Back to Basics
Derek Smith • 10 July 2020
Kaya
Photo By: Derek Smith
Hypericum
Photo By: Derek Smith
Back to Basics
Recently someone I know bought a new camera, and of course they had many questions, I had to research these to find the right answers, and the first question was:
What is Lens Focal Length?
Focal length, usually represented in millimeters (mm), is the basic description of a photographic lens. It is not a measurement of the actual length of a lens, but a calculation of an optical distance from the point where light rays converge to form a sharp image of an object to the digital sensor or 35mm film at the focal plane in the camera. The focal length of a lens is determined when the lens is focused at infinity.
Lens focal length also tells us the angle of view—how much of the scene will be captured—and the magnification—how large individual elements will be. The longer the focal length, the narrower the angle of view and the higher the magnification. The shorter the focal length, the wider the angle of view and the lower the magnification.
As an example use a short focal length 24mm (16mm* or 12mm**) to capture the interior of a room, or a landscape view.
* = APS-C crop sensor camera ** = Micro Four Thirds crop sensor camera
What is Aperture in Photography?
Aperture refers to the opening of a lens's diaphragm through which light passes. It is calibrated in f/stops and is generally written as numbers such as 1.4, 2, 2.8, 4, 5.6, 8, 11 and 16. Lower f/stops give more exposure because they represent the larger apertures, while the higher f/stops give less exposure because they represent smaller apertures. This may seem a little contradictory at first but will become clearer as you take pictures at varying f/stops. Be sure to check your manual first to learn how to set Aperture Priority for your camera, then try experimenting to get comfortable with changing the aperture and recognising the effects different apertures will have on the end-result image.
Selecting a wide aperture of f/2 would ensure that only a small portion of the image would be sharp, whereas a narrower aperture of f/10 would ensure that a greater part of the image would be in focus.
What is ISO in Photography?
In digital cameras ISO measures the sensitivity of the image sensor, the lower the number the less sensitive your camera is to light and the lower the noise in the image.
Higher ISO numbers mean your sensor becomes more sensitive to light which allows you to use your camera in low light situations, the trade-off of doing so is more noise in the final image.
An example of a situation you might want to choose a higher ISO would be photographing an indoor sporting event where the light is low and your subject is moving fast. By choosing a higher ISO you can use a faster shutter speed to freeze the movement.
What is exposure in photography?
The light meter in a digital camera calculates the correct exposure of the image based on 3 parameters: ISO, shutter speed, and aperture. This is known as the "exposure triangle". Creatively the photographer chooses 1 or 2 of these parameters based upon the subject. As an example when photographing a moving subject you may select a shutter speed of 1/500 to "freeze" the action, ensuring the the subject is sharp. In the case of a portrait in the front of a distracting background the photographer might select an aperture of f/2 to isolate the subject from the background. The choice of ISO again is an artistic choice, the photographer may choose to set the ISO to "Auto" if the light is variable, alternatively in the case of the portrait set the ISO to the base level of 100 or 200, to give a noise free image.
In the case of the portrait of Kaya, I used a lens with focal length of 90mm (60*, 45**) our location was in shadow under a railway bridge, I set the aperture to f/1.8, and set the ISO to 400. I was using "Aperture Priority" as the camera mode, with the ISO, and aperture fixed the camera calculated the correct shutter speed of 1/200 to give the correct exposure.
The photo of the Hypericum flower was captured with a 120mm macro lens (80*, 60**) ISO 800, aperture f/4, and a shutter speed of 1/60 calculated by the camera.
For further reading on the exposure triangle I found this website to be useful:
https://photographylife.com/what-is-exposure-triangle
Recently someone I know bought a new camera, and of course they had many questions, I had to research these to find the right answers, and the first question was:
What is Lens Focal Length?
Focal length, usually represented in millimeters (mm), is the basic description of a photographic lens. It is not a measurement of the actual length of a lens, but a calculation of an optical distance from the point where light rays converge to form a sharp image of an object to the digital sensor or 35mm film at the focal plane in the camera. The focal length of a lens is determined when the lens is focused at infinity.
Lens focal length also tells us the angle of view—how much of the scene will be captured—and the magnification—how large individual elements will be. The longer the focal length, the narrower the angle of view and the higher the magnification. The shorter the focal length, the wider the angle of view and the lower the magnification.
As an example use a short focal length 24mm (16mm* or 12mm**) to capture the interior of a room, or a landscape view.
* = APS-C crop sensor camera ** = Micro Four Thirds crop sensor camera
What is Aperture in Photography?
Aperture refers to the opening of a lens's diaphragm through which light passes. It is calibrated in f/stops and is generally written as numbers such as 1.4, 2, 2.8, 4, 5.6, 8, 11 and 16. Lower f/stops give more exposure because they represent the larger apertures, while the higher f/stops give less exposure because they represent smaller apertures. This may seem a little contradictory at first but will become clearer as you take pictures at varying f/stops. Be sure to check your manual first to learn how to set Aperture Priority for your camera, then try experimenting to get comfortable with changing the aperture and recognising the effects different apertures will have on the end-result image.
Selecting a wide aperture of f/2 would ensure that only a small portion of the image would be sharp, whereas a narrower aperture of f/10 would ensure that a greater part of the image would be in focus.
What is ISO in Photography?
In digital cameras ISO measures the sensitivity of the image sensor, the lower the number the less sensitive your camera is to light and the lower the noise in the image.
Higher ISO numbers mean your sensor becomes more sensitive to light which allows you to use your camera in low light situations, the trade-off of doing so is more noise in the final image.
An example of a situation you might want to choose a higher ISO would be photographing an indoor sporting event where the light is low and your subject is moving fast. By choosing a higher ISO you can use a faster shutter speed to freeze the movement.
What is exposure in photography?
The light meter in a digital camera calculates the correct exposure of the image based on 3 parameters: ISO, shutter speed, and aperture. This is known as the "exposure triangle". Creatively the photographer chooses 1 or 2 of these parameters based upon the subject. As an example when photographing a moving subject you may select a shutter speed of 1/500 to "freeze" the action, ensuring the the subject is sharp. In the case of a portrait in the front of a distracting background the photographer might select an aperture of f/2 to isolate the subject from the background. The choice of ISO again is an artistic choice, the photographer may choose to set the ISO to "Auto" if the light is variable, alternatively in the case of the portrait set the ISO to the base level of 100 or 200, to give a noise free image.
In the case of the portrait of Kaya, I used a lens with focal length of 90mm (60*, 45**) our location was in shadow under a railway bridge, I set the aperture to f/1.8, and set the ISO to 400. I was using "Aperture Priority" as the camera mode, with the ISO, and aperture fixed the camera calculated the correct shutter speed of 1/200 to give the correct exposure.
The photo of the Hypericum flower was captured with a 120mm macro lens (80*, 60**) ISO 800, aperture f/4, and a shutter speed of 1/60 calculated by the camera.
For further reading on the exposure triangle I found this website to be useful:
https://photographylife.com/what-is-exposure-triangle
Louth Photographic Society
At our meeting last night one of our members, Harry Kerman gave a talk on one of his favourite genres, flower photography. Harry's talk was accompanied by a slick, professional standard power point presentation, he also had his camera a Canon R6 II, a Sigma 105mm macro lens, a Lens Baby 56mm manual focus lens, and the standard 24-70mm zoom. Harry demonstrated his use of the equipment, which included backgrounds, a plamp to hold flowers in place, and a light box. After the break Harry presented some of his images, projected onto the screen, not all the images were "perfect" he wanted to show some of his mistakes so that we could learn from them, he also welcomed feedback from members, all of the flower images he showed were stunning, and you can see some of them on this post. It was an inspiring evening, providing many techniques, and creative ideas for members to emulate. Harry's passion for flower photography shone through during the whole talk, his clear narration, power point presentation, demonstrations, and images completed a very successful night. Thank you Harry for a fascinating evening, and to Richard Hildred for the refreshments during the break.
Good morning, All Last week at the club we held a retro night, with four members showing pre year 2000 transparencies. It turned out to be a really interesting evening, I didn't know Richard Hildred had started out at an early age photographing trains, it turned out himself and member Chris Birchmore were travelling on the Flying Scotsman in 1967 at the same time. There is a full report on the evening on our blog. This week, Wednesday 29th October, Harry Kerman, one of our members will be showing some of his projected images, and talking about his interest in flower photography. Don't forget Harry is now taking entries for our PDIOTY (Projected Digital Image Of The Year) competition. (closing date 12th November) Regards Graham
Last night was a nostalgic trip down memory lane, with four of our members presenting a slide show taken before year 2000. Now we all remember sitting in a darkened living room showing your latest holiday slides to friends, and neighbours, that click and whir as the slides changed, the stuck slide, the one that was upside down, or back to front, and uncle Jim dozing on the settee! It wasn't quite like that for last night's presentation, Richard Hildred began the evening with some amazing images of railways from British Rail days, we might ride one of the preserved heritage lines, and see the gleaming clean steam engines pulling a line of carriages, Richard's images returned us to the reality of steam powered passenger and freight operations, with the dirt, the grit, and grime of daily steam running, this image captures the essence of steam hauled mixed goods traffic, Richard's slide was in colour, but renders better here in monochrome. Next up was Tony Gaskins, many of his slides featured his first trip to the Maasai Mara game reserve, and the Ngorongoro Crater, Tony also showed slides from his trip to Canada, his slides and narration made for a great presentation. This image of a mother elephant, and calf was taken in the Ngorongoro Crater. After the break, Chris Birchmore presented many images from the Lincolnshire area, some of the disused, and crumbling buildings in the images made interesting subjects for photography, I have used this image of Bolingbroke castle, and from this viewpoint the church is clearly visible in this image, compared with today where only the church tower is visible. Graham Harrison was our last presenter, last but not least, the variety of images shown was remarkable, several from Wales, and quite a few that had been entered into club competitions previously, and were of high quality, as this image of a Flamingo shows. It was a fascinating, and interesting evening, thanks to each of our presenters, and to Dave Mann for the refreshments.
Good Afternoon, All, Last week at the club we held our monthly print competition, with the categories of "Mono" and "Open", judged by Diane Seddon. It was a very good evening with Diane critiquing our prints with helpful comments on how we could improve our images as well as praise. The results are on our website but well done to David Whitehouse for best print in the mono and Dave Turner for best print in the open. This week, Wednesday 22nd October, we go back in time to before the millennium with transparency slides to be shown by Tony Gaskins, Chris Birchmore, Richard Hildred and myself. You can start sending Harry your entries for the PDI of the year, all the rules etc are on our website, but the important thing is you can enter any PDI's as long as they have never been in a PDI of the year before. There are six subjects and an overall max of six PDI's, no more than three per subject. Regards Graham
A print competition was held last night with the categories of; "Monochrome" and "Open". Diane Seddon from Cleethorpes Camera Club was the judge for the evening, Diane is very skilled, and thorough in her judging, providing useful insight, and critique of the prints. Many of her comments centered around the best cropping of an image to optimise the subject within the frame, and giving the subject "room to breathe" in the framing. Congratulations to David Whitehouse placed first in the "Monochrome" category, with his superb rendering of a face sculpture, and Dave Turner placed first in the "Open" category with his stunning print of the sunrise over Whitby Harbour. Thanks to Diane Seddon for a great evening, and as she remarked at the end of the competition all the prints were of an extremely high standard. The Competition Page has been updated with the highest placed images, but currently the score sheets for the competition are unavailable.
Good Morning All Last week Dave Bennett came to the club again, it has been a while since we have seen his photography but well worth the wait. Dave's photographs were excellent and his story telling along with AV's made it a very good night. This week, Wednesday 15th October, we are holding a print competition, with the categories of "Mono" and "Open", our judge for the evening will be Diane Seddon AFIAP CPAGB BPE3* she is well qualified to judge our prints. The following week we are going to try a retro night again, with Transparencies taken prior to the year 2000, please let me know if you want to take part and have a time slot allotted, time will depend on the numbers wanting to take part. Regards Graham
Last night Dave Bennett came to the club to show us AV's and narrate other sets of photographs on a theme. Dave started with photos along the Humber and then carried on the evening with AV's on nature, flowers and transport as well as talks and photographs showing us Grimsby docks including detailed photographs of fish smoking and engineering. Dave's photography is of a very high standard with strong colours, lot's of use of depth of field and they tell a story. A great night, thank you Dave.
Good Morning All Last week at the club we held a local PDI competition with a category of "5 Minutes From Your Home", we had some very good entries in each category with myself, and Dave Turner judging on the night. All the results are on our website, but well done to Derek for his mobile phone picture of a remembrance seat in Horncastle and Harry for his hellebores in the "Open" category. This week, Wednesday 8th October, Dave Bennett is coming to the club to show us what he has been taking lately, Dave does quite a bit of AV so as usual it will be a very good night. A reminder, send your print titles for the next print competition to Dave Turner by midnight Wednesday and bring your prints in this Wednesday night as well please. If you have any more N&EMPF Exhibition PDI entries send them to me by midnight tomorrow (Monday) please. Regards Graham
Our PDI "Local" competition was held last night, with the categories of "5 Minutes From Your Home", and "Open". Dave Turner, one of our members began the evening with judging the "Open" category, always a difficult category in my opinion because of the variety of subjects entered into the competition. Dave had previewed the images on his home computer, and had notes on each of the images, he provided excellent feedback on each image. After the break, Graham Harrison began judging the "5 Minutes From Your Home" category, this was a very unusual subject category which stretched the creative ingenuity of members, and it was particularly interesting to see what members had submitted. Graham judged the entries very fairly, and provided very good critique of the images. The standard of images submitted was high, which makes judging a competition such as this difficult, and as always is subjective, but a big thank you to both judges, it was an interesting evening. The first placed images, from each category are shown on this post, "At the Going Down of the Sun" by Derek Smith, "5 minutes from your home", and "Hellebores" by Harry Kerman in the "Open" category. The website Competition Page has been updated with the top three placed images, and the scoresheets.
Good Morning All Last week at the club member Tony Gaskins gave us an excellent presentation of his recent trip to Kenya on safari. Tony showed us the animals and birds he had encountered on his trip. It was an evening of excellent wildlife photography as well as a very informative talk, thank you Tony. There is also a report on our website blog. This week, Wednesday 1st October, we are holding a local PDI competition, with the subject categories of "5 Minutes From Your Home" and "Open", Dave Turner has kindly offered to judge the Open with myself the subject, and you have until midnight tonight to enter. Dave Turner is also asking members to send him the titles of their prints for the next print competition, the categories for this are "Mono" and "Open". Regards Graham
