Frederik is a photographer, blogger and youtuber living in Denmark in the Copenhagen region. Outdoor photography is the preference, but Frederik can also be found doing flash photography applied to product shoots and stills.
The golden hour is the time just before or just after sunrise or sunset. The light is very different from the rest of the day, as the sunlight has to travel through the atmosphere “sideways” and hence travels a much longer distance than if the sun is right above your head in zenith during noon of day. The light during the golden hour has a much more red cast that the rest of the day, the light hits subjects sideways and it is much softer light with gentle transitions from light to dark.
The sun at noon sends its light waves directly downwards and hence the shortest distance through the atmosphere. Early morning or late evening, the light travels much longer through the atmosphere.
In the image below, other than clearly having a red cast, the light travels sideways and lights up the side of the train to the right. During mid day the light would obviously have hit the top of the train which is a far less interesting view.
Also during the golden hour, the power of the sun is significantly reduced, and especially in the morning you can find that mist and traces of light are much more frequent than during the day:
Rays of light travels though the treetops on a misty morning.
So, in conclusion, if you can set the alarm clock to get up in the morning or you have the endurance to go shooting during sunset, you will capture images that are very different from what you can shoot during the day. The golden hour term is no exaggeration.
I guess a sun star is rather self explanatory just by the name as such. But it does not necessarily come from a sun – it can be any bright light source like a lamppost at night or your smartphone, as this low key image illustrates:Sun star, here the light comes from an iPhone!
To produce a sun star you obviously need a bright light source like the sun, a spot, a lamppost or the like. And then you need stop down the lens, i.e. go to a high f-stop number – this will help produce the sun star. If then in addition partly block the bright light source so it is a very small spot that produces the bright light, then that further helps the sun star to appear.
I usually shoot in aperture priority mode and that allows me to set the aperture and let the camera calculate the shutter speed to get a correct exposure. In order to avoid too slow shutter speeds, I may increase the ISO from base ISO to say 800 or 1200 to secure that camera shake and motion blur is prevented. For most cameras you can easily set the ISO to values between 800 and 1200 without affecting the image quality.
Sunstars can be produced also without the sun!
The number of peaks in the sun star is a function of the number of aperture blades in your lens, so that the number of peaks is double the number of aperture blades. Your blades can also be shaped a bit differently: straight blades in my opinion gives the most beautiful sun stars, whereas rounded blades make then less well defined. But this is all personal preference.
The sun star here underlines the beautiful windless morning
A sun star can be used as a tool to emphasise a scene. In the example above the sun star underlines the beautiful quiet morning with the sun rays seeping through the trees to light up parts of the grass. You will also notice a bit of lens flare top right of the sun star – you can minimize this in general using a lens hood, or if you shoot into the sun, try to point directly into the sun so the lens flare is put on top of the sun itself.
A high key image is one that in its tonal range is dominated by lighter mid tones and white highlights.
In this product shoot there is a very bright white desktop to set the scene, and on top of it most subjects are very bright as well. The Notebook and the coffee, together with the pen, are in stark contrast to the otherwise high key image.
This happens naturally if you a shooting where there is lots of light and/or bright surfaces to reflect the light. Or it can be achieved by over-exposing the image or post processing it in post to achieve the same effect.
High-key image example
If you study the histogram of a high-key image, you will see that it “tilts” very much to the right, with almost no blacks or shadows. The few black tones that you do see however, stand out so much more because of the “light” impression of the image overall.
In the example above you can see that the seagull and the black sails of the boat stand out, whereas the rest of the image is highlights or whites. This helps the subjects “pop”, i.e. they stand out because the contrast to the rest of the image is so significant.
High-key images have a light and positive feel to them, quite contrary to low-key images that in all aspects are the exact opposite.
A low key image – lots of blacks and shadows, but not many whites or highlights.
I short introduction to MTF charts and how to read them. Deliberately made not-too-technical.
A MTF (Modulation Transfer Function) chart gives information about how a given lens performs when it comes to sharpness and contrast.
Indication, nothing more
It is by no means a perfect tool, but it does give some information that can be useful when you are in the process of selecting your next lens. There are many reasons why the MTF chart is not perfect, but here are some:
For zoom lenses these are only tested at the wide and long end – how the lens performs in between is often not defined.
Some lens manufacturer like Nikon only give data for the lens wide open. How the lens performs stopped down is not shown (Canon does better here). Compare of lenses with different speeds is hence not on a “level playing field”.
The test is done on a lab lens with a close-to-perfect copy of the lens. However, during production, there will be sample variations between lenses and hence your copy may perform slightly different from what the MTF chart shows.
Manufacturers do not test the MTF charts the same way, so you can only (meaningful) compare MTF charts from the same manufacturer.
Lens performance is also a function of which camera the lens co-operates with. The MTF chart are produced in a camera agnostic way, so the performance of the lens tested and your specific camera may vary relative to the MTF chart
So, please, take the MTF charts as an indicator and not the entire truth!
The MTF chart
There are some technical aspects of the MTF chart that I will not cover here as it gets too technical for me and I also fear that we loose sight of the bigger picture. What I want to cover here is how to read the chart:
Chart from the Nikon home page. The 50mm 1-8G lens.
The x-axis on the chart is the distance from the center of the lens. All the way to the left is the center point and going right it moves further and further away from the center. The point here is to test how the lens performs in the corners, which traditionally is the weak point for lenses.
Lets say the y-axis is an indication of how the lens performs (this is not the real story, but sufficient to read the graph). A value of zero is super poor performance, a value of one (1) is perfect performance. A perfect lens would hence have a flat curve going straight from left to right with all values on the y-axis reading 1. Or, as Nikon coins it: the higher and straighter is better.
The two colors show the sharpness (blue) and the contrast (red) respectively.
Contrast, red: In the graph above the contrast is very good in the center of the lens, it stays good to around 17-18 mm from the center of the lens and then it drops.
Sharpness, blue: The sharpness is really good in the center and then falls with an almost constant slope moving away from the center. The corner sharpness does not appear to be impressive.
Mind you that this is only a graph for the lens at full throttle (f=1.8) – you can see in the bottom right of the graph that Nikon has made a note to make us aware of this. The lens probably performs much better stopped down, but we get no wiser in this regard studying the graph, unfortunately.
You will also notice that there are two lines for both sharpness and contrast, a solid and a dotted. When they test the lens, they do so with small lines drawn very close to each other. The direction of these lines varies between the solid and the dotted graph. The point when it comes to reading the graph lines is that the closer they stay together the better the lens performs. You cans see that the blue lines indicating sharpness stays well together almost to the edge of the lens, whereas the contrast lines drift apart when moving towards the edge of the lens (some types of aberrations start to surface for example).
Even though Nikon says that higher and straighter is better, a good question is: What does good looks like? How high in the graph do you need to be in order to have a good lens? I think you get a feel for this when you have compared charts from a few lenses, but as a rule of thumb I think of anything above 0.8 as stellar, 0.6 to 0.8 as really good and anything below that as “I need to think about this before buying”.
Mind you that no lens is perfect, so you will never get a straight line in the graph. But some do come close. Take a look at the f/1.8 50mm prime from Nikon for the Z-mount. What a lens! I think it makes sense to compare it to the graph above as it is same manufacturer, same focal length, both primes and equally fast (f= 1.8). I have no doubt that this lens technically a much better performer. I do say “technically” because some absolutely love the look of a Nikkor vintage lens, but then again I would assume they do not study MTF charts!
I hope this gave you a good introduction to what an MTF chart is and how to read it. Questions and comments are of course more than welcome.
A short post about what exposure compensation is and how you use it.
When your camera calculates the correct exposure in the automated or semi-automated exposure modes, the camera sets the shutter speed and aperture to achieve a technically correct exposed picture.
Exposure compensation is simply that you ask the camera – on top of the calculated exposure – to deviate from that exposure as per the exposure compensation settings. So if you dial in a exposure compensation of say -1 stop, then the resulting image will be slightly under exposed.
Dials
The exposure compensation dial in the Fuji X-T20 ranging from 3 stops over exposed to 3 stops under exposed and all in between in 1/3rd stops
The image above shows the Fuji X-T20 exposure compensation dial where you simply turn the dial to the desired compensation. A more traditional implementation is a little push button on top of the camera with a +/- sign. When you hold down this button and at the same time turn the command dial, you can set the exposure compensation value. The top LCD will typically show you the values while you push the +/- button.
The exposure compensation button on the Nikon D4. The Nikon D700, D750 and Z50 has exactly the same implementation.
Use
You can use this a as a creative tool, where you systematically over or underexpose your images (low key and high key) to achieve a creative effect. Or you can use this to compensate for the automated exposure when you know your camera will get it wrong – for example shooting portraits in the snow, where your camera will have a tendency to under expose in attempt factor in all the white in the frame.
If you shoot in RAW format, then a lot of tweaking to the exposure can be done in post processing as the RAW format give a lot of headroom for adjusting the exposure. However, many prefer to get the exposure right “in camera” to simplify their workflow and save time.
A histogram is an illustration of how light is distributed across the tonal ranges in your frame. You have black to the left, white to the right, and shadows and highlights in between.
A histogram on my Fuji X-T20 rear LCD
What is it for?
Let me first say that photographers have for many years taken excellent photos without any histograms. So you can do well without them. Some absolutely love them and others shy away from them. It is all up to personal preference.
As the histogram shows you how light is distributed across the tonal ranges, it gives you good insight to the exposure of your image: where is the “weight” put in the tonal range?
If it it under exposed, then the graph is heavy to the left (lefty as some say).
“Lefty”
Is it over exposed, then the graph peaks to the right.
If you loose details in the dark areas, then the graph touches the left hand side. If you clip the highlights, then the graph touches the right hand side. If it touches both sides, then you have a high contrast scene and exposure bracketing may be a way forward.
Some histograms show only the red, green and blue color channels in one combined graph whereas others split them up. In the image above, you can see that my Fuji X-T20 show both the color channels and the combined result (grey – on top).
Some make rules based on the histogram, like: your histogram should be evenly distributed and center weighted! Others run away when they hear such rules – the option to use over- and underexposure as a creative tool should not be hampered by rules that restrict your creativity.
Either which way you look at it, the histogram gives information about your exposure and if and how you choose to use it is up to personal preference.
Where is it?
If you are so lucky to have a mirrorless camera, it is very likely that the electronic viewfinder (EVF) can show the histogram as and integral part what you otherwise would see in the viewfinder. And it will even update the histogram as the light in the scene changes. This is very convincing.
A DSLR does not have this option in the optical viewfinder, but if you shoot in live view mode then it may be able to present a histogram in the rear LCD just like the mirrorless does in the EVF.
These options are all before you hit the shutter. Post shooting, you can review images in the rear LCD and here most modern cameras can show the image with a histogram. Just as the picture in the start of this post shows.
In post processing software like Lightroom, you also can see the histogram, and as you pull the exposure slider there, you will be able to see the changes the editing does to the histogram.
An ND-filter or a neutral density filter is like a pair of sunglasses that you put in front of your lens. The purpose it to reduce the amount of light that hits the sensor, just like you want to protect your eyes from the strong light on a sunny day.
A variable ND-filter sitting on my beloved Nikkor 16-35 mm lens.
The point with an ND filter is to allow you to keep the shutter open for longer time without clipping the highlights in your picture or in other words simply avoid that you over expos your picture.
Why would you then want to keep the shutter open for a long time? Take a look at the picture below. It is taken over several seconds. The stones of course do not move, while the waves of the sea are reduced to pure silk. Moving parts become blurred, stationary items stay sharp. That is one effect you can get with an ND filter. You can also shoot waterfalls, harbors, etc. with this technique and get similar results.
Long exposure. The stones stay put, the waves of the water are reduced to pure silk…
Another application is simply that there is so much light that even when you shoot at the fastest shutter speed your camera offers and base ISO, you still get too much light. Then an ND filter – like sunglasses – comes in handy to reduce the amount of light.
You can also use the long shutter opening to move the camera instead, and this is what is done in intentional camera movement where you move the camera to create a blurry effect.
ND filters come in variable and fixed ones. I prefer the variable, because I can then turn the ring to reduced effect (ND8), so I can actually see what I am shooting and then once focused, return the ND filter strength to full throttle (ND2000) and get the most out of the filter. If you have a filter with a fixed value, you typically find you have to take it off the lens in order to focus, and the re-mount to take the picture. The variable filter saves you a bit of work.
The light reduction your ND filter yields is typically measured in ND values – if you look at the picture of my ND filter above, you can see it ranges from ND8 to ND2000. That is a reduction of 3 stops to 11 stops. That is a lot! You may be able to get by with less than that.
ND filters are not cheap, and you want to get a good one. The “neutral” in ND is to be taken very literally – you don’t want the ND filter to change the color or toning of the light. It should really stay neutral. Cheap filters unfortunately often has this un-wanted side effect. Make sure you get a filter with good reviews – it is quite expensive, yes, but you will not enjoy a filter that alters the colors. Believe me – been there, seen it, done that. Not to be repeated.
I think of the shutter as a curtain in the theater that comes up, exposes the show for a little while and drops again. For how long the curtain is up defines the speed of the shutter.
Others use the eyes and the eye lid as an analogy to the shutter speed: closed eyes, open them – take in the view – and close again. The duration of your eyes open is the shutter speed.
The longer the shutter speed the more light will hit the sensor. A fast shutter speed is great if you want to avoid camera shake (you move the camera while the shutter is open) or motion blur (the subject moves while the shutter is open).
The shutter speed dial sits just to the left of the red shutter release button on the Fuji XT20. As you can see the camera is in “A” mode where the shutter speed is chosen automatically. Below the “A” you can select 1/4000th down to 1/1, then timer release and bulk.
Shutter speed is expressed in fractions of a second, so a shutter speed of 250 is 1/250th of a second. The fastest of cameras can go to 1/4000th or 1/8000th of a second. That is fast! On the other end of the scale you can have the shutter open for several seconds, even minutes, when photographing in extreme low light like astrophotography.
Back in the day all shutters were mechanical, and if it was not for the mirror flickering in your DSLR, you probably could hear some mechanics working in there. There actually is a little black curtain moving when you hit the shutter. Most modern cameras can both work with the mechanical shutter and the electronic shutter – the electronic shutter being the new kid on the block. The electronic shutter works by switching the sensor on and off. This happens super fast of course! It simply switches on the sensor and allow light to hit it, and then off again to allow the camera to read the sensor values.
Thank you for reading this far! Comments and questions more than welcome!
Outlining the various exposure metering modes that a modern camera offers.
Exposure is vital
Unless you have a very old vintage camera, it is most likely that a light meter is built into your camera!
A good old light meter from back in the days when a meter was not so common as an integral part of the camera…
The light meter measures the amount of ambient light available and based on this, the camera can choose camera settings (aperture, Shutter speed and ISO) to get a correct exposed picture. (PS: Take the wording “correct exposed” with a grain of sand, as exposure can be used as a creative tool and hence “correct exposure” is more the technical correct exposure.)
The meter in your camera can read the light in different ways and give priority to different aspects to help you get the exposure you want. Mind you that the camera has no idea what it is you are shooting, so any help you can give it will help bring the exposure closer to what you are after. The exposure modes are just different ways of reading the light.
There are variations in how the different camera manufacturers name their exposure modes, but the principles are roughly the same. Here I use the names from Nikon, but when you read the manual for your specific camera, I am sure you can recognize the different modes.
Spot metering
Spot metering measures the light only in the focus point or in area just around it. It ignores the amount of light in the rest of the frame. This pin prick way of measuring the light makes it possible to have blown out areas or loosing details in the shades with no problem – the camera only meters the focus point. This is useful if you want to make sure than the eye of a person is correctly exposed in a scene where there is lots of either bright or dark areas or both.
Center-weighted
Center weighted metering takes the entire scene into account, but gives more priority to the center of the frame. This is a classic metering mode for portraits, as it helps get the person exposed well, with less weight to the outer parts of the frame. This of course provided you put your subject in the center of the frame! You can via the menu system control how much emphasis the camera is to put on the center part relative to the rest of the frame.
Highlight-weighted
Highlight weighted takes the brightest area of the frame and makes sure it does not get blown out, but on the other hand ignores that details are potentially lost in the shadows. In other words, if there are very bright areas in your frame, this mode will deliberately under expose your picture to secure the highlights are preserved. Very useful if you are shooting with the sun or some spotlights in the frame and want to preserve all the details in the bright areas.
Evaluative / Matrix metering
The matrix or evaluative metering takes the entire frame into consideration when metering the light. It is the most automated of the metering modes, as it gives a good balance between bright and dark areas. However, as it is a highly automated mode, the camera will try to find the “middle of the road” and make compromises to make the best of the scene without knowing what you shoot.
What should you choose?
If you don’t know what to choose, the evaluative / matrix metering is the option to go for. It gives you a good compromise and many photographers never leave this metering mode. And if you shoot RAW, there are lots of options for working with the exposure in post to recover details in the dark or details in the bright areas.
I typically shoot in RAW and use the evaluative / matrix metering. If I shoot where the light is very harsh, for example in the middle of a summers day, then I switch to the highlight weighted mode to avoid blown out parts, but I do so knowing that I may loose details in the dark.
All of the above is less relevant if you shoot in the automated mode (i.e. not P, A, S and M). In the fully automated mode (green A on the mode dial) the camera ignores your metering settings and makes its own decisions!
Thank you for reading this far! Questions and comments are more than welcome!
Lens flare is bright areas of light in your image, that you do not find in reality! It is caused by the way light hits the front side of the glass in the lens and is scattered inside the lens.
Here below I have taken a shot of me holding my iPhone up in the dark and taking a picture of it. You see leftmost a hectogon shaped green light (the same shape as the aperture blades) followed by several colored bright spots. This is flare. None of these were there when I studied my iPhone with the naked eye:
A bright light source (here from an iPhone – more typical the sun) in stark contrasts often brings out lens flare.
If the light comes into the lens from a very steep angle, then the result can be a milky white area – sometimes covering the entire frame. And the contrast in that area is significantly reduced – things appear to be washed out.
Here I hold the light from the iPhone so it comes into the lens from almost 90 degrees and from the left. If you’re thinking: 2001: A space odyssey, then you know what creative tools Stanley Kubrick used.
If you want a good test if your lens has flare, go out at night, find a tall lamppost and point your lens towards it. Move the light from the lamppost in and out of the frame to provoke flare. You will probably be able to get some flare effects, especially if you leave the lens hood at home and choose a zoom lens. Zoom lenses have more complicated constructions than primes and tend to produce flare more easily.
Some love flare. In my experience, videographers love flare. When you watch TV or go to the movies, you will quickly spot flare used as a creative tool. It certainly underlines the strength of the sun on a sunny day. Also some photographers love flare, they even add it to the image in post processing!
Others do not love flare so much. If you want realism in your photos, the flare is to be avoided, as it is a thing created by your lens. It sort of gives away that a lens was part of producing the image.
Some lens constructions are better at reducing flare than others. Modern coating of the lens glass greatly reduces flare, but cannot eliminate it fully. Zoom lenses have more complicated constructions and are hence more prone to flare – primes less so. And finally, you can use a lens hood to reduce the flare. I sometimes even hold the hand against the sun to protect my lens from getting the light that produces flare.
In my opinion there is no right and wrong when it comes to flare. It is a creative tool. The problem comes when it is there and you don’t want it or the other way around. But hopefully this article has given you some ideas what to do in these cases.
Thank you for reading this far! Questions and comments are more than welcome!
