A lens flare is a light artifact in shots which is a result of light entering the lens. The appearance of the lens flare depends on your lens diaphragm but usually it's a circular-type shape at its centre, with streaks emanating out of it.Usually lens flares are undesired artifacts which dilute the contrast of the shot, but sometimes they can be used to enhance a photo.
How do lens flares form?
To understand how lens flares form, first you need to understand that there are two main types of light:
1.) Image light: These are light rays which bounce off the objects within the image you are trying to capture.
2.) Non-image light (aka "stray light"): These are light rays which are entering the camera from places outside your intended shot.
When non-image forming light enters your camera lens, it can create a lens flare through the internal reflection of stray light in the lens.
The most common non-image forming light is from the sun being in your shot i.e. pointing your camera onto a scene that has the sun within your viewfinder, or just outside it. Aside from the sun, lens flares may be the result of other very bright objects shining light into the shot or just outside it, including light bulbs, the moon, and reflective surfaces.
Not all lenses are equally prone to lens flares. The higher the magnification of the lens, the more internal reflections of stray lights occur so zoom lenses are more prone to the lens flare effect. Wide-angle lenses are far less prone to lens flare.
How do you avoid lens flare?
If you use a lens hood it can reduce the amount of non-image light entering your shot.
Another option is to ensure the light source if behind your camera rather than in the direction in which you are shooting a photo.
Thursday, 26 May 2011
What is a telephoto? and what is a telephoto lens?
What is a telephoto?
A telephoto is one taken with a telephoto lens.
What is a telephoto lens?
It is not a complete coincidence that telephoto and telescope sound a bit alike. Both serve in magnifying things. In fact, with a big enough telephoto lens, you can kind of use it like a telescope and have a play with astrophotography.
A telephoto lens is an expensive, long lens you can buy to fit over an SLR or DSLR and it's purpose is to achieve great magnification of things that are really far away. It has an optimal effect where it flattens a scene so that the picture appears as though it's nearby when in fact you may be miles away. You can also get super-telephoto lenses which have even greater magnification. This makes them useful for wildlife photography, photographing things like planes or nature shots of landscapes in the distance, and it's also useful for stalkers.. :D
Some signature marks of a telephoto include beautiful bokeh, and also the fact that it's notoriously prone to get blurry shots unless you keep the camera perfectly still. Even pressing the shutter to take the photo can vibrate the camera so that the whole picture comes out blurry.
A telephoto is one taken with a telephoto lens.
What is a telephoto lens?
It is not a complete coincidence that telephoto and telescope sound a bit alike. Both serve in magnifying things. In fact, with a big enough telephoto lens, you can kind of use it like a telescope and have a play with astrophotography.
A telephoto lens is an expensive, long lens you can buy to fit over an SLR or DSLR and it's purpose is to achieve great magnification of things that are really far away. It has an optimal effect where it flattens a scene so that the picture appears as though it's nearby when in fact you may be miles away. You can also get super-telephoto lenses which have even greater magnification. This makes them useful for wildlife photography, photographing things like planes or nature shots of landscapes in the distance, and it's also useful for stalkers.. :D
Some signature marks of a telephoto include beautiful bokeh, and also the fact that it's notoriously prone to get blurry shots unless you keep the camera perfectly still. Even pressing the shutter to take the photo can vibrate the camera so that the whole picture comes out blurry.
Wednesday, 25 May 2011
Photography Blogs & Websites
Just bookmarking some cool photography websites & blogs as I find them:
Websites to learn from
Websites to learn from
- Digital Photography School - I heard about this even before I got into photography so it must be good! :D I've checked out one or two article so far and it looks useful and clearly written.
- Cambridge in Colour - I've read a few great tutorials on here so far
- photography-basics.com - Looks like a useful blog for newbies like me.
- Luminous-Landscape Tutorials
- Purple Face Photography - Such beautiful photos!
- 500px - Top photos, continual new content posted
What is ISO in photography?
ISO stands for the International Organisation for Standardization. What does this mean? It's a standardization that was introduced to film rolls before the days of digital cameras, and refers to how sensitive the film was to light. So ISO is all about exposure to light and how bright or dark your photo will be.
Low light sensitivity film (low ISO) had to be exposed for a long time in order to get a photo with a reasonable amount of light registering, whilst high sensitivity film (high ISO) only needed to be exposed for a short duration.
It's pretty much the same thing with digital ISO, which you can control for every shot. Changing the ISO settings changes the camera's light sensor's sensitivity to light. The higher the ISO the more sensitive the sensor is to light and the brighter your photo will be.
ISO usually ranges from 100 to about 3200.
Benefits of low ISO
When should you use low ISO? What are the benefits of low ISO?
When should you use high ISO? What are the benefits of high ISO?
Low light sensitivity film (low ISO) had to be exposed for a long time in order to get a photo with a reasonable amount of light registering, whilst high sensitivity film (high ISO) only needed to be exposed for a short duration.
It's pretty much the same thing with digital ISO, which you can control for every shot. Changing the ISO settings changes the camera's light sensor's sensitivity to light. The higher the ISO the more sensitive the sensor is to light and the brighter your photo will be.
ISO usually ranges from 100 to about 3200.
Benefits of low ISO
When should you use low ISO? What are the benefits of low ISO?
- It's handy for outdoor shots and shots where there is already sufficient light present. Using flash and/or other special lighting devices allows you to use a low ISO whilst maintaining enough light in your photos. If you have low ISO and insufficient light, increasing aperture and exposure time also helps (i.e. set your camera to a slow shutter speed). You can also use a tripod to help you use slower shutter speeds to maintain a lower ISO.
- Low ISO gives better quality shots: The lower the ISO the better quality the image will be, so as a general rule of thumb, you should aim to use the lowest ISO possible. This enables you to blow up the picture to larger sizes and still maintain better quality. When you use high ISO, the picture is at risk of appearing grainy or speckled because ISO introduces "digital noise" to the photo. It generally creates an effect that isn't as clean and sharp as you'd perhaps like and take note that this graininess is often not perceivable when looking at your shots through the LCD screen after shooting, but it will be noticeable when you upload your pictures and scrutinize them on your computer. Good cameras should exhibit less digital noise, but even the best cameras probably have some at high ISOs.
When should you use high ISO? What are the benefits of high ISO?
- It's useful in indoor situations where there isn't as much light, or in generally darker situations where you need to boost light but aren't allowed to use a flash or lighting devices.
- If you want to create a grainy, speckled effect in your photos, you can use high ISO to achieve this. Some photos look better with grain, although there are post-editing programs that allow you to create this effect on photos too.
- It's useful for when you need high shutter speeds and you need as much light sensitivity as possible without allowing for it with shutter speed exposure. High shutter speeds may be important if you're holding the camera on a very wobbly surface (e.g. from a moving vehicle), or if you're trying to photograph a still shot of a moving object.
- If you know you need a low quality, small image and grain doesn't matter, increasing ISO can be a quick-fix for getting the lighting right.
Photography forums
I'm just bookmarking some photography forums that I want to check out. If I have any comments on them as I go I'll come back here and add commentary.
Tuesday, 24 May 2011
What is a hot shoe?
A hot shoe is the place on the camera where you can attach an extra flash. It's also known a flash socket.
Why is it called a hot shoe?
It's called a hot shoe because the heat refers to the fact that it's electrical, and if you look at the hot shoe you can see the electrical contact points. It's called a shoe because you slide the flash into the hot shoe much like you'd slide your foot into a shoe.
Related Products
Why is it called a hot shoe?
It's called a hot shoe because the heat refers to the fact that it's electrical, and if you look at the hot shoe you can see the electrical contact points. It's called a shoe because you slide the flash into the hot shoe much like you'd slide your foot into a shoe.
Related Products
What is focal length?
The focal length is the distance between the lens and the camera's sensor (or film if you're using a non-digital camera).
At first glance this seems confusing because books and blogs talk about varying the focal length and my first thought was: "Isn't the distance between the lens and the camera's sensor a constant, unvariable thing?" Well, turns out the distance between the lens and the sensor is indeed something that can be modified.
How can you change the focal length?
1.) Zooming in and out change the focal length
One very clear example of modifying the distance between the lens and the sensor is when you use the zoom. As the camera zooms in, it projects the lens outwards, effectively increasing the distance between the lens and the sensor, and thus increasing the focal length.
Usually if you look at your camera on the bit around the lens, it should give a number in milimeters. On my Canono PowerShot Pro1 for example it says 7.2-50.8mm on it for example. This number gives your camera's focal length. i.e. On my camera, the distance between the sensor and the lens at maximal zoom is a little over 5cm, and 7.2mm when no zoom is on. This is revealing of my camera's zooming capabilities: 7.2 x zoom capabilities = 50.8 ; so my zoom capabilities are about a x7 zoom.
2.) Changing the lens on your SLR or DSLR to one with a different focal length
One of the benefits of SLRs and DSLRs is that unlike point and shoot cameras, you can change the lenses. If you want, you can fit a lens with a different focal length on it to automatically get a different focal length.
What is the significance of a short or long focal length?
In simplest terms, increasing the focal length increases the magnification.
In more complicated terms, this is how it works: The shorter the focal length, the less room there is for the light rays to travel before hitting the sensor, therefore they have to bend at a steeper angle in order to hit the sensor than at a longer focal length and this means that the image that it captures is over a larger area (ie you can get a large chunk of a landscape in shot).
With a longer focal length, the light rays can bend more gently to reach the same spot on the sensor, which means that the area over which the picture is coming in from is narrower, and you can get far less of the surroundings into your shot. ie out of a whole landscape you might just be able to capture a little bit of it.
The more you zoom in and when it starts to use digital zoom, there comes a point when you exceed the camera's capabilities and any zoom beyond this point starts to appear less sharp. For this reason you really should avoid using the digital zoom if you want super-crisp and sharp photos.
Related Products
At first glance this seems confusing because books and blogs talk about varying the focal length and my first thought was: "Isn't the distance between the lens and the camera's sensor a constant, unvariable thing?" Well, turns out the distance between the lens and the sensor is indeed something that can be modified.
How can you change the focal length?
1.) Zooming in and out change the focal length
One very clear example of modifying the distance between the lens and the sensor is when you use the zoom. As the camera zooms in, it projects the lens outwards, effectively increasing the distance between the lens and the sensor, and thus increasing the focal length.
Usually if you look at your camera on the bit around the lens, it should give a number in milimeters. On my Canono PowerShot Pro1 for example it says 7.2-50.8mm on it for example. This number gives your camera's focal length. i.e. On my camera, the distance between the sensor and the lens at maximal zoom is a little over 5cm, and 7.2mm when no zoom is on. This is revealing of my camera's zooming capabilities: 7.2 x zoom capabilities = 50.8 ; so my zoom capabilities are about a x7 zoom.
2.) Changing the lens on your SLR or DSLR to one with a different focal length
One of the benefits of SLRs and DSLRs is that unlike point and shoot cameras, you can change the lenses. If you want, you can fit a lens with a different focal length on it to automatically get a different focal length.
What is the significance of a short or long focal length?
In simplest terms, increasing the focal length increases the magnification.
In more complicated terms, this is how it works: The shorter the focal length, the less room there is for the light rays to travel before hitting the sensor, therefore they have to bend at a steeper angle in order to hit the sensor than at a longer focal length and this means that the image that it captures is over a larger area (ie you can get a large chunk of a landscape in shot).
With a longer focal length, the light rays can bend more gently to reach the same spot on the sensor, which means that the area over which the picture is coming in from is narrower, and you can get far less of the surroundings into your shot. ie out of a whole landscape you might just be able to capture a little bit of it.
The more you zoom in and when it starts to use digital zoom, there comes a point when you exceed the camera's capabilities and any zoom beyond this point starts to appear less sharp. For this reason you really should avoid using the digital zoom if you want super-crisp and sharp photos.
Related Products
Subscribe to:
Posts (Atom)