DOF on Wide Angle lenses
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Canon Bob
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DOF is a function of aperture and magnification so a wide angle has no more DOF than any other lens IF the shot is identically framed.....ie, 50mm lens at 10 metres or a 10mm lens at 2 metres.....they would give an identical image in these conditions.
If, on the other hand, the same shooting position is used then the wide angle's DOF will be greater as the magnification of the wide angle lens will be far less.
If the image from a wide angle was later cropped to be the same as the 50mm lens then the DOF would reduce to the same value as the portion of the image would be magnified during the process.
The hyperfocal distance is the point where everything from infinity down to half the focal distance is within acceptable focus.
Bob
If, on the other hand, the same shooting position is used then the wide angle's DOF will be greater as the magnification of the wide angle lens will be far less.
If the image from a wide angle was later cropped to be the same as the 50mm lens then the DOF would reduce to the same value as the portion of the image would be magnified during the process.
The hyperfocal distance is the point where everything from infinity down to half the focal distance is within acceptable focus.
Bob
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Depth of field is much greater with wide-angle lenses. With my 28mm wide angle I used to get sharp focus from 6ft to infinity at f5.6. I'll try to explain how; I'm not sure if this is the same as using hyperfocal distance.
It's not as easy to use this method with zoom lenses; in fact I suspect its impossible because there's no depth of field scale on zoom lenses.
Set your aperture - say f5.6. Adjust focus until infinity lies just within the f5.6 mark on the lens depth of field scale. If you look at the other end of the DoF scale you wil see where sharp focus extend forwards as far as. In the example above 6 ft. The image in the viewfinder will probably mostly look blurred, but the image on fim/sensor will be sharp.
At f8 sharp focus will extend even nearer to the camera. Set the infinity mark just within f8 on the DoF scale.
It's actually much easier to do than to explain. Try it out!
It's not as easy to use this method with zoom lenses; in fact I suspect its impossible because there's no depth of field scale on zoom lenses.
Set your aperture - say f5.6. Adjust focus until infinity lies just within the f5.6 mark on the lens depth of field scale. If you look at the other end of the DoF scale you wil see where sharp focus extend forwards as far as. In the example above 6 ft. The image in the viewfinder will probably mostly look blurred, but the image on fim/sensor will be sharp.
At f8 sharp focus will extend even nearer to the camera. Set the infinity mark just within f8 on the DoF scale.
It's actually much easier to do than to explain. Try it out!