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07-30-2008, 05:44 AM   #1
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dslr focal length multiplier and lens hoods

Does the angle of view change on a lens due the focal length multiplier (1.6x)?

If I put my 50mm on an slr, is it the same angle of view on my k200d?

The reason I ask is that I'm looking for a lens hood for my 50mm. Should I be looking for a hood that will accommodate a 50mm or an 80mm?

Does size even matter? Would the slightly longer lens hood even make a difference?

This is assuming that the larger resulting focal length will give a narrower angle of view.

Thanks -Dave-

07-30-2008, 06:04 AM   #2
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The 50mm lens on a crop sensor DSLR will have the same angle of view as a 80mm lens on a 35mm film slr yes.

This should mean that you can use a narrower hood on the 50mm, but in practice i dont think it will make a lot of difference. Just get a "normal" hood or the one designed for the 50mm lens.
07-30-2008, 06:18 AM   #3
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QuoteOriginally posted by dmoon911 Quote
Does the angle of view change on a lens due the focal length multiplier (1.6x)?

If I put my 50mm on an slr, is it the same angle of view on my k200d?

The reason I ask is that I'm looking for a lens hood for my 50mm. Should I be looking for a hood that will accommodate a 50mm or an 80mm?

Does size even matter? Would the slightly longer lens hood even make a difference?

This is assuming that the larger resulting focal length will give a narrower angle of view.

Thanks -Dave-
Technically, you will want a lens hood designed for a longer lens if the hoods are designed for film use. You will find that most of the time it won't make a heck of a lot of difference, and that some of the time it will make all the difference in the world if you use a shorter than optimal hood.
This is the one and only time when I see a reason for the silly focal length multiplier that people insist on using.
Your 50mm lens does not magically turn into a 75mm lens when you mount it to a DSLR, but the hood that goes onto the lens should be designed for a 75mm lens (presuming the hood is designated for film use).
07-30-2008, 06:34 AM   #4
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you might wish to try this link
Custom lens hoods

What you need to remember is that the lens diameter IS NOT the filter diameter, but the actual lens diameter of the front objective.

You have to pay to get teh PDF Output, but the Idea is to make your own out of relatively stiff material, and wrap in around a filter ring.

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