Understanding Depth of Field
Derek Smith • 15 December 2020
Depth of field when taking photographs can be a help or a hindrance, dependent on the type of image required. The definition of depth of field can be best described as; “the area of an image that is in sharp focus.”
When taking portraits, a lot of photographers will try and blur the background, limiting the depth of field from the tip of the nose to the back of the head, this is achieved by opening the aperture on the lens to one of the lowest f numbers, only by experimenting with the camera / lens combination will a photographer be able to know what works best for them. With my previous full frame Sony, and 85mm lens f/1.8 gave a far shallower depth of field, and so I favoured an aperture setting of f/2 to f/4.
This image of Rachel from a recent photoshoot with my micro four thirds system camera using a 25mm prime lens (50mm FF) has a field of view of 38 degrees, and at f/1.8 the depth of field is 0.06m, enough to keep the nose, and both eyes sharp, with the ears just beginning to soften, the background is suitably blurred, keeping the emphasis on the face.
In portraiture the focus point will usually be set on the eyes, and I would typically use f/1.8 – f/2.8 aperture in an outdoor situation. Indoors, or in a studio depending on the lighting and distance from the subject, an aperture of f1.8 – f/8 could be employed to give the correct depth of field, and exposure.
Interestingly we find that the depth of field will double for every two stops that the lens aperture is stopped down, hence with the micro four thirds 25mm prime lens:
At f/2.8 depth of field = 0.015m.
At f/4 depth of field = 0.02m.
At f/5.6 depth of field = 0.03m.
At f/8 depth of field = 0.04m.
The images of the TV remote show the quite dramatic difference with the first image taken at f/2, and the second image taken at f/8.
In shooting landscapes, the photographer will be looking to have a greater depth of field, ensuring that the scene is sharp from the foreground to the furthest distance away, use a mid-range aperture usually f/5.6 – f/11 depending on the sensor size, and lens used, because most lenses are sharper in the mid-range, often called the "sweet spot". Another tip is to focus a third of the way into the scene, this is a rough rule of thumb to ensure sharpness throughout the scene. In this example image of a tree in a glade, my zoom lens was set at a focal length of 18mm (36mm FF), and aperture of f/5.6, focusing on the tree, which is about a third of the way into the scene, gave a depth of field from 2.06m to infinity ensuring the whole scene was pin sharp throughout.
For shooting macro insect photography, the photographer is often tempted to push the front element of the lens as close as possible to the creature, but the closer the lens is to a subject the shallower the depth of field, so move back, it is far easier to crop into an image than try to rescue an unsharp image, and we have all been there!!
So, this morning I would encourage you to get the camera out, dust it off, and try different camera, and lens combinations, experiment with different apertures, and find what suits you in the various scenarios.
Rachel
Photo By: Derek Smith
TV Remote f/2
Photo By: Derek Smith
TV Remote f/8
Photo By: Derek Smith
A Woodland Glade
Photo By: Derek Smith
Louth Photographic Society
At our meeting last night we held a PDI (printed digital image) competition, with the categories of "Local Unedited", and "Open". As this was a members competition one of our members judged the competition, Tony Gaskins was our first judge for the "Local Unedited" category, these were .jpg images taken straight from the camera, without any editing, apart from the resizing for projection. Presenting an image such as this in a competition is quite a difficult task, the photographer has to ensure that the correct exposure is chosen, the composition, and subject matter has to be precise, everything done in camera. Normally for competition entries, a degree of post processing would be involved, simple edits like toning down highlights, or even removing extraneous objects from a scene, emphasising a moody sky, all not allowed. Tony Gaskins did an excellent job with his judging, providing clear and concise critique of the images presented, he "held back" 8 images for further consideration, awarding higher points, and finally choosing the top three placements. After the break it was Robin Begley's turn to judge the "Open" category, as these were post process edited images the standard was higher than the unedited images, but surprisingly not markedly so. Robin is potentially hoping to become a N&EMPF approved judge, and he had a different style, able to suggest edits that could have improved an image, again his critique was clear and concise communicating well with members. Robin chose 8 images for further consideration, awarding higher points, and finally selecting the top three placements. It was a fabulous, and interesting competition with excellent images, many thanks to both our judges, it's not an easy job, probably nearly as bad as being a referee in a football match!! Many thanks to both our judges, well done.
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Roger Hance Memorial Lecture 16th October
Last night Lee Dixon from Cleethorpes Camera Club gave his first ever presentation to a camera club, which we were privileged to view. His presentation consisted of portraiture, creative, and his genre of choice; wildlife. Lee is an extremely talented photographer, with a highly creative portfolio, his portraits are quite atmospheric, unusual, and capture the essence of the model, and scene. For Lee’s creative work, he buys props from charity shops, often very cheaply, reusing those props in various scenes. For his composite work he will often take one of his photos of a room, and blend it with a subject in Photoshop using “blend” modes. For wildlife he visited Lake Kerkini in Greece to photograph the Pelicans, if the sky is a little on the bland side, Lee will often over expose the image resulting in a striking white background to the subject. On safari in Africa Lee showed us some amazing images of the wildlife, the close-up images of elephants, the wildebeest migration, and this stunning image of a cheetah. Lee was ably assisted by Mike Bennett. More of Lee’s work can be found on his website: https://leedixonphoto.co.uk/ Lee his kindly given permission for his images to be used in this post. Many thanks to Lee, and Mike for an amazing evening.
Good Morning All Last week at the club we held our monthly PDI competition, with the categories of "Objects in the Air" and "Open", there was a very high-quality entry in both competitions and judge Mike Bennett had quite a job on his hands scoring the entries. Well, done to Dave Turner for first place in the Objects in the Air and Tony Gaskins for first place in the Open. All the results are on our website. This week, Wednesday 30th September, our speaker will be Lee Dixon from Cleethorpes Camera Club showing us his natural history, Creative and many other photographs he has taken. It will be the first time Lee has shown his photographs at our club. If anyone else wants to enter PDI's in the 2027 N&EMPF Exhibition, the deadline is this Wednesday at midnight. Harry is still taking entries for the PDI competition, with the categories of "Local Straight from Camera" (unedited .jpg), and "Open", to be held on Wednesday 7th October. Regards Graham
At the meeting last night Mike Bennett judged our competition with the categories of “Objects in the Air”, and “Open”. The standard of entries was excellent, and it gave Mike a tough task of judging the images, Mike gave some very good critique of the images displayed, the feedback helps members to develop compositional skills. Dave Turner was awarded first place for his image of the “Tiger Club Display Team” in the “Objects in the Air” category. Tony Gaskins was awarded first place for his image of the “Spectacular Rustgill” in the “Open” category.
Good Morning All, Last week at the club we watched the N&EMPF PDI Exhibition for 2026, it was a very good evening viewing very high standard images from all over the East Midlands. Dave Turner and I did manage to get images accepted; there is a full report on our website. This week, Wednesday 23rd September, we will hold our monthly PDI competition, with the categories of "Objects in the Air" and "Open", please send entries to Harry by midnight tonight. Harry is also accepting images for the PDI competition, with the categories of "Local Straight out of the Camera (only resizing permitted)" and "Open". Regards Graham
Members were shown the 2026 N&EMPF PDI Exhibition video last night with all of the accepted PDI images in the first part, and after the break the awarded PDI images. There were some stunning images on view, and Louth was successful in having 3 PDI images accepted, Graham Harrison with his image of a Stonechat, and Dave Turner with his portrait of Paul Rudd, and his monochrome image of Kings Cross railway station "Going Down". Overall it was a good inspirational evening.
Good Morning All Last week at the club members had 15 minutes to show what they had done over the summer. It was a very interesting evening with eight members taking part. There were many locations on show and as usual some excellent photography. There is a full report on our blog. This week, Wednesday 16th September, we will be showing the N&EMPF exhibition, this is part one showing all the PDI's that were accepted. This is the highest standard of photography we as individuals take part in as a club. Members sent around 50 entries but only 3 were accepted. If you are inspired to enter the 2027 Exhibition after seeing the show, I send the clubs entries and I can give you more information. Closing date is the end of September. The Maximum size for N&EMPF is 1600 x 1200 3MB sRGB Harry is still taking entries for the monthly PDI competition, with the categories of "Objects in the Air" and "Open". Harry did ask about what can be accepted, and we couldn't really say as long as it's an object in the Air. The best way is to look up the definition of an object first. Harry is also accepting entries for the Local and Open competition in October. Robin is going to judge the Open competition, does anyone fancy judging the "Straight from the camera" category? Regards Graham
The Louth Photographic Society has returned after the summer break. It was an incredible return, with members providing us with some stunning images from over the summer break. A full, and varied smorgasbord of well executed photos, many of us visited Whitby, the North Yorkshire Moors Railway, and further north images from Staithes, and Sandbanks. Tony showed us his long exposure minimalist calming coastal scenes, from the Lincolnshire coast, and Whitby.. Chris brought us some beautiful photos taken of local churches, many of which many of us have never seen. Now I’ve never really seen the attraction of an expensive Leica camera, but when Mark showed his photos from his visit to the German Leica factory in Wetzlar, I now understand, camera bodies, and lenses milled from solid blocks of aluminium, hand polished, hand finished lens glass, and textured leather applied to the camera body, not a robot in sight, just craftsmen, and women making a superb photographic instrument. Sue brought us “pink” ladies driving tractors to raise money for cancer research. Last but definitely not least Richard showed his monochrome, and infrared images of trees, his compositions, and photographic eye bring these tree studies to life, we appreciate them even if some judges don’t understand. Many thanks to all of those members who contributed.
