Summary: an in-depth look at negative film versus positive film and a short comparison with digital cameras. I discuss differences and main characteristics of all three from user's point of view. Very short technical background is also included to improve understanding.


Many film shooters have one same basic dilemma - do you choose slide (positive) or reversal (negative) film? What's the difference and why would you pay more for something you're not even sure is right for you?
Most know the obvious difference you can see by just looking at the shelves in your photo lab - slides are more expensive to buy and develop and also for every 20 labs that develop reversal films (C-41), there is only 1 that can also develop slide film (E-6).
So you may wonder, like I have back in the day, why would anyone (who can do without projecting their vacation slides to bore their friends and relatives) choose slide film over simple, cheap, hassle-free negatives?

This article is aimed to answer just that.



It all began last summer when I decided to do some tests for myself, which I've been turning over in my head since, until I decided to share them with you.

I took a widely available, consumer grade (but more than decent) negative film Fuji Superia 100. I also picked one good slide film, Fuji Provia 100F, about three times the price of Superia where I bought it. We were going to a trip to a nearby island, so in the middle of the shooting, I decided to take a couple of shots of the same subject with same lens but on two different films, just so I can have a direct comparison once I develop them. Both were taken under exact same conditions and lighting, I just took a little different frame to justify wasting expensive film.
The results amazed me. See for yourself.





Before I comment on these - all of these are straight 100% unmanipulated scans. I did the scanning on Nikon Coolscan 5000ED myself, so I can vouch for it.
On the sunflower shot, I also added a shot done by a decent compact digital camera. I didn't manipulate that shot either, but as some of you know, digital cameras (especially compacts) will do that by themselves. That's why you have such saturated colors and boosted contrast. Use an SLR in RAW mode and you will have a duller shot with less contrast.
Camera doesn't have powerful macro mode, so the image looks "zoomed out". That doesn't matter, example is here so you can compare colors and contrasts, the overall atmosphere.


Now let's get a bit into analysis. I'll try not to get too technical, because no matter what I say, these shots speak more.
Negative film is widespread because it's very versatile. You can shoot anything, and it will turn out decent. However, sometimes you may want that extra touch, and this is when you might consider shooting positive film.
Firstly, negative film is much easier to expose right. It will tolerate a mistake of 1 stop so good you won't ever know you missed the exposure. Overexpose it by 2 stops, and photo will often be more or less fine. Usable at least, especially with a good scanner. Underexposure of 2 stops will be on the edge for most films, but you will usually be able to salvage enough so you can still have some use for that shot.

Positive film, on the other hand, requires perfect exposure. If you overexposed it by 1 stop, you can forget about that shot, you'll get pure white instead of tender highlights and that's that. Mostly useless for artistic purposes. Underexposure of 1 stop is also catastrophical, but if you have a very very good dedicated film scanner and are masterful at scanning to the point where you understand what analog gain is, you will be able to salvage the shot. Probably.
Over- or underexpose slide film by 2 stops and you can forget about it. You might get something out for spy purposes (to identify what's on the image), but that's that. Game over, go sit in the corner.

Because of this, anyone just starting to shoot slide film should live by the proverb: meter light 10 times, shoot once.
So as a rule of thumb, when in doubt, overexpose negative film, and avoid doubts when shooting slides, because you'll just throw away a frame of expensive film. But if you really must choose, underexpose it. This way information might be preserved even if you can't get to it without a $2000 scanner.

Many who often shoot slides invest in a good external lightmeter and/or a grey card. If you're among those and don't know what grey card is, investigate a bit, it might save you a lot of trouble (not to mention money).



Second important difference between slides and negatives is the dynamic range. You often hear this term - in short, dynamic range is difference between lightest and darkest tone your film or sensor can record. Anything brighter will be pure white, anything darker will be pure black. For example, you shoot a sunny scenery. Scenery will be visible just fine, but sun will always be pure white. That's because it's outside your film/sensor's dynamic range.
So to make a long story short, color negatives will have between 8-9 stops of dynamic range, digital SLRs about 8-10 stops, B&W film about 10-12 stops, and color slides between 4 and 5,5 stops.
These differences are huge so don't think "it's just numbers". What does that mean when you need to shoot slide film with 4-5 stops? It means problems. Most photographers will tell you you just don't do it. However, if you're creative you can use this to your advantage, get interesting effects. Let's look into that a bit.

Dynamic range, this virtual and perhaps unintuitive concept has direct and inversely proportional relation with something very very important in photography - contrast.
Bigger difference between brightest and darkest tone (higher dynamic range) will mean greater contrast. Lower contrast will mean less of a difference between light and dark portions of the image. Ultimate low contrast would be shooting dense fog - everything would be the same grayish tone, virtually no difference between darkest and lightest tone.

What all this means is that films with low dynamic range, like slide film, will have naturally high contrast and saturated colors. Negatives might capture sunlit and shadowy parts of a forest, but in other non-extreme circumstances they will produce flatter and less interesting images with lower contrast and faded colors. Compare how shadows seem to be deeper and somehow more intense on above jungle example when shot on slide film.


Now one last thing, so you can fully understand the color differences in those first sunflower examples. Slides are designed to shine light through them and see a realistic image. That means they need to have faithful colors, or at least such colors which people will find appealing. If you ever held a slide in your hand, you know you can see what's on it by holding it against the light - no imagination necessary.

Negatives, for various reasons, don't only have inverted colors, but also what's known as orange mask. If you ever saw a negative, you might have noticed it's mostly same color, brownish-orange, and it takes a LOT of imagination to figure out what's on the shot. As a kid, I always used to wonder how in the world they get correct colors from what seemed monochrome image to me ("orange-and-black"). One reason why negatives have orange masks is because that helped when making prints 60 or 70 years ago. (also note you can't make a direct print off slide - before scanners it was expensive and complicated to do it.)
Anyhow, that orange mask isn't the same on various negatives, it's always a bit different. In these digital days of scanning and digital photolabs, that varying orange mask presents significant challenge to remove and compensate for. It requires much color correction which not only degrades image quality somewhat, but is never perfect. So if you look at the sunflower example, you will see how my scanner had hard time interpreting colors of the sunflower, hence everything turned out a bit greenish. Anyone shooting negatives and scanning them later on should have this in mind, especially if you have others doing color correction for you (they usually don't really care in photolabs). You just scan a slide and that's it, but with negatives it's a never-ending story. Especially with some problematic new generation films like new Kodak Portra or Fuji Pro.

Professionals and their employers often choose slide film just because of this -- what you see is what you get. With negative, you never know what's gonna turn out and whether or not you'll have to spend hours getting it right later on.
It should also be said that if scanning the film is your intended destination, you should seriously consider shooting only slide film. This is given you can afford it and have access to at least half a decent scanner, because scanning slides poses different challenges to scanner. Namely, slides have very dense pigments, so to get through them you need a high quality low-noise scanner. Otherwise you will just get overly contrastly scans... but at least with correct colors.


One last important difference is the film structure. Negatives have coarser and more visible grain structure, but with more apparent sharpness. (grain causes increased apparent sharpness, I won't go into that now)
Slides have much finer grain, almost invisible if exposed properly, but sometimes tend to look a bit blurry when scanned at 4000dpi or more. Look at this example, it's all 100% crops of 24 megapixel images scanned at 4000dpi (digital is only about 5 megapixel, that's what camera produced).



Digital cameras at low ISOs have virtually no noise (digital cameras don't have grain, they have noise - it's a crucial difference I won't go into right now). At higher ISOs, they have very unappealing noise which has no fans whatsoever. (Film grain has a fan club; just personal preference really)
Digital SLRs are much better off than compacts when it comes to noise, it has all to do with sensor size and in-camera noise reduction algorithms, but it's a long and off-topic story.

However, all this should be taken with a grain of salt, because average digital camera will produce a 10-12 megapixel image with good resolution, but film can easily be scanned into 24 megapixel image without exceeding its resolution. So even if grain shows, there's still much more pixels you can work with.


All of this may or may not matter to you, but is good to keep in mind, especially if you can see yourself making big prints in the future. By big prints I mean 45x30cm (18x12") or larger. I personally find grain more appealing than general blurriness at those sizes, but that's just my personal preference. Some slides are much better than others regarding resolution, and it's usually proportional to their price.


Also, as with all film, each and every slide is different. For example, legendary Fuji Velvia (not the 'F' version) has just 4 stops dynamic range. It produces outwordly contrasts coupled with warm tones which is why it's so famous among scenery photographers, it greatly influences the scene being photographed. Fuji Sensia is a consumer grade slide, excelling at nothing (I personally love it because it cross-processes amazingly). Fuji Provia is very expensive wide dynamic range slide (about 5,5 stops), with slightly colder tones (bluish), very small grain and vivid colors. The 400 version can easily be pushed to ISO 3200 and even 4800 (officially!). Fuji Astia is another expensive animal with 6 stops range popular in fashion photography because of its extremely precise color rendition. Kodak Ektachrome has different versions. G is the standard version, GX has warmer tones, and VS stands for vivid saturation. It's very sensitive to exposure bias, I'd give it about 4,5 stops dynamic range, but it's just my estimate. Some Ektachromes can be pushed to 800 (official info). Agfa Centuria is cheap slide with very cold tones, significant blue shift and very poor resolution.

Here are few examples from slide film which was properly exposed and scanned, showing slide film potential for producing captivating images with strong contrast and bold colors. You can find film and shooting information below each shot to learn more.






So at the end, a short summary. If you forget everything you read, here's the least you should remember:


Positive (slide) film:
- very high contrast (low dynamic range)
- extremely sensitive to exposure mistakes, but prefers underexposure if absolutely unavoidable
- saturated colors
- very fine grain, moderate resolution
- faithful colors, no-fuss scanning
- expensive, hard to process


Negative (reversal) film:
- low to moderate contrast (high dynamic range)
- tolerates exposure bias up to 2 stops, prefers overexposure
- washed-out or normal colors (depending on film)
- grainy even at low ISO
- difficult color calibration
- mostly cheap, easy to process anywhere


Digital sensors:
- moderate contrast (low with some special Fuji sensors)
- tolerates exposure errors (prefers underexposure)
- lacks true colors due to Bayer filter pattern (except Foveon sensors), but is mostly saved by post-processing
- very smooth image at low ISO, noisy at high ISOs
- easy color calibration with choice of color space (mostly in SLRs)
- after initial investment, free to run



Hope this made things a bit clearer; feel free to note me with any questions.
Happy shooting!