Tag: creative photography

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Quality criteria for lenses

Quality criteria for lenses

How do you find the perfect lens? To be honest: I have no answer to that. But I can show you how to find the right lens. I have a couple of criteria that are crucial for this.

Quality of the lens

With lenses, of course, the first impression counts. What material was used for the lens? There are lenses that are made from 100% plastic; even the glasses. Now it depends on your requirements. It is not bad to use a cheap lens, but if you want to take photos in the rainforest, I would advise against such a lens.

For beginners, I recommend a cheap zoom lens or a fixed focal length. If you are in the advanced field or even in the professional field, you should rely on first-class workmanship and weatherproof lenses, especially when it comes to sharpness and strong weather influences.

Most manufacturers have special series for this, such as the Sigma ART series, the Canon L series or the Nikon series with the golden ring on the lens. These are built in such a way that they can withstand dust, dirt, moisture and temperature fluctuations much better.

Focal length

The focal length is not decisive for the quality of a lens, but you should definitely include it when planning your lens purchase. This should match the area and the way you are photographing. There is no point in buying a lens that covers every focal length . On the one hand it makes a lazy photographer and on the other hand the quality drops. If the lens can cover a larger focal length range, you usually have a dull picture and a lower light intensity.

Extreme focal lengths also have an impact on quality. If the focal length is in the extreme wide-angle or telephoto range, the lenses are often very expensive or quality losses can be expected. This can be blurring or distortion.

Light intensity or maximum aperture

The light intensity is decisive for many when it comes to lenses. With a high light intensity, you can open the aperture wider and get significantly more light on the image sensor. This makes it possible to take pictures in dark light situations without increasing the ISO value .

So if you often take photos in such situations or if you have a blurry background (i.e. you need a shallow depth of field) you should pay attention to an appropriate aperture .

The aperture can be opened much wider, especially with fixed focal lengths . With zoom lenses, a corresponding revelation is usually associated with a higher price.

Sharpness

From my point of view, this is extremely important. If the lens is sharp, you get completely different images. This cannot really be copied with image processing.

With different glasses and significantly better processing, a completely different sharpness and a completely different contrast can be achieved.

I can promise you that here, of course, but what do you think if I just show you. The following images are both unprocessed and not sharpened. One was made with a € 100 prime lens and the other was made with a € 750 prime lens.

Optical resolution

Let me elaborate on the previous part. Because what we perceive as sharpness is called optical resolution. This optical resolution indicates how many lines the lens can display. It’s kind of like an eye test at an ophthalmologist. The finer the lines that can be displayed, the higher the optical resolution.

I have the following opinion on this: The lens should match the camera. It is much more beneficial to use a high-quality lens on a cheap camera than the other way around. Sure, 50 megapixels sound great in a camera, but if the lens can’t reproduce it, they won’t do anything. The many pixels on your camera are then just mud.

But don’t just rely on laboratory tests. Try lenses for yourself.

Bokeh

Bokeh not always back. Anyone who thinks that this is just a blurry background will quickly be taught better. Because depending on the lens, you get a completely different blur in the background. But let me show you more in the following example.

In this picture you can see the 50mm 1.8 from Canon and the 50mm 1.2 from Canon. Both set to f / 1.8. If you pay close attention, you will see that the 50mm 1.2 has a much softer background. Of course there is about 1000 € between the two lenses, but I wanted to demonstrate that you get a completely different bokeh .

If you can’t really see that difference now, then you don’t really need to worry about a more expensive lens. At least as far as the bokeh is concerned 😉

Close focus limit

This is interesting for all macro photographers.

Every lens has a close focus limit. This unit describes the minimum distance between the subject and the image sensor. If the subject is closer to the sensor, the lens can no longer focus and the image becomes blurred. Incidentally, it does not matter whether you focus manually or automatically.

So if you like to get close to your subject, you should pay attention to this value and combine it with the correct focal length . A minimum distance of 2.2 meters sounds a lot, unless you use a focal length of 600mm. It all depends on the right combination.

Autofocus

Auto focus is very important with a lens. Of course, otherwise, all images would be out of focus, but what exactly makes a good autofocus?

Speed

Faster is better? In any case, it should also be precise. It’s not just up to the camera how fast your autofocus is, the lens also has a part in it. Because the glass elements in a lens have to be moved in order to change the focus. A more powerful engine or a more sophisticated system can change a lot here and be decisive for a sharp photo.

Precision

What good is a great lens if it is often wrong? Well, it’s not normal for lenses to be wrong, but there’s a moment when they do. This is due to the back or front focus. With DSLR cameras, this is to blame for the fact that your subject can be blurred. This can often be adjusted with cameras, but it is laborious and not possible with every camera model.

Balance front or back focus

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Incidentally, this problem does not exist with DSLM cameras. Due to their design, these are not prone to this error.

But why am I addressing this topic? With third-party manufacturers in particular, it can often happen that the focus is far off. This became known especially at Sigma with the 35mm 1.4. This lens is only half the price of the Canon original, but many have complained that the autofocus failed and went wrong far too often. Once calibrated and the lens is just awesome…

Noise

Probably less important for most people, but if you want to film or take photos in an environment in which you should avoid loud noises, this point is important. I recommend an ultrasonic motor  here. This technology ensures almost silent focusing.

Image stabilizer

The image stabilizer is a great tool that offers great support, especially in low light or high focal lengths. But it is not only there to avoid blurring with the free hand, but also to be able to expose longer. You may still remember the rule of thumb from the exposure time . If we apply this, we can only expose for a certain time. What if we want to expose longer? Then an image stabilizer can help 🙂

A good image stabilizer can give you a buffer of 2, 3 or even 4 f-stops in exposure time . If we apply the reciprocal shutter speed rule, in which the exposure time corresponds at least to the focal length , we come to the following result.

Focal lengthmin. timeStabi 2 panelsStabi 4 panels
25mm1/251/81/2
100mm1/1001/251/6
200mm1/2001/501/13
400mm1/4001/1001/25

So if you often shoot in situations where you are photographing still subjects on your free hand, you should definitely consider using an image stabilizer. It is helpful in many other situations as well. You will almost always benefit from an image stabilizer and if not, it can simply be switched off 😉

Distortion

Most lens distortion occurs in the wide-angle range. Then the edges of the picture are shown distorted and your motifs are unreal. If you like to photograph architecture, that’s something extremely annoying and the photo quickly looks unprofessional and ugly.

Even if these errors can often be corrected easily in image processing, it doesn’t do any harm to have a lens that does not allow such errors in the first place. Above a certain price range, the distortion becomes less and less and sometimes disappears completely. But remember: The whole thing is based on physics. This can only be tricked to a certain extent. This means that from a certain focal length it does not matter how expensive your lens is, such distortions occur.

The extreme example with an 11mm fisheye lens

Vignetting

In addition to the optical distortion, it can happen with lenses that the edges of the image are darkened or blurred. The darkening is something that I actually really like. In portrait photography in particular, this effect ensures that the viewer’s gaze focuses more on the center of the picture and the subject. If you want to place the motif in a different place, that is again unfavorable. However, at least the dark edges of the image can be easily removed in image processing.

Stray light

Have you ever photographed in the sun with your mobile phone and the picture was simply outshone and nothing really visible? That’s a different matter with high-quality lenses. Extreme light situations and backlighting in particular ensure significantly less reflection and a natural contrast with the appropriate compensation and value .

Chromatic aberration

Chromatic aberration is a color fringing that can appear on contours. But don’t worry, you can get a grip on this quite easily in image processing.

Now what’s a good lens?

Unfortunately, I can’t tell you that, because this feeling is completely subjective. Everyone has different demands on their lenses and different ideas about a good lens. However, I have a few tips on how to use the previous points to find exactly what you are looking for. Even if the last points sounded like everything could easily be corrected while editing, it is definitely not so. A good lens can make a difference like day and night. You don’t believe me

Borrow lenses before you buy them!

Borrow a lens before you buy it. But not just any run-of-the-mill lens. Also take a high quality one. My world and my understanding of good pictures changed completely when I tested the Canon 50mm 1.2. I didn’t buy it and went for a Sigma lens, but it’s worth it just to find out what’s possible.

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The aperture in photography

One of the most important factors in photography is the aperture . The aperture is a lamellar opening in the lens that opens and closes. It has two influences on a photo. On the one hand, it controls the brightness and, on the other hand, the depth of field (or depth of field).

General information about the aperture

Surely you know the portraits or macro shots where only a small part of the picture is sharp. The rest disappears in a blur. With this type of image we speak of a shallow depth of field. We sometimes control the size of this area through the aperture and have different areas of application for this. In landscape photography, we want to be as sharp as possible. But for this it is not necessary to close the shutter as far as it will go! Depending on the lens and camera, aperture values ​​of 5.6 or higher are enough to speak of a high depth of field. The opposite are low aperture values. These open the aperture further and ensure a low focus range.

Aperture value

The aperture value is a little bit confusing, because with a higher value we have a closed aperture and with a lower value we have an open one. This is because the aperture value is a fraction. We don’t actually set an aperture of 4, but an aperture of f / 4. This is because the aperture value is calculated from the focal length of the lens and the diameter of the light passage. This explains why lenses are sometimes very thick, but is difficult to remember for beginners.

Aperture step

If that wasn’t too much for you, I have another tip for you. Because we have a certain approach to the aperture values. As you may have already noticed, you cannot set an aperture of 3.8 on your camera ; an aperture of 4 works though … Why?

It has to do with a very simple calculation and logic. If the aperture makes a full step (from 5.6 to 8, for example), only half as much light falls into the camera. Conversely, of course, from f / 4 to f / 2.8 we let twice as much light into the camera. In this case one speaks of an aperture step. This is available in whole steps and in thirds.

Whole aperture steps:

1 – 1.4 – 2 – 2.8 – 4 – 5.6 – 8 – 11 – 16 – 22

In order to be able to adjust the aperture more finely, there are now third steps. These can be found in most cameras between all the steps for the blind. ( 2 – 2.2 – 2.5 – 2.8 ). Many values ​​in photography are based on this aperture value; also the exposure time and the ISO value.

In simple terms, however, you can say that if you turn a setting wheel on the camera three steps in a certain direction, you have halved or doubled the amount of light. Depending on which direction.

The focus range

The area of ​​focus is the area in an image that is in focus. The size of the focus area is controlled, among other things, by the opening of the aperture . If you keep it open, the area of ​​focus will get smaller, and if you close it it will get bigger.

With the autofocus, you can control at which point the image is in focus, through the aperture how far this focus spreads to the front or back. Please note that this focus area spreads on the camera axis. Everything that is left or right of your subject can therefore also be sharp.

Take pictures with the aperture open

There are several advantages to opening the bezel . In this way, you can keep the focus area in your photo small, which makes for a wonderfully focused look in portrait photography or macro photography.

Take pictures with the aperture closed

The complete opposite is of course the closed aperture . The closed aperture ensures that the picture is naturally darker. Less light comes into the camera, so the picture becomes darker. This can be an advantage if we want to expose longer or if we need a large focus area.

Closing the aperture (f / 5.6 -> f / 8 or smaller) increases the focus area . This is great for group pictures or landscape shots, because at this moment we want everything to be sharp. To do this, it is not necessary to close the aperture to f / 22, i.e. as far as it will go. In most cases an aperture of 5.6 is sufficient. That depends on other influences on the sharpness range. I’ll explain this to you now.

Further influence on the focus range

The focus area depends on the distance to the subject and the focal length used . If you take photos at a wide angle, the field of focus (also depth of field) is significantly larger than with a telephoto lens at the same distance.

An example with aperture 2 and a distance of 4 meters:

  • 17mm = 20.92m depth of field
  • 50mm = 0.77m depth of field
  • 200mm = 0.05m depth of field

The distance to the subject has the same influence. Have you ever noticed that the distance to the subject changes the blurring in the background? With a lot of distance the focus area is quite large, with a short distance it becomes smaller and smaller.

Again the example with aperture 2 and a focal length of 50mm

  • 1 meter distance – 0.05m depth of field
  • 2 meters distance – 0.19 m depth of field
  • 5 meters distance – 1.21 m depth of field

So if you want to have blurring in the background of your portraits, you should not only choose an open aperture , but also get close to your subject (and keep a distance from the background).

The connection between all these influences and factors is certainly not easy to understand at the beginning, but over time this becomes easier and easier. With a little practice you will develop a feeling for which combination of aperture , distance and focal length is the right one for the respective situation.

Limits of the lens

You have already learned a lot about aperture and depth of field. As you have probably already noticed, not every lens can set every aperture . The reason for this is usually the zoom. The zoom requires space in the lens. Every moving part takes its toll and usually ensures this limit. This is why you can usually not open the aperture any further, but what is the solution?

Lenses with the largest open aperture are fixed focal lengths. A fixed focal length is a lens without zoom and usually creates f / 1.8 or even more open (f / 1.4 or f / 1.2). There are also zoom lenses that work in a similar field, but these are often very expensive. So if you want to work with a small depth of field, you should use a prime lens.

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The compact camera – camera purchase advice

The compact camera - camera purchase advice

Which camera should I buy? One of the most frequently asked questions in the beginning of a photographer and beyond. On this page I’ll show you why compact cameras are the right choice for you; or not. Let’s go 😉

1 What is a compact camera?

2 The advantages of a compact camera

3 disadvantages of compact cameras

4 Who is the compact camera for?

What is a compact camera?

The compact camera is, as its name suggests, compact, i.e. very small and handy. All components are designed to be as small and light as possible. A small flash is usually built into the camera housing and the lenses are specially developed for the smaller cameras and are also smaller. They are mostly designed to turn them on and just get started. For this reason, the lens, which cannot always be changed, is designed to simply photograph everything. Some cameras offer further setting options, but the primary focus is often the simple “point and shoot”. Hold on and release.

The advantages of a compact camera

Mobility

Regardless of whether it is a pocket, a backpack or simply in the hand the compact camera simply fits everywhere. You can just take them with you wherever you go. Due to its small size and hardly any weight, it is extremely mobile and no problem even on long journeys. This is a real advantage compared to a SLR camera 🙂

Service

These cameras are designed to be operated by laypeople and are therefore extremely easy and intuitive to use. They are entry-level cameras and although you can control aperture , ISO and exposure time in some models , you will look in vain for one or the other professional function. But that’s not bad, because it makes operation easier and one must not forget: the cameras are not made for this.

Universal

A compact camera with its fixed lens can be used universally in all situations. With a DSLR or DSLM you would have to take several lenses with you, such as a macro lens, a wide angle lens, a telephoto lens, etc … The compact camera combines all of this in one lens. Super zoom and macro are functions that can be found with these cameras. So you are prepared for every situation and it is not necessary to change the lens.

Depth of field

Now it’s getting a bit technical. Compact cameras have a very small sensor. The size of the image sensor has an influence on the focus area. This means that with a small image sensor you can get a large area of ​​focus. If you want to have as much sharpness as possible in the pictures, you need a small image sensor. Architecture and landscapes can be reproduced very well, while cameras with a larger image sensor would have to close the aperture significantly and therefore need more light.

Price

We’re still with the small image sensor. Because small sensors are cheaper to manufacture. There are also devices in the field of compact cameras that exceed £ 2000, but these also have a large image sensor. The purchase and entry into photography is extremely cheap with these cameras, and the enormous spread of smartphones further lowers the price.

Disadvantages of compact cameras

Of course the world is not perfect. Everything has its disadvantages and so of course compact cameras too. Below I have listed the most important ones for you.

Limited image quality

Compact cameras are all-rounders. They can do anything, but that also means they are not really good at anything. Anyone who can do a lot, offers everything and that at a reasonable price has to compromise somewhere. In this case, the small image sensor is to blame. Compared to DSLR / DSLM cameras, you have to compromise on sharpness, dynamic range and the ability to take photos in the dark ( ISO noise). Especially in demanding situations it is very difficult to achieve useful results for these small karmas. Taking photos freehand in the dark? Not a very good idea.

Limited quality of the lens

I already said that you always have to cut corners with an all-rounder. The same goes for the lens. The size of the lens and the usually enormous zoom result in a loss of sharpness, vignetting and chromatic aberration. In addition, every light reflex is reflected across the lens and makes photography almost impossible in some situations. Of course, I am comparing € 1,000 lenses with a £100 camera-lens combination, but you should know what you’re getting yourself into … It gets better (it always gets better)

Handling

A problem that I’ve had with many DSLM and bring cameras: They are simply too small. That makes it very mobile, but it is also demanding to use the small buttons and it happens again and again that you press 3 buttons at the same time. The cameras also have no eyepiece and you have to rely completely on the display. This can work, but in strong sunlight this display is almost useless.

Lens change

There are compact cameras in the higher-priced segment that offer the option of changing the lens. However, I now assume that you are using a device that does not offer this functionality. A lens that is permanently installed has advantages, but an upgrade or a change is simply not possible here. As a photographer you always want to adapt the camera to the given situation and that only works semi-well here.

Who is the compact camera for?

I can answer this question very easily. For everyone who wants a camera that just works. You don’t want to deal with many setting options? Just hold on, pull the trigger and receive a photo as a memento? Then this type of camera is perfect for you. It is small, light, universally applicable and also inexpensive. However, if you now expect the ultimate camera that perfectly photographs every situation at the push of a button, then you will be more likely to be disappointed. These cameras have technical limitations and are perfect for someone who just wants to capture memories.