these may be darft questions....

M

minimadgriff

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Ben
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Yes
but I would still like them answering :)


Darft Question Number 1 :-

The lens hood on lenses what exactly do you need them for?

Darft Question Number 2 :-

What does this mean

The 70-300mm G is a full format lens but naturally it works perfectly on Sony Alpha APS-C DSLRs with a field-of-view equivalent to 105-450mm.
Click to expand...

Thanks

Ben
 
The 70-300mm G is a full format lens but naturally it works perfectly on Sony Alpha APS-C DSLRs with a field-of-view equivalent to 105-450mm.

Ignore that bit. Its written for gullible idiots, who think that a crop camera gives them "reach". Lucky you didn't fall for it :)

The lens will work fine on all Sony bodies, and is a 70-300 lens on all bodies.

You need the hood to keep out stray light, and its also the excellent protection against knocks and bumps.
 
minimadgriff said:
but I will still like them awswering :)

Darft Questions Number 1 :-

The lens hood on lenses what exactly do you need them for?

Thanks

Ben
Click to expand...

A lens hood protects from extraneous light which can cause lens flare - the effect where you see halos or light spots on the picture where you don't want them

puddleduck said:
The 70-300mm G is a full format lens but naturally it works perfectly on Sony Alpha APS-C DSLRs with a field-of-view equivalent to 105-450mm.

Ignore that bit. Its written for gullible idiots, who think that a crop camera gives them "reach". Lucky you didn't fall for it :)

The lens will work fine on all Sony bodies, and is a 70-300 lens on all bodies.

You need the hood to keep out stray light, and its also the excellent protection against knocks and bumps.
Click to expand...

Actually for once a retailer got it right stating Field-of-view rather than effective-focal-length!

Ben - this is referring to what you actually see when you put the lens on the camera. Because digital sensors are smaller than 35mm film they cut off some of the picture you may have expected if you had used film for a long time.

Some people seem to think that this gives you extra "zoom" by making small things appear bigger, it doesn't, it just means it fills up proportionally more of a smaller area
 
A good analogy for a lens hood is when you shade your eyes against bright light, or flip down the sun visor when driving. It can make a big difference in reducing flare some situations, but most lens hoods are not long enough and are mainly for protection.

Focal length doesn't change when you fit a lens to a camera with a smaller format sensor, but since the sensor is smaller, it only records the image area from the middle portion of the lens. How much of the image is 'cropped out' in this way is determined by the crop factor, which is 1.5x in the case of Sony, relative to a full frame sensor, such as the A900. (Nikon is the same, Canon is 1.6x, and both these formats are known as APS-C which is an old film format of roughly similar size.)

Which means that a 70-300mm lens has an actual field of view that is equivalent to a 105-450mm lens on full frame. When you look through the viewfinder, that's what you see and that's what the sensor records. It is not an illusion, but other things also change along the way.
 
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