P3D RBT X4, lenses, sharpness

[Jon Golden <3dman@xxxxxxxxxxx>]

Mark Dottle wrote,

>> The problems? I'm getting less than 50%
>>successful shots right now......the camera is not perfect and I'm trying
>>to determine what is causing many shots to look "soft". I'll post my
>>test results tomorrow.

Hi Mark....and Hi Dr T.....I much enjoyed your comments on the X4 and
thought I would add a few tips for shooting with zoom pairs.

First of all....I will tell you all a neat story.  Tomorrow AM, Jan and I
are invited tom go on a hike up Mt Khatadin in Baxter State Park (Maine),
with an older gentleman named Paul Knaut.  I wont go in to the long chain
of events that lead us to meet Paul (actually for Paul to meet us), but
Paul is a classic Maine scenic photgrapher , who shot stereo images  of
Maine and the Northeast US for View Master back in the late 50's and early
60's.  He is also a retired radio weatherman who Maine locals relied of for
over 40 years of extremely reliable forecasting......so tomorrow we are
taking this trip because he called the shots based on the best weather.  I
have spoken to him three times in the last few days...and his weather
predictions have been DEAD ON!

We will all be with stereo attire.  Paul will use his Wollensak and also
try my Belplasca...and here are the RBT setups we will all use.

RBT X3B 75mm with Cosina 35-70mm zooms, yellow filters, AGFA SCALA 200 B &
W slide film

RBT X4B 75mm with Pentax SMC FA 28-70mm zooms, UV filters, FUJI Velvia 50
color slide film

Many who know RBT cameras will note the above swapping of the lens setups
and camera bodies, re: normally the X4 has the Cosinas...etc...etc.  I did
this to balance out the weights of the two RBTS (this is where the S1 is
the best).....for hiking purposes.

We will have two tripods with us....and this is  a lesson I learned from
Simon Bell many years ago, when I travelled the WA peninsula with him.
Although more cumbersome that a hand held shot (due to futzing around with
the tripod), Simon showed me that the tripod insures NO CAMERA SHAKE.  I
used to think I was pretty steady to 1/25th of a second (I still am), but
when I started using a tripod, I immediately saw the sharpness factor go up
a few notches.

When using an RBT ...with zoom lenses, you have to work harder to achive
maximum DOF.  One luxury the X3 affords the user is electronic DOF preview,
which I have come to really appreciate  The lenses' zoom-in magnification
factor,  coupled with the forward weight of those lenses.... will magnify
any potential camera shake caused by the user.  Using a TRIPOD , eliminates
that, but ALSO allows the user to stop down the lenses to F11,16 and
22...especially in lower light conditions...or when using slower speed
films, which may mean lowering the shutter speeds.

So at any rate...no magic here....all I have suggested is not rocket
science...but basic and practical ideas.

Well...off to Mt Khatadin tomorrow, supposedly a sunny day with some
scattered but puffy nice clouds....65-70 degrees....thats what Paul
says!.......regard-d-d-s!  Jon G