AF280T Flash query
Posted 29/07/2004 - 08:39
Link
G'day.
You should try the Sigma 600mm f8 mirror lens.
I swear that the bloody focus ring goes round 3 times.
Hooroo
Regards, Trevor
Grafton
Australia
You should try the Sigma 600mm f8 mirror lens.
I swear that the bloody focus ring goes round 3 times.
Hooroo
Regards, Trevor
Grafton
Australia
Posted 29/07/2004 - 13:50
Link
Hi,
I am not sure about the flash question. I haven't noticed any real difference in recharge time with eith the 400t or the 280t on my LX.
As to the lens question, there are 2 reasons. The longer the focal length of the lens the more the glass has to move to cover the same distances. So if you look at the 28, the front will only move a small amount compared with the 50 from either extreme. The second is the wider the lens, the greater the depth of field at a set distance. Therefore, the longer the lens the more critical the focussing has to be and so the gearing is reduced slightly to make it more accurate. Hence the 600mm mirror going round nearly 3 times.
Hope this helps
Kim
I am not sure about the flash question. I haven't noticed any real difference in recharge time with eith the 400t or the 280t on my LX.
As to the lens question, there are 2 reasons. The longer the focal length of the lens the more the glass has to move to cover the same distances. So if you look at the 28, the front will only move a small amount compared with the 50 from either extreme. The second is the wider the lens, the greater the depth of field at a set distance. Therefore, the longer the lens the more critical the focussing has to be and so the gearing is reduced slightly to make it more accurate. Hence the 600mm mirror going round nearly 3 times.
Hope this helps
Kim
Posted 30/07/2004 - 03:30
Link
Trevor
I've got a 500mm mirror that needs both hands!
Kim,
thanks for clearing up the lens thing. As for the flash query, maybe it's just mine that has the problem. And they wonder why I feel paranoid.
I've got a 500mm mirror that needs both hands!
Kim,
thanks for clearing up the lens thing. As for the flash query, maybe it's just mine that has the problem. And they wonder why I feel paranoid.
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2277 posts
24 years
And now for something completely different:
Why does the travel of a focussing ring differ so much between lenses? My 28mm goes from infinity to nearest focus in about a 45 degree turn but my 50mm, on the other hand, requires almost 360 degrees of movement. What's that all about?