On 5/9/2016 10:15 AM, Chris Trask wrote:
By way of good fortune, I found a set of 7mm and 14mm Olympus extension
tubes on evilBay for just $15 each, which is damned cheap, especially since
they come with the original boxes. The Vivitar extension tubes I've been using
only go down to 12mm, and there are times when that is a bit too much. The 7mm
extension tube is actually shorter than screwing together the end pieces of the
cheap 5-piece extension tube sets. This is probably because the release
mechanism for the older OM mount requires far less thickness than does the
newer OM 4/3 mount.
I've always thought that the Oly 7 mm tube is quite a clever bit of engineering.
My expectation is that the 7mm Olympus extension tube will be more usable
than the 12mm Vivitar
That's what I found.
, and will make a less expensive substitute for the +0.5 close-up lens, plus I
won't need to be concerned about an extra piece of glass. The only drawback is
that I can only use this with OM-mount lenses, but that is of little or no
inconvenience. BTW: I did find a 67mm B&W (German) +0.5 close=up:
http://www.ebay.com/itm/B-W-67mm-Close-up-NL-0-5-Filter-with-case-/172087736125?hash=item28113a773d:g:NUAAAOSwFqJWsoh-
Single element, not achromat. OTOH, it may not make a practical difference at
+0.5 diopter.
I was surprised to see that there we very few, if any, native extension
tubes for Pentax and Nikon. But then it has been my experience that the old OM
line had many more accessories to offer.
Oly's OM accessory gear was/is second to none in 35 mm, in both range and quality. I was using a simple focusing rail
recently, and having trouble because turning the adjustment knob was moving the image around. Sloppy tolerances. I
finally broke down and bought a second Oly Auto Bellows. I've been keeping an eye out for a reasonably priced focusing
rail alone for ages. Now I have the rail, spare bellows parts, and don't have to pull the bellows apart, then mount the
focusing stage, to use the rail alone - all for less than most rails alone are going for (and mint).
What a joy to focus with it!
Pentax did have a significant advantage in that they kept with their P/K
bayonet mount from the very beginning right to the very end, burying the
electrical contacts into the mating flange rather than designing an entirely
new bayonet mount, as did everyone else.
Weeelllll . . . Nikon has kept the original F mount, with as little modification as possible. On their high end models,
even the mechanical Auto aperture mechanism is supported (or was, I don't keep up.)
Canon ditched an awkward, not ready for AF, mount long before digital. Doesn't seem to have hurt them. And Pentax's
retention of the P/K mount hasn't propelled them to great success, only survival by acquisition.
No Lash Moose
--
What if the Hokey Pokey *IS* what it's all about?
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