Here is a bubbleicious Bokeh, from an old Tope Picture I took, with the 50mm
F3.5 macro OM:
http://www.tope.nl/tope_show_entry.php?event=4&pic=18
Unfortunately the OM does not have a really smooth round aperture, like the
Meyer-optik.
Tim
________________________________
From: Moose <olymoose@xxxxxxxxx>
To: Olympus Camera Discussion <olympus@xxxxxxxxxxxxxxxxx>
Sent: Monday, December 1, 2014 10:31 PM
Subject: Re: [OM] Simple lens designs like Tessar on Digital cameras.
On 12/1/2014 5:20 PM, Hughes wrote:
> Moose commented in another thread about simple tele lens designs being good.
> I always think that is maybe because they did not have lots of surfaces and
> thick glass.
Here's the lens design of the Nikkor-Q 200/4.
<http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/6070nikkor/telephoto/200mmf4.pdf>
Only six air to glass surfaces, but that central element is quite thick. Single
coated, but at least the sliding hood is
built-in, as with the Zuikos. I wonder if some of the reason they are good,
while simple, is that they don't go far into
true tele design.
We've all known for a long time how difficult it is to design retrofocus WAs
for (D)SLRs without lots of elements, size
and weight, compared to the much simpler designs for rangefinders, where the
rear node can be internal.
Telephoto, as a type of design, not just a long lens, does the reverse,
locating the front node out in front of the
glass. In the case of Mike's CV 180/4, the front node is about 55 mm in front
of the front element. For the OMZ 200/4
the distance in front is about 27 mm. The 200/5 is the same FL, but with a
shorter body shorter, so 49 mm behind the
front node. I imagine that's what required one more element than the 200/4.
The Nikkor then stands out as a different sort of design, with the front node
roughly in, or just behind, the front
doublet element, hence much easier to design for performance only.
> I still use and like some Novoflex lenses like that,but being SC they need
> very good lens hoods.
>
> The first interchangeable lens camera I owned in high school, had an east
> german 50mm f2.9 Tessar lens,which was such a step up on what had owned
> previously and I really liked it.
Praktiflex? Carl Zeiss Jena 50 mm Tessar? If so, most likely f2.8. I've got
camera and lens sitting right here, and did
some research into the lens back when I was trying to figure out how to use it
on a 5D. There's a big rear protrusion.
In any case, there were a gazillion of them made, and I don't recall any
mention of an f2.9. Typo?
On APS-C, where the mirror clears, it's a fine lens. I don't recall the details
now, but it was basically as good as a
Zuiko miJ 50/1.8 at f4 and below. I don't remember about f2.8. It was an
informal test, and I may have skipped that as
wide open on the Tessar. I couldn't, of course, see the FF corners.
I was hoping that the simpler design would yield better bokeh than the faster
double Gauss 50 mm lenses. Not really.
Anything you would like me to take a picture of with it?
Should I get an A7II, just to try it out? I'd rather do that than load up film
in an OM for tedious testing. Digital
is ever so much better for that sort of thing.
> Over the years there have been lots of small cameras still using the
> venerable Tessar design.
>
> Olympus Trip 35,Mju,Minox, Rollei 35 ,Zeiss Ikon,Rolleiflex etc.all of which
> had respectable performance.
The one on my Rolleicord was good, probably limited by film non-flatness. Not
wild about the one on the Rollei 35 I have.
> I was thinking it might be fun to mount an old tessar lens on a digital body.
As above, it's a cinch to get a 50/2.8 in LTM, adaptable to pretty much any
mirrorless. The preset aperture is ideal for
manual use.
> A donor Rollei 35 would give an extremely compact sliding tube lens, for
> example.
Always looking for the harder solution? More fun?
T. Sar Moose
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What if the Hokey Pokey *IS* what it's all about?
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