Re: [Cameramakers] Homebrew shutters
Well, yes, almost! I have done many of the steps in making a shutter to be controlled electronically. Indeed, there is an AutoCad file of the blade shape and I also had the electromechanical parts up and running on the blades of an old Ansco lens. This was a two blade type but they are not all that bad and in smaller sizes can do faster than 1/100 sec, and I wasn't really trying. The electronic controller is no problem and one has great flexibility in the design, but I have never actually built it, though there are schematics in the drawer. That is an old story and I might consider doing it with a microprocessor if I were designing it today. They cost so little and can give great flexibility and precision without much effort (a little programming and a little less solder.) (If you coupled in the diaphragm opening you could correct the fast speeds to yield constant effective exposure with opening, for example. Of course, you would need a way for the processor to know the opening, but that just adds to your fun in making the thing. The easiest way to get a decent shape for the blades is plagiarism! Just enlarge the blades of a good example. These shutters are especially easy to drive. (The three and more blade types usually run from a rotating ring and the total effort is substantial.) I would make the blades from shim stock, blackened, and shaped by photoetching. Cutting thin stock without rolling up the edges is not so easy, though you can master it. With photoetching it does not happen. Bob At 10:30 11.03.02 -0500, you wrote: >Hello: > >Has anyone here ever accomplished or considered a homebrew shutter? > >I'm thinking linear or rotary focal plane or 'venetian blind' louver kind of >thing. > >Electric/electronic is fine with me...I've got a pretty good understanding >now of how the electric shutters work (except for deciding how to >interpreting/averaging the opening and closing time relative to the >effective exposure time). > >Someone's loaning me a 'Speedcomputer' shutter controller to 'study'. > >I have one of those Aero-Ektar 309 mm f/2.5 giant lenses and because of it's >'speed' it'll need a relatively fast shutter unless I just want to do >nighttime work! > >Thanks - Murray > > > >___ >Cameramakers mailing list >[EMAIL PROTECTED] >http://rmp.opusis.com/mailman/listinfo/cameramakers ___ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
Re: [Cameramakers] Homebrew shutters
Murray, I don't know if you'd consider this a homebrewed shutter, but have you considered using an fp shutter from an old speed graphic? I am using such a setup with some big aero lenses myself. I cut away all but the portion necessary to house the shutter, and mounted it on a strong base with a homemade focusing rack. Old Speeds with missing parts are cheap and offer fast effective exposure times, though not so fast actual exposure times. Mine is a 4x5 though my camera started out as a 3x4. If I had to do it over again, I probably would go with a 4x5 to get more room in there. one of the lenses I'm using is a 3 inch wide angle that is physically huge and the rear element just barely fits. Gene - Original Message - From: "Murray" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, March 11, 2002 7:30 AM Subject: [Cameramakers] Homebrew shutters > Hello: > > Has anyone here ever accomplished or considered a homebrew shutter? > > I'm thinking linear or rotary focal plane or 'venetian blind' louver kind of > thing. > > Electric/electronic is fine with me...I've got a pretty good understanding > now of how the electric shutters work (except for deciding how to > interpreting/averaging the opening and closing time relative to the > effective exposure time). > > Someone's loaning me a 'Speedcomputer' shutter controller to 'study'. > > I have one of those Aero-Ektar 309 mm f/2.5 giant lenses and because of it's > 'speed' it'll need a relatively fast shutter unless I just want to do > nighttime work! > > Thanks - Murray > > > > ___ > Cameramakers mailing list > [EMAIL PROTECTED] > http://rmp.opusis.com/mailman/listinfo/cameramakers > ___ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
[Cameramakers] Homebrew shutters
Hello: Has anyone here ever accomplished or considered a homebrew shutter? I'm thinking linear or rotary focal plane or 'venetian blind' louver kind of thing. Electric/electronic is fine with me...I've got a pretty good understanding now of how the electric shutters work (except for deciding how to interpreting/averaging the opening and closing time relative to the effective exposure time). Someone's loaning me a 'Speedcomputer' shutter controller to 'study'. I have one of those Aero-Ektar 309 mm f/2.5 giant lenses and because of it's 'speed' it'll need a relatively fast shutter unless I just want to do nighttime work! Thanks - Murray ___ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
