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
When we see a photograph what do we actually see? Does the image grab our attention? Does the image tell a story, or do we have to fill in the blanks with our own memories, and experiences? If we see a complete picture, or just a detail, which stirs our emotions most? At a recent competition a print was shown of fishing boats pulled up on the beach at North Landing, Flamborough, it was an excellent print, but the judge remarked “it’s just boats on a beach”. Do we feel the same emotion with a “normal” view, or do we want more, a storm raging, or fishermen launching the boats? Anyway, here are a few of my “abnormal” photos, first up a rusted bolt, you see I ask “who put that there?”, “what did it once hold?” Second, a vehicle excise disc, surely that stirs memories? Thirdly, a stone carved column, who carved the details? Was it shaped according to an architect’s brief, or a stone masons pattern? What emotions were felt by the stone mason? Lastly, a door handle. Where does this lead? How old is it, and how many hands have opened this door? Finally, I think that I’ve got my “mojo” back, I’ve been out more with my camera, and enjoying the experience, and surely that’s what photography is all about, the joy of capturing an image that pleases me.
The Exhibition will be in place from 10th - 29th September 2026
I was scrolling through the archives yesterday, and found these "Still Life" images. Still Life is an interesting photographic genre that requires good lighting, and compositional skills, but the results can be amazing. Here are four images of the genre, "Breakfast" showing cereal falling into a bowl, "Four Candles" (no not the ones from the Two Ronnies sketch), the moody "Decaying Tulip", and the simple but effective monochrome "Opener". Perhaps these images might give you some inspiration.
I joined the NELPS outing at Chambers Farm Woods on Wednesday. The NELPS visit to Chamber Farm wood and butterfly garden was well attended, with several members from NELPS, Grimsby, Dunholme and Louth, kind thanks to all that came, although it was very hot the butterfly garden, being rather full and slightly unkept did not let us down with butterflies, two less common were seen, a Comma butterfly and a humming bird moth, with loads of very lively common blue butterflies. Most of the insects in the butterfly garden were highly active, and by the time an insect was spotted, it was off!! I managed to just about get an image of the Comma butterfly, and nobody stood a chance with the humming bird moth, it was too fast. The dragonfly was more accommodating remaining fairly still posing for us. The next NELPS outing will be to the Peoples Park in Grimsby on Wednesday 19th, I'm busy on that day, but I will be attending the meeting at the Sandtoft Trolleybus Museum on Wednesday 26th. Many thanks to NELPS for organising these outings, it was a thoroughly pleasurable morning.
A visit to Whitby for a sunset picture didn't quite go to plan. Unknown to me today is the last day of the Whitby Regatta. Whitby in the summer is usually busy, but today it rivaled Time Square in New York. My planned shoot of the East Pier was a non-starter because for tonight only there's a fun fair along West Pier where I planned to shoot from. I had to re-think and resort to plan b, which was also a non-starter because the East Pier was closed as it was packed with fireworks. Plan c was OK though and I got an image I'm pleased with.
I've been up to RSPB Bempton Cliffs this week, and have taken some excellent photographs, the weather was fine, and the lighting was less harsh than usual. This pair were on the cliff top, obviously well established, and saw off this interloper trying to muscle in on their space, those beaks look very vicious. I hope that everyone else is having a productive summer break.
For club interaction, we are invited to these NELPS photo shoots. So lets start this club interaction, NELPS are now on there summer break, but it does not stop there. The NELPS club president has put together some outdoor photo shoots:- Lincoln 5th Aug meet at the Cathedral 11am Not forgetting the photo exhibition by Lincoln Camera Club in the Usher Gallery! Chambers Farm Wood & Butterfly Farm 12th Aug meet at 10am. Peoples Park Grimsby 19th Aug meet at 10am. Trolley Bus Museum Sandtoft 26th Aug meet at 10am Cadwell Park 10th Aug motorbikes, 24th Aug cars and both are track days so free to get in.
Sutton & Trusthorpe Camera Club have their annual Exhibition at the Meridale Hall, Sutton on Sea, on 29th / 30th August. Drink and a Home-made cake only £3!
I’ve lost my photographic “mojo”, that desire to go out and take impactful photographs. That creative spark has gone, vanished, will it ever return? Writers talk of a “writers block”, when they just sit in front of a blank page, and can’t think of anything else to write, I’m the same, still out with my camera, but just not creating anything meaningful. Some of this I suppose is due to the fact that I’ve almost stopped my genre of model photography, we had the Studio evening, and other than that I’ve only had 2 model shoots this year. So what is my photography genre now? I know that I’m not a bird photographer, I haven’t got the patience to sit in a bird hide for hours with a long lens, waiting for the right bird shot to appear. Landscape, possibly, but I look at the work of some of our members, and YouTube videos, and don’t know whether I can achieve as good a standard in my work? I do enjoy macro photography, but again do my photos reach a good standard? One way forward is to look at our Societies annual project, this year it’s “water” one photo a month depicting water. Then of course there are the planned photo competitions for the rest of the year, those subjects could inspire me to go out and take some images. Anyway, that’s me, enjoy the rest of the summer, and if any of our members could share a photo, with a line or two of text I will be very happy to post on this blog.
Good Morning All Last week we had a very good evening at Kirkby Gravel Pits, it was a warm sunny evening and there was wildlife about to photograph. There were Dragonflies about, but all flying, but we did manage to photograph some Damselflies and grasshoppers etc. We then called at the local pub in Kirkby on Bain for refreshments. There were only 7 of us, if you have other ideas for outings please let me know and I will look into them for next year. Derek has also done a blog on the evening. Louth did make it through to the LPA Battle finals coming fifth overall, the final is on the 18 th October at Nettleham village hall. That was the last event before the summer break, so we now have a break before returning in September. I won't be doing any newsletters unless there is something to report. If you do anything interesting over the break you can always send Derek a blog for our website. There are things you can do over the break, the monthly project of water, preparing for the PDI competition in September, with the categories of "Objects in the Air" and "Open". In September our first meeting back will have members speaking on the topic "15 minutes on what you have done over the summer", you may want to prepare something for this. Have a good summer, Graham
