Research: is there really a difference between real and simulated film photographs?
To answer this question, I researched the foundations of film and digital photography; and which factors can influence the style of the results for my bachelor thesis. During my research, I found that both the properties of a film and many external factors in the photographic process have an impact on the result and that there is no absolute/unique “film style“.
Let pause and state for the record that I love the look of Kodak Tri-X 400…but film photography becomes expensive at some point. Some time ago, I heard about the DxO FilmPack for simulating several classic film types and I asked myself if we humans are able to recognize the difference between a real film photograph and a digital film simulation.
For the same thesis, I shot several photographs using Kodak Tri-X 400 film with my Canon AE-1 while also capturing the exact same photographs with my Nikon D7000. After that, I simulated the look of Kodak Tri-X 400 on my Nikon D7000 frames using DxO’s FilmPack (v5) and let people compare both shots.
I’d like to share the results with you here.
That’s the simple version, the more complex detail begins below. Here’s what I discuss in this article.
At the time of writing, I have been “into” photography for over 8 years and always found the look from old photographs to be interesting and unique. A few years ago during a conversation with my professor – as we were talking about the unique style from Polaroid photos – we came to the topic of the “film look“.
The topic was largely influenced by the black and white photographs from Sebastião Salgado, one of my biggest role models (and yes… I am in my creative black and white phase…). That was the main reason I decided upon Kodak Tri-X 400 as the subject of my research. Everything became even more interesting after I found an article in which Salgado describes how he “renounced” Kodak Tri-X 400 in 2008 and simulates the style of this film on the PC using the same DxO FilmPack I’d decided to use.
During my research, I had to deal with a wide spectrum of topics: I learned a lot about old photographic methods, the similarities between digital and film photography, factors which affect the look of the photograph, how film simulation software works, and about the creation and analysis of an online survey as well.
I decided to investigate if people with knowledge and experience in photography have a “trained eye” for differentiating photographs made using traditional photographic film from the digital film simulations.
So, enough preface, let’s dive into the survey that formed the basis for my findings. First I will answer the following question:
Why a survey?
As you may know, our perception is subjective, and in photography, there is no “true” or “false”. Since the purpose of my research was to find out how well the DxO FilmPack simulates film, I decided to start a survey where the participants should decide which photographs were made using real Kodak Tri-X 400 film and which were made using the simulation.
I felt that this would lead to more opinions about the comparison and with the results, I would be able to analyse if knowledge and experience in photography have an influence while comparing both types of photographs.
I created a total of 24 photos for the comparison: 12 with a film camera, 12 with a digital camera. The Kodak Tri-X 400 photographs were made using a Canon AE-1 and 50mm f/1.8 lens. The digital photographs were made using a Nikon D7000, with a Sigma 18-35mm f/1.8. Since the Nikon D7000 has a crop factor of 1.5, I was able to shoot at 35mm for maintaining the field of view of the 50mm lens on the Canon AE-1.
I shot each photograph using exactly the same exposure settings on both cameras (focal length, aperture, ISO). That’s why you should be able to see a difference in the depth of field…Perhaps next time I should consider the difference in the depths of field while using identical sensor/film sizes…! 😉
The film was developed and scanned by a competent local lab, assuming a comparison between results on film that are easily obtainable/replicable by anyone with the interest to try.
As I have already stated, I wanted to investigate if people with knowledge and experience in photography have a “trained eye” for differentiating photographs made using Kodak Tri-X 400 from the digital film simulations. With this in mind, I started by dividing the main group (all persons) into smaller groups:
- People with photography knowledge
- People without photography knowledge
I also made the assumption that all people who take photographs have some photography knowledge – even if just taking photographs for Instagram. Otherwise (if you don’t take photos at all) you don’t have photography knowledge. After that, I continued by dividing the groups of people with photography knowledge into two further groups based on their income (as defined by PhotoShelter):
- Professional Photographer (If you earn more than 50% of your income from photography)
- Enthusiast Photographer (If you earn less than 50% of your income from photography)
This extra grouping should help answer if the photographer type has an influence on their selection – my thinking, anyway. To find out if knowledge also plays an important role, I decided to ask the following questions:
- Have you ever worked with film?
- Do you use software for film simulation?
- Do you use “vintage” apps on your smartphone for simulating old film styles?
Of course, there are many more criteria for evaluating the results, like monitor resolution, the country where participants lived, which camera they usually use, etc., but it’s possible to introduce too many variables and thus dilute results beyond any hope of a meaningful conclusion so for this study, I decided to just stop right there and evaluate the results based on the criteria described above.
I created an online survey using Google Forms (which is still active) and saved the results to a Google Spreadsheet, so I can check them anytime. Creating an online survey has a lot of pros: everybody (with an internet connection) can take part in it, it’s anonymous, it’s easy to share, and so on… But nowadays we have different types of monitors, resolutions, screen DPIs, etc., so it’s very hard to control the viewing conditions of everybody’s display.
I decided to export the photos in Full HD (1920x1080px) using the JPEG format and 100% quality (so the grain is still visible). It’s also important to mention, that the whole survey and study is about the overall impression of the photographs, and not about a deep analysis of the grain structure using a magnifying glass! That would be a topic for other research, where the photographs could/should be printed (of course, the survey form would then be different too).
So: the results of this survey are just valid with the conditions I described and should not be generalised for all film types and film simulation programs!
Here are the photograph pairs (you can also access them directly in the Google Survey).
At the moment I began evaluating the results of the survey, it had a total of 114 participants. At the time of writing this number has increased, since more people took part in it, but I am writing about the results with the initial 114 participants. For the evaluation of the results, I just counted the correct answers. That means, I only counted the participants’ selections, where they chose the photographs made with film.
The average number of correct answers from all participants is 6.24 out of 12. This means that the participants could identify the film photograph in only 52% of the cases. So it can be deduced that people can not really differentiate between a film photograph and a digital film simulation; and that DxO FilmPack v5 simulates the style of Kodak Tri-X 400 well enough to fool/cheat the human eye.
As I wanted to find out more about my participants’ selections, I started to dive deeper into the results and I continued by dividing the main group as I described earlier. The following pie chart shows the division of the participants in persons with and without photography knowledge:
As you can see, most of the people who took part in the survey have photography knowledge (A total of 104 participants), and just 10 participants didn’t really take photos at the time. And that’s pretty ok, since most of us take photographs almost every day with an SLR, compact camera, or smartphone.
I continued by dividing the group of persons who take photos (from the 91.2% above) in two groups based on their level of experience, as I described earlier (photo enthusiasts, and photo professionals):
A total of 95 participants considered themselves as “photo enthusiasts” and just a few (9), as “professional“. Since the difference between these groups was so large, I was not able to give the professional photographers too much relevance during the evaluation.
For that, I would need more professional photographers taking part in this survey. If the difference between the two groups was smaller or if both groups have the same number of participants, then the results would be more representative.
You might be interested in…
After that, I defined a total of 9 different groups, according to their answers (thanks boolean algebra, I can finally use you):
|Group||Have you ever worked with film?||Do you use film simulation software?||Do you use vintage apps on your smartphone for simulating old film style?|
I = Persons without photography knowledge
I had three expectations on the analysis of the results:
- The average of correct answers from Group I (Persons without photography knowledge) would be the lowest.
- The average of correct answers from people who worked with film (Groups E, F, G, H) would be much greater than the average of correct answers from people who haven’t worked with film (Groups A, B, C, D).
- The average of correct answers from Group H would be the highest, and the average of correct answers from Group A would be the lowest.
The next bar chart shows the average of correct answers from the groups described above:
The first thing you will see on the chart, is the peak on groups C and D, with an average of 8 correct answers in each! Then, you may deduce, that people belonging to these groups can differentiate better between both types of photographs, right? So, if I just use film simulation software on the PC (Group C) for putting some filters on the pictures I take, I have a better eye to see the differences, right? Or if I also use Instagram (Group D), then I have a trained eye, right?
Wrong but why?
Because there are only 2 people in each of these groups so their answers are not really representative. For clarifying the results plotted on the chart, take a look at the next table. It shows the average of correct answers and the number of participants in each group.
|Group||Nr. of participants||Average # of
Analysing the results, and comparing them with my expectations, there are a few things I can say about that:
Expectation Nr. 1: Right!
Group I (persons without photography knowledge) shows the lowest average of correct answers. This might be because they just made some random choices about the photographs (maybe they don’t know where to look, what to compare, etc).
Expectation Nr. 2: Wrong!
The general average from group A, B, C, D is even higher than the general average from group E, F, G, H! The first group has an average of 6.54 and the second one of 6.33. This is actually a very small difference (3.2%), and the first group (33) had fewer participants that the second one (71). Maybe, if the first group have had more participants (the same number than the second group), the general average may have decreased… So, this means, that experience with film photography doesn’t really lead to better results on the comparison.
Expectation Nr. 3: Right!
Group H’s average is higher than group A’s, and in this case, it is valid, because both groups have almost the same number of participants (17 against 15). This means, that people who have already worked with film, use film simulation software on PC and use vintage apps like Instagram, can differentiate better than people who don’t.
On the one hand, I made the following findings by analyzing the results of the survey research:
- People are able to see the differences between a real film photograph and a digital film simulation in the viewing conditions defined for this research, in just 54,35% of the cases.
- People who have photography knowledge can differentiate between both types of photographs in 53.50% of the cases.
- People, who don’t have photography knowledge, can just differentiate between both types of photographs in only 35% of the cases.
- Experience in film photography does not really lead to a better or trained eye for differentiating both types of photographs.
On the other hand, it has to be considered that the differences between the averages of correct answers from the groups are not so large. There could be two reasons for this:
DxO FilmPack 5 simulates the style of Kodak Tri-X 400 so well that we can just barely see a difference between the photographs or, the chosen method for this survey and the viewing conditions (display, resolution, ambient brightness, photo quality, photo size, …) were not adequate, so that it leads to a wrong interpretation of the results.
Once again, The results of this survey are just valid with the conditions I described and should not be generalised for all film types and film simulation programs!
Some takeaway points
The goal of this research was to answer this question:
“Can the human eye recognize the difference between a real film photograph and a digital film simulation under the given viewing conditions?“
For answering this question, I researched the foundations of film and digital photography, and which factors which can influence the style of the results. I found that both the properties of a film as well as many external factors in the photographic process have an impact on the and that there is no absolute/unique “film style”.
In this work, I just examined the style of just one film and used just one film simulation program. Future work should take into account a larger number of film stocks, which can be simulated with different film simulation programs. This would serve to check the accuracy of film simulations in general. If they are not good enough, suggestions for improvements to the software manufacturers can be sent, so that programs can be optimized.
In addition, the survey research can be used as a basis for future studies of this topic. They could be improved by taking into account further demographic characteristics of the participants. And the more participants, the more precise the results will be.
If further investigations confirm the question asked in this study, then this would mean that film simulation programs have met in this context one of the main intentions of computer science: the simulation of reality.
This study also encouraged me to think about the philosophical aspects of film photography.I share the opinion of other photographers (like Eric Kim) about this: sometimes we don’t really use film because of the quality or because of the unique style it achieves, but much more because of the moments we experience by shooting with film.
We think a lot more about composition and about the light (among other aspects) before we press the shutter. It slows us down in that we perceive our “reality” differently. And this experience is something that can’t be simulated (or at least not yet).
An important takeaway from the work gone into the preparation of the study and results would be that it’s very hard to say how long it took to process an image using the software – it depended on each image. Sometimes I was not happy with the result and would re-prepare the photo in Lightroom then re-edit it in FilmPack. I’d say, on average, it took between 5-10 minutes to develop an image in FilmPack, including working with the channel-luminance-sliders.
I think the most important personal conclusion about my research is that there is no unique “Kodak Tri-X 400 film look”. It just doesn’t exist.
There are so many parameters that affect the development of real film (developing time, temperature, etc.,) and they are very hard to control. Varying them would lead to very different results. Nevertheless, I think that DxO FilmPack does a great job at simulating grain. It looks so real…I also think that this research affected my own film and digital photography.
On the one hand, it boosted my joy for film photography and since then, I have continued shooting and learning more about film. Film photography is great for learning or “re-learning” the principles of photography: Shutter Speed, Aperture and ISO. And since once you load and start shooting your film, you can’t change the ISO anymore, there are only two things that you have to play with for “correct” exposure: shutter speed and aperture.
Compare those two things with all the features of actual digital cameras, there are so many things that you can change before making the shot, that you sometimes can’t really focus on the subject you are photographing. Film photography simplifies it for you by reducing the variables of the equation.
That’s why I love it. I can focus on the subject, think, decide, and shoot.
On the other hand, the study affected my digital post-production workflow. Today I use Snapseed for developing and adding grain to my digital images, and the VSCO-Lightroom-Plugin, as well as DxO FilmPack for post-production on the PC.
I like how adding grain and playing with the curves make the images look more “real”. Plain digital photographs tend to look very “plastic”, perfect and even unreal sometimes. And that’s because today everybody is seeking perfection. By adding grain and simulating film styles, I am able to give my images that imperfect look I like from film photography.
Thank you very much for reading! If you found this article interesting or useful, please leave me a comment or write me a mail 🙂 Also feel free to share this article and take part in the ongoing survey (you will see the current results after you complete it). You can also thee the original article I published about this test on my blog. I would be very interested in a deeper discussion about this topic!
Read the full article here
Leave a Reply