I'm with Ralf on this one. Trying to get a sharp image of a mountain 50
miles away at 600mm equivalent would be difficult even with careful
technique on a tripod let alone a moving train. And I'm not
particularly bothered by the focus stopping ahead of infinity. The
hyperfocal distance for an E1 at f/5.6 and 300mm is about 0.6 miles. If
you were focused at least that far out you got infinity. You might have
gotten better results at f/8 or even f/11 if the lens performs better
there but by f/11 on an E1 diffraction is beginning to take a toll.
Also shooting at f/8 of f/11 would have required a slower shutter speed
or higher ISO and I think slower shutter would have been detrimental.
So, although I'm not surprised by the results I do see one thing that
bothers me. At about 40% of the image height from the bottom are two
snow patches at extreme right and left of the image. There seems to be
a distinct difference in sharpness between the two with the left side
showing more clearly defined edges. Whether this is lens or something
else I can't tell. Like Ralf did, I suggest some controlled tests on a
tripod.
Chuck Norcutt
Lawrence Woods wrote:
> I just got back from a trip to Alaska, and have been plowing
> forward through the accumulated OM digests - am now up to June
> 16th - but wanted to post a few pictures and ask a couple
> questions.
>
> These pictures were taken from a moving train when we were
> about 50 miles from Mt. McKinley. I've fiddled with them using
> Lightroom, which I don't really know how to use yet, going for
> a postcard effect.
>
> The pictures are from my E-1, ISO at 200.
>
> 14-54 lens @ 42mm, f/7.1, 1/800
> http://users.rcn.com/rmwoods/OM/P6150189_1K.jpg
>
> 70-300 lens @ 70mm, f/4, 1/2500 ISO 200
> http://users.rcn.com/rmwoods/OM/P6150205_1K.jpg
>
> 70-300 lens @ 300mm, f/5.6, 1/2500 ISO 200
> http://users.rcn.com/rmwoods/OM/P6150178_1K.jpg
>
> And another mountain
> 14-54 lens @52mm, f/4 1/2000 -1EV
> http://users.rcn.com/rmwoods/OM/P6150209_1K.jpg
>
> The 300mm picture is something of a disappointment in terms of
> sharpness and contrast. Is this just in the nature of a 600MM
> FOV and the accumulated atmosphere between the subject and me?
> Or would stopping down have helped?
>
> When both lenses autofocused, they stopped well short of the
> infinity stop. This was true at all focal lengths. I tried
> manual focusing, and the sharpest I could focus seemed to be
> at the same point the autofocus picked. Is this normal, or do
> my lenses need to be recalibrated? A 50 mile subject distance
> ought to be infinity in my book, even for a 300mm lens.
>
>
> ----- Larry Woods
> lmwoods@xxxxxxx
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