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johnriley

Joined: 19th March 2002

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johnriley
I used to have one and it's a pretty good lens that improves with stopping down.

It's absolutely useable but probably not as good as current zooms and certainly not as good as prime lenses.

Comment by johnriley posted on Pentax M 24-50mm f1:4 zoom at 16/07/2007 - 12:48

johnriley
Very nice colour and sharpness just where it counts.

Comment by johnriley posted on Poppy about to burst ! at 14/07/2007 - 19:21

johnriley
There is nothing to beat natural light in all its glorious and infinite possibilities.

Comment by johnriley posted on Refelective Lighting at 13/07/2007 - 20:35

johnriley
I don't want to add anything to this that confuses the issue, so can I just mention that there is one very important accessory that will be invaluable - an assistant.

It's much much harder to do a wedding on your own, so I hope someone will go with you to help organise both the photographer and the subjects. You can't think of everything at once...

Good luck.

Comment by johnriley posted on Pre wedding test results at 13/07/2007 - 18:03

johnriley
Quote:
Switching to vertical, meant short travel distance, therfore shorter travel time....(1/180 or even 1/200 sec).
And higher maximum shutter speeds.

Comment by johnriley posted on straining the "motor" on the k10d at 13/07/2007 - 17:15

johnriley
A reply I got elsewhere indicated that the shutter speed was determined by how long the CCD was activated for. After activation the shutter closed whilst the data was transferred to the camera's processor, after which the shutter opened again to resume the live view.

This certainly fits in with the slower response of compacts and the interruption to viewing that occurs when a shot is taken. It's similar to the sequence of shutter events when leaf shutters were fitted to SLRs, such as the Voigtlander bessamatic of 1959.

Comment by johnriley posted on straining the "motor" on the k10d at 13/07/2007 - 15:34

johnriley
I can see there is still some confusion over focal plane shutters. They consist of two blinds, either rubberised silk running horizontally (Spotmatic, K1000, MX, etc) or metal slit running vertically (all electronic cameras usually).

At slow speeds the first blind opens, then after an interval the second blind closes and at some point the whole frame is open to light - hence electronic flash can be used at these speeds. This is all speeds up to and includung the "flash synch" speed.

At faster speeds the second blind is closing before the first one has completed its traverse across the frame, hence it is in effect a moving slit and the frame is exposed a bit at a time. The narrower the slit the faster the shutter speed. As the frame is never totally open, flash gives incomplete coverage and black blank areas would be evident.

Hope that clarifies it rather than clouding it....

Comment by johnriley posted on straining the "motor" on the k10d at 12/07/2007 - 23:37

johnriley
No, the DSLR uses a shutter.

But the "hybrid shutter" you mention is what I suspected, but I don't know for sure what the details are.

Comment by johnriley posted on straining the "motor" on the k10d at 12/07/2007 - 18:04

johnriley
I'm not sure that's right though. The K10D has an interline/interlace scan CCD and this refers to how the information is removed from the sensor a line at a time. Very very quickly of course!

The exposure time is certainly via the shutter and the CCD receives its light all in one go - the information then exits to the processor in orderly lines.

As regards a compact camera, it can't have a shutter in the same sense, and I really must find time to research that properly.

Comment by johnriley posted on straining the "motor" on the k10d at 12/07/2007 - 17:33

johnriley
DSLRs certainly have a shutter, bridge and Compact digital cameras don't need one, do they? The view is constantly live and I would have thought the "exposure" was more akin to a freeze frame. Then again, they are supposed to have an electr-mechanical shutter so maybe at some speeds it's a freeze and at others an actual shutter mechanism.

Does anyone lnow definitively the answer?

Comment by johnriley posted on straining the "motor" on the k10d at 12/07/2007 - 16:04

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