I read a post a few days ago which about what different people use as a shutter for barrel lenses. Someone suggested that it would be a good thing if someone came up with a shutter that could be used with these lenses and it got me thinking about the situation. I work for a company that does initial design of both mechanical and electro-mechanical devices. We have a full machine shop and people who spend their days thinking about similar projects. My current project is a medical device for testing the nervous system. All the basic design work has been done and I am working with the approved prototype to set up the initial production run. This device has three hand held sensors that feed data into a PDA which records the data on a smart card (SD) which is then inserted into the doctor's computer for analysis of the data based upon a program developed by one of our inhouse EEs.
I don't own any barrel lenses as none of my lf cameras(4x5") have a fp shutter and I did not see any need to purchase such a lens when I bought my gear. So I have a few questions for those who do own and use them.
1. My Schneider Super Angulon 90mm and my Zenar 210mm both protrude into the camera body at least an inch and in the case of the 90mm probably closer to 1.5". Do barrel lenses do the same? If so is there any standard length or does it vary with the focal length?
2. Is there a maximum intrusion length I could use in my intitial design stages?
3. Would it horrify the lf and ulf crowd were I to design a shutter using digital technology for the timing of a mechanical shutter? Personally I find the concept amusing in that the ultra modern digital technology would be serving the analog image maker.
I'm so far thinking along the lines of a "Galli" type shutter(see the above mentioned thread) with two thin metal plates held together on one side just in front of the rear element and opening by one plate being pulled up and the other pulled down to open an angled opening wider than the rear element of the lens. Digital circuitry would be used to set the varying times settings for the shutter to remain open. Possibly the shutter plates would be pulled open by solenoids but I have to come up with a way to buffer the attendant vibration.
The problems I envision so far are that the shutter must be very close to the rear element and there must be a cover of some sort over what ever depth the lens intrudes into the camera body to keep light from bouncing off the rear of the shutter and possibly making its way to the film. In that the length of that intrusion will vary then the shutter mechanism must be built on a length ajustable frame to account for the varying lens depths. And the entire shutter mechanism would have to be installed on the rear of a lens board.
So far I don't see a problem that is insurmountable but that might easily be because of my ignorance of barrel lenses.
A little help please.
The original post: (there was a url link here which no longer exists)
I don't own any barrel lenses as none of my lf cameras(4x5") have a fp shutter and I did not see any need to purchase such a lens when I bought my gear. So I have a few questions for those who do own and use them.
1. My Schneider Super Angulon 90mm and my Zenar 210mm both protrude into the camera body at least an inch and in the case of the 90mm probably closer to 1.5". Do barrel lenses do the same? If so is there any standard length or does it vary with the focal length?
2. Is there a maximum intrusion length I could use in my intitial design stages?
3. Would it horrify the lf and ulf crowd were I to design a shutter using digital technology for the timing of a mechanical shutter? Personally I find the concept amusing in that the ultra modern digital technology would be serving the analog image maker.
I'm so far thinking along the lines of a "Galli" type shutter(see the above mentioned thread) with two thin metal plates held together on one side just in front of the rear element and opening by one plate being pulled up and the other pulled down to open an angled opening wider than the rear element of the lens. Digital circuitry would be used to set the varying times settings for the shutter to remain open. Possibly the shutter plates would be pulled open by solenoids but I have to come up with a way to buffer the attendant vibration.
The problems I envision so far are that the shutter must be very close to the rear element and there must be a cover of some sort over what ever depth the lens intrudes into the camera body to keep light from bouncing off the rear of the shutter and possibly making its way to the film. In that the length of that intrusion will vary then the shutter mechanism must be built on a length ajustable frame to account for the varying lens depths. And the entire shutter mechanism would have to be installed on the rear of a lens board.
So far I don't see a problem that is insurmountable but that might easily be because of my ignorance of barrel lenses.
A little help please.
The original post: (there was a url link here which no longer exists)