Greetings, volks. Welcome to Hohenfels Volks, THE place for our place! WOW! The annual Hohenfels Volksfest was a great time and the weather was perfect. Now the clouds are puffing up some, and that makes for great outdoor photos that include the sky!
Today we’re going to introduce rating and EI.
Your camera has a range of ISOs you can choose from, most likely running from ISO100 to ISO3200 in third stop increments. Camera and film manufacturers used the International Standards Organization methods to set the speed, or ISO, of your sensor or film. They generally are set to favor overexposure, as underexposure is harder to correct. Therefore, in test conditions ISO 100 performs at ISO 80-100 to get you exposed at the general target for the contrast and exposure standards set by the organization. This used to be referred to as a film’s “box speed.” For digital work, I’ve come to think of it as “nominal.” Therefore, when I say I shot it at ISO 125, that’s what I was set and exposed for.
The ISO recognized that most scenes deviated from test conditions, as did developing or processing. A film may be rated at ISO 100, when developed in a certain developer for a specific time, but not for any other combination. Film shooters would “rate” their film at different speeds for their methods, including exposure and development controls. For instance, some would shoot FP4+, which is ISO125 in Ilford’s ID11 developer, rated at EI80 developed in Kodak D-76 for their preferred method of exposing and developing a standard shot.
EI, or “exposure index,” is what you rate your film at for your methods, and usually refers to speed rating assigned that’s different from the film's actual speed. Generally, when you shoot with your digital SLR, you shoot maybe at ISO 100, and edit it in your manufacturer’s provided application and get decent results. You are shooting and making your shot at nominal speed, or box speed with film.
You may find that in high contrast scenes at nominal speed, you are getting shadows that are clipped to black and whites that are blown and have no detail. In that case, it’s time to change your EI, or rate your speed different. To do this correctly, you should test your camera, and we’re going to cover the procedures to do that for YOUR best results. Since this test is based on your equipment, metering, and editing, someone else will get different results using the same equipment. This test is based on your style and methods, which others may not follow. Keep that in mind when “rating” your gear, you can recommend your “rating” to others with the same camera, they will most likely appreciate the information, but each “rating” is subjective, and will work best in your hands.
This testing becomes especially important when shooting at extremes of lighting. In very low light, like that in most old buildings, noise is a real concern when trying to increase your image brightness during editing, and in bright daylight lit landscapes skies and clouds can become just blotches of white without any detail.
The procedures for setting your EI involved a gray card, meter, and your camera. You should be set up for this in light conditions that match your intended shooting conditions to effectively use this method.
Step 1, set up your gray card in lighting that matches your shooting conditions. Step 2, set your desired ISO reading on your camera, and select RAW mode. Step 3; set your camera to f/8 or f/11 and AV mode. Step 4, meter your gray card, use spot metering and fill as much of the frame as possible with the gray card. Note the shutter speed. Step 4, set your camera to manual mode, and enter the shutter speed metered in step3, which should give you an 18% gray image. Step 5: compose your test shot. You can pull back some, including other elements. I have a test screen that includes black and white pieces and collapses nicely into a camera bag, and prefer to use that to check contrast ranges while doing this test. Step 6, take the following series of shots- at the metered reading obtained previously, -1/3 stop, -2/3 stop, -1 stop, +1/3 stop, +2/3 stop, and +1 stop. Step 7, load the images onto your computer. Then open your image editing application. Step 8, Open each image in turn, and find the one that is MOST CLOSELY identical to the gray card in exposure for your set up. Make sure to perform absolutely no adjustments to the images, as we are looking for the most closely identical image. Take note of the settings used for this shot. Step 9, this is your EI for that type of scene with that ISO selected. For example if –1/3 stop produced the best rendition for ISO100, then your EI would be 125 or EI125. You will effectively be rating your ISO100 shots at 125, and removing 1/3 stop on all your shots in those conditions. To accomplish this, when shooting at ISO100 simply remove 1/3 stop exposure, either by increasing your shutter speed 1/3 stop or closing down your aperture 1/3 stop.
Rating your sensor or speed before shooting can save a lot of time editing and the heartbreak of a shot that doesn’t live up to your expectations. It’s not perfect, and varies based up taste, style, and personal preference, but it will bring you closer to achieving your vision. It’s definitely something to try in conjunction with this week’s exercise on contrast and contrast control. Combine it with M+ and M- exposure placement for even better results. By exposing properly, you can keep your contrast in the desired range, and make it easier to achieve your vision in your final processing stage.
For those interested in more information about film speed, Wikipedia has a great article. It includes formulae and details about how box speed and nominal are attained.
I’m looking forward to seeing your results and hearing from you. Let me know what you think and how you’re using your camera! Share your thoughts here or at the Hohenfels Volks Facebook page. Of course, commenting on both Facebook and here is always appreciated, too! Don't forget, we're on Google+, too!
Showing posts with label tools. Show all posts
Showing posts with label tools. Show all posts
Friday, May 4, 2012
Friday, January 20, 2012
Nostalgia or Something Else?
Greetings, volks. Welcome to Hohenfels Volks, THE place for our place! Over the last 2 or 3 posts, we’ve discussed some stuff that seems outdated and unnecessary.
Today’s digital cameras do everything for us. They meter, set the shutter speed, set the aperture, set the ISO, focus, and tell us when to push the button. Using all the bells and whistles in your camera makes taking photos easy, right? All the hard parts are a thing of the past, isn’t that so? Why do it, when the camera can?
There are a couple answers. The first one is probably the simplest, although they both go together. ALL photography, notice the emphasis, is built on light. Whether you shoot your shot on an old view camera, making a daguerreotype or you shoot digital, your images are ALWAYS built the same. Light strikes a surface that is sensitive to it, and there is a reaction creating something. To have an image you need the light to have form and varying intensities. If you’re using color film or a digital camera, the color information is recorded as well. That is what all photography is. Because those who shot before us went through the pains of creating the systems we have today and discovering the rules and methods, we have a way to be on the same sheet of music. By knowing these methods, formulae, and standards, we can create great images.
If you’re using a digital camera or a film camera, ISO 100 is the same. When shooting both types with identical lenses and lighting, f/16 will allow the same amount of light for film or digital. 1/125 second on a film camera takes the same amount of time as 1/125 second on a digital. Time didn’t change for digital photography. Neither did light, nor the laws of physics change. DOF is still determined the same way it was when Hurrell shot Hollywood’s most glamorous. Exposure is still figured out the same way it was when Ansel Adams made his images. Lighting is still used by us; the same way Karsh used it to capture royalty and great figures of his day. The theory hasn’t changed because the camera can do it, the camera can do it because these things don’t change.
The second answer is only slightly more complicated. Throughout the history of photography, those who picked up the camera strive to learn more, to prefect their photography, and to share their vision. This knowledge gives us the tools to do just that, as it did for those who came before us. See and shooters don’t care, but those who appreciate a good photo or enjoy making something great do care. The more control we take away from the camera, the more control over our vision we have. You wouldn’t let your stove cook your dinner, would you? So why let your camera take a picture, when you can make one. Remember, Ansel Adams said, “You don't take a photograph, you make it.”
Start using the tools available, visualize your image, and when the 2 come together, you can make something so much more than you thought. Remember to work on making your images for this week’s theme, and don’t forget to vote for next week. While you’re at it, check out the great new images in Your Works.
Have a great weekend, everyone, and try to keep warm with the cold weather coming in! Don’t forget to post any of your images you’d like to see here at the Hohenfels Volks Facebook page. Of course, commenting on both Facebook and here is always appreciated, too!
Today’s digital cameras do everything for us. They meter, set the shutter speed, set the aperture, set the ISO, focus, and tell us when to push the button. Using all the bells and whistles in your camera makes taking photos easy, right? All the hard parts are a thing of the past, isn’t that so? Why do it, when the camera can?
There are a couple answers. The first one is probably the simplest, although they both go together. ALL photography, notice the emphasis, is built on light. Whether you shoot your shot on an old view camera, making a daguerreotype or you shoot digital, your images are ALWAYS built the same. Light strikes a surface that is sensitive to it, and there is a reaction creating something. To have an image you need the light to have form and varying intensities. If you’re using color film or a digital camera, the color information is recorded as well. That is what all photography is. Because those who shot before us went through the pains of creating the systems we have today and discovering the rules and methods, we have a way to be on the same sheet of music. By knowing these methods, formulae, and standards, we can create great images.
If you’re using a digital camera or a film camera, ISO 100 is the same. When shooting both types with identical lenses and lighting, f/16 will allow the same amount of light for film or digital. 1/125 second on a film camera takes the same amount of time as 1/125 second on a digital. Time didn’t change for digital photography. Neither did light, nor the laws of physics change. DOF is still determined the same way it was when Hurrell shot Hollywood’s most glamorous. Exposure is still figured out the same way it was when Ansel Adams made his images. Lighting is still used by us; the same way Karsh used it to capture royalty and great figures of his day. The theory hasn’t changed because the camera can do it, the camera can do it because these things don’t change.
The second answer is only slightly more complicated. Throughout the history of photography, those who picked up the camera strive to learn more, to prefect their photography, and to share their vision. This knowledge gives us the tools to do just that, as it did for those who came before us. See and shooters don’t care, but those who appreciate a good photo or enjoy making something great do care. The more control we take away from the camera, the more control over our vision we have. You wouldn’t let your stove cook your dinner, would you? So why let your camera take a picture, when you can make one. Remember, Ansel Adams said, “You don't take a photograph, you make it.”
Start using the tools available, visualize your image, and when the 2 come together, you can make something so much more than you thought. Remember to work on making your images for this week’s theme, and don’t forget to vote for next week. While you’re at it, check out the great new images in Your Works.
Have a great weekend, everyone, and try to keep warm with the cold weather coming in! Don’t forget to post any of your images you’d like to see here at the Hohenfels Volks Facebook page. Of course, commenting on both Facebook and here is always appreciated, too!
Wednesday, January 18, 2012
Tools of the Trade: Flash Part II
Greetings, volks. Welcome to Hohenfels Volks, THE place for our place! Today’s post is going to deal with using your flash in manual mode.
For some Volks, manual mode and photography don’t seem to go together. They leave everything on automatic, letting the camera tell them when to click the shutter, which seems a bit too much like serving the camera, not the camera serving us. By now, most of you have been shooting manual for a while. Chances are, though, that your flash is doing the majority of your work when you use it. I hope that this post will change that some!
First, we’re going to learn some terms and concepts. Flashes are rated by something called the GN, or Guide Number. It’s a measure of a flash's output. You have to know this number. The YN-560 that I have is rated by the manufacturer for 58 meters at 105mm, ISO 100. The actual rating is more like 35 meters at 35mm, ISO 100, which should give us about 50-55 meters at 105mm. I haven’t formally tested it in a controlled manner, but that seems about right. What that means is shooting at ISO 100, 105mm, and with the flash at full power, my max range for the flash is about 58 meters. At that distance, the light has fallen drastically in intensity, but spread out in coverage. The next thing we need to understand is aperture, or the size of the opening in our lens. A larger aperture means more light and conversely a smaller aperture means less. Aperture is measured as f/stop, a ratio of your aperture’s diameter to the level of light it allows. That’s oversimplified, but you get the idea. You already know about aperture, but will need to understand it for flash work. The last thing we’re going to bring up is distance between the flash and the subject. These 3 things are how you determine a manual flash’s power and set your exposure correctly. A flashes GN is the rating assigned to it by the manufacturer, so you have to be careful to read the specs before buying one. Some makers will call their flash GN58, but if you look at the tiny print, it’s at ISO 200 or even 400. That makes it more like a GN20 at ISO 100. Also, make sure the units your GN is listed in, feet or meters, or both are consistent throughout your calculations. Also remember that we're dealing with light, so sometimes it doesn't seem to make sense due the inverse square law. That's why we use GN!
The 3 things listed above are what you need to know to expose properly for manual flash. We’re going to start this part by giving you the equations to use, then giving some examples.
The first calculation is to determine your GN. First, set your flash to manual mode, full power, and if it has it, full zoom. Then place your flash a measured distance to your subject, say 5 meters. Then shoot a series of shots at successive f/stops. Note the aperture that gives you a proper exposure. For this we’re going to say f/8. Now multiply the distance by the f/stop. For this we’re going to multiply 5 meters by f/8, which means 5x8=40, or a GN of 40 at ISO 100, full power, max zoom, or about 20 at half power.
The next calculation is to determine your f/stop for that GN. If you have a GN 20 at ISO 100 flash, what f/stop do you use for 4.5 meters? The calculation for that is GN divided by distance. For GN 20, that would be 20/4.5=4.5 or f/4.5. Set up the above flash, GN 40 at half power, 4.5 meters and shoot using f/4.5, you should be almost dead on every time!
Last, we have figuring out your distance for a GN with a desired aperture. That is calculated by dividing GN/f/stop. As above, GN 20 at half power, we’ll say f/8. To get that we divide 20 by 8, or 20/8= 2.5, or 2.5 meters.
Here are the calculations listed:
Your GN=f/stop x distance to subject
F/stop= GN/distance to subject
Distance to subject= GN/f/stop
Here are some things to note. The distance is ALWAYS the distance from the flash head to the subject, not the camera to subject or flash to camera. Light modifiers like a Sto-Fen or umbrella lower your flash power by about 1-2.5 stops. Measure with them in place for more accurate readings. The same applies to bounce flash, count your distance as being from the flash to the reflector + the reflector to the subject, or adjust your exposure to compensate. A few times doing this with your calculator and flash manual will give you a great starting point for your flash shots, then before you know it, you’ll be nailing them every time!
Now that you know all that, use your camera's built in spot metering mode, go to AV or aperture priority, set your required f/stop, and meter for the rest of the scene. That shutter speed will allow you to balance your flash with the ambient light to create a nearly perfect exposure. Tinker with it, and you'll make that magic of having your image match your vision that much easier!
Working with your flash off camera in slave mode can also be a trial. The secret to that is point your optical sensor at the camera and rotate your flash head toward the subject. The sensor detects the flash from your camera and triggers the flash. It also has to be where it can see the flash from on camera. For some flashes, this will trigger it before it should go. The Yongnuo flashes have a mode called S1 that trips the flash at the very first blip of flash, and S2 that only triggers when the actual flash goes for the shot. Use S2 to ignore the red eye and pre-flashes your camera sends out. Also, turn of red eye reduction or pre-flash. Having your flash off camera will help prevent this phenomenon from occurring. Of course, you can also buy a wireless RF trigger and receiver from anywhere online for about $30 and avoid slave mode altogether.
A great resource for all things flash related is Strobist. We have a link to them in our links and they can really up your knowledge levels on flash. They put out some good tutorials and lessons in Lighting 101. Give them a read!
You’re probably bored after all that math and calculating. Get out there and shoot something, it’ll wake you back up! While you’re out shooting, don’t forget the milk, I mean your shots for this week’s theme! Complimentary colors with a contrasting subject. Should be something great in there and I can’t wait to see your work!
Don’t forget to post any of your images you’d like to see here at the Hohenfels Volks Facebook page. Of course, commenting on both Facebook and here is always appreciated, too!
For some Volks, manual mode and photography don’t seem to go together. They leave everything on automatic, letting the camera tell them when to click the shutter, which seems a bit too much like serving the camera, not the camera serving us. By now, most of you have been shooting manual for a while. Chances are, though, that your flash is doing the majority of your work when you use it. I hope that this post will change that some!
First, we’re going to learn some terms and concepts. Flashes are rated by something called the GN, or Guide Number. It’s a measure of a flash's output. You have to know this number. The YN-560 that I have is rated by the manufacturer for 58 meters at 105mm, ISO 100. The actual rating is more like 35 meters at 35mm, ISO 100, which should give us about 50-55 meters at 105mm. I haven’t formally tested it in a controlled manner, but that seems about right. What that means is shooting at ISO 100, 105mm, and with the flash at full power, my max range for the flash is about 58 meters. At that distance, the light has fallen drastically in intensity, but spread out in coverage. The next thing we need to understand is aperture, or the size of the opening in our lens. A larger aperture means more light and conversely a smaller aperture means less. Aperture is measured as f/stop, a ratio of your aperture’s diameter to the level of light it allows. That’s oversimplified, but you get the idea. You already know about aperture, but will need to understand it for flash work. The last thing we’re going to bring up is distance between the flash and the subject. These 3 things are how you determine a manual flash’s power and set your exposure correctly. A flashes GN is the rating assigned to it by the manufacturer, so you have to be careful to read the specs before buying one. Some makers will call their flash GN58, but if you look at the tiny print, it’s at ISO 200 or even 400. That makes it more like a GN20 at ISO 100. Also, make sure the units your GN is listed in, feet or meters, or both are consistent throughout your calculations. Also remember that we're dealing with light, so sometimes it doesn't seem to make sense due the inverse square law. That's why we use GN!
The 3 things listed above are what you need to know to expose properly for manual flash. We’re going to start this part by giving you the equations to use, then giving some examples.
The first calculation is to determine your GN. First, set your flash to manual mode, full power, and if it has it, full zoom. Then place your flash a measured distance to your subject, say 5 meters. Then shoot a series of shots at successive f/stops. Note the aperture that gives you a proper exposure. For this we’re going to say f/8. Now multiply the distance by the f/stop. For this we’re going to multiply 5 meters by f/8, which means 5x8=40, or a GN of 40 at ISO 100, full power, max zoom, or about 20 at half power.
The next calculation is to determine your f/stop for that GN. If you have a GN 20 at ISO 100 flash, what f/stop do you use for 4.5 meters? The calculation for that is GN divided by distance. For GN 20, that would be 20/4.5=4.5 or f/4.5. Set up the above flash, GN 40 at half power, 4.5 meters and shoot using f/4.5, you should be almost dead on every time!
Last, we have figuring out your distance for a GN with a desired aperture. That is calculated by dividing GN/f/stop. As above, GN 20 at half power, we’ll say f/8. To get that we divide 20 by 8, or 20/8= 2.5, or 2.5 meters.
Here are the calculations listed:
Your GN=f/stop x distance to subject
F/stop= GN/distance to subject
Distance to subject= GN/f/stop
Here are some things to note. The distance is ALWAYS the distance from the flash head to the subject, not the camera to subject or flash to camera. Light modifiers like a Sto-Fen or umbrella lower your flash power by about 1-2.5 stops. Measure with them in place for more accurate readings. The same applies to bounce flash, count your distance as being from the flash to the reflector + the reflector to the subject, or adjust your exposure to compensate. A few times doing this with your calculator and flash manual will give you a great starting point for your flash shots, then before you know it, you’ll be nailing them every time!
Now that you know all that, use your camera's built in spot metering mode, go to AV or aperture priority, set your required f/stop, and meter for the rest of the scene. That shutter speed will allow you to balance your flash with the ambient light to create a nearly perfect exposure. Tinker with it, and you'll make that magic of having your image match your vision that much easier!
Working with your flash off camera in slave mode can also be a trial. The secret to that is point your optical sensor at the camera and rotate your flash head toward the subject. The sensor detects the flash from your camera and triggers the flash. It also has to be where it can see the flash from on camera. For some flashes, this will trigger it before it should go. The Yongnuo flashes have a mode called S1 that trips the flash at the very first blip of flash, and S2 that only triggers when the actual flash goes for the shot. Use S2 to ignore the red eye and pre-flashes your camera sends out. Also, turn of red eye reduction or pre-flash. Having your flash off camera will help prevent this phenomenon from occurring. Of course, you can also buy a wireless RF trigger and receiver from anywhere online for about $30 and avoid slave mode altogether.
A great resource for all things flash related is Strobist. We have a link to them in our links and they can really up your knowledge levels on flash. They put out some good tutorials and lessons in Lighting 101. Give them a read!
You’re probably bored after all that math and calculating. Get out there and shoot something, it’ll wake you back up! While you’re out shooting, don’t forget the milk, I mean your shots for this week’s theme! Complimentary colors with a contrasting subject. Should be something great in there and I can’t wait to see your work!
Don’t forget to post any of your images you’d like to see here at the Hohenfels Volks Facebook page. Of course, commenting on both Facebook and here is always appreciated, too!
Wednesday, November 30, 2011
Tools of the Trade- More on Lenses
Greetings, Hohenfels, welcome to Hohenfels Volks, THE place for our place. Here’s hoping today sees you starting on the downhill run of a great week!
Today it’s time to talk a little about lens attributes and traits.
We’ve already talked a little about lenses, so today we’re going to concentrate on some of the quality issues and features of your lenses. It’s a little long, for which I apologize.
One of the first things most folks need to know is that your old film lenses will work on digital cameras. They may have a crop factor, for instance 1.6X for APS-C, but if they can mount on your camera, you can use them. On the other hand, your newer digital lenses are unusable on full frame or film cameras. When you put a film lens on an APS-C sensor, the crop factor comes from the distance from the back of the lens to the sensor. The film lenses cover a larger area than the sensor; this in turn causes an apparent increase in focal length and the crop. Canon’s recent systems, the EOS cameras, use EF lenses, which have a 1.6X crop on your APS-C sensor. Their digital line of lenses for the EOS system is the EF-S line. They require no crop factor and apparent focal length is actual focal length. The reason the digital series of lenses don’t work on full frame or film cameras is due to their smaller projection of the image onto a smaller sensor. They won’t fill the frame or film, and most likely won’t even focus properly even if they could be mounted.
Another concern about your lens on zoom lenses is often the aperture. Less expensive lenses read something like 28-135 f/3.5-5.6. This is because the aperture size doesn’t change during zooming, that is the largest it can go. The area of the aperture remains constant, requiring a change in f-number. If you remember, your f-number is a ratio of focal length and aperture. It represents the focal length divided by that number, that’s why it’s written f/2, f/5.6 etc. The longer a lens is, the less light reaches the sensor. That’s why the f/number changes throughout the range of zooms. If your area doesn’t change, your f-number must. The reason for this is the cost and weight added to vary the aperture size throughout the zoom range. That doesn’t mean a constant aperture means a cheap lens, it doesn’t mean less quality, it just means less light as you zoom in.
A great feature of lenses over the past few years is the addition of IS. The affordability of technology has made it possible to use feature that used to be unavailable to the hobbyist. IS allows slower shutter speeds when enabled. Using it hand held, you can get down to about 3 stops lower that the handheld limits. The systems work by compensating for motion with motion in the opposite direction. When hand holding your shot, using proper shooting styles, with arms tucked in etc, will enable the IS to really slug it out with vibration. The most important thing to remember is turning it on for handheld, and ALWAYS turn it off for tripod shots. When on a tripod, the IS searches for motion in the lens and can cause vibration rather than reducing it. The big drawback to IS is that it uses your camera’s battery for power.
The last thing I’ll bring up for now is a quality issue. The problem is chromatic aberration or CA. This is distortion caused by different colors, or wavelengths, of light focusing at differing areas on your sensor. There are several types and names, but we’re not going into it that deep here. It often causes the purple fringing that you see along borders with bright highlights and dark shadows together. Using a smaller aperture can help mitigate this, as can a longer lens. Low dispersion glass and good coatings can combat this effectively. There seems to be many complexities involved in CA, including the types and calculations. The best practice when purchasing a lens, if possible, is to take a test shot using that lens of a high contrast area, and zoom in looking for fringing. CA can also cause blurriness in Black and White photography, so keep that in mind. You can see examples on Google to get more information and some idea of what to look for. According to the reviews I’ve read, Canon makes the most advanced software correction to mitigate CA and other distortions available. Because Canon’s EF lens system is actually all electronic, and records the information on individual lens models, Digital Photo Pro can compensate for it. Yet another advantage of shooting RAW!
Whenever you look to purchase a lens, make sure you read a variety of reviews, and look at loads of test photos taken with that lens, it could save you some headaches! If you have a lens that you favor and would like to write it up here, let me know, and I’ll get it posted for you!
Now on to other things, remember to get your votes in for next week’s theme. This week our theme is “Morning Moments.” Dazzle me with your work! Get shooting and start posting at the Hohenfels Volks Facebook page. Of course, commenting here is always welcome, too!
Today it’s time to talk a little about lens attributes and traits.
We’ve already talked a little about lenses, so today we’re going to concentrate on some of the quality issues and features of your lenses. It’s a little long, for which I apologize.
One of the first things most folks need to know is that your old film lenses will work on digital cameras. They may have a crop factor, for instance 1.6X for APS-C, but if they can mount on your camera, you can use them. On the other hand, your newer digital lenses are unusable on full frame or film cameras. When you put a film lens on an APS-C sensor, the crop factor comes from the distance from the back of the lens to the sensor. The film lenses cover a larger area than the sensor; this in turn causes an apparent increase in focal length and the crop. Canon’s recent systems, the EOS cameras, use EF lenses, which have a 1.6X crop on your APS-C sensor. Their digital line of lenses for the EOS system is the EF-S line. They require no crop factor and apparent focal length is actual focal length. The reason the digital series of lenses don’t work on full frame or film cameras is due to their smaller projection of the image onto a smaller sensor. They won’t fill the frame or film, and most likely won’t even focus properly even if they could be mounted.
Another concern about your lens on zoom lenses is often the aperture. Less expensive lenses read something like 28-135 f/3.5-5.6. This is because the aperture size doesn’t change during zooming, that is the largest it can go. The area of the aperture remains constant, requiring a change in f-number. If you remember, your f-number is a ratio of focal length and aperture. It represents the focal length divided by that number, that’s why it’s written f/2, f/5.6 etc. The longer a lens is, the less light reaches the sensor. That’s why the f/number changes throughout the range of zooms. If your area doesn’t change, your f-number must. The reason for this is the cost and weight added to vary the aperture size throughout the zoom range. That doesn’t mean a constant aperture means a cheap lens, it doesn’t mean less quality, it just means less light as you zoom in.
A great feature of lenses over the past few years is the addition of IS. The affordability of technology has made it possible to use feature that used to be unavailable to the hobbyist. IS allows slower shutter speeds when enabled. Using it hand held, you can get down to about 3 stops lower that the handheld limits. The systems work by compensating for motion with motion in the opposite direction. When hand holding your shot, using proper shooting styles, with arms tucked in etc, will enable the IS to really slug it out with vibration. The most important thing to remember is turning it on for handheld, and ALWAYS turn it off for tripod shots. When on a tripod, the IS searches for motion in the lens and can cause vibration rather than reducing it. The big drawback to IS is that it uses your camera’s battery for power.
The last thing I’ll bring up for now is a quality issue. The problem is chromatic aberration or CA. This is distortion caused by different colors, or wavelengths, of light focusing at differing areas on your sensor. There are several types and names, but we’re not going into it that deep here. It often causes the purple fringing that you see along borders with bright highlights and dark shadows together. Using a smaller aperture can help mitigate this, as can a longer lens. Low dispersion glass and good coatings can combat this effectively. There seems to be many complexities involved in CA, including the types and calculations. The best practice when purchasing a lens, if possible, is to take a test shot using that lens of a high contrast area, and zoom in looking for fringing. CA can also cause blurriness in Black and White photography, so keep that in mind. You can see examples on Google to get more information and some idea of what to look for. According to the reviews I’ve read, Canon makes the most advanced software correction to mitigate CA and other distortions available. Because Canon’s EF lens system is actually all electronic, and records the information on individual lens models, Digital Photo Pro can compensate for it. Yet another advantage of shooting RAW!
Whenever you look to purchase a lens, make sure you read a variety of reviews, and look at loads of test photos taken with that lens, it could save you some headaches! If you have a lens that you favor and would like to write it up here, let me know, and I’ll get it posted for you!
Now on to other things, remember to get your votes in for next week’s theme. This week our theme is “Morning Moments.” Dazzle me with your work! Get shooting and start posting at the Hohenfels Volks Facebook page. Of course, commenting here is always welcome, too!
Monday, November 7, 2011
Tools of the Trade, Powering Up
Welcome to Hohenfels Volks. I hope Monday was good to everyone. I was off and went to Regensburg to buy some gear and a hamster for the princess. Of course, time limits prevented getting the gear, so I’ve ordered some online. The weather was extremely nice today, and made for some great photo ops. Tomorrow should be some great autumn pics coming! I’m hoping to get out and check out some areas between Hohenfels and Regensburg I discovered today.
Speaking of gear, today we’re going to do a paragraph about battery grips and their benefits.
DSLRs use rechargeable batteries, and those batteries are good for somewhere between 300 and 900 shots usually. I’ve gotten 600 in one night, and 300 more the next. It sounds like a lot, eh? Sometimes, though, the extra power comes in handy. If you chimp a lot, then that extra bit helps. It also helps when shooting bursts, as the buffer can clear a little faster.
Another advantage of the battery grip is that using 2 batteries means half the charging. If you have either 2 chargers or a dual charger, you have the same time to charge them, but get twice the shots between charges.
The other big advantage is the addition of controls to portrait mode shooting. You have full access to your camera controls from portrait orientation, allowing for continued shooting without rotating your camera to make changes or view settings.
An unsung plus is the weight. For some volks, the extra weight is too much. The reality is that having the extra weight, adds anywhere from 1/3 stop to a full stop of stability to your handheld shots. It’s a trade off, the choice is yours to make. I like the thought of extra stability. If you’re using a string-pod, it’s even better in low light!
Well, that’s it for today. Thinking about traveling? Check out the battery grip for your camera and keep shooting longer.
Keep shooting, both Hohenfels and beyond. Remember to share your pics and post your questions at the Hohenfels Volks Facebook page, and or by commenting here!
Speaking of gear, today we’re going to do a paragraph about battery grips and their benefits.
DSLRs use rechargeable batteries, and those batteries are good for somewhere between 300 and 900 shots usually. I’ve gotten 600 in one night, and 300 more the next. It sounds like a lot, eh? Sometimes, though, the extra power comes in handy. If you chimp a lot, then that extra bit helps. It also helps when shooting bursts, as the buffer can clear a little faster.
Another advantage of the battery grip is that using 2 batteries means half the charging. If you have either 2 chargers or a dual charger, you have the same time to charge them, but get twice the shots between charges.
The other big advantage is the addition of controls to portrait mode shooting. You have full access to your camera controls from portrait orientation, allowing for continued shooting without rotating your camera to make changes or view settings.
An unsung plus is the weight. For some volks, the extra weight is too much. The reality is that having the extra weight, adds anywhere from 1/3 stop to a full stop of stability to your handheld shots. It’s a trade off, the choice is yours to make. I like the thought of extra stability. If you’re using a string-pod, it’s even better in low light!
Well, that’s it for today. Thinking about traveling? Check out the battery grip for your camera and keep shooting longer.
Keep shooting, both Hohenfels and beyond. Remember to share your pics and post your questions at the Hohenfels Volks Facebook page, and or by commenting here!
Tuesday, October 11, 2011
Tools of the Trade- Lenses
Welcome to another Hohenfels Volks photography article. Today in Tools of the Trade, we’re going to discuss lenses. The lenses are like the eyes of the camera. Without them, your light is useless!
You may hear someone talking about their “glass.” Photographers like to refer to them that way, it’s a kind of insider speak. A fine example is the statement that for shooting pro-sports, you need “fast glass.”
Here are the basic parts of a lens;
The Focusing Ring - this allows you to focus your lens on your desired center of interest.
The Zoom Ring - this allows for changing your focal length on zoom lenses.
Front Optical Lens- the front-most element in a lens. This is where the light enters your lens for image recording.
Rear Element- the last element before the curtain or sensor. This is special because of back focus.
Lens Mount- this is where your lens connects to your camera body. It usually has electrical contacts for the camera to communicate with the lens.
Auto-focus On/Off selector- turns off the lenses auto-focus motor.
IS On/Off selector- if your lens is equipped with IS, this turns it on or off.
Diaphragm Blades- these are the blades used to adjust your aperture. they are sensitive and easily damaged. The more blades, the more circular your aperture.
Never try to mount a lens with a different mounting system than yours to your camera. Canon’s lenses cannot be used on a Nikon without a special adaptor, and vice versa. When mounting your lens, remember to align the mounting marks, and firmly seat the lens on the body. Once your lens is seated, you’re off to the races!
When shooting on a tripod or at higher speeds, turn your IS off. This saves battery life and prevents blurring caused by the IS looking for motion that doesn’t exist. A sufficiently high speed is no slower than 1 over your focal length in seconds. For a 300mm lens, you can safely handhold at no slower than 1/300 second.
When handling your lenses, never touch the glass!
Always keep the camera side of the lens facing down whenever the cover is removed to prevent dust settling on it.
When your lens is mounted, the best option is either a cheap UV filer or Circular polarizer. This will protect the glass of your lens from being scratched or broken.
Clean your lenses with either a cleaning kit or soft lint free microfiber cloth.
Always use a blower bulb to remove the dirt before wiping. Then wipe in a circular motion from inside to outside.
If it still needs cleaning, place a couple drops of lens cleaning solvent on the cloth and wipe again. Never put liquid on the lens.
Store your lenses in a clean dry place. Try to ensure it is free from dust, dirt, and moisture.
The case most lenses come with is a good place to store them.
Never subject your lenses to hard banging or jostling. This can damage the diaphragm blades used to adjust your aperture.
Take care of your lenses and they will provide a lifetime of great images and memories!
Not all lenses are created equal, some are better than others, but taking the time to learn about yours will make it more valuable and your images that much better!
Well, after that long-winded discussion, I’m sure your dying to get out and take some pics. Choose your lens and shoot away! There’s enough around Hohenfels to give all your lenses a workout! Make sure you post the pics to the Hohenfels Volks Facebook page and share the joy with all of us!
Remember; leave your comments and questions here and on our Facebook pages, also.
I'm looking forward to hearing from you!
Thanks to all of you, have a great day!
You may hear someone talking about their “glass.” Photographers like to refer to them that way, it’s a kind of insider speak. A fine example is the statement that for shooting pro-sports, you need “fast glass.”
Here are the basic parts of a lens;
The Focusing Ring - this allows you to focus your lens on your desired center of interest.
The Zoom Ring - this allows for changing your focal length on zoom lenses.
Front Optical Lens- the front-most element in a lens. This is where the light enters your lens for image recording.
Rear Element- the last element before the curtain or sensor. This is special because of back focus.
Lens Mount- this is where your lens connects to your camera body. It usually has electrical contacts for the camera to communicate with the lens.
Auto-focus On/Off selector- turns off the lenses auto-focus motor.
IS On/Off selector- if your lens is equipped with IS, this turns it on or off.
Diaphragm Blades- these are the blades used to adjust your aperture. they are sensitive and easily damaged. The more blades, the more circular your aperture.
Never try to mount a lens with a different mounting system than yours to your camera. Canon’s lenses cannot be used on a Nikon without a special adaptor, and vice versa. When mounting your lens, remember to align the mounting marks, and firmly seat the lens on the body. Once your lens is seated, you’re off to the races!
When shooting on a tripod or at higher speeds, turn your IS off. This saves battery life and prevents blurring caused by the IS looking for motion that doesn’t exist. A sufficiently high speed is no slower than 1 over your focal length in seconds. For a 300mm lens, you can safely handhold at no slower than 1/300 second.
Lens Care
When handling your lenses, never touch the glass!
Always keep the camera side of the lens facing down whenever the cover is removed to prevent dust settling on it.
When your lens is mounted, the best option is either a cheap UV filer or Circular polarizer. This will protect the glass of your lens from being scratched or broken.
Clean your lenses with either a cleaning kit or soft lint free microfiber cloth.
Always use a blower bulb to remove the dirt before wiping. Then wipe in a circular motion from inside to outside.
If it still needs cleaning, place a couple drops of lens cleaning solvent on the cloth and wipe again. Never put liquid on the lens.
Store your lenses in a clean dry place. Try to ensure it is free from dust, dirt, and moisture.
The case most lenses come with is a good place to store them.
Never subject your lenses to hard banging or jostling. This can damage the diaphragm blades used to adjust your aperture.
Take care of your lenses and they will provide a lifetime of great images and memories!
Not all lenses are created equal, some are better than others, but taking the time to learn about yours will make it more valuable and your images that much better!
Well, after that long-winded discussion, I’m sure your dying to get out and take some pics. Choose your lens and shoot away! There’s enough around Hohenfels to give all your lenses a workout! Make sure you post the pics to the Hohenfels Volks Facebook page and share the joy with all of us!
Remember; leave your comments and questions here and on our Facebook pages, also.
I'm looking forward to hearing from you!
Thanks to all of you, have a great day!
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