Re: [Cameramakers] ROTATING CAMERA PROJECT IDEAS
Hi ! Please explain, you project to construct a rotating camera to cover 360degrees on one pice of sheet film 4 x 5 inches size ? Remember you that the length, for a full 360 degree turn, of the film size is twice the focale length multiply by 3,1416 !!! Have a look at http://www.pano360.org/ Good luck in your construction, feel free to ask more. Regards, Michel DUSARIEZ Source of Larscan system from the inventor Lars Larsen. Hello! I could use some input. I have an idea for a rotating 4x5 slit camera. The plan is to have the camera rotate 360 degrees, while exposing through a lens and slit a rotating 360 degree image around the center of a 4x5 sheet film. I can do the woodworking out of 1/4 oak. I did the calculations and will use a 40mm lens (from a 35mm camera). So here is where i can use some help: 1) Camera Rotation: I see that a steping motor with some type of controller (a bit expensive) A DC motor with a voltage controller (less Expensive) A spring motor like in some rotating cameras, but I have no idea how to get that to work And my favorite since it would be cheapest, a motorless camera ala the 35mm Lookaround camera. This is a hand holdable wooden 35mm camera with wings that are spun around and at some point the shutter/film transport is triggered??? 2) slit shutter: Since the image will be exposed around a circle (imagine a record player) I need to be able to open the slit shutter and close it at exactly 359 degrees, so I don't over expose. Alsi it would not be good to close the shutter before completing the rotation. The simplest idea I have, is a thin metal shutter, with a light spring. Some type of small electro magnet can be triggered to open, and than at a set point in the rotation released, closing the shutter by the spring. Any ideas where I can scavenge such a magnet? i like to steal parts from disposable cameras, broken cameras, VCRs etc. I'll try and put up some drawings incase I havent explained the project clearly. Any advice would be appreciated. This is a real experimental camera. I think the effect ls like applying the Polar Coordinants filter in Photoshop. Thanks! Mac ___ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers -- http://www.pano360.org/ Michel DUSARIEZ UNLIMITED FIELDS RESEARCH PANOPTIC IMAGING asbl KITE AERIAL PHOTOGRAPHY WORLDWIDE ASSOCIATION - FOUNDATION 14, Avenue Capitaine PIRET B-1150 BRUXELLES - BELGIUM Fax 32 2 512 68 29 ___ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
Re: [Cameramakers] ROTATING CAMERA PROJECT IDEAS
I insert some comments below; Bob At 10:07 22.10.01 -0400, you wrote: OK. Here it is. Is this what you are interested in? http://www.rit.edu/~andpph/text-conical-strip.html Sam Hello! I could use some input. I have an idea for a rotating 4x5 slit camera. The plan is to have the camera rotate 360 degrees, while exposing through a lens and slit a rotating 360 degree image around the center of a 4x5 sheet film. I can do the woodworking out of 1/4 oak. I did the calculations and will use a 40mm lens (from a 35mm camera). So here is where i can use some help: 1) Camera Rotation: I see that a steping motor with some type of controller (a bit expensive) A DC motor with a voltage controller (less Expensive) A spring motor like in some rotating cameras, but I have no idea how to get that to work # You can drive a stepping motor with a 2 - phase oscillator. If you can do the electronics, so much the better, but otherwise somebody might help you. There are designs in data books from semiconductor manufacturers, National Semiconductor, for example. You also will probably need a small power amplifier (stereo for the two channels.) Running the motor on a pair of sine waves 90 degrees out of phase should give rather smoother motion than running with the usual sharp pulses. If you can build it will be quite cheap. (I think you could do it for $10 or less with all new parts but not counting a PCB if decide to use one. It is not needed!!) And my favorite since it would be cheapest, a motorless camera ala the 35mm Lookaround camera. This is a hand holdable wooden 35mm camera with wings that are spun around and at some point the shutter/film transport is triggered??? 2) slit shutter: Since the image will be exposed around a circle (imagine a record player) I need to be able to open the slit shutter and close it at exactly 359 degrees, so I don't over expose. Alsi it would not be good to close the shutter before completing the rotation. ### Does it really do damage to have a little overlap? If you scan 380 degrees nobody will care! The shutter can close anywhere in the, say, 20 degrees overlap. The simplest idea I have, is a thin metal shutter, with a light spring. Some type of small electro magnet can be triggered to open, and than at a set point in the rotation released, closing the shutter by the spring. You can probably arrange some sort of cam to open the shutter when the camera rotates to touch the cam and then close the shutter when the camera reaches a similar mechanical device, like another cam. (It would work with a shutter having a Time setting with minimal trouble.) No electromagnets, nothing! If you like the electromagnetic shutter, there are some around. Some of the newer oscilloscope cameras had them but you must find the correct models. I could offer you such a thing but the one I have is a little big (it worked with a typical oscilloscope lens, which is usually about 75 mm focal length.) You can have it at my typical cost plus the postage but I think you can do as well at ebay because the post from here is not all that cheap. Still, if you want it, I am sure I can come up with one (with lens, if you want. 75 mm might be better on 8x10, or 4x10! Any ideas where I can scavenge such a magnet? i like to steal parts from disposable cameras, broken cameras, VCRs etc. ###You could rotate the shutter out of the way with a motor out of a dead camera or a CD player (or CD ROM) The motors in CDROM drives are quite small (the one for the drawer of the head motion. The motor for the CD rotation is unlikely to be useful.) I'll try and put up some drawings incase I havent explained the project clearly. Any advice would be appreciated. This is a real experimental camera. I think the effect ls like applying the Polar Coordinants filter in Photoshop. Thanks! Mac ___ 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] ROTATING CAMERA PROJECT IDEAS
On Mon, 22 Oct 2001, Michel Dusariez wrote: Please explain, you project to construct a rotating camera to cover 360degrees on one pice of sheet film 4 x 5 inches size ? Yes, I would also be interested in knowing the details about how you plan to do this? Remember you that the length, for a full 360 degree turn, of the film size is twice the focale length multiply by 3,1416 !!! Yes, that gives you the circumference of the circle mapped out by the lens of a given focal length. This is the normal design criterion I've seen used for creating panoramic cameras. I have wondered however, if this is the only approach? If the speed of the film translation through the camera is changed it seems that this would either compress or expand the recording of the image while at the same time changing the effective shutter speed. It seems like there may be some resolution issues, but off the top of my head it seems like it may be possible to deviate from the circumference computation. However, I'm not terribly certain about this. Thought it would be a good topic for discussion though. Good luck in your construction, feel free to ask more. Is your book on panoptic camera construction still available? I have a copy and it is quite nice. I'd suggest people looking into building one of these get a copy if it is still available. a lens and slit a rotating 360 degree image around the center of a 4x5 sheet film. I can do the woodworking out of 1/4 oak. I did the calculations and will use a 40mm lens (from a 35mm camera). So here is where i can use some help: As noted above, we would really be interested in seeing your computations. 1) Camera Rotation: I think this is pretty much six one way and half a dozen the other. You'll have to choose the method that you feel fits the best with your abilities and sensibilities. 2) slit shutter: Since the image will be exposed around a circle (imagine a record player) I need to be able to open the slit shutter and close it at exactly 359 degrees, so I don't over expose. Alsi it would not be good to close the shutter before completing the rotation. Slit cameras don't usually use or need traditional shutters. You are recording a slice of the scene on a narrow piece of your film and the shutter is actually the movement of the slit with respect to the film. You could simply take the lens cap off to let the light in, start the camera, and then put the lens cap back on when done. You might overexpose at stripe of the film at the beginning and end, but if the film is long enough that usually isn't a big problem. On a 4x5 sheet that might be a bigger issue. This is partly why many slit cameras may make more than a 360 degree revolution. If you expose for 720 degrees with an overexposed stripe at each end, you can select the segment of film that has the best image and exposure. The simplest idea I have, is a thin metal shutter, with a light spring. Some type of small electro magnet can be triggered to open, and than at a set point in the rotation released, closing the shutter by the spring. You could probably do that, use a film cap, or incorporate a copal shutter or something scrounged from a junk camera. Any ideas where I can scavenge such a magnet? i like to steal parts from disposable cameras, broken cameras, VCRs etc. Well you could just wind one using a nail and some magnet wire. On the commercial side, you are looking for a solenoid. Available from any electronic parts supplier. Another source would be the coil out of a relay. You'd be able to find these in old cameras, VCR's, etc.. This is a real experimental camera. I think the effect ls like applying the Polar Coordinants filter in Photoshop. Yes, we'd be interested in knowing more details. I can't see how this would be like using polar coordinates? That would imply a circular sweep. What I'm envisioning is a moving slit which would give you cylindrical coordinates not polar. - Wayde ([EMAIL PROTECTED]) ___ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
Re: [Cameramakers] ROTATING CAMERA PROJECT IDEAS
On Mon, 22 Oct 2001, Sam Wang wrote: OK. Here it is. Is this what you are interested in? http://www.rit.edu/~andpph/text-conical-strip.html The web space at RIT as well as the cameramakers archive is also searchable at http://rmp.opusis.com/htdig/search.html - Wayde ([EMAIL PROTECTED]) ___ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
Re: [Cameramakers] ROTATING CAMERA PROJECT IDEAS
OK. Here it is. Is this what you are interested in? http://www.rit.edu/~andpph/text-conical-strip.html Sam Thanks! I am familar with his work! Mac ___ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
Re: [Cameramakers] ROTATING CAMERA PROJECT IDEAS
On Mon, 22 Oct 2001, Michel Dusariez wrote: Please explain, you project to construct a rotating camera to cover 360degrees on one pice of sheet film 4 x 5 inches size ? Yes, I would also be interested in knowing the details about how you plan to do this? Here is a link that may clear things up: http://www.rit.edu/~andpph/text-figures/spie-conical/fig-7.jpg I want a clean 360 degree image, so I neet to figure out a way to open and close a slit shutter before I overexpose the begining of the image. Mac ___ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
Re: [Cameramakers] ROTATING CAMERA PROJECT IDEAS
There is a nice low voltage solenoid inside the plastic pyramid shaped Polaroid cameras. Also a nice little motor, some rollers and gears and a great first surface mirror. I buy them at thrift stores all the time for 1-3 dollars. Gene springtyme wrote: Hello! I could use some input. I have an idea for a rotating 4x5 slit camera. The plan is to have the camera rotate 360 degrees, while exposing through a lens and slit a rotating 360 degree image around the center of a 4x5 sheet film. I can do the woodworking out of 1/4 oak. I did the calculations and will use a 40mm lens (from a 35mm camera). So here is where i can use some help: 1) Camera Rotation: I see that a steping motor with some type of controller (a bit expensive) A DC motor with a voltage controller (less Expensive) A spring motor like in some rotating cameras, but I have no idea how to get that to work And my favorite since it would be cheapest, a motorless camera ala the 35mm Lookaround camera. This is a hand holdable wooden 35mm camera with wings that are spun around and at some point the shutter/film transport is triggered??? 2) slit shutter: Since the image will be exposed around a circle (imagine a record player) I need to be able to open the slit shutter and close it at exactly 359 degrees, so I don't over expose. Alsi it would not be good to close the shutter before completing the rotation. The simplest idea I have, is a thin metal shutter, with a light spring. Some type of small electro magnet can be triggered to open, and than at a set point in the rotation released, closing the shutter by the spring. Any ideas where I can scavenge such a magnet? i like to steal parts from disposable cameras, broken cameras, VCRs etc. I'll try and put up some drawings incase I havent explained the project clearly. Any advice would be appreciated. This is a real experimental camera. I think the effect ls like applying the Polar Coordinants filter in Photoshop. Thanks! Mac ___ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers ___ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
