Excuse my tardy response. I tried to submit this some time ago but didn't
know then the list was on a different server. I didn't get back on the list
until earlier this week and for all I know this business has been resolved.
Anyway, re the vibration study:
Two ideas that occur to me: mirror lock-up ought to be incorporated in
there somehow for what seems to me obvious reasons (correct my thinking if
I'm off base) and I would also like to see the use of the recommended (by
Olympus experts in their manuals over the years) of "hand-cradling" of the
camera body. (I've fallen into the "don't do anything so silly!" school of
thought with the latter technique in mind and I'd love to finally see
objective test results.)
Shouldn't these test exposures _always_ be made at precisely the same light
levels?
How about different tripods?
It's assumed here the test will be conducted in a closed, windless
environment versus outside. But how do the various camera platforms perform
_in the field_ compared to one another? Isn't that important?
I haven't used this Ilford film emulsion you mention. Come to think of it I
can't recall you talking about it. What's the story? Just off the top of my
head, and while I understand your C41 concern and the convenience it
offers, but I'd have probably gone with a slower (and higher-resolution)
emulsion like Tech Pan for a test of this nature. (Even a color print film
like Portra 160 might well do for the needs, plus it, too, offers the
convenient processing of C41. For 400 B&W film for sure I'd have used (what
used to be) the industry's reference B&W emulsion, Tri-X. And does anyone
other than me notice how old and basically in the way we're (I'm) getting
to be? <g>)
By the way, my seeming bias against Ilford product dates back to my first
trial of it when I shot for newspapers (half-tones on newsprint are hardly
definitive tests but really, the difference between HP5 and Tri-X was
noticeable even there). Admittedly, I haven't tried the company's line a
whole lot since and for all I know this new 400 B&W product is a very good
performer. For this test, however, the only useful quality it could bring
to the test would be C41 compatibility and I wholly question the wisdom of
that.
Tris
At 02:18 PM 1/6/2004 -0800, you wrote:
> >>" Maybe Dan can create the Tripod-Vibration study."
> >
> >By far the best head would be the Wimberly
>
>Ok, That's nice. But I'm less interested in antidotal evidence
>than actual science.
>
>What Gary had created with his lens tests was a scientific study
>of comparing lens resolutions in a viable manner. The study
>wasn't flawless and was applicable to a fixed reproduction size,
>but it created a "reference point" to work from. His tests
>were, perhaps, the most important contribution to the OM
>community that has come from members of this list.
>
>I'd like us to scientifically approach this and develop a study
>in which we all can contribute to. If we all follow exactly the
>same procedure and use exactly the same resolution chart and
>film, then this is a possibility. I would absolutely
>participate!
>
>My recommendation is Ilford XP-2, which is easily processed by
>any one-hour C41 lab and *could* be anylized by the individual
>doing the test. Otherwise, if mailed to me, I'll examine the
>processed roll (no prints necessary) and compile the results
>into an HTML page that can be posted on whoever's website. XP-2
>is a wide-latitude film that is exceptionally sharp and capable
>of exceeding the requirements of the test. I would also process
>any roll of Pan-F+ sent to me for this test too. (a voluntary
>contribution to cover chemistry costs would be acceptable).
>
>We need to define the scope of the study.
>We need to define the desired results of the study.
>We need to define the procedures of the study.
>
>(It's been awhile since I've commissioned scientific
>studies--what else do we need in the planning stage?)
>
>I have a resolution chart that can be emailed and printed out on
>glossy paper in high-res mode by anybody wishing to participate
>in the study.
>
>Before getting everybody going on this, I will prototype this
>study on my own equipment to make sure that a common setup is
>viable and what it would look like. Off hand, here is what a
>test roll *could* look like:
>
>Frame 01, Tripod Full Height, Lens 01, Orientation-H, Flash
>Frame 02, Tripod Full Height, Lens 01, Orientation-H, 1 Sec
>Frame 03, Tripod Full Height, Lens 01, Orientation-H, 1/2 Sec
>Frame 04, Tripod Full Height, Lens 01, Orientation-H, 1/4 Sec
>Frame 05, Tripod Full Height, Lens 01, Orientation-H, 1/8 Sec
>Frame 06, Tripod Full Height, Lens 01, Orientation-H, 1/15 Sec
>Frame 07, Tripod Full Height, Lens 01, Orientation-H, 1/30 Sec
>Frame 08, Tripod Full Height, Lens 01, Orientation-H, 1/60 Sec
>Frame 09, Tripod Full Height, Lens 01, Orientation-H, 1/125 Sec
>Frame 10, Tripod Full Height, Lens 01, Orientation-V, 1 Sec
>Frame 11, Tripod Full Height, Lens 01, Orientation-V, 1/2 Sec
>Frame 12, Tripod Full Height, Lens 01, Orientation-V, 1/4 Sec
>Frame 13, Tripod Full Height, Lens 01, Orientation-V, 1/8 Sec
>Frame 14, Tripod Full Height, Lens 01, Orientation-V, 1/15 Sec
>Frame 15, Tripod Full Height, Lens 01, Orientation-V, 1/30 Sec
>Frame 16, Tripod Full Height, Lens 01, Orientation-V, 1/60 Sec
>Frame 17, Tripod Full Height, Lens 01, Orientation-V, 1/125 Sec
>Frame 18, Tripod Half Height, Lens 01, Orientation-H, Flash
>Frame 19, Tripod Half Height, Lens 01, Orientation-H, 1 Sec
>Frame 20, Tripod Half Height, Lens 01, Orientation-H, 1/2 Sec
>Frame 21, Tripod Half Height, Lens 01, Orientation-H, 1/4 Sec
>Frame 22, Tripod Half Height, Lens 01, Orientation-H, 1/8 Sec
>Frame 23, Tripod Half Height, Lens 01, Orientation-H, 1/15 Sec
>Frame 24, Tripod Half Height, Lens 01, Orientation-H, 1/30 Sec
>Frame 25, Tripod Half Height, Lens 01, Orientation-H, 1/60 Sec
>Frame 26, Tripod Half Height, Lens 01, Orientation-H, 1/125 Sec
>Frame 27, Tripod Half Height, Lens 01, Orientation-V, 1 Sec
>Frame 28, Tripod Half Height, Lens 01, Orientation-V, 1/2 Sec
>Frame 29, Tripod Half Height, Lens 01, Orientation-V, 1/4 Sec
>Frame 30, Tripod Half Height, Lens 01, Orientation-V, 1/8 Sec
>Frame 31, Tripod Half Height, Lens 01, Orientation-V, 1/15 Sec
>Frame 32, Tripod Half Height, Lens 01, Orientation-V, 1/30 Sec
>Frame 33, Tripod Half Height, Lens 01, Orientation-V, 1/60 Sec
>Frame 34, Tripod Half Height, Lens 01, Orientation-V, 1/125 Sec
>
>Notice the "reference" frames using a flash. This would be
>necessary to accomodate the variations in lens sharpnesses.
>When using lenses of lesser resolution, some eyeball estimating
>will be necessary. Not sure quite how to deal with the exposure
>variances. I was thinking that direct sunlight or open shade
>would be a good choice, however, that would require varying the
>aperture which could alter the accuracy of the test (see Gary's
>lens test website). Maybe the resolution chart could be
>modified with multiple target areas using tinted backgrounds to
>lower the apparant exposure values. I'll fiddle with this and
>if anybody has any thoughts, I'm listening.
>
>My desire is to show that the sympathetic vibrations vary
>according to tripod selection, height, camera body, lens and
>camera orientation. The sympathetic vibrations occur at
>specific frequencies that would affect certain shutter speeds
>which vary with these changing variables. I'm assuming that we
>need to test at all common shutter speeds from 1 second to 1/125
>as a specific setup my be problematic at 1/30, but not at 1/60
>or 1/15. A simplified test could be done at maybe three test
>speeds, but may miss valuable results.
>
>If, during the prototype test, it is determined that no
>appreciable difference occurs between Vertical and Horizontal
>orientations, or between several shutter speeds, we may lessen
>the number of "test points". Fewer test points mean more
>participation and a wider range of tested equipment. More test
>points mean greater detail, but possible skewed results due to
>variations in manufacturing and wear.
>
>Off-hand, I'm thinking that 1/4, 1/15, 1/60 and reference flash
>might be sufficient or 1/2, 1/8, 1/30 and flash. Horizontal
>only.
>
>Thoughts?
>
>AG-Schnozz
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