Category: Learning photography

Post about learning photography, such as exposure, composition and colors. You can also find reviews of books about photography.

What is bokeh? What is OOF?

Bokeh is just another word for out of focus, often abbreviated to OOF!

But why is that suddenly important in photography when everybody talks about sharp images and getting the subject in focus? It has to do with the isolation of your subject – to make sure that the background does not steal the attention from your subject,  be it a flower, a tree or a model just to name a few examples. Just like in a movie where you want the main actors to stand out and shine, your supporting actors should be support the main actor without stealing the limelight.

In the example below the birch stem is the star, albeit not a very interesting one, but it illustrates background blur or bokeh very fine. What you see to the right of the birch stem is actually sun lit leaves, but because of the strong element of bokeh, it appears to be just a soft backdrop of white and brown colors.

There are several factors that determine the bokeh, but most notably the aperture you shoot at and the distance from your subject to the background. Larger apertures (smaller f/stop numbers) gives a more so called depth of field, i.e. the depth of the interval that appears to be sharp. So if you shoot at a very wide aperture, the depth of field is narrow and if you have focused correct on your subject, the background is more likely to be OOF Similarly, if there is a big distance from your subject to the background, then it is more likely the background is OOF as the depth of field cannot reach so far.

Photographers can study out of focus elements for hours and comment on their shape and size. In the example above the light behind the coffee mug is certainly out of focus, and the light appears as round balls. You can see that the rightmost ball is very round whereas the ones to the left are more oval – it has to do with how close you are to the corner of the image. Also, sometimes bokeh balls like these appear square rather than round – that is because the aperture blades are in use and determine the shape of the bokeh.

As a rule of thumb you want the bokeh to be creamy and pleasing to look at. In other words, the edges of the bokeh balls should not have rings or hard transition to the areas outside the bokeh.

Related reading

What is aperture? And why important?

What is lens vignetting?

What is lens flare?

What is a DSLR?

SLR is an abbreviation for Single Lens Reflex. It simply means that there is only one lens and that you via a mirror look through the lens that sit on front of your camera. This is as opposed to a rangefinder camera, where the viewfinder gives you a preview of the scene based on another lens that what the camera will be using to capture the image. Hence only a single lens in a DSLR.

The mirror flicks away when you take the shot (and it makes a noticeable noise).  This is why you will see the viewfinder go black during the exposure – the light is sent to the sensor rather than the viewfinder.

The D in DSLR is Digital, as your camera has a digital sensor rather than a piece of film. So it is Digital Single Lens Reflex camera or DSLR.

A mirrorless camera (ML) has no mirror and simply sends the light directly to the sensor, that then via a small electronic viewfinder (a small TV!) presents the preview for the photographer in real time.

Related reading

What is Live View on a DSLR?

DSLR versus mirrorless

Credits

Illustrations used:

User: Kolossos – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=925806

http://orig01.deviantart.net/6d63/f/2009/019/a/1/eye_in_profile_by_evaldaz.jpg

 

What is PASM on your camera body? What are exposure modes?

Introduction to the PASM modes on your camera.

PASM

PASM is abbreviations for program, aperture priority, shutter priority and manual exposure modes. You typically find these modes on a dial top left of your camera. If you are shooting Fuji, you will not have a PASM dial – the camera figures out the mode based on your selections.

The PASM dial on a Nikon D750. Most manufacturers name the modes the same way you may find that S is called Tv and A is called Av.

The point with the PASM dial is to control how much control you have of how correct exposure is achieved. You may recall that the exposure triangle gives 3 variables to control the exposure: Aperture, Shutter speed and ISO. Lets get back to ISO a bit later, as ISO is not controlled  by the PASM dial.

The PASM dial gives you varying degree of control for shutter speed and aperture:

(P)rogram mode: Camera controls aperture and shutter

(A)perture priority: You control aperture, camera controls shutter

(S)hutter priority: Camera controls aperture, you control shutter

(M)anual mode: You control aperture and shutter

So what is the point with different degrees of control? It all comes down to what it is your are shooting and what you want to achieve. Not a very helpful answer, but some examples might help:

Lets say you want so shoot something that moves very fast and you want to freeze the action. In that case you want to secure that the wings for the bird for example are not a big blur but is captured razor sharp. So here shutter priority is a good choice, as you set the shutter speed to say 1/1000th of a second and ask the camera to adjust the aperture to get a correct exposed image.

In another situation you are shooting a landscape with very little moving parts. But you want to have as much of the landscape sharp as possible, so you set the aperture very narrow to maximize the depth of field. You leave it up to the camera to determine the shutter speed.

The thing to realize is that your camera, no matter how clever it is, cannot tell what it is you are shooting. Only you know that. So if you go for the automated (P)rogram mode, you get some “middle of the road” camera settings that may not work for what it is you want to achieve. So by taking the camera out of the automated exposure mode (P) and move to the semi automated modes (A) and (S), you get more control. And the top of the pop is manual mode (M) where you can control both shutter speed and aperture at the same time. This can be used for example to deliberately under or over exposing your image to achieve a high key effect. It all comes down to what you want to achieve.

What is then the difference between Auto mode and Program mode? You probably have auto mode as a green option on the mode dial on your camera. In auto mode, the camera controls EVERYTHING – you are really going with an auto pilot here. In program mode, the camera only automates the exposure settings – you control many other options, for example if a flash is to be used or not. In auto mode, the built in flash (provided your camera has one) pops up as soon as the camera finds there is too little ambient light.

What about ISO then? ISO is typically controlled irrespective of the exposure mode. You can control ISO via the menu system and sometimes via buttons on the camera body. ISO comes in 2 option: Auto or a specific value. If you set the camera in Auto ISO mode, it is one more dimension the camera can use to get a usable image. But be aware that you pay a price for using high ISO values: grain. There is no free lunch in photography.

Related reading

What are exposure metering modes?

What is exposure compensation?

 

 

What is RAW format in photography?

Unprocessed

RAW format is a way of storing information about an image so that it gets as close as practically possible to what the camera sensor recorded.

It is not about resolution. The resolution of the image is (unless cropping) determined by the resolution of the sensor. You can have two images in different formats (say JPG and RAW) and they hold the same resolution, but what is different is how much information is stored about each point or dot (pixel) in the image.

RAW format stores much more information about each pixel than other formats do. This maximizes the options for you to work with the image in post processing – you can recover shades in the dark, clipping in the highlights and work with the colors to a degree that no other format allows you to.

But there is no free lunch in photography. The price you pay for all this flexibility and headroom is the file size. RAW format takes up much more space than JPG or HEIC formats, even when the resolution of the image is the same. That is why many edit their images in RAW format and finish their work by exporting the file to a format that takes up less space – this makes sharing on social media much easier.

Related reading

What is a camera image sensor?

What is PASM on your camera body? What are exposure modes?

What is lens vignetting?

Vignetting is simply that the corners or edges of your image are darker than the center. It is caused by the lens, but can also be created artificially in post processing software. The term light falloff is also used for the same.

Some use vignetting to draw attention to the center of the image and hence find it useful.

Most lenses exhibit some level of vignetting and it is most common for lenses that can open up and let in a lot of light (say f/1.4 or f/1.2). Some cameras are able to correct the vignetting as part of the cameras processing of the image, so it is never visible to the photographer.

Review: Landscape photographer of the year, collection 10

Book review

Landscape photographer of the year, collection 10
Landscape photographer of the year, collection 10

I believe they produce a book similar to this one every year, or at least regularly. This is the edition 10, with 1-9 preceding obviously. So it is not the latest and greatest I am reviewing here, but the images are timeless and hence the edition number is of less interest.

It is VisitBritain as sponsor amongst others, so there is an agenda here other than just distributing some absolutely lovely award winning British images.

And I am happy to see that one of my favorite ocean photographers Rachel Talibart is one of the winners that made it into this book (the Sunday Times magazine award), but there are simply so many other talented British photographers that you have to see it to understand it. This is only the top of the iceberg – there must be so many hard working photographers out there that are not on display in this book.

One of the things I really enjoy about this book – other than the beautiful images – is that the photographers tell a little story about each image and in the back of the book they document what camera, settings and lens they used, and in addition briefly describe their post processing work. This is valuable insights, and shows that cameras of different make and price range are all able to produce beautiful images. It is the photographer that makes the big difference. A decent quality and camera is merely the means to an end.

Related reading

Review: And then there was silence, by Jan Grarup

Review: Photo basics by Joel Sartore

 

Review: WILD! What you love you will protect, by Helle and Uri Løvevild Golman

Book review

The two Danish photographers Helle and Uri have captured images of wildlife that are nothing short of astonishing. This 200+ page coffee table book is filled with one wonderful image after another. Their passion for wildlife and nature shines from every single image, carefully selected from numerous journeys into the wild: South America, Greenland, New Guinea, Antarctica -the list goes on and on.

It is seldom that I am blown away by even a single image, but in this case I was blown away by almost every single image in this giant of a book. Their work is truly impressive. It is the combination of their love for nature that shines from each page and the technically impeccable images that lifts this book to a level that I have seldom seen. There are a few introduction pages and forewords, but other than that the book is filled with one wonderful image after another.

I can only recommend this book wholeheartedly, even if you are not a nature lover, you will be impressed by the sheer quality of the images presented.

Related reading

Wild and Fearless by Uri Løvevild Golman

Link to their homepage: weareprojectwild.com

Review: Photo work: Forty photographers on process and practice, edited by Sasha Wolf

Book review

Forty photographers on process and practice
Photo work: Forty photographers on process and practice, edited by Sasha Wolf

This book is as academic as they come! That is my review in short! If you are curious to look over the shoulders of 40 acclaimed photographers (like Andrew Moore or Paul Graham) and understand their process and workflow, then this is the book to read!

All 40 have been given the same questionnaire of 12 questions like “Do you create with presentation in mind, be that a gallery show or a book?”. The book is simply the documentation of 40 answers to these 12 questions.

This is not your beginners book about photography, nor the advanced book about photography, rather it is an look into the minds and workflows of some highly creative people. I could as well have been a book about painters – the questions and their answers are that agnostic to photography.

So only if you have a keen interest in this highly specialized area can I recommend this book – otherwise I would stay clear of the 255 pages of process and insights.

 

What is diffraction?

When light travels though the lens, the aperture blades can reduce the diameter of the hole the light travels through. Most lenses can close down the aperture to a very, very small area – the size of a pinhead or even smaller.

When light has to travel through such a small hole it simply changes slightly. This can get very technical, but the effect is that your images appear soft, i.e. as if out of focus – even when you have focused perfectly.

Photographers debate exactly when the effect sets in and how large the effect is. Macro photographers often shoot at crazy high f-stop numbers (closed down apertures) and seem to be doing fine, and in many find that the effect of diffraction is exaggerated.

The best you can do is to notice if your lens/camera combination gives diffraction – I think you should start to worry about this from around F/16 and onwards.

 

What is focus shift?

When your DSLR focuses, it typically does so by opening the aperture up as much as possible to allow all the available light to flow to the auto focus system. So if for example you are shooting with a f/1.8 lens at f/8, the camera will open up to f/1.8 to focus and then shift down to f/8 to take the picture.

Some lenses, especially lenses that can go very wide, i.e. a low f-stop number, suffer from focus shift, which means that the lens moves the focal plane as a consequence of changing the aperture.

This is nothing short of a catastrophe for an auto focus system, as the camera gets the focus sharp at f/1.8, but then when the image is taken at f/8 the subject is no longer in tac sharp focus.

There are a few ways to mitigate focus shift, as you can of course shoot at the maximum aperture – then the focus aperture and the shoot aperture is one and the same. You can also shoot in live view on your DSLR, as it the uses a different focus system than when not shooting in live view mode. The best option of course is to get a lens that does not suffer from focus shift!