Samsung S22 Ultra: depth of field and digital photography by Jose Antunes

To get the best blurred backgrounds when shooting with a smartphone, you need to ditch manual control and embrace digital photography. But you can still set some things…

While smartphone cameras are also bound by optical laws when it comes to depth of field, computational photography has introduced some unique options that, despite limitations, are worth exploring, if you know where to look and understand how to bend the camera. ‘AI to your own Goals.

I’ve been exploring, since the first days I got my Samsung S22 Ultra, how available cameras work with depth of field, and I’ve reached some cool workflow methods that can help others achieve best photos with this model but also with other smartphones. I mostly explored the two included telephoto lenses, 70 and 230mm, as they offer closer focal lengths to those I like to use with conventional cameras.

Depth of Field, or DoF for short, is a key element for many of my photography, and I’ve played with it, mostly when shooting flowers, as I call it “my way”. The recipe is simple – a long focal length and a wide aperture – but the way to get the results I want is a bit more complex. Let me explain the concept to you before continuing.

Samsung S22 Ultra: depth of field and computational photography
Getting closer to the subject (right) and opting for a more distant background helps either with a smartphone (here) or with a normal camera

Depth of field issues

Photographing flowers “my way” results in an image where the flower is detailed against a blurred background. In nature, where you cannot move your subjects from their position, for better lighting and composition you need to find a subject that can be placed close to the lens but at the same time is far enough away from the lens. background so you get the soft bokeh, which can either be a blur of different colors – other flowers, sky, patches of green – or a single tone, darker or lighter depending on the lighting conditions.

While some may imagine a macro setting I use to shoot flowers with the long end of a zoom lens, in my case a 100-400mm paired with an APS-C sensor, which gives me the field of vision of a 640 mm. Since the lens I’m using focuses at 90cm, I can get really close to my subject and, thanks to the af/5.6 aperture, everything behind the flower is out of focus. This is usually done by holding the equipment in your hand.

Because optics is rule-based, I often have to give up photographing a specimen that is very beautiful to the eye, for various reasons: I can’t get close enough to the flower or the distance between the flower and the background isn’t enough for the result I want, and, in many other cases, none of the conditions are met.

Samsung S22 Ultra: depth of field and computational photography
Because of the way smartphone lenses – here a 230mm – deal with out-of-focus subjects, it’s wise to choose darker backgrounds for flower photography, if you have the chance.

Pro and Expert RAW mode

What was already a difficult task with a classic camera and a long lens becomes even more demanding when trying to create the same type of images with a smartphone that is less ergonomic to stay stable, with a main telephoto lens of only 230 mm (which is ideal for this type of camera, however…) and because of the way the optical system works, it is more difficult to obtain a bokeh similar to a conventional camera, AFAICS.

After playing around with cameras for a while I have a series of notes with distances and camera modes and what they allow you to achieve which I think can help others to achieve better results with their smartphones. While some of the concepts apply to smartphones in general, the results shared here are from the Samsung S22 Ultra and reflect my experience trying to get the best results, when photographing flowers, with the 70 and especially with the 230mm lens.

As a rule, I never use the basic camera mode available on this model. As I want to control the editable settings – ISO, speed, focus and WB – I use either the Pro mode of the Camera app or the Expert RAW app. I’ve shared my reservations about Expert RAW before, so for this article I’ll just say that in general and as far as DoF is concerned, Pro mode and Expert RAW work the same way. I also posted a long text on MFD – minimum focus distance – before, so if you want to know more about it, go read it.

Samsung S22 Ultra: depth of field and computational photographyNo control over the opening

Shooting flowers outdoors is possible with the Samsung Galaxy S22 Ultra, but for this test, where I wanted to measure distances and try out different settings, I recreated a typical outdoor situation setup – this time on my kitchen table while my cats decided to sleep on the studio – with an orchid and some dried flowers in the background. As expected and within the rules, the closer you are to the subject and the further away the background is, the more diffuse it becomes.

One aspect to consider, before continuing, is that the 230mm telephoto lens of the S22 Ultra allows me to get really close to the flower, so I only get part of its petals, but since I want to get the whole flower , I need to shoot from afar, which in itself means the background will be less blurry, for the same setup. Another thing to remember is that I have no control over the aperture – which changes DoF – so the f/4.9 aperture remains constant.

With the 70mm (left image), filling the frame with the flower while leaving some negative space reveals the background space too much, even if everything is – slightly – blurry. But it’s a busy environment. The 230mm telephoto lens (second image from the left) works best, with an almost identical sized image but with a smaller angle of view that only reveals the dried flowers, but continues to be a cluttered background which doesn’t help define what the Subject key is. Moving the dried flowers back blurs the background more, but as with any conventional camera, if you can’t keep the background away you’ll never get the results desired. the solution is revealed in the third image from the left. Keep reading!

Samsung S22 Ultra: depth of field and computational photography
The left image shows what can be achieved with Portrait mode, while the right image is the best I can do with the 230mm on the S22 Ultra in Pro mode

Portrait mode and 3x crop

This exercise helped me confirm that unless you can effectively control the distance between the subject and the background, you won’t be able to separate it from its surroundings, and this is true for flowers or any other subject. If you go for close-up or macro, you can get better separation, but with flowers – read subjects – of medium size that you want to capture in full, distracting backgrounds can be a problem. This means that we are exactly where we started: bound by the laws of optics!

Now, because this is a smartphone and computational photography plays a role, I have good news for you. It is possible to separate the flower from the background. Although the optical rulers are still present, they are apparently broken by some magic. I can tell you what happens, but you’re probably not going to like it. Portrait mode in smartphones is a neat trick for photographing people, as it does calculations under the hood and creates a “mask” with a blurred background around the subject.

While it’s not a perfect solution – you’ll soon find out why, if you start using it… – it does work in certain situations… and it can be applied to more than just portraits of people. There are a few “rules” to follow, subjects need to be between 3 and 5 feet for the automatic system to work, and the system is usually paired with the wide angle lens. The Samsung Galaxy S22 Ultra has an added bonus though, as it gives you the option to use 3x digital zoom in Portrait mode, which means you get better background separation when you “zoom in”.

Samsung S22 Ultra: depth of field and computational photography
The left image uses Portrait mode, while the right image shows what can be achieved with the 230mm telephoto lens in Expert RAW or Pro mode

The Basic Camera app to the rescue

The basic camera app isn’t something I use, but the only way to use Portrait is through this mode, so I spent a few weeks using it, just for “portraits”, of different subjects/objects, to test the system, both inside and outside. It works, as shown in the images posted here, but a word of warning: if you open the EXIF ​​file, you’ll find that even though the info says the 70mm lens was used, which is used, in fact , that’s the wide-angle lens – 23mm – with 3x digital zoom applied. It’s a “dirty secret”, especially if you prefer to use optical lenses instead of digital trickery.

Two things are true, however: the resulting imagery is very detailed, and it’s an easy way to get backgrounds blurred – most of the time – even if it’s not always perfect as I see it. would like. It would be fantastic if Samsung could make this usable with the true 70mm lens – at least – but I guess computational photography isn’t something that can be used everywhere. One more note on Portrait mode: you can adjust the focus area and the intensity of the effect after taking the photo, and there are various effects to choose from.

A final note for anyone who, at the moment, has asked: does this work with video? Yes it is, as there is a Portrait Video mode which can be accessed by opening the “more” option in the basic Camera app, in the S22 Ultra. You can capture video with the wide angle lens and also with 3x digital zoom value – or crop – (70mm), and you have access to some of the filters associated with the option, as well as the possibility to define the intensity of the effect.

Stewart C. Hartline