protar VII
Michael Dowdall
I was hopeing someone here could help. This past weekend I got a good deal
on a Zeiss Protarlinse VII comvertable set. I'm looking to find out what
angle of coverage it has, as well as possible dates on serial numbers. It
dosn't have f-stops marked on the barrel but the apperature diamater in mm.
With a single element mounted in front or behind the appurature blades
effect the calculation of the appurature. Diamater over focal length =
f-stop. The lengths and serial numbers are as follows;
48cm nr.670143
41cm nr.407862
35cm nr.656105
29cm nr.656056
The last two cells apear close in serial numbers, the others not. would be a
problem in them not being a matched set?
Michael
Richard Knoppow
"Michael Dowdall" <aw...@iprimus.ca> wrote in message
news:v7rda.7986$wz5.45...@news.primus.ca...
Any Series VII Protar cell can be used with any other,
within the limit of allowable focal length ratio.
The lenses with 65xxxxx and 67xxxxx numbers date from
about 1925, the 40xxxxx lens from about 1920. They may still
have been an original set.
This series of focal length cells was sold by zeiss as
Convertible Set D, intended for 7x9" cameras. It also
included a shutter, either a Compound or, from this date,
perhaps a dial set Compur. The shutter will be calibrated in
millimeters for the stops. A chart showing the f/stop
settings for all combinations was originally included in the
box with the lenses and shutter.
The speeds of the individual cells is f/12.5. coverage as
small stops (f/32 or smaller) is an image circle about equal
to the focal length, or a bit less, perhaps 50degrees.
Coverage of the combinations is around 75degrees at f/45
and a bit less at smaller stops.
The focal lengths of the combinations are:
29+35cm = 18.5cm = 7-1/4", f/7.0
29+41cm = 20cm = 8" f/7.7
35+51cm = 22cm = 8-3/4 f/7.0
35+48cm = 23.5cm = 9-1/4" f/7.7
41+48cm = 26cm = 10-1/4" f/7.0
The 29cm and 48cm can not be used together.
The _longer_ focal length cell should be on the front of
the shutter or barrel (in front of the stop).
Single cells should ideally be used on the back of the
shutter or barrel, i.e., behind the stop for best correction
of aberrations. However, if some reduction of image quality
in the margins can be tollerated the bellows draw can be
reduced by putting the lens in front of the stop.
This is due to the location of the principle points of
single meniscus lenses. They are slightly retrofocus when in
back of the stop and slightly telephoto when in front.
Individual Protar cells are corrected for coma so the lens
is truely convertible. Individual Dagor cells are not
corrected for coma and must be used at very small stops
(f/45 or smaller) to be reasonably sharp. Although the Dagor
was patented and sold as a convertible, it really is not
since it depends on symmetry for coma correction.
The performance of individual Protar cells is surprizingly
good. They are well corrected for chromatic aberration, not
always the case for convertible lenses. the combined lens is
excellent.
Bausch and Lomb made a similar lens set under Zeiss
license. The B&L Protar sets usually also included a Protar
Series V f/18 Extra Wide Angle lens. This is not a
convertible and of a different design from the Series VII
although both are based on the original Paul Rudolph Protar.
Price of the D set of lenses with a Compound shutter, in
1927 was $230. Multiply this by somewhere around ten to
twenty times for something like current values.
Where two cells of equal focal length are used the speed
is f/6.3.
--
---
Richard Knoppow
Los Angeles, CA, USA
dick...@ix.netcom.com
Sandy King
<dick...@ix.netcom.com> wrote:
> The focal lengths of the combinations are:
>
> 29+35cm = 18.5cm = 7-1/4", f/7.0
> 29+41cm = 20cm = 8" f/7.7
> 35+51cm = 22cm = 8-3/4 f/7.0
> 35+48cm = 23.5cm = 9-1/4" f/7.7
> 41+48cm = 26cm = 10-1/4" f/7.0
>
> The 29cm and 48cm can not be used together.
Just curious to know the reason why the 29cm and 48cm cells can not be
used together?
Sandy King
Richard Knoppow
"Sandy King" <san...@clemson.edu> wrote in message
news:sanking-2003...@192.168.1.100...
> In article <b55s1g$l0l$1...@slb1.atl.mindspring.net>,
"Richard Knoppow"
> <dick...@ix.netcom.com> wrote:
>
> > The focal lengths of the combinations are:
> >
> > 29+35cm = 18.5cm = 7-1/4", f/7.0
> > 29+41cm = 20cm = 8" f/7.7
> > 35+51cm = 22cm = 8-3/4 f/7.0
> > 35+48cm = 23.5cm = 9-1/4" f/7.7
> > 41+48cm = 26cm = 10-1/4" f/7.0
> >
> > The 29cm and 48cm can not be used together.
>
> Just curious to know the reason why the 29cm and 48cm
cells can not be
> used together?
>
> Sandy King
>
length ratio of greater than about 1.414 are not shown in
any listings. I suspect some of the abberations become too
large but have never seen any specific analysis of it.
There is no reason not to try it although you will have to
figure out the equivalent focal length and stop. The
combination would be rather slow.
Michael Dowdall
is 215 mm. Very close to the other combinations;
29+41=20cm
35+41=22cm
The f stop is aprox' f:9
Didn't see any problems with the image. Would have to expose a transparency
to see I guess. Not something I'm Going to invest in at the moment. Will
post the results of B+W negs as they come.
Michael Dowdall
Richard Knoppow
ratio so couldn't test them.
Convertible lenses are not covered very well in texts on
photographic optics, probably because they are considered
old fashioned.
Jean-David Beyer
He designed it about 10 years ago or so.
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Richard Knoppow
"Jean-David Beyer" <jdb...@exit109.com> wrote in message
news:3E7E6607...@exit109.com...
AFAIK, the Wisner lenses were designed and built by
Schneider. They may have modified the design of the
convertible version of the Symmar but its essentially the
same lens. Wisner offers corrector lenses of some sort to
work with the individual cells. The original reason for
convertible lenses was economy and I rather think that's
lost here. A complete symmetrical or nearly symmetrical lens
will be better than a single cell of a combinable lens if
for no other reason than that symmetry automatically
corrects coma, lateral color, and geometrical distortion. It
seems to me that Wisner is jumping through hoops to get
something more easily gotten in another way.
Jean-David Beyer
>> I do not consider my Wisner Convertable Plasmat set old
>
> fashioned.
>
>> He designed it about 10 years ago or so.
>>
>
> AFAIK, the Wisner lenses were designed and built by Schneider. They
> may have modified the design of the convertible version of the Symmar
> but its essentially the same lens. Wisner offers corrector lenses of
> some sort to work with the individual cells. The original reason for
> convertible lenses was economy and I rather think that's lost here. A
> complete symmetrical or nearly symmetrical lens will be better than a
> single cell of a combinable lens if for no other reason than that
> symmetry automatically corrects coma, lateral color, and geometrical
> distortion. It seems to me that Wisner is jumping through hoops to
> get something more easily gotten in another way. --
>
My understanding is that Ron Wisner designed the lenses and that he had
Schneider manufacture the glass. Ron then mounted the glass in brass
cells and rebuilt a Copal #1 shutter to accept the cells (they seem to
be mounted a little closer than the #1 normally permits).
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Le Grande Raoul
<jdb...@exit109.com> wrote:
> Richard Knoppow wrote:
>
> >> I do not consider my Wisner Convertable Plasmat set old
> >
> > fashioned.
> >
> >> He designed it about 10 years ago or so.
> >>
>
> >
> > AFAIK, the Wisner lenses were designed and built by Schneider. They
> > may have modified the design of the convertible version of the Symmar
> > but its essentially the same lens. Wisner offers corrector lenses of
> > some sort to work with the individual cells. The original reason for
> > convertible lenses was economy and I rather think that's lost here. A
> > complete symmetrical or nearly symmetrical lens will be better than a
> > single cell of a combinable lens if for no other reason than that
> > symmetry automatically corrects coma, lateral color, and geometrical
> > distortion. It seems to me that Wisner is jumping through hoops to
> > get something more easily gotten in another way. --
> >
> My understanding is that Ron Wisner designed the lenses and that he had
> Schneider manufacture the glass. Ron then mounted the glass in brass
> cells and rebuilt a Copal #1 shutter to accept the cells (they seem to
> be mounted a little closer than the #1 normally permits).
I have the same feeling as Richard regarding the Wisner lenses. They
seem like a wonderful product and probably worth what one pays for
them. However, I just can't see myself taking a lens apart to change
its focal length in the field. With "old school" lenses, it kind of a
case of two/three lenses for the price of one.- you remove a cell to
change the focal length. The Wisner works kind of the same way but, in
order to get the full utility, you need to carry all the cells with
you. A cell you don't have with you is of no use. Also, there is the
question of the problems inherent in the convertable concept but that
can be argued about endlessly in the manner of its done with 'bokeh'.
I think I would rather have two or three separate lenses rather than
one of these convertables. I find that I generally only want to use
one or two focal lengths with my 8x10 anyway.
With opinions, as always, YMMV.
Jeff
Jean-David Beyer
Unscrewing a cell from the shutter, placing it in the felt-lined wood
box, removing another cell, and screwing it into the shutter is not that
big a deal. If I were in a sandstorm, I might worry, but in that case I
would worry about any shutter I have ever seen anyway, as they sure do
not seem dust proof. A little care may be required, but the same care is
pretty much needed for everything else.
> With "old school" lenses, it kind of a
> case of two/three lenses for the price of one.- you remove a cell to
> change the focal length. The Wisner works kind of the same way but, in
> order to get the full utility, you need to carry all the cells with
> you. A cell you don't have with you is of no use.
But since all the cells fit in a wooden box 3.25"x3.5"x6", why would you
not take them all with you? And most of the time, I use two cells at
once, so I do not get the inferior performance of typical old-style
convertable lenses when using only one cell at a time. The reason the
cells are so small is that they are f/13 if used separately, but can
come out to f/9 (best case) when used in pairs.
> Also, there is the
> question of the problems inherent in the convertable concept but that
> can be argued about endlessly in the manner of its done with 'bokeh'.
>
> I think I would rather have two or three separate lenses rather than
> one of these convertables. I find that I generally only want to use
> one or two focal lengths with my 8x10 anyway.
In any given day, I sure do not use all 11 focal lengths available to me
with the Wisner set. But I seldom know, in advance, just which focal
lengths I will be needing when walking around with all that L.F. stuff
in my backpack and tripod over my shoulder. (Also, 90mm f/8 S.A. usually
comes along.) I do not think I would wish to put three, say, Symmar-S
lenses in there instead of the Wisner set: too heavy even if someone
else were paying for them. I used to carry an f/9 Nikor M 300mm, a 210
f/5.6 Caltar-S, a 135mm f/5.6 Symmar-S, and the 90mm f/8 S.A., but that
was heavy and bulky, and gave me fewer choices. With the set, I can use
the longest lens shorter than the one I need, so I can crop less in the
darkroom.
>
> With opinions, as always, YMMV.
>
YMMV for sure.
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Le Grande Raoul
> > I have the same feeling as Richard regarding the Wisner lenses. They
> > seem like a wonderful product and probably worth what one pays for
> > them. However, I just can't see myself taking a lens apart to change
> > its focal length in the field.
>
> Unscrewing a cell from the shutter, placing it in the felt-lined wood
> box, removing another cell, and screwing it into the shutter is not that
> big a deal. If I were in a sandstorm, I might worry, but in that case I
> would worry about any shutter I have ever seen anyway, as they sure do
> not seem dust proof. A little care may be required, but the same care is
> pretty much needed for everything else.
You must be better coodinated than me, J-D. I'm not sure I could
balance the cells and screw 'em into the shutter without buggering them
up.
>
> > With "old school" lenses, it kind of a
> > case of two/three lenses for the price of one.- you remove a cell to
> > change the focal length. The Wisner works kind of the same way but, in
> > order to get the full utility, you need to carry all the cells with
> > you. A cell you don't have with you is of no use.
>
> But since all the cells fit in a wooden box 3.25"x3.5"x6", why would you
> not take them all with you? And most of the time, I use two cells at
> once, so I do not get the inferior performance of typical old-style
> convertable lenses when using only one cell at a time. The reason the
> cells are so small is that they are f/13 if used separately, but can
> come out to f/9 (best case) when used in pairs.
>
You have experience while I only have opinion. Maybe it is practical
to use the Wisner system. But I still wouldn't trust *my* ability to
manipulate the cells.
> > Also, there is the
> > question of the problems inherent in the convertable concept but that
> > can be argued about endlessly in the manner of its done with 'bokeh'.
> >
> > I think I would rather have two or three separate lenses rather than
> > one of these convertables. I find that I generally only want to use
> > one or two focal lengths with my 8x10 anyway.
>
> In any given day, I sure do not use all 11 focal lengths available to me
> with the Wisner set. But I seldom know, in advance, just which focal
> lengths I will be needing when walking around with all that L.F. stuff
> in my backpack and tripod over my shoulder. (Also, 90mm f/8 S.A. usually
> comes along.) I do not think I would wish to put three, say, Symmar-S
> lenses in there instead of the Wisner set: too heavy even if someone
> else were paying for them. I used to carry an f/9 Nikor M 300mm, a 210
> f/5.6 Caltar-S, a 135mm f/5.6 Symmar-S, and the 90mm f/8 S.A., but that
> was heavy and bulky, and gave me fewer choices. With the set, I can use
> the longest lens shorter than the one I need, so I can crop less in the
> darkroom.
Hmmm.. Would seem if the 210/5.6 was replaced with a smaller lens (say,
the 210/6.3) the weight would be the same or less. You would take the
90SA in both cases. Of course, you may think the 210/6.3 is shite, too.
;) The multiplicity of focal lenghts would be lost, though.
I guess another difference is the way that I photograph. I 'trained'
myself by shooting 8x10 with a 375 and a 240 for a year. A couple
hundred exposures and, with 8x10, that's a lot... I found that I could
'make do' with the two lenses and spent less time worrying about
equipment and more time concentrating on composition and exposure. Of
course, focal lenght and composition are closly linked but I found I
did a better job composing when I worried more about the composition in
front of me than the lens for which I was doing the composing.
> >
> > With opinions, as always, YMMV.
> >
> YMMV for sure.
Yes, that's true. I'm not arguing with you. It's more like a couple
of fellas having a chat over a beer, not a fistfight! ;)
Jeff
Jean-David Beyer
>>Unscrewing a cell from the shutter, placing it in the felt-lined wood
>>box, removing another cell, and screwing it into the shutter is not that
>>big a deal. If I were in a sandstorm, I might worry, but in that case I
>>would worry about any shutter I have ever seen anyway, as they sure do
>>not seem dust proof. A little care may be required, but the same care is
>>pretty much needed for everything else.
>
> You must be better coodinated than me, J-D. I'm not sure I could
> balance the cells and screw 'em into the shutter without buggering them
> up.
>
Maybe so. But I do not seem to work that way, and need not balance
anything. I normally put my backpack on the ground, and the camera is on
the tripod. So, if I do not like the focal length combination I have on
the camera, I remove the lens board, unscrew the undesired cell and put
it into the empty slot in the box, remove the desired cell from the box
and screw it (carefully, or course) into the shutter. Sometimes I must
do this twice because, by Murphy's law, whatever cell is on the back I
want on the front. E.g., if there is a 250 mm in front and a 350 in
back, then I would want 350 in front and 400 on the back. So 250 to box.
350 from back to front, then 400 from box. But it is really pretty easy
and simple once you have done it a few times.
>
>>But since all the cells fit in a wooden box 3.25"x3.5"x6", why would you
>>not take them all with you? And most of the time, I use two cells at
>>once, so I do not get the inferior performance of typical old-style
>>convertable lenses when using only one cell at a time. The reason the
>>cells are so small is that they are f/13 if used separately, but can
>>come out to f/9 (best case) when used in pairs.
>
> You have experience while I only have opinion. Maybe it is practical
> to use the Wisner system. But I still wouldn't trust *my* ability to
> manipulate the cells.
>
You know yourself better than I do.
>>In any given day, I sure do not use all 11 focal lengths available to me
>>with the Wisner set. But I seldom know, in advance, just which focal
>>lengths I will be needing when walking around with all that L.F. stuff
>>in my backpack and tripod over my shoulder. (Also, 90mm f/8 S.A. usually
>>comes along.) I do not think I would wish to put three, say, Symmar-S
>>lenses in there instead of the Wisner set: too heavy even if someone
>>else were paying for them. I used to carry an f/9 Nikor M 300mm, a 210
>>f/5.6 Caltar-S, a 135mm f/5.6 Symmar-S, and the 90mm f/8 S.A., but that
>>was heavy and bulky, and gave me fewer choices. With the set, I can use
>>the longest lens shorter than the one I need, so I can crop less in the
>>darkroom.
>
> Hmmm.. Would seem if the 210/5.6 was replaced with a smaller lens (say,
> the 210/6.3) the weight would be the same or less. You would take the
> 90SA in both cases. Of course, you may think the 210/6.3 is shite, too.
> ;) The multiplicity of focal lenghts would be lost, though.
Well, I doubt the weight saving by moving from an f/5.6 to f/6.3 would
be all that much.
>
> I guess another difference is the way that I photograph. I 'trained'
> myself by shooting 8x10 with a 375 and a 240 for a year. A couple
> hundred exposures and, with 8x10, that's a lot... I found that I could
> 'make do' with the two lenses and spent less time worrying about
> equipment and more time concentrating on composition and exposure. Of
> course, focal lenght and composition are closly linked but I found I
> did a better job composing when I worried more about the composition in
> front of me than the lens for which I was doing the composing.
>
Of course you can "make do." I used just the 210mm for a year when I
first started out with l.f. Better equipment does not make better
images, it just makes making them easier.
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ArtKramr
>From: Le Grande Raoul ra...@olympus.net
>I think I would rather have two or three separate lenses rather than
>one of these convertables. I find that I generally only want to use
>one or two focal lengths with my 8x10 anyway.
>
>
Accordimg to Ron,these lenses were designed ot fill a niche marlet made up of a
small select group of photographers who used and treasure convertables . They
have been using Protars, Satz Plasmat sets and even the occasional (ugh)
Tiurner Riech. They all wanted modern versions made of modern "clean" glass
produced after WW II using clean room techniques in pouring, cooling and
asembly; lenses free of artifacts such as bubbles and excessive strain.
Ron's lenses fill that need and were never meant to do anything otherwise. I
think if Adams and Weston were alive today, they would be first in line for
that Ron hath wrought.
Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer
Le Grande Raoul
<artk...@aol.com> wrote:
Makes good sence... I'm not against the Wisner lenses. To the
contrary, I'm all for them. Used by someone other than me, that is...
;)
No, from what I have been able to tell, the Wisner convertables are
truly a premium product. I hope he sells all that he makes and the
buyers enjoy them.
Jeff
Jean-David Beyer
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ArtKramr
>From: Jean-David Beyer jdb...@exit109.com
>Date: 4/30/03 4:54 AM Pacific
>> Accordimg to Ron,these lenses were designed ot fill a niche marlet made up
>of a
>> small select group of photographers who used and treasure convertables .
>They
>> have been using Protars, Satz Plasmat sets and even the occasional (ugh)
>> Tiurner Riech. They all wanted modern versions made of modern "clean"
>glass
>> produced after WW II using clean room techniques in pouring, cooling and
>> asembly; lenses free of artifacts such as bubbles and excessive strain.
>> Ron's lenses fill that need and were never meant to do anything otherwise.
>I
>> think if Adams and Weston were alive today, they would be first in line for
>> that Ron hath wrought.
>>
>Wow! I _love_ to be included in the group including Adams and Weston. ;-)
>
And well you might be. (grin) I do seem to remember Ron saying that his new
lenses shared at least one element with the Clarons.
Jean-David Beyer
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ArtKramr
>Accordimg to Ron,these lenses were designed ot fill a niche marlet made up
>>>
>>>of a
>>>
>>>>small select group of photographers who used and treasure convertables .
>>>
>>>They
>>>
>>>>have been using Protars, Satz Plasmat sets and even the occasional (ugh)
>>>>Tiurner Riech. They all wanted modern versions made of modern "clean"
>>>
>>>glass
>>>
>>>>produced after WW II using clean room techniques in pouring, cooling and
>>>>asembly; lenses free of artifacts such as bubbles and excessive strain.
>>>>Ron's lenses fill that need and were never meant to do anything otherwise.
>>>
>>>I
>>>
>>>>think if Adams and Weston were alive today, they would be first in line
>for
>>>>that Ron hath wrought.
>>>>
>>>
>>>Wow! I _love_ to be included in the group including Adams and Weston. ;-)
>>>
>>
>>
>>
>> And well you might be. (grin) I do seem to remember Ron saying that his new
>> lenses shared at least one element with the Clarons.
>>
>My guess is that it would be the two 250mm elements.
>
Might very well be. (s)