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 architecture, product shoots and stills.
The title of the book as per the headline is a very precise description of what this book is all about. It “puts some of the most important photographic landmarks under the microscope” as it says on the cover. And very much so.
Photo icons, 50 landmark photographs and their stories, by Hans-Michael Koetzle.
The 50 images are presented and analyzed over the 400+ pages of the book, giving an average of 4 pages per iconic photograph. Enough to cover the basics and tell the story around each picture.
The table of content has an excellent overview with each picture in icon size and annotated with the relevant year and page to look up. The 50 images range from year 1827 to 2001. So you can quickly dive into the images of interest (I doubt you will read the book from front to back unless you are equally interested in each image).
Photographer Peter Leibings picture “Leap to Freedom” from 1961, just after the wall between East and West Berlin was in effect.
As I “cherry picked” the images of most interest, I have not read every single page in the book, but many of them, and I really enjoyed the “behind the scenes” view that you get to each image: What was the story, the photographer, what was going on in the world at the time the shot was taken, was it staged or candid, etc. Hans-Michael Koetzle really packs a lot of information into very few pages for each picture – it is a condensed read, but certainly worth the while.
So as a photographer it is not a book that will make you wiser in terms of photo technique (f/11 vs f/5.6), but it really documents how a photograph – even with all the videos and movies available today – can be powerful and influence what we remember and how we see history. And as such it for me adds a layer to my motivation to shoot the best pictures I possibly can.
Focus shift shooting is not a new thing as such, but the automation of it is new to me, owning primarily DSLRs like the Nikon D4, D750 and D700. The Nikon Z6ii offers an automation of a series of shots where the focus is shifted a little bit for each – moving from near to far. When you do focus shift shooting, the Z6ii will produce a series of images to be merged in post processing.
It is a precondition that the camera is able to control the focus of the lens, so manual focus lenses of course cannot be used when shooting focus shift. As the Nikon ML cameras do not have mechanical AF motors built into them (nor does the FTZ adapter), this means that AF and AF-D lenses do not work, nor does AI and AIS lenses unfortunately.
Focus shift shooting enables you to have images where the depth of field is indefinite, as you in post processing combine the images into one image, picking the sharpest part from each. The only “price” you have to pay is that the shots need to be taken from the same viewpoint and angle (using a tripod) and that you cannot have any moving parts in the frame while the shots are taken. But both these are easy to fulfill as a landscape photographer.
Another thing to be aware of is the lens and if it suffers from focus breathing. If that is the case, then the images will be very difficult to merge in post processing, as you involuntarily will be zooming during the shots. Merging images with different angles of view is mission impossible. So make sure to use a lens that does not have focus breathing.
Best results are achieved shooting where the lens is the sharpest, typically around f/8 or f/5.6 – avoid very open apertures (e.g. f/1.8) and very closed apertures (e.g. f/22) as your lens most likely is not the sharpest in these extremes. Use a “middle of the road” aperture, where you know your lens is sharp.
Configuration
To initiate the shooting, you first have to find the “focus shift shooting” menu in the “photo shooting menu”. It is the second last item in a long list that spans across several pages.
You find the focus shift shooting menu item in the photo shooting menu, second last item.
After selecting that one, the “focus shift shooting” menu appears. When you hit “start” (highlighted in yellow below) the camera starts shooting a series of images according to the parameters set below.
The focus shift shooting menu from the Nikon Z6ii, but I believe it is very similar to the Z7.
The menu above looks a bit long and intimidating at first, but don’t worry, it is relatively few parameters you will be changing after the initial setup.
The number of focus shots can be set to a very high value, like 100. The camera stops shooting new images when it reaches infinity, so for landscapes you cannot really set this value too high. I think the large possible number here is intended for macro photography. In my experience 5-6 images are more than plenty for a landscape shot.
The focus step width is not very well documented in the Nikon manual, but it has to do with how large steps the camera takes between shots. Values range from 1 to 10. You have to give it a try here. I have set mine to 5 and it works fine. In my experience, the chosen aperture has more influence on the number of shots than this parameter.
The interval to next shot is intended to give flashes time to recycle power and for landscapes I do not use flashes, so it is set to 0″ in my case.
The first frame exposure lock is important to have switched on. It secures that the exposure values are not changed throughout the shots. Provided that there are no changes in ambient light during the series, you should get consistent exposure results across the images in a series. You can of course fix this in post processing if you really know your software, but IMHO it is much easier to get right in camera.
The silent photography is switched on in my case. I like that I can hear what the camera is doing when it shoots the series. This tells me how many images are there and when the shooting is done. It is of course a matter of personal preference, so entirely up to you. But the camera is not very informative when it is done shooting, so I like to have some sound to relate to.
The starting storage folder can be handy for separating the images from others, as you will be generating quite a lot of images.
Shooting
Be fore you give the camera green lights to shoot a series, it is important that you initially have focused on the closest part that you want to be sharp in the frame. So if you have a stone or the like in the foreground that you want to be sharp, make sure to focus here before initiating the shot. Once the shot is done, the camera leaves the focus to infinity.
Other than keeping the camera still using a tripod, shooting at a middle aperture and selecting a scene with no moving parts, there is actually not much more to it than that. Only remember to focus near every time before the first shot. And then pray that the ambient light stays constant throughout the series.
Post processing
The first time I read about focus shift shooting, I was hoping that it would also do the post processing in camera, just like your smartphone effortlessly merges several images together when you instruct it to shoot HDR. Unfortunately that is not the case – we “only” get a series of images and have to do the post processing ourselves.
If you open the images as layers in Photoshop, the process is not complicated at all: first ask photoshop to align the images, then ask photoshop to merge the images and finally you may want to crop the image a bit as the edges may look funny after the alignment is done. You find the items you need in the edit menu. The first item is named Auto-Align layers… and the second one is named Auto-Blend images. When you select these a menu appears in both cases – I just say OK to the default values.
Here the 2 images in the top of the series have been taken out, and you can see how Photoshop via masks join the images into one. The two images removed (no “eye” bottom right) are the ones focusing on the near part in the picture.
I recently shot a scene with a icicle in the foreground and a path in the woods leading to some trees in the background. When merging the series of images in Photoshop, you can see that photoshop uses masks to select the sharp parts from each image – black conceals, white reveals. In the example above I have deselected the two images that deliver the part closest to the camera (the white part).
The image is sharp from the icicle in the foreground to the tree in the background. Bottom right you can see that Photoshop via masks has merged 6 pictures together to one.
So if you have managed to keep the camera still etc., the resulting image should be one with what appears to be infinite depth of field. Everything in the frame is sharp, from front to back.
If you like this kind of shooting is of course entirely up to you. Some think it looks a bit artificial, and prefer that sharpness is a function of the aperture and a single focus point. I have added it to my toolbox as an option that I sometimes use subject to – well – the subject. It is all up to you!
It is seldom that I praise a product for being easy to use. Somehow, when everybody tells me a product is easy to use, I manage to find the wrong way to go about things, and a well designed easy to use product suddenly becomes complicated. Not so with the Røde wireless go. It is just plug and play – no need to pray!
The essentials: A sender, a receiver, two dead cats and a connector cable from receiver to camera (red).
It consists of a sender unit, a receiver unit and a cable to go between the receiver and the camera. In addition there are two “dead cats” to mount on top of the sender, to reduce noise from wind and the like. The sound is then wirelessly transmitted in real time from the sender (with the mike) to the receiver. No cable to be tangled up with or other cumbersome things. A simple solution to getting the sound from a microphone in front of the camera, to the camera’s mike input connector.
Here the red connector is applied between camera and Røde receiver. The receiver fits into the hot shoe of the camera. On my Sony A7Rii the receiver is not visually dominating at all.
The tin promises that this is an ultra compact wireless solution with digital transmission and a built in microphone. All this is true. The marketing department did not exaggerate at all.
The tin promises digital transmission, built in microphone and a ultra-compact wireless setup. I tend to agree….
To activate the system, you hold in the button marked “ø” for a few seconds, and the units turn on. The sender and receiver connected the first time I turned them on. No need to pair them or the like. Brilliant!
A microphone is built in. It does a good job, but if you want a more discrete microphone, use a small cabled microphone and hide the receiver in a pocket. The connector is left to the microphone on the right hand unit. The units measures approx. 4,3cm x 4,3cm x 1,3cm and seem really small.
The sender has a built in microphone, but I prefer not to use this one. The sound is great, but it requires that you have the unit close to the one speaking and hence very visible. The unit is small, but not very discrete when recording a video close up!
The DB button changes mike sensitivity. Toggle between high, medium and low. I always use medium.
You can regulate the sound level hitting the “dB” button. It circles between high, medium and low. I have only used the medium setting – it works fine and further adjustments can be made in post to fit your needs.
The receiver has a battery indicator display for both the sender and the receiver. The green bar in the middle is the sound level. Triangle bottom left shows the mike sensitivity and bottom right is the strength of the wireless communication.
The receiver unit has battery indicators for both the sender and the receiver, so there is no display on the sender. I seldom record for more than an hour at a time, and for my needs there has always been plenty of battery power on both sender and receiver, so for my needs battery power is more than sufficient.
If you care to download the user guide (PDF) from the Røde homepage, you will find that it is short and informative. Here the description of buttons and display on the receiver unit. Credit: Røde.
Two blue diodes on the sender indicate if the sender is connected to the receiver and if it has sufficient battery. If you need more details, you need to consult the receiver.
In terms of connectivity I have not stress tested the connection, but recording a video recently where I was out and about with perhaps 10 meters distance between sender and receiver, I experienced no issues with the connectivity. Clear and crisp sound all the way with no dropouts or similar issues. It just works.
If you have a microphone with a TRRS connector (4 rings), it will not work with the sender. You need an adapter to take you from TRRS to TRS (3 rings).
The only thing that may be a bit tricky is the connector when you want to use your own microphone. The Røde Go system requires a TRS connector, and your microphone may have a TRRS connector. In that case, you need an adapter as shown in the image above. So count the number of rings on your connector, and if it is 4, then make sure to get an adapter when you order your copy of the Røde Go.
Both sender and receiver charge via USB-C. Brilliant!
A final thing that I want to bring up is the fact that both units charge via USB-C. I cannot underline the importance of industry standards and USB-C is exactly such one. I am so glad the Wireless Go comes with no chargers at all! Wonderful! If you knew how many chargers I have on stock for my cameras and flashes…. I welcome USB-C so very much. And of course also the USB to USB-C cables that came along with the Wireless Go system.
Conclusion
If you want a simple cable-free solution to transmit sound from a microphone in front of your camera to your cameras input port, this is a really easy to use and stable solution for exactly that need. Just make sure you have an adapter if your microphone has a TRRS connector.
The solution reviewed here is not applicable if you want to record an interview or other situations where several channels need to be recorded in parallel. I believe Røde also has a more advanced solution for such situations, but that is not the product reviewed here.
I have used this solution for my YouTube videos and for my needs (walking and talking in front of a camera), this solution fits my needs spot on. It is simple to use, stable and with good connectivity. Exactly what I need, for less than 100 EUR. Highly recommended.
When I started reading this book, my immediate reaction was: what a life this guy has had! And my next was: hmm, is my life a little boring perhaps?
The first 2/3rds of the book is a super entertaining and seemingly endless stream of adventures, beautiful women, new friendships, more adventures, great food and lots of alcohol! We follow Uri as he describes his life as a ski bum, bartender, a soldier in the Israeli army and travel adventurer.
Wild and Fearless by Uri Løvevild Golman – the epic life story of a National Geographic photographer
About 2/3rds the focus shifts towards Uri’s career as a wildlife photographer and how he and Helle (2nd wife) finally makes it as National Geographic Photographers. The adventures continues, but with Helle and photography in the center.
I must admit that I bought the book to see if I would be able to look over the shoulders of one of the greatest wildlife photographers of all times, but I was in that sense a bit disappointed. There is no description of f/8 versus f/11 or how Uri learned to photograph. Only his photography mentors are briefly mentioned. However, you do get to understand how much hard work there is in wildlife photography – one example is hiking 3 weeks in icy mountains only to come home with zero images of the snow leopard!
But I got something else: I got insight into a man with a mentality that very few posses. At age 42 he was attacked and stabbed to a degree where most of us would have given up, and he was dead for several minutes before being revived. The attack left him injured with permanent disabilities as his brain was deprived oxygen for several minutes. He says towards the end of the book: “I have finally come to terms with the truth: I will never be able to walk freely again; no more hiking under the stars in the tundra or the forest. Nor will I be able to work my camera”. However, he refuses to take the role as a victim and he does not show any signs of feeling sorry for himself.
It is Uri’s hope that the book will give others inspiration to follow their hearts and dreams. Speaking for myself, I can say: mission accomplished.
The other day I was out shooting, a happy camper that did not consult the weather forecast. I paid the price for my ignorance, and was soon caught in a heavy downpour in January. The problem with January in Denmark in combination with rain is that there are no leaves on the trees, and hence nowhere to seek shelter.
I hope you can see here how heavy the rain came down. This is actually a quiet lake on a windless day, but the hard rain makes all the difference!
Towards the end of the shoot I arrived at a big lake where the rain came down as if I had stepped into my morning shower wearing all my clothes! I was wearing proper clothing for the weather fortunately, but my camera gave up just when I was about to take a shot of the dramatic lake.
As you can see in the surface of the lake, the rain was pouring down. This was shot on my iPhone, as my camera had stopped working.
Lucky for me, I was able to use my iPhone to take a shot. The iPhone was difficult to operate because there was so much water on the screen that the phone had difficulties figuring out what was rain and what was my fingers trying to give instructions! But I succeeded as you can see above. I am still today really annoyed that I was not able to take shots with the Nikon Z6ii that I had brought along with the Nikon AF-S 70-200mm VRii. But the camera had stopped working and the iPhone image is all I got.
This is the error message I got from the camera. I figured that the camera and the lens did not communicate well anymore, as there was water shortcutting the CPU contacts, so I turned off the camera and walked home.
If you remember mounting a lens on a DSLR without setting the aperture locked at the minimum value (say f/32), then you probably also know the “FE” error, where the camera tells you that you need to change the aperture on the lens. This is exactly the message I got in the top LCD, and a more elaborate version in the rear LCD. The camera had stopped working, and there was nothing I could do out in the rain. It was clear to me that the CPU contacts had been short-circuited by rain getting into the camera somehow.
The water got in between the F-mount lens and the FTZ adapter. Here traces of water where it should not be – in the FTZ adapter. After drying the adapter for a few hours, the problem was solved.
Arriving at home I could get the Nikon Z6ii to work with a S-series lens, so the camera was fine. And I could get the Nikon AF-S 70-200mm VRii to work with my Nikon D4. So the problem was isolated to the FTZ adapter. And I found water inside the FTZ adapter, that should not be there, so no wonder the camera could not talk properly to the lens.
After drying the FTZ adapter for a few hours it all started to work again and I was very relieved. I would have been sorry to see my almost brand new Nikon Z6ii being damaged for obvious reasons, and also I would have hated my beloved Nikon AF-S 70-200mm VRii lens to stop working. I could have accepted the FTZ adapter to be damaged, but was so lucky that also this one got back in operation.
My solution to all this is to get a rain cover for the camera. They come in different sizes and price ranges, but I am sure they would have saved me for the watery experience. I know that both lens and camera are waterproof, but going forward I prefer to be better safe than sorry, and will bring a rain cover for eventualities.
When Nikon launched their mirrorless camera series, they did so introducing a new lens mount called the Z-mount. It was a brand new design with a larger diameter than the classic F-mount and also it had a much shorter flange distance, both – according to Nikon – to improve image quality.
The new Nikon Z-mount is only compatible with a brand new line of lenses, known as the Z-mount lenses or S-lenses. These lenses fit directly to the Z-mount. As all the S-lenses have motors built into them, there is no need for a focus motor in the mirrorless camera bodies.
In order to give some backward compatibility with all the good glass made from the middle of the former century and still being made today, Nikon decided to market an adapter, the so called FTZ adapter, or the F-mount to Z-mount adapter. It was probably also because the amount of glass available to the Z-mount was very limited when the ML series was new, so many focal lengths were simply not available for the Z-mount previously.
The back of the FTZ adapter shown to the left. This side faces the Nikon mirrorless camera when mounted.
The FTZ-adapter allows you to shoot with all the glass that is made for the F-mount, as the adapter takes F-mount glass on the front and fits to the Z-mount on the back. The only downside of this adapter, other than the price of it and that is slows down AF speed a little bit, is that it has no focus motor built into it. All the glass with mechanical auto focus is dependent upon a motor in the camera body, and hence you are left with manual focus for these lenses. AF-S glass with the motor built into the lens of course auto focuses as it should, but many will probably hold on to their DSLRs to maintain auto focus for AF and AF-D glass.
The Nikon FTZ adapter sits between the F-mount lens and the camera body.
Many have speculated that Nikon would produce a FTZ-adapter with a motor built into it, but I doubt it will happen. Nikon did produce a FTZ adapter version 2, but this one is specifically designed for the Z9 camera body, and still has no motor built into it.
The classic 50 mm f/1.2 mounted on the FTZ adapter mounted on the Nikon Z6ii.
So my best guess – and it is a guess – is that we will not see mechanical auto focus motors in the FTZ-adapter. I think Nikon finds that you have lots of aid in focusing manually in the ML system, if you insist to use vintage glass with the mirrorless cameras.
So the FTZ-adapter is relevant if you have F-mount glass that you love and want to hold on to, and at the same time want to upgrade to a mirrorless camera body. Other than giving you the benefits of a mirrorless camera relative to a DSLR, it also opens up a new (and expensive) world of S-series glass that in most cases have got excellent reviews for stunning results.
No, I did not make up the headline above – it is a quote from the Waycap cardboard box! And it certainly does sound promising! I am not sure your coffee capsules can save the world, but moving from disposable coffee capsules to re-usable ones sounds to me like a small step in the right direction in terms of doing something positive for the environment. If you then in addition can save some money and on top of that have better control of what coffee goes into your capsules, then I think we are approaching something that sounds like good answers to the “why?” question: (1) Eco-friendly, (2) saves you money and (3) potentially gives you better coffee.
The promise on the tin.
I must admit that I recycle also my disposable coffee capsules from Nespresso, so maybe the gain in that light is less, but saving money and making better coffee also sounds attractive to me. The review here is using a Nespresso coffee machine, but it works with many other brands according to the tin.
Waycap in the front, more traditional disposable alternative in the back. Notice the hollow ring where the needles from the coffee machine will go to.
The content of the package is two capsules, a tamper, a dispenser and a set of rubber rings to replace the ones mounted from the factory.
Content according to the tin, but you also get a range of plates to control the water flow and spare rubber bands to seal the capsules.
In addition to this a few plates with L-shaped holes in it is supplied. The point is that you can vary how long the water is to flow though the capsule, and you can experiment with different options to adjust to taste.
The plates to be mounted inside the capsule. The number of holes (L-shaped) determines how long time the coffee is in contact with the water. More holes, less time.
After you have mounted a plate inside the capsule, the simple process is to use the dispenser to get coffee into the capsule and after that use the stamper to pack the coffee.
The user guide is a bit intimidating at first, but once you get a hang of the system it quickly becomes a routine. But my first attempt at reading it Christmas eve was not successful. Find a quiet moment to take in the details.
The two capsules comes with a plastic tube to aid filling coffee into the capsule and a plastic tamper (right) to help you pack the coffee in the capsule.
A precision made super thin thread allows you to screw the lid on the capsule. It seems to me like really well made precision work by the Italian factory, and although I have not used the system for more than a few days, I would expect this to be a durable product that will last many years.
Also, there seems to be a solid supply of rubber rings to keep you going for many years forward, so this product should last you for many years.
The two capsules comes with a lot of rubber rings to replace the ones mounted from the factory.
I do miss somewhere to store both the extra plates and the rubber rings, but in daily use (once you have selected your favorite plates) the only thing you need is the capsules themselves, and they store neatly in the dispenser using the supplied lids for the top and bottom.
The plastic tube to aid filling the coffee into the capsules, doubles as a storage container, when the two lids (top and bottom) are added.
Verdict
Does it work? Yes, it does. I will say though that mounting the capsules, as well as removing it again, requires use of more force with my Nespresso machine than the disposable capsules, actually to a level where I in the beginning suspected that something was wrong. I am not sure if this will have a negative long term effect on my machine – time will tell, but there definitely is a big difference in the force you need to apply.
Any downsides? Yes, the time required to prepare a cup of coffee. One of the wonderful things about the Nespresso system is the ease and speed. And that you only make one cup, so you don’t waste coffee by brewing a full bowl only to drink a fraction. The latter is still maintained with the Waycap system, but it takes a lot more time to fill the capsule yourself. The speed and convenience drops. If you are willing to make this investment in going from fast-food to slow-food, then of course it is not an issue. But brewing 4 fast cups when friends drop by is not that easy. The use case is a bit different.
Any upsides? Yes, other than the gain for the environment, I can confirm that it is both cheaper and that you get better coffee. I love the Nespresso coffee, but you can afford to buy some really good coffee and still save money relative to the 1/2 EUR per cup that Nespresso charges. You will have to play a bit with the number of holes in the plates, the coffee type and how fine the coffee is grinded, but once you get that under control, it is a pure pleasure.
Any quirks? Yes, other than the capsules being a bit tougher to mount in the machine, I find that removing the plates with the holes from the capsules can be a pain. I think it is because water between the plate and the capsule creates a small vacuum that is difficult to overcome. The user guide also mentions that the capsules are rather hot just after you’ve made a cup, but I find that it gets cold much faster than the 10 minutes the guide recommends you wait.
Bottom line? I really like the Waycap system. It seems like a solid product of very high quality. And its key selling arguments are solid if you ask me. But sometimes I miss the speed of my disposable capsules. And for that reason I probably will use both, but the Waycap system will definitely make my use of disposable capsules drop dramatically. And that is not bad at all.
EV is an abbreviation for exposure value. It is a way to express exposure in one number, i.e. the combination of shutter speed, aperture and ISO. To be quite honest, I doubt that many use EV’s today, as most rely on the exposure meter in their cameras, possibly in combination with the histograms.
But you can study EV as a way to understand exposure better. For example, if you shoot at f/4 and 1/125th, you are at EV 11, but if you open up the aperture to f/5.6 and maintain the shutter speed, you are now at EV 12. This is referred to as going one stop up. So walking up and down the EV scale is referred to as stops of light. The light is doubled or halved for each stop. This gives you a “settings independent” way of talking about exposure, and you can say go one stop up in aperture and one down in shutter speed and arrive at the same EV. So shooting at f/4 and 1/125th gives the same EV as shooting at f/5.6 and 1/60th. I half the light that comes though the lens (f/4 -> f/5.6) but double the exposure time (1/120th -> 1/60th). Both are EV 11.
For simplicity I have kept the ISO out of the description above, but it is the same logic: doubling of halving the ISO is the same as going one stop up or down in exposure. So the ISO scale is: 100 – 200 – 400 – 800 – 1600 etc. Many cameras allow you to select ISO values more granularly than full stops, and that can be handy, but remember to double/half to make a full stop difference.
Another area where EV is useful is when it comes to the spec list for a camera. The cameras dynamic range is expressed as an EV. For example the Nikon D750 over at DxOMark is listed as having a dynamic range of 14.5 EV’s, whereas the Nikon D810/D850 has 14.8 EV’s. Higher is better, as it enables you in one shot to span across more difference in light in the scene, without blowing out the highlights or loosing details in the shadows. So if dynamic range is important for your kind of shooting, then the EV for a camera you consider buying could prove an important part of your decision making.
The image sensor has replaced the 35mm film as the receptor of light. This gives many advantages, for example that you don’t have to change film every 24 or 36 images, that you can preview the result immediately and don’t have to wait for the lab to deliver results. Further, you can carry a very large number of pictures on a small memory card and it is easy to transfer the files to a PC for post processing. Most shoot with digital cameras these days, but – just like the revival of the vinyl records – there as some that mix film shooting into their work simply because they like the expression you get this way.
The 35mm film has been replaced by a sensor that is able to read the light it is exposed to.
The image sensor is the unit that has replaced where the film used to be – and this is very literally. The sensor sits in the same position as the film used to do and the size is – provided you shoot full frame – also the same (35 mm).
The camera image sensor, here from the Nikon Z50. In a mirrorless camera the sensor is completely exposed when the lens is removed; on a DSLR the sensor is hidden behind a diagonal positioned glass.
With the introduction of mirrorless cameras you can now actually see the sensor when the glass is removed from the camera body. This also makes the sensor vulnerable to dust and dirt if you change lenses in the field. With a DSLR, the sensor is to some extend protected behind the mirror.
The sensor is not exposed entirely, as there is a thin layer of glass in front of the sensor; otherwise the sensor would be too vulnerable. You can buy sets to clean the sensor and to blow air onto the sensor in order to remove dust and particles. Never remove dust from the sensor using your breath – it contains moist and that is dangerous for your camera in general and the electronics in particular. Always use a (rocket) air blower for such work.
The sensor reads the light just like the film used to do and the values read are then made into an image stored on the memory card in the camera. You cannot change the sensitivity of the sensor, it remains the same as when the sensor left the factory. But you can change the ISO value, which is a factor applied to the light read by the sensor by the cameras image processing software (firmware). Unfortunately, cranking up the ISO means that both signal and noise is amplified, and with a weak signal, it can be difficult for the camera to distinguish between signal and noise. For that reason images taken with high ISO values are grainy and have washed out colors.
A mirrorless (ML) camera is as the name says, a camera without a mirror, nor does it have an optical viewfinder. Light flows directly from the lens to the camera sensor. The ML camera can be seen as a natural evolution of the DSLR and even the SLRs, but the ML concept is also used in cameras that do not have an interchangeable lens system, like a point-and-shoot camera or a smartphone.
The image below shows how a DSLR works. The light is sent to the optical viewfinder via several mirrors, most notably the first one that keeps the light away from the sensor (or film).
With a mirrorless camera, the light is constantly and directly sent to the sensor. The optical viewfinder is replaced by a electronic viewfinder, which basically is a small TV screen located where the optical viewfinder used to be. Not all ML cameras have a viewfinder, but instead uses the rear LCD as viewfinder.
Many DSLR cameras can flick away the mirror and show on the rear LCD what you can see in the electronic viewfinder of the ML camera. In that way, the DSLR can work as a ML when using the rear LCD.
The lack of a mirror is not to be confused with the shutter. Many ML cameras have both a mechanical and an electronic shutter. The mechanical shutter has two curtains that allow the sensor to be exposed according to the selected shutter speed by moving the curtains across the sensor. The electronic shutter turns the camera sensor on and off to get the same effect. It is all about measuring the light at the timeframe dictated by the shutter speed. Notice that for flash photography a mechanical shutter is required.
On a DSLR/SLR, the focus system is often a separate system that via a small hole in the glass uses a small area of light to determine focus or not. Therefore a DSLR focus system often only allows you to select a focus area in the center of the frame. With a ML system, the entire sensor in real time receives light and determines focus or not – this requires good software and computing power, but it also opens up for selecting focus points in the entire frame (incl. corners) and intelligence to recognize people (their eyes) and animals, and thereby take the sophistication of the auto focus systems to a new level.