zone system test with filter on lens?

"Phil Lamerton" wrote in
message
om...
I'd like to photograph a gray card outside on an overcast
day, in
order to do some zone system testing with my new camera
and lenses.

Since I will eventually be using the camera in the
portrait studio
with a yellow/green filter, would it be wrong to do the
testing with
the filter over the lens?

Thanks in advance for your advice on this.

phil lamerton

This is a good idea. The contrast of films changes with
color. Some films change one way, some the other, so this
sort of testing will tell you both speed and contrast under
conditions of actual use.


--
---
Richard Knoppow
Los Angeles, CA, USA

What 'camera and lenses'?

Koni Rapid Omega with 90mm and 180mm lenses. I'm uncertain as to why
you should ask this?


3. Because leaf shutters are less efficient at high shutter speeds and
large apertures. It takes time for the blades to open all the way, and
thus the full aperture is not available during the entire exposure. At
lower shutter speeds and small apertures, the percentage of time
during which the entire aperture is used is much higher. Electronic
flash is so quick that this does not matter, and thus your exposure
will not be the same.

Thanks, I had no idea that leaf shutters behaved like this.

It would seem from what you say that it would be difficult to conduct
a zone system test outdoors, with my leaf shutter lenses, even for the
purposes of outdoor photography.

How do people get round this? Should I avoid certain shutter speeds
both for the test and for taking pictures?

Can the shutter speeds be checked and adjusted by a camera technician,
or is this aspect of the design something that can't be adjusted?

Thanks again, phil lamerton

Phil Lamerton wrote:
: What 'camera and lenses'?
:
: Koni Rapid Omega with 90mm and 180mm lenses. I'm uncertain as to why
: you should ask this?


: 3. Because leaf shutters are less efficient at high shutter speeds and
: large apertures. It takes time for the blades to open all the way, and
: thus the full aperture is not available during the entire exposure. At
: lower shutter speeds and small apertures, the percentage of time
: during which the entire aperture is used is much higher. Electronic
: flash is so quick that this does not matter, and thus your exposure
: will not be the same.

: Thanks, I had no idea that leaf shutters behaved like this.

: It would seem from what you say that it would be difficult to conduct
: a zone system test outdoors, with my leaf shutter lenses, even for the
: purposes of outdoor photography.

As a rule you should always stop a lens done a couple of stops which makes
the issues with the leaf shutter less of an issue then scarpitti is making it
seem. A number of of MF format camera makers have lenses with leaf shutters
that studio photographers use instead of the focal plane shutter built into
the body.

: How do people get round this? Should I avoid certain shutter speeds
: both for the test and for taking pictures?

When using leaf shutters make sure that the flash duration is shorter then
the shutter speed used. With modern electronic flashes you can use a much
higher shutter speed with leaf shutters then you can with a focal plane shutter.

: Can the shutter speeds be checked and adjusted by a camera technician,
: or is this aspect of the design something that can't be adjusted?

There isn't a lot of adjustment that can be made on the leaf shutter. If the speed
is out a very tight tolerance it will need to be repaired. Don't worry about the
issues that scarpitti is pointing out. It's simply not an issue with quality and
properly operating shutters.

--




Keep working millions on welfare depend on you
-------------------

Frank Pittel wrote in message ...
Phil Lamerton wrote:
: What 'camera and lenses'?
:
: Koni Rapid Omega with 90mm and 180mm lenses. I'm uncertain as to why
: you should ask this?


: 3. Because leaf shutters are less efficient at high shutter speeds and
: large apertures. It takes time for the blades to open all the way, and
: thus the full aperture is not available during the entire exposure. At
: lower shutter speeds and small apertures, the percentage of time
: during which the entire aperture is used is much higher. Electronic
: flash is so quick that this does not matter, and thus your exposure
: will not be the same.

: Thanks, I had no idea that leaf shutters behaved like this.

: It would seem from what you say that it would be difficult to conduct
: a zone system test outdoors, with my leaf shutter lenses, even for the
: purposes of outdoor photography.

As a rule you should always stop a lens done a couple of stops which makes
the issues with the leaf shutter less of an issue then scarpitti is making it
seem. A number of of MF format camera makers have lenses with leaf shutters
that studio photographers use instead of the focal plane shutter built into
the body.

: How do people get round this? Should I avoid certain shutter speeds
: both for the test and for taking pictures?

When using leaf shutters make sure that the flash duration is shorter then
the shutter speed used. With modern electronic flashes you can use a much
higher shutter speed with leaf shutters then you can with a focal plane shutter.

: Can the shutter speeds be checked and adjusted by a camera technician,
: or is this aspect of the design something that can't be adjusted?

There isn't a lot of adjustment that can be made on the leaf shutter. If the speed
is out a very tight tolerance it will need to be repaired. Don't worry about the
issues that scarpitti is pointing out. It's simply not an issue with quality and
properly operating shutters.


Thanks, I can appreciate the advantages of testing with electronic
flash lighting; it will allow me to test under studio conditions
(something I want to do quite often) and will overcome the problem of
leaf shutter inefficiency explained previously.

However, the camera I want to use is a very old Koni Rapid Omega (they
stopped making them some thirty years ago. I'm having it fully
serviced but, given the age, I wonder if the quality will still be
there. If I want to establish film speed and normal development times
for outdoor photography with a test in ambient light, surely I need to
take leaf shutter inefficiency into account if I want a useful test
result? I've since read elsewhere that a leaf shutter can be 3/4 of a
stop out with a large aperture and fast shutter speed.

Another thing I should mention, I particularly wanted to use the
lenses wide open because of the interesting pattern they give in the
out of focus area of the image.

regards, phil lamerton

Phil Lamerton wrote:
: Frank Pittel wrote in message ...
: Phil Lamerton wrote:
: : What 'camera and lenses'?
: :
: : Koni Rapid Omega with 90mm and 180mm lenses. I'm uncertain as to why
: : you should ask this?
:
:
: : 3. Because leaf shutters are less efficient at high shutter speeds and
: : large apertures. It takes time for the blades to open all the way, and
: : thus the full aperture is not available during the entire exposure. At
: : lower shutter speeds and small apertures, the percentage of time
: : during which the entire aperture is used is much higher. Electronic
: : flash is so quick that this does not matter, and thus your exposure
: : will not be the same.
:
: : Thanks, I had no idea that leaf shutters behaved like this.
:
: : It would seem from what you say that it would be difficult to conduct
: : a zone system test outdoors, with my leaf shutter lenses, even for the
: : purposes of outdoor photography.
:
: As a rule you should always stop a lens done a couple of stops which makes
: the issues with the leaf shutter less of an issue then scarpitti is making it
: seem. A number of of MF format camera makers have lenses with leaf shutters
: that studio photographers use instead of the focal plane shutter built into
: the body.
:
: : How do people get round this? Should I avoid certain shutter speeds
: : both for the test and for taking pictures?
:
: When using leaf shutters make sure that the flash duration is shorter then
: the shutter speed used. With modern electronic flashes you can use a much
: higher shutter speed with leaf shutters then you can with a focal plane shutter.
:
: : Can the shutter speeds be checked and adjusted by a camera technician,
: : or is this aspect of the design something that can't be adjusted?
:
: There isn't a lot of adjustment that can be made on the leaf shutter. If the speed
: is out a very tight tolerance it will need to be repaired. Don't worry about the
: issues that scarpitti is pointing out. It's simply not an issue with quality and
: properly operating shutters.


: Thanks, I can appreciate the advantages of testing with electronic
: flash lighting; it will allow me to test under studio conditions
: (something I want to do quite often) and will overcome the problem of
: leaf shutter inefficiency explained previously.

The flash will be a big help since the shutter will be open when it triggers
the flash.

: However, the camera I want to use is a very old Koni Rapid Omega (they
: stopped making them some thirty years ago. I'm having it fully
: serviced but, given the age, I wonder if the quality will still be
: there. If I want to establish film speed and normal development times
: for outdoor photography with a test in ambient light, surely I need to
: take leaf shutter inefficiency into account if I want a useful test
: result? I've since read elsewhere that a leaf shutter can be 3/4 of a
: stop out with a large aperture and fast shutter speed.

Don't worry about the age of the camera to much. I shoot LF 90+% of the time
and have a number of lenses that are more the 40 years old and at least one
that's over 50. The timing of the shutters of the older lenses are still within
spec and are very accurate by today's standards. I do recommend that you send
it in for a CLA though. I have yet to see a leaf shutter with a faster shutter
speed the 1/500th of a second. In my experience with leaf shutters I simply
haven't noticed any exposure error with the higher shutter speeds and a wide
open lens. I do have to say that in my case I like to stop down to f22-f45
which when combined with 100 speed film results in shutter speed in the 1/15+
range. With shutter speeds of 1/4 and 1/2 not being unusual.

I just took a look at the performance numbers for a Copal shutter that I had
a CLA done on a few monthes ago. At the 1/500 speed which is works out to 2.0
milliseconds. The actual time is 3.6 milliseconds. The shutter was checked and
repaired by S.K. Grimes a well respected company in the LF field. It appears that
there is compensation built into the time for the time required to open and close
the shutter completely. Once again I've never noticed any issues with the timing
at the higher speeds. Even when using transperancies.


This does have me interested and if I find time this weekend I'll
run the following test over the weekend. I'll set up my camera to take an
image of a grey card and make an exposure with the aperature wide open with a
shutter speed of 1/500. I will then stop down and make an exposure with a
shutter speed of 1/30. The exposures will be equivalent. I will then develop
both sheets of film and compare the density of the negative with a densitometer.

In any case if you know what shutter speed and aperature you will be using most
of the time run your film tests with those settings.

: Another thing I should mention, I particularly wanted to use the
: lenses wide open because of the interesting pattern they give in the
: out of focus area of the image.

: regards, phil lamerton

--




Keep working millions on welfare depend on you
-------------------

Frank Pittel wrote in message ...
Phil Lamerton wrote:
: Frank Pittel wrote in message ...
: Phil Lamerton wrote:
: : What 'camera and lenses'?
: :
: : Koni Rapid Omega with 90mm and 180mm lenses. I'm uncertain as to why
: : you should ask this?
:
:
: : 3. Because leaf shutters are less efficient at high shutter speeds and
: : large apertures. It takes time for the blades to open all the way, and
: : thus the full aperture is not available during the entire exposure. At
: : lower shutter speeds and small apertures, the percentage of time
: : during which the entire aperture is used is much higher. Electronic
: : flash is so quick that this does not matter, and thus your exposure
: : will not be the same.

: : Thanks, I had no idea that leaf shutters behaved like this.

: : It would seem from what you say that it would be difficult to conduct
: : a zone system test outdoors, with my leaf shutter lenses, even for the
: : purposes of outdoor photography.
:
: As a rule you should always stop a lens done a couple of stops which makes
: the issues with the leaf shutter less of an issue then scarpitti is making it
: seem. A number of of MF format camera makers have lenses with leaf shutters
: that studio photographers use instead of the focal plane shutter built into
: the body.
:
: : How do people get round this? Should I avoid certain shutter speeds
: : both for the test and for taking pictures?
:
: When using leaf shutters make sure that the flash duration is shorter then
: the shutter speed used. With modern electronic flashes you can use a much
: higher shutter speed with leaf shutters then you can with a focal plane shutter.
:
: : Can the shutter speeds be checked and adjusted by a camera technician,
: : or is this aspect of the design something that can't be adjusted?
:
: There isn't a lot of adjustment that can be made on the leaf shutter. If the speed
: is out a very tight tolerance it will need to be repaired. Don't worry about the
: issues that scarpitti is pointing out. It's simply not an issue with quality and
: properly operating shutters.


: Thanks, I can appreciate the advantages of testing with electronic
: flash lighting; it will allow me to test under studio conditions
: (something I want to do quite often) and will overcome the problem of
: leaf shutter inefficiency explained previously.

The flash will be a big help since the shutter will be open when it triggers
the flash.

: However, the camera I want to use is a very old Koni Rapid Omega (they
: stopped making them some thirty years ago. I'm having it fully
: serviced but, given the age, I wonder if the quality will still be
: there. If I want to establish film speed and normal development times
: for outdoor photography with a test in ambient light, surely I need to
: take leaf shutter inefficiency into account if I want a useful test
: result? I've since read elsewhere that a leaf shutter can be 3/4 of a
: stop out with a large aperture and fast shutter speed.

Don't worry about the age of the camera to much. I shoot LF 90+% of the time
and have a number of lenses that are more the 40 years old and at least one
that's over 50. The timing of the shutters of the older lenses are still within
spec and are very accurate by today's standards. I do recommend that you send
it in for a CLA though. I have yet to see a leaf shutter with a faster shutter
speed the 1/500th of a second. In my experience with leaf shutters I simply
haven't noticed any exposure error with the higher shutter speeds and a wide
open lens. I do have to say that in my case I like to stop down to f22-f45
which when combined with 100 speed film results in shutter speed in the 1/15+
range. With shutter speeds of 1/4 and 1/2 not being unusual.

I just took a look at the performance numbers for a Copal shutter that I had
a CLA done on a few monthes ago. At the 1/500 speed which is works out to 2.0
milliseconds. The actual time is 3.6 milliseconds. The shutter was checked and
repaired by S.K. Grimes a well respected company in the LF field. It appears that
there is compensation built into the time for the time required to open and close
the shutter completely.

I don't see how that can be done, as the amount of compensation
necessary depends on the aperture being used.

Michael Scarpitti wrote:
: Frank Pittel wrote in message ...
: Phil Lamerton wrote:
: : Frank Pittel wrote in message ...
: : Phil Lamerton wrote:
: : : What 'camera and lenses'?
: : :
: : : Koni Rapid Omega with 90mm and 180mm lenses. I'm uncertain as to why
: : : you should ask this?
: :
: :
: : : 3. Because leaf shutters are less efficient at high shutter speeds and
: : : large apertures. It takes time for the blades to open all the way, and
: : : thus the full aperture is not available during the entire exposure. At
: : : lower shutter speeds and small apertures, the percentage of time
: : : during which the entire aperture is used is much higher. Electronic
: : : flash is so quick that this does not matter, and thus your exposure
: : : will not be the same.
:
: : : Thanks, I had no idea that leaf shutters behaved like this.
:
: : : It would seem from what you say that it would be difficult to conduct
: : : a zone system test outdoors, with my leaf shutter lenses, even for the
: : : purposes of outdoor photography.
: :
: : As a rule you should always stop a lens done a couple of stops which makes
: : the issues with the leaf shutter less of an issue then scarpitti is making it
: : seem. A number of of MF format camera makers have lenses with leaf shutters
: : that studio photographers use instead of the focal plane shutter built into
: : the body.
: :
: : : How do people get round this? Should I avoid certain shutter speeds
: : : both for the test and for taking pictures?
: :
: : When using leaf shutters make sure that the flash duration is shorter then
: : the shutter speed used. With modern electronic flashes you can use a much
: : higher shutter speed with leaf shutters then you can with a focal plane shutter.
: :
: : : Can the shutter speeds be checked and adjusted by a camera technician,
: : : or is this aspect of the design something that can't be adjusted?
: :
: : There isn't a lot of adjustment that can be made on the leaf shutter. If the speed
: : is out a very tight tolerance it will need to be repaired. Don't worry about the
: : issues that scarpitti is pointing out. It's simply not an issue with quality and
: : properly operating shutters.
:
:
: : Thanks, I can appreciate the advantages of testing with electronic
: : flash lighting; it will allow me to test under studio conditions
: : (something I want to do quite often) and will overcome the problem of
: : leaf shutter inefficiency explained previously.
:
: The flash will be a big help since the shutter will be open when it triggers
: the flash.
:
: : However, the camera I want to use is a very old Koni Rapid Omega (they
: : stopped making them some thirty years ago. I'm having it fully
: : serviced but, given the age, I wonder if the quality will still be
: : there. If I want to establish film speed and normal development times
: : for outdoor photography with a test in ambient light, surely I need to
: : take leaf shutter inefficiency into account if I want a useful test
: : result? I've since read elsewhere that a leaf shutter can be 3/4 of a
: : stop out with a large aperture and fast shutter speed.
:
: Don't worry about the age of the camera to much. I shoot LF 90+% of the time
: and have a number of lenses that are more the 40 years old and at least one
: that's over 50. The timing of the shutters of the older lenses are still within
: spec and are very accurate by today's standards. I do recommend that you send
: it in for a CLA though. I have yet to see a leaf shutter with a faster shutter
: speed the 1/500th of a second. In my experience with leaf shutters I simply
: haven't noticed any exposure error with the higher shutter speeds and a wide
: open lens. I do have to say that in my case I like to stop down to f22-f45
: which when combined with 100 speed film results in shutter speed in the 1/15+
: range. With shutter speeds of 1/4 and 1/2 not being unusual.
:
: I just took a look at the performance numbers for a Copal shutter that I had
: a CLA done on a few monthes ago. At the 1/500 speed which is works out to 2.0
: milliseconds. The actual time is 3.6 milliseconds. The shutter was checked and
: repaired by S.K. Grimes a well respected company in the LF field. It appears that
: there is compensation built into the time for the time required to open and close
: the shutter completely.

: I don't see how that can be done, as the amount of compensation
: necessary depends on the aperture being used.

It does work though. After all leaf shutters have been in use for a long time and
are still in virtually exclusive use in LF cameras and are prized by studio
photographers with MF cameras. I know for a fact that the Mamiya cameras have lenses
with leaf shutters that can be used with cameras with focal plane shutters ( the focal
plane shutter is simply opened and the exposure is made with the leaf shutter ).

Although Mamiya and conventional lenses are common and going cheap on Ebay as studios
are dumping their MF cameras and going digital. The lenses with leaf shutters are rare
and go for a lot of money. It simply isn't the issue you're trying to make it out to
be.
--




Keep working millions on welfare depend on you
-------------------

Frank Pittel wrote in message ...
there is compensation built into the time for the time required to open and close
: the shutter completely.

: I don't see how that can be done, as the amount of compensation
: necessary depends on the aperture being used.

It does work though. After all leaf shutters have been in use for a long time and
are still in virtually exclusive use in LF cameras and are prized by studio
photographers with MF cameras. I know for a fact that the Mamiya cameras have lenses
with leaf shutters that can be used with cameras with focal plane shutters ( the focal
plane shutter is simply opened and the exposure is made with the leaf shutter ).

Although Mamiya and conventional lenses are common and going cheap on Ebay as studios
are dumping their MF cameras and going digital. The lenses with leaf shutters are rare
and go for a lot of money. It simply isn't the issue you're trying to make it out to
be.

If you're 'calibrating' it may very well be.

Michael Scarpitti wrote:
: Frank Pittel wrote in message ...
: there is compensation built into the time for the time required to open and close
: : the shutter completely.
:
: : I don't see how that can be done, as the amount of compensation
: : necessary depends on the aperture being used.
:
: It does work though. After all leaf shutters have been in use for a long time and
: are still in virtually exclusive use in LF cameras and are prized by studio
: photographers with MF cameras. I know for a fact that the Mamiya cameras have lenses
: with leaf shutters that can be used with cameras with focal plane shutters ( the focal
: plane shutter is simply opened and the exposure is made with the leaf shutter ).
:
: Although Mamiya and conventional lenses are common and going cheap on Ebay as studios
: are dumping their MF cameras and going digital. The lenses with leaf shutters are rare
: and go for a lot of money. It simply isn't the issue you're trying to make it out to
: be.

: If you're 'calibrating' it may very well be.

It may be an issue but it's not. I understand that you don't have any significant experience
with leaf shutters. They do work and they work well.
--




Keep working millions on welfare depend on you
-------------------

Frank Pittel wrote in message ...
Michael Scarpitti wrote:
: Frank Pittel wrote in message ...
: there is compensation built into the time for the time required to open and close
: : the shutter completely.

: : I don't see how that can be done, as the amount of compensation
: : necessary depends on the aperture being used.
:
: It does work though. After all leaf shutters have been in use for a long time and
: are still in virtually exclusive use in LF cameras and are prized by studio
: photographers with MF cameras. I know for a fact that the Mamiya cameras have lenses
: with leaf shutters that can be used with cameras with focal plane shutters ( the focal
: plane shutter is simply opened and the exposure is made with the leaf shutter ).
:
: Although Mamiya and conventional lenses are common and going cheap on Ebay as studios
: are dumping their MF cameras and going digital. The lenses with leaf shutters are rare
: and go for a lot of money. It simply isn't the issue you're trying to make it out to
: be.

: If you're 'calibrating' it may very well be.

It may be an issue but it's not. I understand that you don't have any significant experience
with leaf shutters. They do work and they work well.

How would you 'know' this? I have lots of experience with all kinds of
cameras and shutters, dating back 40 years.