On Sat, 4 May 2002 23:25:47 +0800, Robert Delfs <[log in to unmask]>
wrote:

>Seeing a lot of different answers to your question (at least some of
>which I think might be off the mark a bit), I searched my hard disk for
>some stuff I'd put together when I still had my MX-10.  For what it's
>worth:

Thanks Robert -- that's exactly the tips I was looking for, except
possibly the interaction with the new YS-40A.  But thanks to Carol's
coaching on how to do a controlled experiment, I think I can handle
that part now.  :-)

>
>With the macro extension, YS-40 strobe, and (assuming ISO 100 film):
>        Dark subject            : f/16  (DoF will be about 30 mm)
>        Normal/light subject : f/22  (DoF will be about 40 mm)
>
>Focus, of course, is fixed.  The framer works pretty well, but you
>might want to zero it in with some test shots at both f/16 and f/22 to
>see how far inside/outside the DoF extends, and if possible to pin down
>where exact focus is relative to framer bars.  (I never used the
>vertical bars that screw in to the extension, just try to imagine the
>plane I was trying to shoot and try to get the camera body as parallel
>to that as possible.)

That's what I noted several PhD shooters do, use only the stick for
distance, and shoot without the vertical plane reference (or rather
judge by eye with camera on the ocean floor, e.g., when shooting a
free floating seahorse) and move with the moving target object.


To my mind, the attachable macro lens is really
>more of a close-up lens than a real macro lens.

As little as I know about UW photog, I've come to that conclusion from
reading just the portion of the mnaual about focal distance alone!


>OK for very large
>nudibranchs, but don't expect see see much if you're shooting anything
>small.

Or very close, except with a WIDE ANGLE lense, as you and the DM who
took some excellent pics of seahorses (at very close range) pointed out.


>The base lens has a fixed focus at 1.2 m (3.9 feet).  Your correct
>instinct to get much closer than that won't work unless you've got the
>lens really shut down.  These are the theoretical settings:
>
>f/4.5   0.91 - 1.66 m   3.00 -   5.45 ft
>        f/5.6   0.87 - 1.80 m   2.85 -   5.90 ft
>        f/8     0.78 - 2.40 m   2.56 -   7.87 ft
>        f/11    0.70 - 4.00 m   2.30 - 13.00 ft
>        f/16    0.60 - infinity 1.97 -  infinity
>        f/22    0.50 - infinity 1.64 -  infinity

That's more extensive than out manual gave.  But I noted the closest
1.64 ft is already about twice as far as the length of the stick for
focal distance on the macro lense!
>
>The camera worked better for me with the 20 mm attachable wide-angle
>lens than with the straight 35 mm.

I am now convinced that THIS is the trick for the MX-10 close-ups.


>If you haven't got the 20 mm, get it.

Got it, but left it at home because we had bungled its proper use so
badly that we seldom use it anymore.  NOW we can revive that sucker on
our next trip, thanks to your tips.

>Here's the settings I used (below), with the proviso that getting
>the strobe to actually illuminate something 5.5 feet away is probably a
>fantasy - never worked for me.  If you stick within 1.5 to 3-4 feet and
>f/5.6 through f/16 you should get some shots.  I don't think the strobe
>output is that consistent, either.

We've had pretty good luck with shots up to 5-6 ft on f/5.6 (more or
less our universal setting without lense attachments), possibly because
of good vis and ambient light on most of our dive sites.

>
>Here are the settings to use with the 20 mm w/a extender:
>
>Range and Depth of Field (ft):
>f/4.5   2.8 -     6.5
>f/5.6   2.7 -     7.6
>f/8      2.3 -   12.6
>f/11    2.0 - 132.6
>f/16    1.7 -   infinity
>f/22    1.4 -   infinity
>
>The range-finder that comes with the 20 mm extender is a bit funny.
>Try aiming below the subject (quite a bit) or you'll find you're
>getting a lot of shots of the top half of a fish.

We resemble that remark.  Even without the wide-angle lense, we have
many half-fish, half-shark, half-turtle, and half-Napolean-wrasse ...
but those are always good for cut-outs for our logbook pages.  :-)
>
>Regards,
>
>Frogfish  (Robert Delfs)

Thanks Frogfish!  I have a nice picture of you (dressed in red) on my
first Cocos trip.  Back then (1992), the MX-10 was good to only 99 ft,
rather than the 45 meters now.  But it survived the 170 fsw I went
looking for the BIGGEST hammerheads (they like the colder water there)
and only a non-essential part of the camera was cracked from pressure. :)
It had cracked another time or two, but serviced us well.  We are really
thankful that it was stolen in January (10 years old) so that we got a
new and updated one from our insurance.  :-))

-- Bob.