Back to Basics
Derek Smith • 10 July 2020
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
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.

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

This was our last outing before the summer break, on this occasion several of us met up at Kirkby Gravel Pits nature reserve for an evening of photography. The evening weather was perfect for photography, and we ambled around the reserve stopping to take some macro photography where opportunities arose. We did see a couple of butterflies, and I managed to take this image of a red admiral. As we walked along the paths, several grasshoppers could be glimpsed in the dry grass, they are very difficult to photograph as they are tiny, and agile, but I captured this one while I was laying down in the grass, at eye level, a lot of patience is needed to capture a quality image. In the brambles damselflies could be seen, one took off straight into a spiders web, luckily Graham was able to release it. On the water a heron, and egret could be observed across the water. It was an excellent evening of photography, as well as a social meetup, these outings are ideal for newcomers to photography to learn camera skills.

Good Morning All Last Wednesday while most of us were watching the football Derek took our LPA Battle prints to Axeholme for the final round, as in Derek's report on the blog we finished 2 nd and should have accumulated enough points to make the final, though not yet confirmed. Congratulations go to Dave Turner and David Whitehouse for the two highest scoring prints over the three rounds. Thank you Derek for taking our prints and missing the football. This week, Wednesday 22nd July, will be our last meeting before the summer break, and it is an outing to Kirkby Gravel Pits near Woodhall Spa. the directions are on the Lincolnshire Wildlife Trust's website. It is usually a good place to photograph Dragonflies and birds (but you know our luck) anyway I hope to see quite a few of you there on Wednesday meeting at 6.30pm, you can go earlier of course and meet up with the rest of the members when we get there. The Willow Emerald Damselflies were there last time and are quite rare. Regards Graham

The LPA Battles competition was held last night at Axholme Camera Club, in Haxey Church Hall. I attended as the Louth Photographic Society representative, bringing the Battles prints with me. It was a closely fought contest with some excellent prints from Axholme, Barton, and ourselves. The judge for the evening was Steve Dormer, from Doncaster, and he was very relaxed in his judging of the prints, providing excellent critique on each print. At break time, Steve had held back a total of 13 prints for further assessment and award of higher points, Axholme, and Louth had 5 each prints held back, with Barton 3 prints. The attached photo shows all the held back prints on the print stand. At the end of the evening Axholme took 1 st place with, 266 points, Louth came 2 nd with 258 points, and Barton 3 rd with 251 points. As the prints were taken off the stand, one print remained, it was a Louth print titled “Sleeping” by David Whitehouse, this print was awarded 20 points, and the judge Steve was very taken with the image, well done David.

Good Morning All Last week members walked along the Swaby valley, we have done the walk before, but it is now very grown up with nettles, grass and brambles. Not put off Chris led us through the valley to Swaby, there were six of us plus three more who caught us up in Swaby. The butterflies we saw as I am finding out this year just don't want to settle but we did manage some photographs before returning and going for a drink in the Massingberd Arms. This week there is an LPA Battle at Axholme on Wednesday starting at 7.30, if anyone would like to attend, please email me for details or look on Axholme's website. We are not having a meeting in Louth this week, probably as well the way the football went last night and with the next match on Wednesday evening. Regards Graham

Last night our members enjoyed a visit to the Swaby valley nature reserve. We crossed over two fields from South Thoresby, then followed the course of the Swaby Beck chalk stream through the valley, the public footpath was bounded by dense vegetation that hindered our progress at times. There was plenty to see around the reserve, myriad butterflies flitted around in a very lively manner, making for difficult photography, I spotted several small grasshoppers, and soldier beetles in the long grass, I tried to photograph a ladybird, but it was gone by the time I focussed on the creature. It was a very enjoyable evening, with good friendly company, and our camera skills were needed for the macro photography, these are a few of my photos from the evening.



