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
Good Morning All Last week at the club Harry and Chris gave us an insight into how our exhibition preparation is going, we have a lot of historical photos to go on show and there may be room for some more up to date ones but Harry and Chris will see how much room we have left when they start putting it all together at the museum. I also took the time to find out what you wanted in the new program, filling in the competition subjects and outings. This week, Wednesday 25th February, it is the Presidents night, so that's my night and I will be showing you what I got up to in 2025. The rainbow at Brough castle gives you idea of one area I visited. Harry is now accepting entries for the next PDI competition, with the categories of "Architectural Detail" and "Open". The new program is nearly done and to give you a chance to get ready for the first two competitions in May and June the subjects are May, PDI comp - Landscapes with water and Open and June, Print competition, Trees and Open. Regards Graham
Good Morning All Last week at the club we held our Print Of The Year (POTY) competition, it's one of our highlights of the year and judged by Grahame Dunkin, it proved to be an excellent night with some very good prints on show. The results are on our website under competitions but the highlights were Dave Turner being placed first in the Pictorial, landscape and best Mono print in show; Robin Begley, First in the Record section, Keith Rossington first place in Portrait, Harry Kerman first in the photo/journalism (including Street) and myself taking first place in the Nature as well as overall Print of the Year. My photograph of a Hairy Shield bug was taken at Chambers wood on a camera club outing. This week, Wednesday 19th February, we are sorting out Prints for our 70th anniversary exhibition at Louth Museum. Please bring along any local prints you may have and maybe a few further afield for selection. Please also bring along any prints you may have that you think will be ok for the LPA Foster challenge and LPA Battles. They need to be mounted on a 500mm x 400mm mount and a maximum print size of A3. Don't forget to take a photograph of water if you are doing this years project, no real excuses at the moment. Regards Graham
Our highlight competition, Print Of The Year (POTY) competition was held last night, with our judge Grahame Dunkin giving his experienced critique on the excellent images submitted. Congratulations to Dave Turner for his Monochrome image of the year: West Pier Watchtower - Whitby, and Graham Harrison for his Colour image: Hairy Shield Bug.
Good Morning All Last week we went to have a look at the Lancaster sculpture at Norton Disney, it is open for visitors at certain times and although work is still ongoing the main Lancaster is finished and a car park in place. The sculpture is full size weighing 100 tons and honours WW2 RAF crews. Last week at the club Derek Smith ran an editing night, members were asked to bring their laptops in and Derek gave us all an SD card with some images to edit and information regarding the free editing software. A different and interesting night and hopefully we all learnt something and anyone new to photography would have learnt quite a lot. Thank you Derek for running the evening. This week, Wednesday 11th February, we have one of the clubs yearly highlights, the Print Of The Year (POTY) competition to be judged by Grahame Dunkin, all the entries are now in and you should have checked the scoresheets to make sure yours are included. Dave Turner is also asking for prints to enter into the Foster Challenge and LPA Print Battles. He will ask to use prints that are in the print of the year but if you have any prints that you think would be good to enter in the two competitions please bring them and hand them into Dave Turner. The following week we are having an evening collecting everything in for our exhibition at the Louth museum, if you can sort out any prints especially local prints that could go into our exhibition please bring them in on the 18th February. Regards Graham
Last Sunday I was in Stockton on Tees working with Izzy, a favourite model of mine she enjoys cosplay, that’s dressing up as a character from Marvel, Hasbro, or film titles. This photo is of Fey, a woodland sprite, pictured against a woodland backdrop that I bought for the photoshoot. I stayed overnight at a Premier Inn, and in the morning drove to Staithes, as I had always wanted to visit this fishing village, Staithes in the February rain wasn’t much fun, and the tide was out, but I did manage to take a few photos, and I captured one for the “Water” project so I was pleased with that. I was quite surprised how vibrant the colours were in the drizzle, and misty light. Driving back over the North Yorkshire Moors in rain, and fog, didn’t allow for much photography either. Yesterday, walking along the harbour front in Bridlington the high tide, and strong winds had thrown lots of debris onto the promenade, seaweed, nets, tree branches, and cuttlefish kept council workmen busy clearing up the mess. With the right clothing, and a weatherproof camera photography can still be enjoyed even in poor conditions.
A photo editing workshop was held last night, with members bringing in their laptops, and post processing sample images. Members were able to practice processing bracketed, and focus stacked images. Simple editing tasks of cloning unwanted items from images, cropping, and resizing of images were shown. The excellent FastStone photo viewer, and editor was able to accomplish most tasks apart from developing of RAW images, this free software is a “must have” for those with Windows computers. The Affinity photo editor has now been acquired by Canva, and the changes applied by Canva have made the software very confusing to use, and on my 14” Lenovo Thinkpad, it was very difficult to view the master layer to apply adjustments. PhotoScape X is a simplistic photo editor, for all that the software was easy to use, and the RAW processing was seamless. It was an interesting evening, and hopefully members will have attained some new skills in post processing, some of the images edited are shown here.
Good morning All I did manage to get to visit Gibraltar Point last week, very few birds to photograph at this time of year but I took a few and a Grey Squirrel. Last week member Dave Mann showed us photographs from his visit to Beamish, it's a great day out and Dave went round most of it and showed us some photographs from the new 1950's town as well as the farm, pit village, town and trains. Thank you Dave, and Harry for helping out with refreshments. This week, Wednesday 4th February, Derek is running an editing night, he has sent us all information on what we could download, if you have a laptop remember to bring it along. Print of the year is fast approaching, if you are entering make sure you send Dave Turner a list of your entries with which subject they are in and bring your prints along this week. Regards Graham
Fed up with watching the rain coming down, I set out yesterday into the rain to Normanby Hall to try and get a photo for the “Water Project”, I have one potentially good image, but I always like to see if I can get something better. My OM Systems OM-1 camera, and 12-40mm Pro lens are weatherproof, but obviously I wasn’t, but really lovely to get out.
Last night Dave Mann gave an excellent talk on his visit to Beamish in May last year. Dave explored much more of the Beamish site than when I visited in April last year, Dave mentioned the difficulties of getting on some of the vintage transport around the site, I experienced the same during my visit. It's a fascinating historic working museum and well recommended for a visit. Many thanks Dave for an entertaining evening.
Good Morning All Last week at the club we had our yearly project night, last year it was one photograph a month with the same focal length, there is a full report on the evening on our blog page, but four members did last year's project with newer member Sam Collet showing photographs at the club for the first time, some excellent photographs taken in Japan. It would be good if a few more members took part this year, just one photograph a month with the subject being water. Attached is my January photograph from last year, it would work for this years project as well. This week, Wednesday 28th January, our catering manager Dave Mann will be having a week off and showing some of his photographs. His presentation will be a mixed bag of photographs. Don't forget to send Dave Turner an email with your titles for the print of the year. Entries will need bringing in on the 4th February. Regards Graham
