
I shot four subjects twice, once using the F2’s meter and once using the my phone’s light meter app. The app consistently had me expose two additional stops!
I shot Ilford FP4 Plus through my 35-105mm f/3.5-4.5 Zoom Nikkor lens (which I like less and less the more I use it). I developed the film in Rodinal 1+50 and scanned the negatives on my Canon CanoScan 9000F Mark II using VueScan. I brought the scans into Photoshop where I unsharp masked them all, corrected perspective if that was necessary, and on one shot toned down the highlights, but otherwise left them alone.
There are so many possibilities in any scene, from how you expose it to how you develop it to what you do with the negative in printing or scanning and post-processing. These pairs show it well. The F2 metered shot is first in each pair. In this first pair, I like the second shot more for its better definition in the houses, and the more silvery reflection in the pond.
In this pair, I prefer the second shot again for its rich, smooth tone in the tennis court surface and the better definition in the houses.
In this pair, I like the first shot better for its slightly better shadow detail. The first photo is the one where I toned the highlights down slightly in Photoshop. The path was a little washed out in the original scan.
In this pair, I like the first shot better for its slightly better shadow detail and its better definition in the sky.
What do you see in these photos? In each pair, which do you like better?
I think to some extent what we’re seeing here is the good exposure latitude of FP4 Plus — these are all technically decent photographs. Also, what we all like in a photograph is subjective.
After I finished this roll I checked my F2’s meter under a bunch of lighting conditions and couldn’t reproduce the odd meter readings I was getting. Soon I’ll mount a lens I know and like better, probably my 35mm f/2.8, and shoot this F2 again to validate the meter’s functioning.
Lab scans of 35mm color negatives are miracles. Any lab I routinely use reliably sends me crackerjack digital images.
Getting usable scans from my CanoScan 9000F Mark II via its ScanGear software, on the other hand, is a lot of work involving a number of subjective choices in scanning and post-processing.
I used to think that the colors I got back from the lab were the film’s true colors. I see now how much of that is in the scanner settings, and that I don’t actually know how any film I typically use renders color.
The improvements I made this time were to scan to lossless TIFF files, and to turn off ScanGear’s Image Adjustment setting (which I had overlooked when turning off all the other image-enhancement settings). It helped? I think?
Here’s my scan of a photo I made on Kodak Gold 200 with my Olympus OM-1 and a 50mm f/3.5 Zuiko Auto Macro lens. There’s a little of that mottling in the blue sky that I keep trying to prevent. But it’s not as bad as in previous scans.
Roberts Camera scanned this film when I had them process it. It’s a touch brighter than my scan. The sky has a slight turquoise tint and lacks any mottling. Otherwise, either scan is fine.
Here’s my scan of a butterfly pausing over this flower. Notice how purple the flowers in the background are.
Roberts made those same flowers quite pink, but brought out the detail lurking in the butterfly’s wings.
I also tried scanning some Kodak Ektar 100 I shot in my Pentax Spotmatic F with a 35mm f/3.5 SMC Takumar lens.
Here’s Robert’s Camera’s scan. They got richer colors than I did, although I’d say the sky in mine looks more realistic. The green tint on the right edge of my scan is clearly an artifact of the negative that Robert’s somehow edited out.
I walked over to the building to make this close shot. My scan:
Roberts Camera’s scan got a richer red, but my scan offers better highlight detail.
It was so much easier when I accepted whatever color I got from my lab scans, as if they were the final word on film and lens. Now I’m suspicious of every scan, because of all the choices it represents. Is it possible that the only way to truly know what colors are in a negative is to make a darkroom print?
This, by the way, is the last in this series of experiments. I’ve learned what I need to. I get good enough black-and-white scans now to start processing and scanning black-and-white film, which was my goal. Now that I work Downtown in Indianapolis, eight blocks from Roberts Camera and their C41 lab, I’m likely to have them process and scan my 35mm color negative film. They charge just $10.