Basic Photo Technique « Photo Notes

November 6, 2010

Gaining Perspective

Filed under: Basic Photo Technique,Photographic Education — John Siskin @ 6:14 pm

Usually I put the shameless plugs at the bottom end of this blog, but not this week. My book Understanding and Controlling Strobe Lighting: A Guide for Digital Photographers is on Amazon.com at number 16 in photographic lighting books! And there was much rejoicing! Here is a sample chapter. Of course I still hope that you will consider purchasing my fine art book B Four: pictures of beach, beauty, beings and buildings. Frankly purchases of this book mean a lot to me. I really hope that people will consider this work. And you know that I teach for BetterPhoto.com. I’ll leave those links to the end of the blog.
There are a few ways to change the shape of the face. The one I talk about most is with lighting. You can use light to shape the face in a two dimensional medium. The more you use large light sources, particularly the light panel/umbrella combination the less strong shadowing you will have, and the less definition you will get.
The second consideration is perspective. This really means where you stand. If you are 2 feet from a persons face the contours of the face are exaggerated. If you shoot at 10 feet from a subject the face is flat. Consider it this way, the distance from your lens to the nose is say 24 inches, then the distance to the ear will be close to 29 inches. The difference between these two numbers is a significant percentage of the total. If you are 72 inches (6 feet) from the nose than you will be about 77 inches from the ear, the difference is insignificant. So if you want to make a shot with a flatter perspective you need to move further away from the subject. This will require a longer lens, to keep the subject the same size in the image. On my full frame camera I generally don’t use anything less than a 100mm lens for a headshot of an average face. For a face with extreme contours I’ll use a 200mm lens. Since most people use smaller chips they will need to convert these numbers, but for instance a 50mm lens is pretty short (about 80mm converted) to use for an average face. Perhaps an 85mm lens might be better, for an average face and you might want 135, for an extreme face. In these two shots I used a 50mm lens on my full frame camera and a 200mm lens. The lighting is the same. You can see a difference in the way the face looks. I think he 200mm shot is ok, but the 50 is certainly too exaggerated.

Shot with a 50mm lenms on a full frame camera.

Shot with a 200mm lens. I think the face looks much better.

This is why it is important to move your camera rather than rely on a zoom lens when you do portraits. If you’re to close or too far away the zoom won’t fix that it will just change the perspective.
Of course changing the angle of the face can also change the shape. If you shoot a profile a strong nose or chin will be very visible.
Please consider taking one of my classes, or even recommending them. I have three classes at BetterPhoto:
An Introduction to Photographic Lighting
Portrait Lighting on Location and in the Studio
Getting Started in Commercial Photography

Just a couple more from B Four;

Comments (2)

September 5, 2010

Controlling the Viewers’ Eyes

Filed under: Basic Photo Technique,Looking at Photographs,Photography Communication,Uncategorized — John Siskin @ 8:39 pm

I’ve written several times about making and taking photographs. My main goal in making a photograph is to keep the viewer engaged with the photograph. If a person looks at an image and says “picture of a motorcycle” and moves on, you haven’t really got any attention. If they look at the shot, and spend time staring at the motorcycle, that’s much better.

One of the ways to keep a viewer engaged in a shot is to give them color and line and shape, but not give them a recognizable object. I enjoy making images of this sort. As you may know, from this blog and my magazine articles, I make a lot of abstract images with the microscope. I was asked to participate in a show last week, and I will probably bring these abstract images.

There are other ways to keep the viewer engaged. One is to place the subject on the left side of the frame, since the viewer’s eye often enters the frame from the upper left it is a good idea to have the subject near that corner of the shot. The eye starts in this corner because this is how people are taught to read English, I have had students who learned to read in the opposite direction, and they seemed to frame in the opposite direction way. Still, people often shoot the subject on the right side of the frame. They scan from the left finally find something on the right and hit the shutter. People could make better pictures if they took more time to re-frame the image.

Another way to influence the viewers’ eye is the use of sharp focus and soft focus in the image. Since the eye is looking for a subject it will naturally look for the sharpest areas of the image. The eye will also look at lighter areas of the image, so you can use these ideas to make better portraits, product shots and even action shots. You can manipulate the focus in an image after you shoot it, with Photoshop or another image manipulation tool. I also like doing this in camera. I use depth of field, dragging the shutter or panning the camera to give different effects. Depth of field is the area that is in focus in front of and behind the actual point where the lens is focused. The amount of distance, that is in focus, is changed by the aperture: a smaller aperture gives more depth of field and a larger aperture gives less. So a wide aperture would allow you to use depth of field to isolate the subject of your shot. There is more information about the aperture in an earlier blog entry.

Shutter drag, or dragging the shutter, is a way to mix the instantaneous light from a strobe with a long exposure of the ambient light. This gives me a chance to mix the image from instant and continuous light. The process of dragging the shutter is less controllable than some of the effects I use so it is good to shoot a lot of frames if you do this. Basically the idea is to use a strobe, which is only on for about 1/1000th of a second, and a long exposure for the ambient light, say a 1/4 second. I have often found this technique effective for shooting people working.

You also use a long exposure for panning. The idea is to move the camera along with the subject. That way the subject is sharp but the background is blurred. As with the shutter drag this doesn’t always work, so you need to take a lot of shots. This is also easier with a range finder camera, since you can see through the viewfinder when the shutter is open. With a dSLR the viewfinder is black when the shutter is open.

Of course there are other ways to accomplish soft and sharp focus, maybe we’ll get to some of them next week. One thing I’m doing different this week: I the links are connected to copies of the images at BetterPhoto. I really don’t know how well this will work for non-members, so if you can’t use the links please let me know.
My article on strobe power is in the current Photo Technique Magazine. I hope you’ll get a copy.
Please consider taking one of my classes, or even recommending them. I have three classes at BetterPhoto:
An Introduction to Photographic Lighting
Portrait Lighting on Location and in the Studio
Getting Started in Commercial Photography

Comments Off

August 10, 2010

Suggestions for Better Photographs

Filed under: Basic Photo Technique — John Siskin @ 12:18 pm

A couple of days ago Jim Miotke asked me for some short suggestions for photographers, I think he asked the other instructors at BetterPhoto also. Here are a couple I gave him:
Practice, test and evaluate. You can’t use a technique effectively until you are really familiar with it.
Practice, musicians do. It is difficult to keep a skill fresh if you don’t use it.
Look at books and prints of classic photographs, monitors make everything the same size and don’t show the artists intent as well as an original print. You need to look at what others have done to train your eye. It improves seeing.
Edit ruthlessly. Don’t show work with problems.
So, the first two are ways of saying the same thing: you need to treat your photography as passionately as a musician treats music: not just working at it when there is an audience, but also when you’re alone. There are several things you should do: practice with camera features you don’t normally use. So one day I practiced with the microphone that holds makes image notes on my camera. I still don’t use it. But I do use the exposure compensation controls, and I can find them with the camera at my eye. I practice with my lights. I just got a special new reflector for my portable Normans. I have photographed the pattern of the reflector in several ways. In the next few days I’ll shoot a model with the reflector to see how it works in practice. I won’t wait until I need it to use it. One more way to practice: when your walking around think about how you would frame photographs, what would you put in and what would you leave out?
I think the third suggestion is even more important. Everybody looks at photographs every day. We are part of an on going visual discussion, but we don’t pay attention. Great photographers not only had a lot to say in the conversation, but they were conscious of how their photographs worked. So I look at images by Edward Weston, Edward Steichen, Alfred Stiegiltz, Margaret Bourke-White, Annie Liebovitz, Ansel Adams, Linda Butler, Eliot Porter, Jerry Ulesmann…. I wish I could afford original prints from all these photographers, but I can afford their books. Books that were designed with the artists’ active participation, so that they represent the way the artist wants to present their work. Looking at great work gives me higher goals and improves the way I look at my subjects.
Finally, editing. People see your work as you show it to them. If you show an image with a long explanation about where your were, or how you took the picture, you will generally bore the audience. If an image pleases you, because of the circumstances of its creation that’s fine, but you shouldn’t show it unless it will really interest the audience. I’ve attached several images made with my microscopes. I hope you find them interesting.
I teach a class in commercial photography , as well as classes in lighting and portraiture at BetterPhoto.com. I hope you will check out the classes soon. My first book: Understanding and Controlling Strobe Lighting: A Guide for Digital Photographers will be published in the fall you can pre-order it. I have a new magazine article coming out in September about strobe power. You can see it in Photo Technique Magazine.
Thanks, John

Comments Off

January 8, 2010

The Right Exposure or the Right Light?

Filed under: Basic Photo Technique,Lighting Technique — John Siskin @ 10:33 pm

Getting a good exposure is important, but getting the right light is MUCH more important. Digital cameras make this much

This is what the shot looked like without strobes. It is the right exposure, but the wrong light.

easier than ever before! People often rely on a meter when they should look at what they are doing. But even when I shot film for a living I didn’t rely on the meter, I relied on the Polaroid instant images I made with the camera. I suspect part of the difficulty is that it is frightening to turn the meter off and rely on your eye and proof image and histogram, but now that we have these tools we should not be so afraid to turn off the meter.

In teaching classes I keep trying to find ways to say that you have to move into the land BEYOND metering. When you use a strobe meter you get a response that tells you how to make a middle density, but the meter doesn’t tell you how to make it look right. There is no automatic way to make it look right, only the application of brains can do that. When I make a shot with strobes and a digital camera, the first thing I do is to put the camera on manual. The camera meter can’t read strobes, except for the proprietary strobe. So the camera meter is useless. I do not use a hand held strobe meter, as it doesn’t give me useful information. The only things I pay attention to are the histogram and the proof image on the camera back, or, even better, an image on a computer tethered to the camera. More than metering these two tools tell you about your image.

In this version I've put in a couple of lights and things look better. I know what to do becaues I am examining what I've done step by step.

Let me suggest a plan for seeking the right exposure:

1)   Set the shutter speed to the sync speed.
2)   Set the aperture to your middle aperture, whatever that is on the lens you are using
3)   Take a picture, it will probably be wrong.
4)   Move the aperture dial to let in more or less light based on test exposure 1, you can look at the histogram to help determine how much to change the aperture, but the proof image should tell you if you need to change the exposure a lot or a little. If you are using more than one light consider the balance of the lights. Remember the aperture affects the strobes, the shutter speed doesn’t.
5)   More test exposures and changes of light placement and light power until the strobes are right.
6)   If you need to use ambient light increase the shutter speed until the balance looks right. This same technique will work if you are mixing strobes and daylight. This was why the Polaroid bill was so high with film cameras, but with digital these test exposures are free, so we should not be afraid to make them. If you practice this you will actually end up being able to find the right exposure quite quickly.

In this version I added a couple more lights to open up the far wall with more light. No meter could have done this. I need to look at what I'm doing.

This is the essential trick with strobes, to evaluate and change our images in search of the right levels for our lights and our exposures. With the histogram and the proof image on camera or in the computer we have better tools for creating the right exposure than any meter could give us, but it does take repeated testing. If you use a hand-held meter you will get an answer, but very often it will be profoundly wrong.

This shows the final placement of the lights.

Comments Off

November 8, 2009

Fluorescent Lights?

Filed under: Basic Photo Technique,Lighting Technique — John Siskin @ 5:16 pm

I have written elsewhere about fluorescent lights for photography. I didn’t say anything complimentary there, and I don’t intend to say much that is nice in this blog. So if you really love the new compact fluorescent lights as studio lights, it might be best to stop now. Still, the results of my tests were somewhat less dire that I had anticipated.

I was finally able to borrow one of these lights (a Top Lighting PB-85 120v 85 watt) so that I could run tests. I certainly didn’t want to buy one. I did several tests: first I used my spectrometer to look at the color distribution of the light, that is look at the light spread into a rainbow. My spectrometer is made from cardboard, a couple of razor blades and a small piece of diffraction grating. It is not a tremendously accurate device. It was not designed to be used with a camera. Still I am including pictures of daylight and of the fluorescent tube. You can see that daylight is continuous, smooth. The fluorescent has big bright lines and big dark lines, so no continuous spectrum. So the nature of this light is very, very different from daylight.

Fluorescent Spectrum, notice how the spectrum is banded rather than continuous

Sunligth Spectrum, it is smoother in the spectrometer.

<p><P>

In my second test I made a picture of a Macbeth Color Chart with strobe light and the fluorescent light. The color of the two shots was very different, so I would not want to use the fluorescent light with my strobe. However when both shots were white balanced, in the computer, the shots were very similar. Really the fluorescent tube was a closer match than I would have expected, after the white balance. Please keep in mind that white balance will not enable to correct a shot for two different light sources.

Fluorescent version of the Color Checker, white balanced.

Strobe version of the Color Checker, white balanced.

<p>

In the third test I made 10 shots at a shutter speed of 1/180 to see if the light would be consistent on all the shots. I did not expect this to go well. Fluorescent tubes are supposed to vary with the cycling of alternating current electricity. In this country the power cycles 60 times a second. So 1/180 should be only part of a cycle. In this shot the color did not vary by as much as 1%, really quite impressive. Since the shots all looked the same, I am not including them.

Finally I compared the overall quantity of light to a 600 watt Smith Victor quartz light. The quartz light was 8 times more powerful than the fluorescent light. Although I could use an array of these lights to increase power, I could not get the power and hard light effect that I can get from quartz lights.

On the whole the light performed better with color than I had anticipated. However the unusual spectrum leaves me suspicious that there will be problems in the real world, especially with fabrics. Certainly the low power disappoints me, but if your camera performs well at high ISO levels, this may be less of a problem for you.

Thanks, John

Please check out my classes

An Introduction to Photographic Lighting

Portrait Lighting on Location and in the Studio

Business to Business: Commercial Photography

Comments (1)

October 26, 2009

FABULOUS NEW BOOTY LIGHT!!!!!

Filed under: Basic Photo Technique,Lighting Technique — John Siskin @ 5:36 pm

Sand Canyon Home There are a lot of lighting products on the market, and many of them are mostly hype. There are only so many ways you can manipulate light, and few of them are new. So you can make a light source larger with an umbrella, soft box or a light panel. If you want to put light in just one part of an image you will probably need a snoot, grid spot, or barn doors. There are other ways to do these things, but they do about the same things. Changing the name doesn’t change the product much.

One of the things people have tried to do for a long time is to make the little light source on a camera mount strobe, like the Nikon SB 900 or the Canon 580, act like a bigger light source. When you have a large light source the light hits the subject from all points of the source, so you get less shadowing and softer transitions between highlight and shadow. Vivitar introduced a bounce card for the 283 strobe in about 1976, so the manufacturers have been at this for a while. The Vivitar bounced all the light off a card, simple but didn’t change things all that much. Later designers bounced light off the walls of the room, so that there was a lot of fill light. This was more effective. So you see products from Sto-fen, Lumiquest and Gary Fong. There are differences in the way they move the light around and where they move the light, but the idea is similar: some light goes directly to the subject and some is bounced. Now this idea works, and it is probably the best idea for event photography, and will work well in other situations.

Taken with a direct flash. See the hard shadows and the high contast? What a difference the BOOTY LIGHT makes!!!

Booty light shot!!

I have decided to introduce a NEW and FABULOUS way to spread light from a camera mount strobe, or many other kinds of strobes. Did I say it is NEW and WONDERFUL? I have to make sure I use enough hype here. It is the BOOTY light, yes this FABULOUS new light is actually a shoe covering. You can by TWO for only 79¢, YES less than a dollar. That makes these WONDEFUL, NEW units less than one half of one per cent as expensive as a Gary Fong Lightsphere II. Didn’t I say this is FABULOUS?

Seriously these are useful tools. I have used them on several occasions, because I needed to be quick of I needed a camera mount strobe to add to a monolight on a stand. In addition to the before and after shots, necessary to introduce something as WONDERFUL as this, I have a shot from a recent project where I used the booty light and just one other strobe with an umbrella. I had to work quick on this shoot. So think about it: Don’t you need a Booty light? Here’s a link: http://www.envirosafetyproducts.com/product/Tyvek-Shoe-Covers.html You can also buy them in quantities of over 100, even CHEAPER!!!

Thanks, John Siskin

Ps. One size fits mostly all! WONDEFUL!!!

Pps. Collapses for easy storage and WILL KEEP THE CARPETS CLEAN!!

My classes:

An Introduction to Photographic Lighting

Portrait Lighting on Location and in the Studio

Business to Business: Commercial Photography

Booty Light on a Norman 200B, one size fits almost all!!

Booty Light on shoe, It's dual purpose!!

Another location shot with the BOOTY LIGHT the booty light is the only light on the outside of the door, the strobe with the umbrella is in the room past the door.

Comments (5)

October 12, 2009

Natural?? Light

Filed under: Basic Photo Technique,Lighting Technique,Photography Communication — John Siskin @ 5:41 pm

Taken with both continuousl light and strobes. Link to an article about the Tools of Light

I’ve seen a lot of photographers, and some of talented armatures talk about natural light. So maybe I should too. I hate the term natural light, simply because in our culture natural is always good and artificial is always bad. When was the last time you saw a product advertised as NEW! Now with More Artificial Ingredients!! So my first problem is that when someone speaks of natural light they are making a value judgment about light sources. Second, people aren’t always consistent about the term; really natural light ought to be used to describe sunlight, moonlight, starlight, and less useful things like molten lava and the back end of lightning bugs. If you use only natural light you are not going to take any pictures more than a few minutes after sundown or, if indoors, never very far from a window. Of course this limits the pictures that you take. Many people seems to include, in their use of the term natural light, any light source that happened to be there, including such poor quality light sources as fluorescent light and sodium vapor light. I would prefer terms like existing light and ambient light or even found light. We could call the light we make for a shot created light or controlled light, or even perfected light.

I think that the real problem that people have with making light is between continuous light sources, like quartz lights, and instantaneous light sources like strobes. There is no question that it is more difficult to place and modify lights that you can’t see. So often photographers are confused because the shot they see has no relationship, or little resemblance, to the shot they took with the camera strobe. Of course the reason is that the strobe was in a place no light came from, and had a quality of light that wasn’t present the moment before you took the image. It’s as if you switched off all the lights and put a spotlight on your head. So if you are going to get strobe to work for you, you need to learn take control of the way the light works. It isn’t the fault of the light, and it isn’t because the light is instantaneous the problem exists because the photographer expects the strobe to work by magic. Instead the photographer must understand how light can be controlled and used. Then we will make better images because we can control the light.

I should also mention that while you can do things with continuous lights, there are problems that only strobes can solve. Strobes are much brighter than other sources, many strobes are brighter than daylight, so you can control a mixed light environment. Also strobes have a true daylight color balance, so they are easier to use with daylight. Strobes are smaller and lighter than continuous lights with equivalent power would be, and they consume less power.

Link to an article about one light portraits.

Comments (1)

August 24, 2009

Lenses and Perspective

Filed under: Basic Photo Technique — John Siskin @ 8:15 pm

The important thing to remember is that changing the focal length of your lens does not change where you stand it only changes the way your picture is cropped. So if you take a picture of a person’s face with your widest angle lens you will be inches from the subject if you fill the frame with just the face (unless you don’t own a wide angle lens). If you frame the shot the same way with your longest lens you may be more than 10 feet from the same subject, depending on how long a lens you own. You should really do this exercise and compare the results. In the image with the wide-angle lens your subject will probably look extended and strange. The telephoto image will look flat. The difference isn’t the lens it is where you stand. If you took a third image with the wide-angle lens, but standing where you stood with the telephoto lens and blew up the image to match the telephoto image, besides fewer pixels, you would notice the same flatness you saw with the telephoto lens. If you want to make images have a greater three-dimensionality stand closer to your subject and use a wider lens. If you want your images to be compressed stand further back and use a telephoto. No amount of new lens technology will change this. People often stand to far away from a person to make an intimate portrait, they find being close to the subject embarrassing. This causes a flatter look in the portrait. I use an 80-100mm lens on my full frame camera for portraits. I make more pictures with wide-angle lenses, 18mm to 40mm on my full frame camera, than often than telephoto lenses.

I’ve included a picture of a friend, Lance, made with a 28mm lens and with a 200mm lens. I tried to keep the size of the head the same. You can see the huge changes in the way the face appears, the charges are a result of the difference in camera position. With the 28mm lens I am just inches from the subject and with the 200mm lens I am almost 10 feet from the subject. You should try this for yourself.

Lance with a 28mm lens

Lance with a 200mm lens

Comments Off

August 13, 2009

Editing

Filed under: Basic Photo Technique,Looking at Photographs,Photography Communication — John Siskin @ 5:07 pm

A hand built super wide camera

Editing photographs is not only difficult, sometimes it is heart wrenching. Often each image seems a special and unique expression of your creative vision, how can you bare to part with even one? Get over it; this feeling is personal. No one else will ever experience your photographs the way you do. You remember the day, what happened before and after, you remember the client and you remember whether you got paid. The viewer doesn’t experience any of this, and for the photograph to be effective for the viewer you have to give him/her an image they can perceive in their own terms. That is the purpose of editing. I am going to attach a photographs I made to this blogl. I designed and built the camera that made the image. Because of that intimacy no one else will ever perceive the shot in the way I do. I hope they will like it, but they will inevitably have a different feel for the image. You may think editing is time consuming, and it is, but it will make you a better photographer.

Made wirth the Super Wide camera

The first step in editing is shooting. You need to shoot a lot of images. The last head shot job I did was around 300 images, on a product job I might shoot only 20 images. Since we are now working in digital it is important to always shoot that extra image, or extra dozen images. It is always easier to shoot more than it is to go back. Although Eisenstaedt was famous for just taking a few shots, we will do better not to emulate him in this.

Made with the Super Wide camera

In order to edit effectively we need to be ruthless. The first step is to remove everything that is clearly a mistake. With a portrait type job this is generally pretty easy. A mistake is an image that has no real subject. A mistake is an image that is out of focus. A mistake is an image that is not focused on the subject. A mistake cuts into important parts of the subject, like the hands. If you shoot in raw a shot doesn’t have to be perfectly exposed, but if the shot is two stops from perfect exposure the shot is a mistake. If the strobes didn’t go off it is a mistake. Get rid of all this stuff, you should have plenty more images. I understand the Photoshop CS 15 will be able to fix everything, but that hasn’t happened yet. Photoshop 16 will be able to make your entire childhood perfect. Yes there are many mistakes you could fix, but you could spend days working in Photoshop. It is better to move through the process quickly. But you might as well save these images somewhere. This is why we have terabyte hard drives.

Made with the Super Wide Camera

Step two is to get rid of everything that makes the subject look like a doofus. So that shot where the subject is checking out your shoes? Gone. At the same time you should part with all the shot where you awkwardly cut off body parts, hands cut in half and so on. Yes a lot of these shots could be saved. If you shot enough you shouldn’t need to save them.

Made with the Super Wide Camera

If I am giving the client a proof disc, that is a disc with all the acceptable images, I will take the images at this point and convert them to jpg with the proprietary program. The proprietary program is often simple than Adobe Raw for this kind of large batch processing.

This should do it for negative editing; that is removing images because of problems. With any luck you have removed any where from 20 to 50 percent of your shots. Good. The other thing you have done is to look at all of the images that are left at least twice; well you went through the images twice didn’t you? That familiarity with your images is going to help a lot in the next go round. When you look through the images this time, look for images that are particularly fine, not just acceptable. They should have something special they may need cropping or other minor work, but the quality of your vision should be apparent. Also you want to look at the images as if you didn’t shoot them, as if you were seeing them not editing them. Look for an image that really connects. Certainly you can keep images you are unsure about, but you should end up with less than 10 percent of the images you started the third go around with.

I do this in Adobe Bridge, but there are certainly other good programs. As I go through each step I display the images larger, so that I get a better feel for the shots. The next step is to bring the images into Adobe Raw. Raw gives me a better look at each image, and I can begin the image processing. In raw I can do batch corrections on color, contrast, saturation and so on. I can also crop my images and do a variety of individual corrections. I will do my final choices on editing in raw. An image may get left behind at this point for a variety of reasons. Sometimes it is something I could fix, but don’t want to, or perhaps two images very similar.

Finally I will open up all of the images that made it through Raw in Photoshop. While I will rarely remove an image form the group in Photoshop I will perfect the images in Photoshop. This is where I will sharpen and do other detail work. Now finally, if the client asks for just there shots (not likely on a head shot) and I don’t have any personal reasons to make a choice, I can say enie minie moe….

Comments (1)

July 25, 2009

Aperture III

Filed under: Basic Photo Technique — John Siskin @ 1:29 pm

This shot was focused mid-way through the image to hold focus back to front. Shot made with a Toyo 4X5 camera.

Well I hope I haven’t lost too many readers by going on about aperture for three blogs, but it is really important to understand this in order to make good pictures. The idea is that the use of the right aperture allows the photographer to control what part of an image the viewer concentrates on.

The next part of understanding aperture I want to discuss is the hyper focal distance. This is the point at which you focus and stop down in order to create the most depth of field possible in a shot. Of course it is different with different focal length lenses, as we saw last week. Of course it is also different at different apertures. The thing to keep in mind, regardless of aperture and focal length is that in order to maximize depth of field you would not focus on infinity. Two thirds of the depth of field exists behind the focus point and one third in front. You would not be using the depth of field efficiently if you focused on the furthest point that the lens could focus on, something closer would make better use of depth of field. Also if everything in you shot is effectively at infinity then depth of field doesn’t matter.

There is a button on most cameras to help you figure that out, and sometimes it does help. The reason I say sometimes is that this button causes the lens to stop down, and that makes the picture darker, but you can see the depth of field. The darker image in the viewfinder can mean that the image is hard to see, which can make the preview pretty useless especially indoors. Modern cameras are set up to let you look through the lens at its widest opening, which makes focusing much easier. The lens stops down to the working aperture at the moment you activate the shutter, this system works very well. Under the right circumstances, usually bright, the depth of field button can give you an indication of how the depth of field will look.

I promised that memorizing the apertures would be helpful, the reason is that these numbers apply to any time that you are

Careful use of aperture and focus point keep the whole image in focus.

working with the area of a circle. For instance when working with light. If you have a light at 5.6 feet from a subject and you bring it closer, to say 4 feet that the light on the subject will be one stop brighter. You went from f5.6 to f4, a one-stop increase in light. Similarly if you had a light at 8 feet from a subject and dragged it back to 11 feet from the subject you would lose one stop of light. Wedding photographers used to use manual strobes like the Norman 200B, they would use this principal to rapidly figure changes in exposure. The same principal made it possible to figure bellows extension, but I won’t trouble you with that now.

The depth of field keeps the whole shot in focus.

Comments (1)

« Newer Posts — Older Posts »

Photo Notes A place to talk about making images.

November 6, 2010

September 5, 2010

August 10, 2010

January 8, 2010

November 8, 2009

October 26, 2009

October 12, 2009

August 24, 2009

August 13, 2009

July 25, 2009