Confused?
Derek Smith • 15 July 2020
The Circle of Confusion
Confused?
We all “know” that a blurred background behind a subject is hard to obtain with a crop sensor camera, and that macro photography is easier with a micro four third sensor camera because of the “increased” depth of field. Well actually both of these statements are “fake news” often touted on YouTube, or in photographic articles.
Professor Bob Newman wrote on this topic in his Amateur Photography article 11th July 2020 entitled “The Great Leveller”.
In camera optics, a circle of confusion is an optical spot caused by a cone of light rays not coming to a perfect focus (also known as the disk of confusion, circle of indistinctness, blur circle, or blur spot). In other words, Depth of Field.
Professor Newman asserts:
“For macro photography, provided we keep the focus distance, the angle of view and aperture the same, and choose the same disc of confusion, then we’ll get the same results whatever the sensor size”
This appears to be borne out by the Wikipedia article on this subject, with the Circle of Confusion diameter limit based on d/1500 of 0.015mm (micro four thirds) to 0.029mm (full frame), and I challenge anyone to see that difference on an 8x10 print!!
I find macro photography as challenging with my Olympus micro four thirds camera, as I did with my full frame Sony A7. As an example, the Depth of Field for a 120mm lens, at f/5.6 = 0.13m on the Sony A7, and with the Olympus 60mm macro lens (2x crop factor = 120mm) at f/2.8 (2x crop factor = f/5.6) my Depth of Field = 0.14m - not much of an advantage there then!!
In conclusion sensor size should not be the determining factor when choosing a camera. Ergonomics, controls, how the camera “feels” in the hand, size, weight, and lens availability, are perhaps far more important in choosing a camera.
Always remember the image is everything, what camera the image was taken on is immaterial. I recall one of our members producing stunning high-quality images in competitions with his diminutive Sony A5100 APS-C camera.
The above photo was taken on a Nokia Lumia 635 Windows phone and was placed 1st in a recent PDI competition – the image is everything.
Article, and photo: Derek Smith
We all “know” that a blurred background behind a subject is hard to obtain with a crop sensor camera, and that macro photography is easier with a micro four third sensor camera because of the “increased” depth of field. Well actually both of these statements are “fake news” often touted on YouTube, or in photographic articles.
Professor Bob Newman wrote on this topic in his Amateur Photography article 11th July 2020 entitled “The Great Leveller”.
In camera optics, a circle of confusion is an optical spot caused by a cone of light rays not coming to a perfect focus (also known as the disk of confusion, circle of indistinctness, blur circle, or blur spot). In other words, Depth of Field.
Professor Newman asserts:
“For macro photography, provided we keep the focus distance, the angle of view and aperture the same, and choose the same disc of confusion, then we’ll get the same results whatever the sensor size”
This appears to be borne out by the Wikipedia article on this subject, with the Circle of Confusion diameter limit based on d/1500 of 0.015mm (micro four thirds) to 0.029mm (full frame), and I challenge anyone to see that difference on an 8x10 print!!
I find macro photography as challenging with my Olympus micro four thirds camera, as I did with my full frame Sony A7. As an example, the Depth of Field for a 120mm lens, at f/5.6 = 0.13m on the Sony A7, and with the Olympus 60mm macro lens (2x crop factor = 120mm) at f/2.8 (2x crop factor = f/5.6) my Depth of Field = 0.14m - not much of an advantage there then!!
In conclusion sensor size should not be the determining factor when choosing a camera. Ergonomics, controls, how the camera “feels” in the hand, size, weight, and lens availability, are perhaps far more important in choosing a camera.
Always remember the image is everything, what camera the image was taken on is immaterial. I recall one of our members producing stunning high-quality images in competitions with his diminutive Sony A5100 APS-C camera.
The above photo was taken on a Nokia Lumia 635 Windows phone and was placed 1st in a recent PDI competition – the image is everything.
Article, and photo: Derek Smith
Louth Photographic Society
NELPS organised an outing to the Trolleybus Museum at Sandtoft, there was some confusion with opening times, and a few of us arrived to find the gates closed, we went for a coffee!! Once inside and parked up we were welcomed by the volunteer staff, and began to take some photos around the site. A Grimsby trolleybus was running this morning, this bus had been painstakingly restored from a bare chassis, with great attention to detail, even down to sourcing the original moquette fabric to upholster the seats, it was great to be able to ride in a trolleybus again. Trolleybuses have a particular nostalgic memory for me, I lived in Uxbridge, on the outskirts of London, and the 607 trolleybus route ran past the end of my road, with a usual frequency of 5 minute intervals the buses were a common sight gliding along the main road. The 607 route was one of the longest in the country 11 miles to Shepherds Bush, taking about an hour for the journey. The trolleybus was whisper quiet, comfortable, and pollution free, and I took several trips on these. In comparison the conventional London bus the “RT” was not as quiet for longer journeys. The London trolleybuses, and eventually the London “RT” buses, were replaced with the iconic diesel fuelled Routemaster “RM” bus. I had an enjoyable visit, and many thanks to NELPS for organising the outing.
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.
