Can pictures ever truly represent reality?
Is photography ever an art or always art? This debate has been raging ever since the invention of the discipline. Even more so now that digital technology and social media exist! Here’s a somewhat detailed explanation using one the fields of photography that probably brings up the most controversy: astrophotography.
Open Instagram. If you weren’t already following #milkyway or #astrophotography accounts, try and search. I can bet you anything that within a few posts, you will find a picture that has you going: ‘wait a minute, how in the world is that possible?’. Even if you know nothing about how astrophotographs are acquired and produced, there is something that automatically catches your attention. How can you get that big of a full moon with perfectly sharp animal silhouettes? How can you get so many meteors in one frame with the milky way in it? Or even, how on Earth can you see deep-sky objects, including the milky way so bright and vibrant while you had the feeling that you had never seen it like that with naked eyes before? ‘This must be fake…’ I can hear you think.
Astrophotography: what it is and how it works.
Astrophotography is by definition the production of photographs of the night sky at different scales (wide-field, medium format, deep-sky…). In theory it can only taken from after sundown till right before sunup, but by extension astrophotography can also regroup photos of astronomical objects even during the day such as solar eclipses… Astrophotographers can typically use all types of cameras to achieve this goal, from compact to DSLRs to mirrorless, CCDs and telescopes. For daytime photography light is not a problem but at night, it becomes the main issue. In most situations, this lack of brightness will force you to set your camera settings to ‘low light’ mode: higher up the ISO film (signal amplification), open up your lens’ aperture (the hole that controls how much light comes in) and increase your exposure time (also controls how much light comes in). If you don’t, you won’t see much in your picture.
Camera versus naked eye
During the day, our eyes have no problem picking up colors because there is enough surrounding light to see them. The rod and cone cells of our retinas receive enough light to analyze shapes and colors as we see them in our every day life. At night, it’s a total different ball game. The amount of light is reduced by a factor 109lux (unit of luminance)! It means that our retinas will struggle to pick up enough light to analyze shapes and colors. We see most of the surrounding objects in shades of grey. We can only pick up the colors of the brightest objects like street lamps, the rising moon, traffic lights etc…
During the day, our eyes can compete with a camera and pretend to see about the same. In comparison to cameras, our central vision can see in a fixed ~5K resolution, 35/50mm focal length equivalent and a very wide palette of colors, a bit less sensitive in the reds. It’s quite hard to compare the settings of a lens-camera system with our eyes. However it has been estimated that the shutter speed of our eyes is about 1/100thof a second, an ISO of 500-1000 and variable aperture of ~f/2.1-11. So even if we assume that a low-light-accommodated eye (after 30 seconds under a dark sky) has and ISO of 1000, a wide-open aperture of f/2.1, the shutter speed remains very short and cannot vary!
A camera can potentially open its shutter for a much longer time than our eyes can. Most of the time, it can also go to much higher ISO’s (>6400) and brighter lens can have even wide apertures (f/1.4). In doing so, it gathers more light, thus detail and colors. That’s why correctly exposed night photographs usually look brighter, more detailed and more saturated than it would be with our naked eyes. In the picture above, the left panel represents a scene as seen with naked eyes. The right panel shows how a camera would see it, taken at ISO 3200, f/2, 10 second shutter speed. As a conclusion, it’s practically impossible to exactly reproduce in a picture what our eyes can see, especially at night. Even if we set our cameras to approximate a human eye setting at night, the awfully dark picture would not present any real relevance, whether for art or science!
Techniques of astrophotography
Panorama of 3 stitched panels taken with the Sony a7s + Sigma 50mm f1.4
As a starting point, no RAW astrophotograph can actually be true-to-life. For non-connaiseurs, a RAW is a picture format used by most photographers that is lossless in comparison to JPEG. It retains all the data captured by the sensor. Very few people or organizations use RAW pictures as they come out of the SD card because even when your camera settings created a correct exposure, the file tends to look quite dark and flat still. From there, astrophotographers usually use a series of tricks to obtain improved shots. They can stack several images of the same subject on top of each other to get more detail and less noise. They can track the sky to keep the frame in the same position as the Earth rotates, allowing a very long exposure time, thus details and colors. They can also use a battery of filters to isolate certain colors. They can shoot at longer focal length, take several panels and assemble them into a giant panorama to get better signal-to-noise and detail. Better yet, they can combine all of the techniques mentioned above to create a monster file! Some astrophotographers also like to do composite images. They consist of assembling different elements in one picture that haven’t been taken under the same conditions (for example a foreground taken during the day merged with a foreground taken at night).
Astrophotography editing: putting oil on the fire…
Panorama of 40 panels. Canon 6D astromodified (allows more red light) + Sigma 50mm f1.4 Art, each panel is tracked (except foreground panels to keep them sharp), 17 second exposure time, ISO 6400, f/2.8. A light pollution filter was used to limit its effects. In post process, each RAW panel was pre-processed in Lightroom, assembled (stitched) in PtGui Pro, post-processed in Photoshop and Lightroom.
Aside from all the techniques mentioned above, almost everyone edits their RAW files. Editing is the process of altering an out-of-the-camera shot. Very few people leave their pictures untouched and publish them the way they are. Even NASA does it for its deep-sky images. By editing a RAW image, you can reveal some data that are hidden in it. You can use a multitude of different softwares to do so, including Adobe Photoshop. Yes I said it! While this pretty powerful tool has acquired such a negative reputation over the last decade, it still enables you to make the best out of your astrophotos.
RAW image (left) and edited version (Lr) comparison. Only a few basic adjustments were done (brightness, contrasts, colors enhancement, noise reduction…).
Editing your image is absolutely subjective. But then again taking an image is by definition already subjective as well as I demonstrated above. On a positive note, editing is probably the part that will make your astrophoto stand out from others. However the downside is, it’s so subjective that you will be confronted to much criticism. It’s up to the astrophotographer to show the world at night according to their own taste. Some people like to keep editing to a strict minimum, some others like to push the adjustments quite far. Some will even add effects and objects that weren’t there to start with.
Photography is ART.
With all the elements that we put forward in this article, there shouldn’t be any ambiguity about astrophotography and photography in general.It is art. It is subjective. By essence and extension, it cannot represent exactly what we see with our eyes, nor what is probably out there. Our eyes have ways of interpreting nature, cameras have their own, and so do our brains when we edit a picture. It should be quite simple then: if you like an astrophotograph, awesome! If you don’t, don’t whine about it and move on! However it’s far from being this way. Comments like ‘this photo is a fake’ or ‘it’s not natural’ appear pretty much everywhere now. Unfortunately a lot of people seem to have forgotten what art is all about. When a photograph doesn’t go by their standards or taste, the word ‘fake’ slips out. The truth is any picture is ‘fake’ since it cannot represent what you see with your own eyes. So I encourage you to take this adjective out of your photography-contemplating vocabulary. To all the arrogant astrophotographers who so religiously try to ‘mimic nature’ or try to keep things ‘natural’ while dissing other photographers for not producing astropictures in the same way as them: newsflash! ‘Keeping things natural’ doesn’t mean anything here!
As an astrophotographer myself, I do not like to alter my RAW pictures too much. Nor do I add objects that weren’t there at the time of shoot. Sometimes though, I do have to make compromises such as removing stitching errors or smoothing out areas that would be too eye-catching. But the point is, I never lie about it. I’m happy to show my RAW files to anyone who asks. I’d also be delighted to explain how I process my shot, which I often do anyways on social platforms. In any case, I take and process my shots the way I like, and that’s very important to me. I enjoy trying out new techniques for different purposes. Art is about creativity, innovation and originality. I have tried compositing but got called out for it, so now I don’t want to renew this unpleasant experience. Because of that, but also for all the right reasons, I don’t go around social media platforms calling pictures fake and unnatural. I actually respect the amount of work and resources used to produce well-made composite shots. If I don’t like the style, I just scroll past!
A lot of people set their astrophotography standards according to renowned photographers, photography competition rules or even organizations like NatGeo, TWAN (The World At Night) or NASA’s APOD (Astronomy Photograph of the Day) to name a few. Most of them promote a ‘true-to-life’ style. It’s honorable but it also doesn’t exist. It is based on the very biased opinion of a few people in a jury or panel. For a couple years now, I’ve decided to stop conforming to a set style or rules. I am not interested in submitting images into an ‘art competition’, which doesn’t make sense to me. I create the images that I like and that transcribe how I view the world at night, or to be more accurate, how I would want to see it if my eyes had the same abilities as my camera. Whether you are a photographer or just someone who enjoys photography, keep in mind that this discipline is an art. Don’t lie to yourself or to others about it! Enjoy it but don’t put it into boxes!