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Magic Lantern Lens vs. Petzval Portrait Lens
ok, I got this lens today and it is indeed a Petzval design with 2 groups,
4 elements with the rear elements "spaced" with a ring. Only trouble is
there is NO provision for any stops. I do know that Darlot ( in the 1880's
at least ) made portrait lenses without provision for stops - but
those were advertised for Magic Lantern use. I also think I recall that
some very early Portrait Lenses didn't come with provisions for stops as they
were just meant to be used wide open.. so what do I have here, a Portrait lens
or a ML lens ?
Thanks
Dan
PS - ( there are no markings on it )
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RE: Magic Lantern Lens vs. Petzval Portrait Lens
Message
There are
differences between ML and PL (ohh!, I like the abbreviations). Both are
Petzval designs, but use determines whether optimized for infinity focus,
or obviously, projection. But hard to see the difference if you do either
with the other.
Physical
characteristics, at first glance, I'd guess it's an ML. Short hood
(angle for projection) and that simple knob.
I could do a piece
on portrait vs projection lenses - anyone interested?
mz
ok, I got this lens today and it is indeed a Petzval design with 2
groups, 4 elements with the rear elements "spaced" with a ring. Only
trouble is there is NO provision for any stops. I do know that Darlot (
in the 1880's at least ) made portrait lenses without provision
for stops - but those were advertised for Magic Lantern use. I also
think I recall that some very early Portrait Lenses didn't come with
provisions for stops as they were just meant to be used wide open.. so what do
I have here, a Portrait lens or a ML lens ?
Thanks
Dan
PS - ( there are no markings on it )
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RE: Magic Lantern Lens vs. Petzval Portrait Lens
Message
Milan a piece on
projection vrs portrait lenses would be most welcome; I don't recall coming
across any information on that distinction. Thanks for your always willingness
to share.
"We
improve lives by mobilizing community assets"
Bob
Kulinski
President, United Way of
Summit County
90 N.
Prospect St
PO Box
1260
Akron,
OH 44309-1260
Direct
Phone: 330.643.5520
Cell:
330.701.8144
Home:
330.835.4961
Fax:
330.762.0317
email:
bkulinski@...
http://www.uwsummit.org/
Visit our Blog: www.unitedwayofsummitcounty.blogspot.com
 
NOTICE: The information in this e-mail is confidential
and may be legally privileged. It is intended solely for the addressee. Access
to this e-mail by anyone else is unauthorized. If you are not the intended
recipient, any disclosures, copying, distribution or any action taken or omitted
to be taken in reliance on it, is prohibited and may be unlawful.
There are
differences between ML and PL (ohh!, I like the abbreviations). Both are
Petzval designs, but use determines whether optimized for infinity focus,
or obviously, projection. But hard to see the difference if you do either
with the other.
Physical
characteristics, at first glance, I'd guess it's an ML. Short hood
(angle for projection) and that simple knob.
I could do a piece
on portrait vs projection lenses - anyone interested?
mz
ok, I got this lens today and it is indeed a Petzval design with 2
groups, 4 elements with the rear elements "spaced" with a ring. Only
trouble is there is NO provision for any stops. I do know that Darlot (
in the 1880's at least ) made portrait lenses without provision
for stops - but those were advertised for Magic Lantern use. I also
think I recall that some very early Portrait Lenses didn't come with
provisions for stops as they were just meant to be used wide open.. so what do
I have here, a Portrait lens or a ML lens ?
Thanks
Dan
PS - ( there are no markings on it )
|
|
RE: Magic Lantern Lens vs. Petzval Portrait Lens
Message
Are you saying the
Petzval Portrait Lens is optimized for infinity ?
There are
differences between ML and PL (ohh!, I like the abbreviations). Both are
Petzval designs, but use determines whether optimized for infinity focus,
or obviously, projection. But hard to see the difference if you do either
with the other.
Physical
characteristics, at first glance, I'd guess it's an ML. Short hood
(angle for projection) and that simple knob.
I could do a piece
on portrait vs projection lenses - anyone interested?
mz
ok, I got this lens today and it is indeed a Petzval design with 2
groups, 4 elements with the rear elements "spaced" with a ring. Only
trouble is there is NO provision for any stops. I do know that Darlot (
in the 1880's at least ) made portrait lenses without provision
for stops - but those were advertised for Magic Lantern use. I also
think I recall that some very early Portrait Lenses didn't come with
provisions for stops as they were just meant to be used wide open.. so what do
I have here, a Portrait lens or a ML lens ?
Thanks
Dan
PS - ( there are no markings on it )
|
|
RE: Magic Lantern Lens vs. Petzval Portrait Lens
Message
Yes, most
photographic lens from the very beginning were/are. Process lenses, for
example, aren't - usually some intermediate working
distance.
mz
Are you saying the
Petzval Portrait Lens is optimized for infinity ?
There are
differences between ML and PL (ohh!, I like the abbreviations). Both are
Petzval designs, but use determines whether optimized for infinity
focus, or obviously, projection. But hard to see the difference if you
do either with the other.
Physical
characteristics, at first glance, I'd guess it's an ML. Short hood
(angle for projection) and that simple knob.
I could do a
piece on portrait vs projection lenses - anyone
interested?
mz
ok, I got this lens today and it is indeed a Petzval design with 2
groups, 4 elements with the rear elements "spaced" with a ring. Only
trouble is there is NO provision for any stops. I do know that Darlot
( in the 1880's at least ) made portrait lenses without
provision for stops - but those were advertised for Magic Lantern use.
I also think I recall that some very early Portrait Lenses didn't come with
provisions for stops as they were just meant to be used wide open.. so what
do I have here, a Portrait lens or a ML lens ?
Thanks
Dan
PS - ( there are no markings on it )
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RE: Magic Lantern Lens vs. Petzval Portrait Lens
Hi gang,
Yes, I'll second Bob's motion! I've never seen a piece discussing the
differences between taking and projecting lenses either.
Best wishes,
David Silver--President
International Photographic Historical Organization
E-mail: silver@... Telephone: (415) 681-4356
Webpage location: http://www.well.com/user/silver/On Mon, 28 Jan 2008, Bob Kulinski wrote:
> Milan a piece on projection vrs portrait lenses would be most welcome; I don't recall coming across any information on that distinction. Thanks for your always willingness to share.
>
> "We improve lives by mobilizing community assets"
> Bob Kulinski
> President, United Way of Summit County
> 90 N. Prospect St
> PO Box 1260
> Akron, OH 44309-1260
> Direct Phone: 330.643.5520
> Cell: 330.701.8144
> Home: 330.835.4961
> Fax: 330.762.0317
> email: bkulinski@...<mailto: bkulinski@...>
> http://www.uwsummit.org/> Visit our Blog: www.unitedwayofsummitcounty.blogspot.com<blocked:: http://www.unitedwayofsummitcounty.blogspot.com/>
> [ http://www.uwsummit.org/images/uwsc2.gif][cid:770370218@28012008-1086]
> NOTICE: The information in this e-mail is confidential and may be legally privileged. It is intended solely for the addressee. Access to this e-mail by anyone else is unauthorized. If you are not the intended recipient, any disclosures, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful.
>
>
>
>
>
>
> ________________________________
> From: woodandbrass-bounces@... [mailto: woodandbrass-bounces@...] On Behalf Of Milan Zahorcak
> Sent: Monday, January 28, 2008 12:53 PM
> To: 'Collectors of 19th Century Cameras &Photographica'
> Subject: RE: [W&B] Magic Lantern Lens vs. Petzval Portrait Lens
>
>
> There are differences between ML and PL (ohh!, I like the abbreviations). Both are Petzval designs, but use determines whether optimized for infinity focus, or obviously, projection. But hard to see the difference if you do either with the other.
>
> Physical characteristics, at first glance, I'd guess it's an ML. Short hood (angle for projection) and that simple knob.
>
> I could do a piece on portrait vs projection lenses - anyone interested?
>
> mz
>
>
>
>
> -----Original Message-----
> From: woodandbrass-bounces@... [mailto: woodandbrass-bounces@...] On Behalf Of DColucci@...
> Sent: Monday, January 28, 2008 9:32 AM
> To: woodandbrass@...
> Subject: [W&B] Magic Lantern Lens vs. Petzval Portrait Lens
>
> ok, I got this lens today and it is indeed a Petzval design with 2 groups, 4 elements with the rear elements "spaced" with a ring. Only trouble is there is NO provision for any stops. I do know that Darlot ( in the 1880's at least ) made portrait lenses without provision for stops - but those were advertised for Magic Lantern use. I also think I recall that some very early Portrait Lenses didn't come with provisions for stops as they were just meant to be used wide open.. so what do I have here, a Portrait lens or a ML lens ?
>
> Thanks
> Dan
>
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=140199480134&ssPageName=STRK:MEWN:IT&ih=004>
>
>
> PS - ( there are no markings on it )
>
>
>
> ________________________________
> Start the year off right. Easy ways to stay in shape< http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489> in the new year.
>
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RE: Magic Lantern Lens vs. Petzval Portrait Lens
Message
What the heck is the
point of optimizing a Petzval for infinity ? Its a one trick lens built
for blazing speed and short focus - why would it be optimized for
infinity..?
Yes, most
photographic lens from the very beginning were/are. Process lenses, for
example, aren't - usually some intermediate working
distance.
mz
Are you saying the
Petzval Portrait Lens is optimized for infinity ?
There are
differences between ML and PL (ohh!, I like the abbreviations). Both are
Petzval designs, but use determines whether optimized for infinity
focus, or obviously, projection. But hard to see the difference if you
do either with the other.
Physical
characteristics, at first glance, I'd guess it's an ML. Short hood
(angle for projection) and that simple knob.
I could do a
piece on portrait vs projection lenses - anyone
interested?
mz
ok, I got this lens today and it is indeed a Petzval design with 2
groups, 4 elements with the rear elements "spaced" with a ring. Only
trouble is there is NO provision for any stops. I do know that Darlot
( in the 1880's at least ) made portrait lenses without
provision for stops - but those were advertised for Magic Lantern use.
I also think I recall that some very early Portrait Lenses didn't come with
provisions for stops as they were just meant to be used wide open.. so what
do I have here, a Portrait lens or a ML lens ?
Thanks
Dan
PS - ( there are no markings on it )
|
|
RE: Magic Lantern Lens vs. Petzval Portrait Lens
Message
Perhaps optimized
isn't the best word . . . there has to be some distance used to formulate
a design. In most of the math, the equations have terms that involve the
sum of squares of things, divided by the sum of other things, etc. That
math gets very complicated, especially when you're dealing with many lens
elements - and combining those elements into one lens.
If you're pushed a
pencil and just have a slide rule and table of logarithms -
you'd use an infinity focus because 1. infinity is a very useful distance,
2. a lot of terms go to either zero or one, and the math is easier
(ha!).
By the way, when
you use infinity and the divisor goes to zero, you have problems, and so
some very large distance is used instead, say 1000 feet. A substitute
for infinity. For wide angle lens, 100 feet is often
enough.
But essentially you
can't second guess too much. And besides, all focal lengths are calculated
at infinity focus - ditto for max stops. so infinity is a good
choice, but it does throw some things out of whack. Up to a point, it doesn't
matter much, but then it does.
For example, that's
why there is a bellows factor for close-up work. An f/4 lens, isn't
an f/4 lens when you're focused on something 6" away - effectively it is a LOT
smaller and slower. That sort of thing.
mz
What the heck is the
point of optimizing a Petzval for infinity ? Its a one trick lens built
for blazing speed and short focus - why would it be optimized for
infinity..?
Yes, most
photographic lens from the very beginning were/are. Process lenses, for
example, aren't - usually some intermediate working
distance.
mz
Are you
saying the Petzval Portrait Lens is optimized for infinity ?
There are
differences between ML and PL (ohh!, I like the abbreviations). Both
are Petzval designs, but use determines whether optimized for infinity
focus, or obviously, projection. But hard to see the difference if you
do either with the other.
Physical
characteristics, at first glance, I'd guess it's an ML. Short
hood (angle for projection) and that simple knob.
I could do a
piece on portrait vs projection lenses - anyone
interested?
mz
ok, I got this lens today and it is indeed a Petzval design with 2
groups, 4 elements with the rear elements "spaced" with a ring. Only
trouble is there is NO provision for any stops. I do know that
Darlot ( in the 1880's at least ) made portrait lenses without
provision for stops - but those were advertised for Magic Lantern
use. I also think I recall that some very early Portrait Lenses
didn't come with provisions for stops as they were just meant to be used
wide open.. so what do I have here, a Portrait lens or a ML lens
?
Thanks
Dan
PS - ( there are no markings on it )
|
|
RE: Magic Lantern Lens vs. Petzval Portrait Lens
Some parts of this message have been removed.
Learn more about Nabble's security policy.
RE: [W&B] Magic Lantern Lens vs. Petzval
Portrait Lens
mz,
Yes! Please!
Christopher Wright
What would focus on for your piece?
At 4:24 PM -0800 1/28/08, Milan Zahorcak wrote:
There are differences
between ML and PL (ohh!, I like the abbreviations). Both are
Petzval designs, but use determines whether optimized for
infinity focus, or obviously, projection. But hard to see the
difference if you do either with the other.
Physical
characteristics, at first glance, I'd guess it's an ML.
Short hood (angle for projection) and that simple
knob.
I could do a piece on
portrait vs projection lenses - anyone interested?
mz
-----Original
Message-----
From: woodandbrass-bounces@...
[mailto:woodandbrass-bounces@...] On Behalf Of
DColucci@...
Sent: Monday, January 28, 2008 9:32 AM
To: woodandbrass@...
Subject: [W&B] Magic Lantern Lens vs. Petzval Portrait
Lens
ok, I got
this lens today and it is indeed a Petzval design with 2 groups, 4
elements with the rear elements "spaced" with a ring.
Only trouble is there is NO provision for any stops. I do know
that Darlot ( in the 1880's at least ) made portrait
lenses without provision for stops - but those were advertised for
Magic Lantern use. I also think I recall that some very early
Portrait Lenses didn't come with provisions for stops as they were
just meant to be used wide open.. so what do I have here, a Portrait
lens or a ML lens ?
Thanks
Dan
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=140199480134&ssPageName=STRK:MEWN:IT&ih=004
PS - (
there are no markings on it )
Start the year off right. Easy ways to stay in shape in the new year.
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uwsc2.gif (7K)