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Ed Vatza
Joined: 07 Dec 2018
Posts: 8
Location: Pennsylvania USA
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 Posted: Fri Dec 07, 2018 7:51 pm Post subject: Optar 135mm f/4.7 on Pacemaker Speed Graphic Issues |
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Let me preface this by saying I am a total newbie to large format and the Speed Graphic. I just picked up this camera in the past week and was working through things when this issue came up. Here goes.
If I open the back to look at the image on the ground glass, I can set the aperture to any setting and shutter works perfectly. f/4.7 is wide open and f/32 is stopped all the way down. I can cock the shutter and with the speed set at say 1/2 sec, I can see the shutter open and close properly for the respective aperture values. Now here is the problem. If I close the back or more importantly insert a film holder, set the shutter to any f setting from f/4.7 to f/32, cock the shutter and release it, it will fire wide open (at f/4.7) for all settings.
I should add that the switch is set to front and the focal plane shutter is set to "O". For the life of me I can figure out what is going on. I would appreciate any help anyone can offer. Thanks.
Ed
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Name is Ed and I'm new to large format and the Speed Graphic. I shoot mostly street and mostly digital (Fuji) with a little film thrown in. At age 70 I am looking at large format as a new horizon for me. Wish me luck! |
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45PSS
Joined: 28 Sep 2001
Posts: 4081
Location: Mid Peninsula, Ca.
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| Posted: Fri Dec 07, 2018 10:03 pm Post subject: |
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| Quote: | | If I close the back or more importantly insert a film holder, set the shutter to any f setting from f/4.7 to f/32, cock the shutter and release it, it will fire wide open (at f/4.7) for all settings. |
How do you determine this? Looking at the front of the lens when tripping the shutter?
A leaf shutter is 3 to 5 blades that operate in a manner so that the lens opening resembles an aperture that goes from no opening to full opening in .2 to .3 milliseconds, stays open for the selected time then goes from full open to full closed in .1 to .15 milliseconds.
There is no mechanical link between the shutter blades and the aperture blades. They are separated by an air space of 1 to 2 millimeters.
The only way an aperture could operate while the shutter is operating is by the user to be moving the aperture while the shutter blades are operating.
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The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU. |
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Ed Vatza
Joined: 07 Dec 2018
Posts: 8
Location: Pennsylvania USA
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| Posted: Fri Dec 07, 2018 10:34 pm Post subject: |
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"How do you determine this? Looking at the front of the lens when tripping the shutter? "
Yes that is what I was doing. Looking at the front of the lens while tripping the shutter. Do I understand you correctly that with the lens aperture set to say f/16 I will see the shutter open fully when I look into the front of the lens while tripping the shutter. If that is the case, why do I see the size of the opening change with the aperture changes when I have the back open and no film holder inserted?
And please excuse me if these questions sound confusing. I have shot 35mm film and limited 120 but this is my first foray into large format and gear of this type... and I'm 70 years old. Never to old to learn something new... I hope!
_________________
Name is Ed and I'm new to large format and the Speed Graphic. I shoot mostly street and mostly digital (Fuji) with a little film thrown in. At age 70 I am looking at large format as a new horizon for me. Wish me luck! |
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45PSS
Joined: 28 Sep 2001
Posts: 4081
Location: Mid Peninsula, Ca.
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| Posted: Fri Dec 07, 2018 11:06 pm Post subject: |
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Side rangefinder or top rangefinder speed?
What is the serial number? Its on the plate riveted to the bed.
What you see as the lens/shutter is a metal housing with the aperture mechanism at the rear of the housing then the shutter and speed timing on a plate above it. The rear lens cell is attached to the rear of the housing and the front lens cell attached to the front of the housing.
Open the view hood, remove the film holder, set the focal plane shutter open so you can see the rear of the lens through the ground glass, set the aperture to f16 or f22, set the front shutter to 1 second, cock the shutter.
Point the ground glass toward a light source, look through the front of the lens and trip the shutter. See the aperture opening? Is it what is set?
Change the aperture and repeat, did the opening seen change to the new setting?
The lens is likely in a #2 Graphex shutter, its repair manual can be downloaded here: http://www.southbristolviews.com/pics/Graphic/manual-pdf/GraphexShutterService.pdf
It has a description of how the shutter works if you're mechanically inclined.
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The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU. |
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Ed Vatza
Joined: 07 Dec 2018
Posts: 8
Location: Pennsylvania USA
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| Posted: Sat Dec 08, 2018 1:57 am Post subject: |
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Thank you for your responses and help.
| Quote: | | Side rangefinder or top rangefinder speed? |
Not sure what you are asking here.
| Quote: | | What is the serial number? |
I can check but I did when I got it and it is a Pacemaker Speed Graphic from 1950.
| Quote: | Point the ground glass toward a light source, look through the front of the lens and trip the shutter. See the aperture opening? Is it what is set?
Change the aperture and repeat, did the opening seen change to the new setting? |
Yes, Yes and Yes. As I said if I do this I see the various aperture settings when there is no film holder, the view hood is open as is the focal plane shutter. It is when the film holder is inserted (or the view hood closed) that I only see the the blades go wide open. If I understand what you said in your first response, that is as it should be because I am seeing leaf shutter which you described as "leaf shutter is 3 to 5 blades that operate in a manner so that the lens opening resembles an aperture that goes from no opening to full opening in .2 to .3 milliseconds, stays open for the selected time then goes from full open to full closed in .1 to .15 milliseconds." Is my understanding correct?
_________________
Name is Ed and I'm new to large format and the Speed Graphic. I shoot mostly street and mostly digital (Fuji) with a little film thrown in. At age 70 I am looking at large format as a new horizon for me. Wish me luck! |
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45PSS
Joined: 28 Sep 2001
Posts: 4081
Location: Mid Peninsula, Ca.
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| Posted: Sat Dec 08, 2018 2:16 am Post subject: |
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| Quote: | | Is my understanding correct? |
Yes.
If you were to shine a light into the lens while operating the shutter with a film holder installed you would be able to see the aperture blades at the setting the aperture is set to while the shutter blades are open.
What you are seeing without a light shinning in and no light coming in through the ground glass is the shutter blades and they should go full open.
Its working as it should.
A 1950 Speed Graphic will be one of three configurations, no rangefinder, a Kalart rangefinder, or a Hugo Meyer rangefinder. The rangefinder will be mounted on the right side of the camera.
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The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU. |
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Ed Vatza
Joined: 07 Dec 2018
Posts: 8
Location: Pennsylvania USA
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| Posted: Sat Dec 08, 2018 2:21 am Post subject: |
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[quote="45PSS"] | Quote: | | A 1950 Speed Graphic will be one of three configurations, no rangefinder, a Kalart rangefinder, or a Hugo Meyer rangefinder. The rangefinder will be mounted on the right side of the camera. |
It's a Kalart.
_________________
Name is Ed and I'm new to large format and the Speed Graphic. I shoot mostly street and mostly digital (Fuji) with a little film thrown in. At age 70 I am looking at large format as a new horizon for me. Wish me luck! |
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45PSS
Joined: 28 Sep 2001
Posts: 4081
Location: Mid Peninsula, Ca.
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