Thanks for the details, Moose. As I have noted recently, I am seriously
considering ordering the new Fuji X-Pro2, at 24MP. I am currently
trying to line up a good quality M42 adapter that will allow me to use
my Takumar lenses with the Fujis. Therein lies a dilemma. Thread mount
lenses are at the mercy of where the thread bottoms out, which can leave
the lens markings at various clockwise locations. To provide some
adjustment, Fotodiox, my preferred manufacturer, uses rim set-screws
which allow the inner ring to be rotated and reclamped. The first
adapter I purchased was M42 to Oly 4/3, and it felt loose with a heavy
lens. My brute force correction involved superglue, which solved the
looseness, but had enough thickness to prevent infinity focus. Sanding
the adapter face with extremely fine emery paper provided the proper
thickness, but, when tightened up, the lens markings are on the side.
Some adapters for M42 won't work with Takumars because of the stop-down
pin. So, I have some inquiries out on a proper solution.
Sorry to ramble on. But, you are correct. The extra MPs are quite
useful, and not just for bragging rights.
Jim Nichols
Tullahoma, TN USA
On 7/18/2016 5:07 PM, Moose wrote:
On 7/17/2016 11:34 AM, Jim Nichols wrote:
After seeing Moose's recent fly captures, I became interested in
trying an extension tube, though I don't have any of the modifying
optics he has been using.
I have often used extension tubes in the yard, and Auto Bellows and
Auto Tube, in film days.
Examples with three lenses here.
<http://zone-10.com/tope2/main.php?g2_itemId=4514>
Another lens here. <http://zone-10.com/tope2/main.php?g2_itemId=12436>
Theoretically, one could easily conclude that adding lens elements,
esp. those not designed for the primary lens, would give poorer
results than extension. There are, however, lenses that just aren't
designed to get any farther from the film/sensor. The OM 21/3.5, is
one example I know of where curvature of field that's already a bit
much at normal close focus gets really bad with extension. Longer FL
MF lenses, such as this Takumar are fine on modest extension.
My reason for my recurring interest in C-U lenses is mechanical, not
optical. The PLeica 100-400 I've been using for C-Us of bugs (and many
other things), is relatively large and heavy, at least in my current
world. I am often shooting in places where there is no place safe and
clean to set gear down, so juggling body, lens and tube is the only
option, and puts a fairly expensive lens at risk. It's also not
uncommon for there to be a breeze carrying dust. And the process of
putting tube in and out is time consuming, while some subjects, such
as insects and other critters, are evanescent.
OTOH, attaching or removing a C-U lens mounted using magnetic rings
takes no more than a very few seconds. So I tried out several C-U
lenses. And indeed, all but two of them were obviously poor optical
matches for my lens, and one of those was not really good. But one,
for whatever reason(s), works exceptionally well, giving tack sharp
images.
My only extension tubes are M42, so I attached the 9.5mm tube to my
Takumar 135/3.5 lens. The usable focusing range seemed to be
approximately 2 - 5 feet, not bad for butterflies. To get a few more
MP, I used my Oly E-510. This gave me the equivalent of a 270/3.5 lens.
This female Spicebush Swallowtail flew up and rested for about five
minutes on the greenery on my fence. This was the only view and
lighting that I had available. I tried focusing at several stops,
and it was not too difficult. I suspect this was taken at f/8.
http://www.gallery.leica-users.org/v/OldNick/Spicebush+Swallowtail+Female.tif.html
Great pose/composition. Not so obvious, at this size, with this
subject, but on the next flutterby, the difference between the E-510
and the Fuji is pretty obvious, with funny artifacts around the
flowers - and it's just not generally as clear as the recent Fuji X-E1
shot of the American Lady.
It may be useful to note that the Fuji X-E1 and a 4/3 sensor differ
hardly at all in multiplication factor in the vertical direction. The
usual smaller multiplier of about 1.5 for the APS-C sensor, vs. the
2.0 of 4/3 is a result of using diagonal measurements. But the APS-C
is 3:2, considerably wider than the 4:3 of 4/3. For these square crops
of flutterbys, the difference in multiplier is quite small, and
insignificant compared to the greater resolution/IQ of the Fuji.
Tech Talk Moose
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