Pixalo Photography Community - View Single Post - How Do You Get The Focus/Un-Focused Effect?

CT · 14-03-2005, 14:14

Good explanation there by Pook. Grasping the reciprocity relationship between shutter speed and aperture and their halving and doubling relationship to each other is the basic key to a good understanding of photography. As you progress you'll find photography is a contant battle and compromise between what you want to do and what the prevailing light will allow you to do. One of the biggest problems is that as the size of the aperture decreases and the shutter speed lengthens, camera shake starts to enter the equation. In other words as we select that small aperture to get everyting in focus from the foreground to the horizon, camera shake becomes more of a potential problem as the shutter speed lengthens. Us human beans are pretty crap camera supports when it comes to long exposures. :wink:

Hand holding the camera.

Grab hold of the thing. don't be afraid to cup your left hand under and around the lens. Pull the camera firmly into you face so that is firmly pressed against your cheekbone and brow. If you wear a neck strap, try winding the slack around your right hand so that it actually tightens the camera into your face Your elbows should stabilise the whole thing by being pulled down onto your chest. Your feet should be spaced for balance, and when you take the shot breath out gently like a marksman as you press the shutter. Practice the technique till it's second nature.

The minimum safe shutter speed for handholding with a 50mm lens is 1/60 sec. That's to eliminate just your movement, and takes no account of any movement in the subject. If you can go faster then you should, but 1/60 is the minimum. That's not to say you should miss a great shot for the sake of trying 1/30 or even 1/15 but it takes practice to achieve those speeds hand held and it's always a bit of a gamble.

The good news is there's a simple way to always know what the safe hand holdable speed is with any lens. ...

The safe speed is equal to the focal length of the lens in use - or the nearest marked equivalent. The longer the focal length of the lens, the more each tiny bit of camera movement will show up in your shots.

28mm 1/30

50mm 1/60 Nearest marked equivalent

80mm 1/125 Nearest marked equivalent

200mm 1/250

500mm 1/500

1000mm 1/1000

Remember these are minimum safe speeds- if you can go faster you should.

Bear in mind that as you vary the focal length on a zoom lens, the minimum safe shutter speed changes. - easily forgotten.

You can see why a good solid tripod (and remote release) is an essential piece of kit if you want to work in all conditions.

Wonder of wonders! we now have image stabilisition lenses (IS) which is something to consider when you're shoppig for glass. These actually give you 2 or 3 stops slower hand-holdable shutter speeds than none IS lenses. Very useful for available light work!

14-03-2005, 14:14	#13 (permalink)
CT Feet under the table Join Date: Mar 2005 Location: West Mids UK Posts: 3,500	Good explanation there by Pook. Grasping the reciprocity relationship between shutter speed and aperture and their halving and doubling relationship to each other is the basic key to a good understanding of photography. As you progress you'll find photography is a contant battle and compromise between what you want to do and what the prevailing light will allow you to do. One of the biggest problems is that as the size of the aperture decreases and the shutter speed lengthens, camera shake starts to enter the equation. In other words as we select that small aperture to get everyting in focus from the foreground to the horizon, camera shake becomes more of a potential problem as the shutter speed lengthens. Us human beans are pretty crap camera supports when it comes to long exposures. :wink: Hand holding the camera. Grab hold of the thing. don't be afraid to cup your left hand under and around the lens. Pull the camera firmly into you face so that is firmly pressed against your cheekbone and brow. If you wear a neck strap, try winding the slack around your right hand so that it actually tightens the camera into your face Your elbows should stabilise the whole thing by being pulled down onto your chest. Your feet should be spaced for balance, and when you take the shot breath out gently like a marksman as you press the shutter. Practice the technique till it's second nature. The minimum safe shutter speed for handholding with a 50mm lens is 1/60 sec. That's to eliminate just your movement, and takes no account of any movement in the subject. If you can go faster then you should, but 1/60 is the minimum. That's not to say you should miss a great shot for the sake of trying 1/30 or even 1/15 but it takes practice to achieve those speeds hand held and it's always a bit of a gamble. The good news is there's a simple way to always know what the safe hand holdable speed is with any lens. ... The safe speed is equal to the focal length of the lens in use - or the nearest marked equivalent. The longer the focal length of the lens, the more each tiny bit of camera movement will show up in your shots. 28mm 1/30 50mm 1/60 Nearest marked equivalent 80mm 1/125 Nearest marked equivalent 200mm 1/250 500mm 1/500 1000mm 1/1000 Remember these are minimum safe speeds- if you can go faster you should. Bear in mind that as you vary the focal length on a zoom lens, the minimum safe shutter speed changes. - easily forgotten. You can see why a good solid tripod (and remote release) is an essential piece of kit if you want to work in all conditions. Wonder of wonders! we now have image stabilisition lenses (IS) which is something to consider when you're shoppig for glass. These actually give you 2 or 3 stops slower hand-holdable shutter speeds than none IS lenses. Very useful for available light work!