Chris S. Offline Upload & Sell: Off
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p.3 #2 · Panasonic LX7 - With Summilux lens! | |
millsart wrote:
You don't think the ND filter is useful ? I wish more camera's had it. Perhaps you don't live in sunny weather or are okay with always having to stop down in bright sunlight ?
How would one rotate an internal polarizer for that matter ??
First the polarizer, since the response is shorter: Rotating an internal polarizer need not be difficult. In polarized microscopes, for example, it is often done with one or two very simple geared wheels. In a small camera, I could easily imagine it being done with a servo motor. Such motors are inexpensive, and are already used for zooming and focus, so camera engineers should be very comfortable with them.
Now, discussing the ND filter: First, let's remember that a polarizer also cuts light, and can be used as a very effective neutral density filter of about 2 stops, depending on the extinction and orientation of the filter. It's a multitasker. I rarely carry my ND filters in the field, but constantly carry polarizers, and on the rare occasion that I want to cut light, tend to do it with a polarizer. To be sure, a polarizing filter may give you unevenly-dark skies in wide angle, or cut glare on water--but are these traits very often problematic in situations where you want to limit depth of field by using a wide aperture? Likely not.
Second, using the "sunny day f/16 rule," we'd expect that in full sun at ISO 80, the shutter speed at f/2 would be about 1/5,000 sec. The LX5 has a maximum shutter speed of 1/4000. If I'd ever wanted to (and can't remember ever having felt this need), I could have shot the LX3/LX5 in full sun very close to wide open. With the LX7's f/1.4 max aperture, we would theoretically need a fastest shutter speed of just over 1/10,000 second to shoot wide open in full sun; Panny might have increased the shutter speed and obviated the need for the ND filter. Or again, just pop on a polarizing filter, and shoot happily wide open at about 1/2,500 second, well within the camera's capability.
Third--I'd ask why anyone would want to shoot wide open under full sun. Full, unmodified sun is ghastly lighting, the maker of flat, uninteresting landscapes and harshly-shadowed portraits. I usually put my cameras away in the middle of the day. Cloudy-bright days are, of course, pretty nice for portraits, but on those days, the sunlight is about two stops less intense than full sun, and well within the range of the camera without ND filters. Or on a sunny day, we might position our subjects in open shade for a more flattering effect--but again, we're loosing at least two stops against full sun, so ND filters are not needed in order to shoot wide open on a Lumix LX5 or, presumably, an LX7.
--Chris
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