Question on reducing blur

Eketelon

Ok, this may be elementary to many of you, but it's driving my brain crazy. I have always decrease blurring of the subject caused by camera shake or subject moving a little with the speed of my shutter. Ok, I believe most everyone does that, right!?

Ok, in Joe McNalley's book "The Hot Shoe Diaries", he mentions several times that the blur is eliminated by the flash use or lightsource. Here is a quote from the book:

"I am using f/11, which gives me a lot of depth of field, and which, of course, when shooting in aperture priority mode will drag my shutter for a while. A quarter of a second, to be exact. During that quarter second, I shake the camera. Her face, the hat, and most of the veil stay sharp because that area is totally dominated by flash. No competing light there. But where the flash falls off and ambient light takes over, there begins to be a bit of blur, or what looks more like vibration."

Ladies and gentlemen, this is not making sense to me. :scratch

Can someone explain this concept to me please or at least provide me with a link that has it spelled out.

Thanks in advance for your help!! Keep shooting.

Joves

Ok what it is, is a matter of the light intensity. The flash makes it so the area is flooded with light and, therefore the shlower shutter speed will then work. Remember that it is the amount of light hitting the subject that effects the what the settings need to be and, the final outcome. Personally I only use flash as a last resort. I will bump up my ISO first to achieve better f-stops and, faster shutter speeds. Unless I want some blur then it is the opposite.

raptorcaptor

Your subject is exposed by the duration of the flash, which can be incredible fast depending on your flash's power setting. The lower it is set the faster the duration. Your camera's settings will control the ambient light, and background unless you are using several strobes for that purpose.

angevin1

Hey,

It reads like it is a phrase from an article on "Dragging the Shutter!" If that's what it is, just google that term. Also look here.

cheers,

Eketelon

Thank you everyone, I will be doing some more research on this with your points you've made, in mind.

time2smile

first welcome to dgin,
Its like this, your shot will only show what is lite by the flash. The camera shake will be bearly visible if not totally invisible. I found it easier to explain it to myself backwords. Tripod mount your camera, set it on bulb at night in a dark place F11 or so, wide lens, manual focus just before infinity. Walk around with a flash in your hand and fire it off at different locations and different angles. You will notice that the photo shows the area lite by the flash clearly, and does not show you in the photo walking, unless you point the flash at yourself. I fired the flash off adozen times in three minuete, I also used different color rosco gel samples in front of the flash. Now if you would introduce another (ambiant light) source, it will start to show up in the shot, and you may see yourself bury in the shot.
So if you think about it, in the dark, it's the lighting that makes the shot clear at any specific time, the rest is there, you just can not see it. The more background light you add, the more it will illuminate the shot, and at a slow speed you will notice blur much easier.
This also makes for good lightning and fireworks shots, where instaed of a flash your using the lightning or fireworks as the light source.

NeilL

The Strobist has a lot of to say about this kind of thing!

Neil

Eketelon

time2smile wrote:

first welcome to dgin,
Its like this, your shot will only show what is lite by the flash. The camera shake will be bearly visible if not totally invisible. I found it easier to explain it to myself backwords. Tripod mount your camera, set it on bulb at night in a dark place F11 or so, wide lens, manual focus just before infinity. Walk around with a flash in your hand and fire it off at different locations and different angles. You will notice that the photo shows the area lite by the flash clearly, and does not show you in the photo walking, unless you point the flash at yourself. I fired the flash off adozen times in three minuete, I also used different color rosco gel samples in front of the flash. Now if you would introduce another (ambiant light) source, it will start to show up in the shot, and you may see yourself bury in the shot.
So if you think about it, in the dark, it's the lighting that makes the shot clear at any specific time, the rest is there, you just can not see it. The more background light you add, the more it will illuminate the shot, and at a slow speed you will notice blur much easier.
This also makes for good lightning and fireworks shots, where instaed of a flash your using the lightning or fireworks as the light source.

Thank you. Your explanation along with the others have really made this clear to me now. I appreciate it and thanks for the welcome as well.

rpcrowe

Everyone is correct...
Everyone who posted is correct. However, perhaps I may add something...

Electronic flash duration is extremely fast and can be as fast or faster than 1/10,000 of second.

If the subject is only lit by the flash, or the flash is powerful enough to overwhelm the ambient light; you will be effectively shooting at a comparative shutter speed of in the area of 1/10,000 second or faster which will freeze just about any action.

However if you are not shooting in the dark or if your flash is not overwhelming the ambient light; there will be enough ambient light to register an image. Depending on the difference between flash intensity and ambient light and your shutter speed; the movement of your subject may be shown as a slight ghost image or a considerable blur.

A similar, but opposite effect happens when you are shooting a very fast moving subject outdoors using fill flash. If you are shooting a fast moving subject at a slower shutter speed (older film cameras sometimes had a maximum shutter speed of 1/60 second and modern DSLR camera will usually sync at a maximum of 1/200 or 1/250 second) and if you have enough flash power to register an image, you will often get a an image blurred by motion with a ghost image that has been stopped by the flash.

The remedy to this outdoors is to use a camera/flash combination with High Speed Sync which allows you to use a higher shutter speed. However, since there is no free lunch in photography; the HSS cuts down the power of your flash.

I use fill flash for most of my outdoor shooting and, depending on the light level, will often be shooting at faster than 1/250 second. I use HSS so I don't have to keep my shutter speed at 1/250 second or below. In this case the power reduction doesn't bother me because I usually shoot fill flash at one or two stops less than the ambient light anyway.

Eketelon

rpcrowe wrote:

Everyone who posted is correct. However, perhaps I may add something...

Electronic flash duration is extremely fast and can be as fast or faster than 1/10,000 of second.

If the subject is only lit by the flash, or the flash is powerful enough to overwhelm the ambient light; you will be effectively shooting at a comparative shutter speed of in the area of 1/10,000 second or faster which will freeze just about any action.

However if you are not shooting in the dark or if your flash is not overwhelming the ambient light; there will be enough ambient light to register an image. Depending on the difference between flash intensity and ambient light and your shutter speed; the movement of your subject may be shown as a slight ghost image or a considerable blur.

A similar, but opposite effect happens when you are shooting a very fast moving subject outdoors using fill flash. If you are shooting a fast moving subject at a slower shutter speed (older film cameras sometimes had a maximum shutter speed of 1/60 second and modern DSLR camera will usually sync at a maximum of 1/200 or 1/250 second) and if you have enough flash power to register an image, you will often get a an image blurred by motion with a ghost image that has been stopped by the flash.

The remedy to this outdoors is to use a camera/flash combination with High Speed Sync which allows you to use a higher shutter speed. However, since there is no free lunch in photography; the HSS cuts down the power of your flash.

I use fill flash for most of my outdoor shooting and, depending on the light level, will often be shooting at faster than 1/250 second. I use HSS so I don't have to keep my shutter speed at 1/250 second or below. In this case the power reduction doesn't bother me because I usually shoot fill flash at one or two stops less than the ambient light anyway.

Thank you for the further insight. I will be practicing this and other techniques surrounding this topic, this week. I am grateful!